CA3015886C

CA3015886C - Feedstock lines for additive manufacturing of an object, and systems and methods for creating feedstock lines

Info

Publication number: CA3015886C
Application number: CA3015886A
Authority: CA
Inventors: Mark Stewart Wilenski; Michael Patrick Kozar; Samuel F. HARRISON; Nick Shadbeh Evans; Faraon TORRES
Original assignee: Boeing Co
Current assignee: Boeing Co
Priority date: 2017-09-15
Filing date: 2018-08-29
Publication date: 2023-04-04
Anticipated expiration: 2038-08-29
Also published as: CA3015886A1

Abstract

A feedstock line for additive manufacturing has an exterior surface defining an interior volume. Elongate filaments extend along at least a portion of the feedstock-line length. A resin covers the elongate filaments. The feedstock line further includes at least one optical structure covered by the resin, interspersed among the elongate filaments, and including at least one outer surface and a core. When electromagnetic radiation strikes the at least one optical structure, at least a portion of the electromagnetic radiation is reflected by the at least one outer surface and/or dispersed by the core to irradiate the resin in the interior volume of the feedstock line that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation.

Description

FEEDSTOCK LINES FOR ADDITIVE MANUFACTURING OF AN OBJECT, AND
SYSTEMS AND METHODS FOR CREATING FEEDSTOCK LINES
FIELD
This disclosure relates to additive manufacturing.
BACKGROUND
A 3D printing process may use a feedstock material, extruded from a print head, to additively manufacture a part by layering the feedstock material. The feedstock material may comprise a polymer and reinforcing fibers, such as carbon fibers, which are opaque to visible and ultra-violet light. When the polymer in the feedstock material is a photopolymer, a source of curing energy may be directed at the feedstock material, dispensed by the print head, to solidify the feedstock material. However, when the reinforcing fibers are opaque to the curing energy, they can cast shadows and can prevent the curing energy, originating directly from the source of curing energy, from irradiating and curing the photopolymer in the shadows.
SUMMARY
In one embodiment, there is provided a feedstock line for additive manufacturing of an object. The feedstock line has a feedstock-line length and an exterior surface, defining an interior volume of the feedstock line. The feedstock line comprises elongate filaments, a resin, and at least one full-length optical waveguide.
The elongate filaments extend along at least a portion of the feedstock-line length.
The resin covers the elongate filaments. The at least one full-length optical waveguide extends along all of the feedstock-line length. The at least one full-length optical waveguide is covered by the resin and is interspersed among the elongate filaments. The at least one full-length optical waveguide comprises a full-length optical core. The full-length optical core comprises a first full-length-optical-core end face, a second full-length-optical-core end face, opposite the first full-length-optical-core end face, and a full-length peripheral surface, extending between the first full-length-optical-core end face and the second full-length-optical-core end face.
The at least one full-length optical waveguide is configured such that when electromagnetic radiation enters the full-length optical core via at least one of the first full-length-optical-core end face, the second full-length-optical-core end face, or the full-length peripheral surface, at least a portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.
Inclusion of at least one full-length optical waveguide in the feedstock line can facilitate penetration of the electromagnetic radiation into the interior volume of the feedstock line for irradiation of the resin, despite regions of the resin being in the shadows of the elongate filaments cast by the direct (i.e., line-of-sight) application of the electromagnetic radiation. In other words, even when the electromagnetic radiation is shielded from directly reaching all regions of the resin, at least one full-length optical waveguide may receive the electromagnetic radiation via one or more of its first end face, its second end face, and its peripheral surface, and may disperse the electromagnetic radiation via at least its peripheral surface to indirectly reach regions of the resin.
In another embodiment, there is provided a feedstock line for additive manufacturing of an object. The feedstock line has a feedstock-line length and an exterior surface, defining an interior volume of the feedstock line. The feedstock line comprises elongate filaments, a resin, and optical direction modifiers. The elongate filaments extend along at least a portion of the feedstock-line length. The resin covers the elongate filaments. Each of the optical direction modifiers extend along only a portion of the feedstock-line length. The optical direction modifiers are covered by the resin and are interspersed among the elongate filaments. Each of the

2 optical direction modifiers has an outer surface. Each of the optical direction modifiers is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first direction to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.
Inclusion of optical direction modifiers in the feedstock line can facilitate penetration of the electromagnetic radiation into the interior volume of the feedstock line for irradiation of the resin, despite regions of the resin being in the shadows of the elongate filaments cast by the direct (i.e., line-of-sight) application of the electromagnetic radiation. In other words, even when the electromagnetic radiation is shielded from directly reaching all regions of the resin, the optical direction modifiers may redirect the electromagnetic radiation to disperse or scatter the electromagnetic radiation to indirectly reach regions of the resin.
As a result of inclusion of at least one optical structure, such as the at least one full-length optical waveguide or the optical modifiers, in the feedstock line, the feedstock line may be more easily cured with the electromagnetic radiation, may be more evenly cured with the electromagnetic radiation, may be more thoroughly cured with the electromagnetic radiation, and/or may be more quickly cured with the electromagnetic radiation. This configuration of feedstock line may be particularly well suited for additive manufacturing of the fused filament fabrication variety, in which the feedstock line is dispensed by a print head, or nozzle, and a source of curing energy (e.g., electromagnetic radiation) directs the curing energy at the feedstock line as it is being dispensed to cure the resin in situ.
In another embodiment, there is provided a system for creating a feedstock line for additive manufacturing of an object. The feedstock line has a feedstock-line length. The system comprises a filament supply, a filament separator, a full-length-optical-waveguide supply, a combiner, and a resin supply. The filament supply is

3 configured to dispense a precursor tow, comprising elongate filaments. The filament separator is configured to separate the precursor tow, dispensed from the filament supply, into individual ones of the elongate filaments or into subsets of the elongate filaments. Each of the subsets comprises a plurality of the elongate filaments. The full-length-optical-waveguide supply is configured to dispense at least one full-length optical waveguide. The combiner is configured to combine the individual ones of the elongate filaments and the at least one full-length optical waveguide or the subsets of the elongate filaments and the at least one full-length optical waveguide into a derivative tow such that each of the elongate filaments and the at least one full-length optical waveguide extend along all of the feedstock-line length and the at least one full-length optical waveguide is interspersed among the elongate filaments.
The resin supply is configured to provide a resin to be applied to at least one of (i) the precursor tow, (ii) the individual ones of the elongate filaments or the subsets of the elongate filaments, (iii) the at least one full-length optical waveguide, and (iv) the derivative tow, such that the elongate filaments and at least the one full-length optical waveguide in the derivative tow are covered with the resin.
Creating the feedstock line from the precursor tow may permit the use of off-the-shelf reinforcement fiber tows. The filament separator separates the precursor tow into individual ones of the elongate filaments or into subsets of the elongate filaments, so that at least one full-length optical waveguide may be operatively interspersed with the elongate filaments. The combiner then combines the elongate filaments and at least one full-length optical waveguide into the derivative tow to ultimately become the feedstock line with the resin. The resin supply dispenses the resin at any suitable location as the feedstock line is being created, including one or more of (i) at the precursor tow before it is separated into individual ones of elongate filaments or into subsets of elongate filament, (ii) at elongate filaments that have been separated from the precursor tow, (iii) at the at least one full-length optical waveguide before it is combined with the elongate filaments, and (iv) at the derivative tow after at least the one full-length optical waveguide has been combined with the elongate filaments.

4 In another embodiment, there is provided a system for creating a feedstock line for additive manufacturing of an object. The feedstock line has a feedstock-line length. The system comprises a filament supply, a filament separator, an optical-direction-modifier supply, a combiner, and a resin supply. The filament supply is configured to dispense a precursor tow, comprising elongate filaments. The filament separator is configured to separate the precursor tow, dispensed from the filament supply, into individual ones of the elongate filaments or into subsets of the elongate filaments. Each of the subsets comprises a plurality of the elongate filaments. The optical-direction-modifier supply is configured to dispense optical direction modifiers to be applied to the individual ones of the elongate filaments or the subsets of the elongate filaments. Each of the optical direction modifiers has an outer surface, and each of the optical direction modifiers is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first direction. The combiner is configured to combine the individual ones of the elongate filaments and the optical direction modifiers or the subsets of the elongate filaments and the optical direction modifiers into a derivative tow such that the optical direction modifiers are interspersed among the elongate filaments.
The resin supply is configured to provide a resin to be applied to at least one of (i) the precursor tow, (ii) the individual ones of the elongate filaments or the subsets of the elongate filaments, (iii) the optical direction modifiers, and (iv) the derivative tow, such that the elongate filaments and the optical direction modifiers in the derivative tow are covered with the resin.
Creating the feedstock line from the precursor tow may permit the use of off-the-shelf reinforcement fiber tows. The filament separator separates the precursor tow into individual ones of the elongate filaments or into subsets of the elongate filaments, so that the optical direction modifiers may be operatively interspersed with the elongate filaments. The combiner then combines the elongate filaments and the optical direction modifiers into the derivative tow to ultimately become the feedstock line with the resin. The resin supply dispenses the resin at any suitable location as

5 the feedstock line is being created, including one or more of (i) at the precursor tow before it is separated, (ii) at the separated elongate filaments, (iii) at or with the optical direction modifiers before they are combined with the elongate filaments, and (iv) at the derivative tow after the optical direction modifiers have been combined .. with the elongate filaments.
In another embodiment, there is provided a method of creating a feedstock line for additive manufacturing of an object. The feedstock line has a feedstock-line length. The method comprises separating a precursor tow, comprising elongate filaments, into individual ones of the elongate filaments or into subsets of the elongate filaments. Each of the subsets comprises a plurality of the elongate filaments. The method also comprises combining the individual ones of the elongate filaments and at least one full-length optical waveguide or the subsets of the elongate filaments and at least the one full-length optical waveguide into a derivative tow such that each of the elongate filaments and at least the one full-length optical waveguide extends along all of the feedstock-line length and at least the one full-length optical waveguide is interspersed among the elongate filaments. The method further comprises applying a resin to cover the elongate filaments and at least the one full-length optical waveguide such that the elongate filaments and at least the one full-length optical waveguide are covered by the resin in the derivative tow.
In another embodiment, there is provided a method of creating a feedstock line for additive manufacturing of an object. The feedstock line has a feedstock-line length. The method comprises separating a precursor tow, comprising elongate filaments, into individual ones of the elongate filaments or into subsets of the elongate filaments. Each of the subsets comprises a plurality of the elongate filaments. The method also comprises applying optical direction modifiers to the individual ones of the elongate filaments or to the subsets of the elongate filaments.
Each of the optical direction modifiers has an outer surface, and each of the optical direction modifiers is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first

6 direction. The method further comprises combining the optical direction modifiers with the individual ones of the elongate filaments or the subsets of the elongate filaments into a derivative tow such that the optical direction modifiers are interspersed among the elongate filaments. The method also comprises applying a resin to cover the elongate filaments and the optical direction modifiers such that the elongate filaments and the optical direction modifiers are covered by the resin in the derivative tow.
Creating the feedstock line from the precursor tow may permit the use of off-the-shelf reinforcement fiber tows. By separating the precursor tow into individual ones of the elongate filaments or into subsets of the elongate filaments, at least one optical structure, such as the at least one full-length optical waveguide and/or the optical direction modifiers, may be operatively interspersed with the elongate filaments. Covering the elongate filaments and the at least one optical structure with the resin may ensure that the elongate filaments and the at least one optical structure are wetted and have suitable integrity for additively manufacturing the object.
In one embodiment, there is provided a feedstock line for additive manufacturing of an object, the feedstock line having a feedstock-line length and an exterior surface, defining an interior volume of the feedstock line. The feedstock line includes elongate filaments, extending along at least a portion of the feedstock-line length, a resin, covering the elongate filaments, and optical direction modifiers, each extending along only a portion of the feedstock-line length. The optical direction modifiers are covered by the resin and are interspersed among the elongate filaments. Each of the optical direction modifiers has an outer surface. Each of the optical direction modifiers is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a first portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first direction to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.

7 Date Recue/Date Received 2022-01-24 The optical direction modifiers include partial-length optical waveguides.
Each of the partial-length optical waveguides includes a partial-length optical core. The partial-length optical core of each of the partial-length optical waveguides includes a first partial-length-optical-core end face, a second partial-length-optical-core end face, opposite the first partial-length-optical-core end face, and a partial-length peripheral surface, extending between the first partial-length-optical-core end face and the second partial-length-optical-core end face. Each of the partial-length optical waveguides is configured such that when the electromagnetic radiation enters the partial-length optical core via at least one of the first partial-length-optical-core end face, the second partial-length-optical-core end face, or the partial-length peripheral surface, at least a second portion of the electromagnetic radiation exits the partial-length optical core via the partial-length peripheral surface to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the .. exterior surface of the feedstock line.
In another embodiment, there is provided a system for creating a feedstock line for additive manufacturing of an object, the feedstock line having a feedstock-line length. The system includes a filament supply, configured to dispense a precursor tow, including elongate filaments and a filament separator, configured to separate the precursor tow, dispensed from the filament supply, into individual ones of the elongate filaments or into subsets of the elongate filaments. Each of the subsets includes a plurality of the elongate filaments. The system further includes a full-length-optical-waveguide supply, configured to dispense at least one full-length optical waveguide and an optical-direction-modifier supply, configured to dispense optical direction modifiers to be applied to the individual ones of the elongate filaments or the subsets of the elongate filaments, originating from the filament separator. Each of the optical direction modifiers has an outer surface and is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a first portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first direction. The

8 Date Recue/Date Received 2022-01-24 system further includes a combiner, configured to combine the individual ones of the elongate filaments with the optical direction modifiers and at least the one full-length optical waveguide, dispensed by the full-length-optical-waveguide supply, or the subsets of the elongate filaments, originating from the filament separator, and at least the one full-length optical waveguide, dispensed by the full-length-optical-waveguide supply, into a derivative tow so that each of the elongate filaments and at least the one full-length optical waveguide extend along all of the feedstock-line length and at least the one full-length optical waveguide and the optical direction modifiers are interspersed among the elongate filaments. The system further includes a resin supply, configured to provide a resin to be applied to at least the elongate filaments, the optical direction modifiers, and the at least the one full-length optical waveguide in the derivative tow such that the elongate filaments, the optical direction modifiers, and at least the one full-length optical waveguide in the derivative tow are covered with the resin.
In another embodiment, there is provided a method of creating a feedstock line for additive manufacturing of an object, the feedstock line having a feedstock-line length. The method involves steps of separating a precursor tow, including elongate filaments, into individual ones of the elongate filaments or into subsets of the elongate filaments. Each of the subsets includes a plurality of the elongate filaments. The method further involves steps of applying optical direction modifiers to the individual ones of the elongate filaments or to the subsets of the elongate filaments. Each of the optical direction modifiers has an outer surface and is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a first portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first direction. The method further involves steps of combining the individual ones of the elongate filaments, the optical direction modifiers, and at least one full-length optical waveguide or the subsets of the elongate filaments and at least the one full-length optical waveguide into a derivative tow so that each of the elongate filaments and at least the one full-length optical waveguide extends along all of the feedstock-line

9 Date Recue/Date Received 2022-07-25 length and at least the one full-length optical waveguide and the optical direction modifiers are interspersed among the elongate filaments, and applying a resin to cover the elongate filaments, the optical direction modifiers and at least the one full-length optical waveguide such that the elongate filaments, the optical direction modifiers, and at least the one full-length optical waveguide are covered by the resin in the derivative tow.
9a Date Recue/Date Received 2022-07-25 BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein like reference characters designate the same or similar parts throughout the several views, and wherein:
Fig. 1 is a block diagram, schematically representing a feedstock line for additive manufacturing of an object;
Fig. 2 is a block diagram, schematically representing a system for creating a feedstock line for additive manufacturing of an object;
Fig. 3 is a block diagram, schematically representing an optical waveguide;
Fig. 4 is a schematic representation of a feedstock line of Fig. 1;
Fig. 5 is a schematic representation of a full-length optical waveguide;
Fig. 6 is a schematic representation of a full-length optical waveguide;
Fig. 7 is a schematic representation of a full-length optical waveguide;
Fig. 8 is a schematic representation of a full-length optical waveguide;
Fig. 9 is a schematic representation of a full-length optical waveguide;
Fig. 10 is a schematic representation of a feedstock line of Fig. 1;
Fig. 11 is a schematic representation of a feedstock line of Fig. 1;
Fig. 12 is a schematic representation of an optical direction modifier comprising a partial-length optical waveguide;
Date Recue/Date Received 2022-01-24 Fig. 13 is a schematic representation of an optical direction modifier comprising a partial-length optical waveguide;
Fig. 14 is a schematic representation of an optical direction modifier comprising a partial-length optical waveguide;
Fig. 15 is a schematic representation of an optical direction modifier comprising a partial-length optical waveguide;
Fig. 16 is a schematic representation of an optical direction modifier comprising a partial-length optical waveguide;
Fig. 17 is a schematic representation of an optical direction modifier comprising an optical direction-modifying particle;
Fig. 18 is a schematic representation of an optical direction modifier comprising an optical direction-modifying particle;
Fig. 19 is a schematic representation of an optical direction modifier comprising an optical direction-modifying particle;
Fig. 20 is a schematic representation of a feedstock line of Fig. 1;
Fig. 21 is a schematic representation of a system of Fig. 2;
Fig. 22 is a schematic representation of a system of Fig. 2;
Fig. 23 is a block diagram of a method of creating a feedstock line for additive manufacturing of an object;
Fig. 24 is a schematic representation of an optical waveguide;
Fig. 25 is a schematic representation of an optical waveguide;
Fig. 26 is a schematic representation of an optical waveguide;
Fig. 27 is a schematic representation of an optical waveguide;
Fig. 28 is a schematic representation of an optical waveguide;
Fig. 29 is a schematic representation of an optical fiber that may be modified to create an optical waveguide;

Fig. 30 is a block diagram of a method of modifying an optical fiber to create an optical waveguide;
Fig. 31 is a block diagram of a method of modifying an optical core to create an optical waveguide;
Fig. 32 is a block diagram of a method of modifying an optical core to create an optical waveguide;
Fig. 33 is a block diagram of aircraft production and service methodology; and Fig. 34 is a schematic illustration of an aircraft.
DESCRIPTION
In Figs. 1-3, referred to above, solid lines, if any, connecting various elements and/or components may represent mechanical, electrical, fluid, optical, electromagnetic and other couplings and/or combinations thereof. As used herein, "coupled" means associated directly as well as indirectly. For example, a member A
may be directly associated with a member B, or may be indirectly associated therewith, e.g., via another member C. It will be understood that not all relationships among the various disclosed elements are necessarily represented. Accordingly, couplings other than those depicted in the block diagrams may also exist.
Dashed lines, if any, connecting blocks designating the various elements and/or components represent couplings similar in function and purpose to those represented by solid lines; however, couplings represented by the dashed lines may either be selectively provided or may relate to alternative examples of the present disclosure.
Likewise, elements and/or components, if any, represented with dashed lines, indicate alternative examples of the present disclosure. One or more elements shown in solid and/or dashed lines may be omitted from a particular example without departing from the scope of the present disclosure. Environmental elements, if any, are represented with dotted lines. Virtual imaginary elements may also be shown for clarity. Those skilled in the art will appreciate that some of the features illustrated in Figs. 1-3 may be combined in various ways without the need to include other features described in Figs. 1-3, other drawing figures, and/or the accompanying disclosure, even though such combination or combinations are not explicitly illustrated herein. Similarly, additional features not limited to the examples presented, may be combined with some or all of the features shown and described herein.
In Figs. 23 and 30-33, referred to above, the blocks may represent operations and/or portions thereof, and lines connecting the various blocks do not imply any particular order or dependency of the operations or portions thereof. Blocks represented by dashed lines indicate alternative operations and/or portions thereof.
Dashed lines, if any, connecting the various blocks represent alternative dependencies of the operations or portions thereof. It will be understood that not all dependencies among the various disclosed operations are necessarily represented.
Figs. 23 and 30-33 and the accompanying disclosure describing the operations of methods set forth herein should not be interpreted as necessarily determining a sequence in which the operations are to be performed. Rather, although one illustrative order is indicated, it is to be understood that the sequence of the operations may be modified when appropriate. Accordingly, certain operations may be performed in a different order or simultaneously. Additionally, those skilled in the art will appreciate that not all operations described need be performed.
In the following description, numerous specific details are set forth to provide a thorough understanding of the disclosed concepts, which may be practiced without some or all of these particulars. In other instances, details of known devices and/or processes have been omitted to avoid unnecessarily obscuring the disclosure.
While some concepts will be described in conjunction with specific examples, it will be understood that these examples are not intended to be limiting.
Unless otherwise indicated, the terms "first," "second," etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, e.g., a "second" item does not require or preclude the existence of, e.g., a "first"
or lower-numbered item, and/or, e.g., a "third" or higher-numbered item.
Reference herein to "one example" means that one or more feature, structure, or characteristic described in connection with the example is included in at least one implementation. The phrase "one example" in various places in the specification may or may not be referring to the same example.
As used herein, a system, apparatus, structure, article, element, component, or hardware "configured to" perform a specified function is indeed capable of performing the specified function without any alteration, rather than merely having potential to perform the specified function after further modification. In other words, the system, apparatus, structure, article, element, component, or hardware "configured to" perform a specified function is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the specified function. As used herein, "configured to" denotes existing characteristics of a system, apparatus, structure, article, element, component, or hardware which enable the system, apparatus, structure, article, element, component, or hardware to perform the specified function without further modification. For purposes of this disclosure, a system, apparatus, structure, article, element, component, or hardware described as being "configured to" perform a particular function may additionally or alternatively be described as being "adapted to" and/or as being "operative to" perform that function.
Illustrative, non-exhaustive examples of the subject matter according the present disclosure are provided below.
Referring generally to Fig. 1, a feedstock line 100 for additive manufacturing of an object 136 is shown. Feedstock line 100 has a feedstock-line length and an exterior surface 180, defining an interior volume 182 of the feedstock line 100. The feedstock line 100 comprises elongate filaments 104, resin 124, and at least one optical structure 101.

Date Recue/Date Received 2022-01-24 In certain examples, the at least one optical structure 101 may comprise at least one full-length optical waveguide 102 and/or optical direction modifiers 123.
The at least one full-length optical waveguide 102 may extend along all of the feedstock-line length, whereas optical direction modifiers 123 may each extend along only a portion of the feedstock-line length. Elongate filaments 104 extend along at least a portion of the feedstock-line length. Resin 124 covers elongate filaments 104. The at least one optical structure 101 is covered by resin 124 and is interspersed among elongate filaments 104.
The at least one optical structure 101 comprises at least one outer surface and a core. In some examples, the at least one optical structure 101 may be configured such that when electromagnetic radiation 118 strikes the at least one optical structure 101, at least a portion of electromagnetic radiation is reflected by at least one outer surface and/or is dispersed by core, to irradiate, in interior volume 182 of feedstock line 100, resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118 incident on the exterior surface 180 of feedstock line 100.
For example, when at least one optical structure 101 comprises at least one full-length optical waveguide 102, the core comprises a full-length optical core 110 and the at least one outer surface comprises a first full-length-optical-core end face 112 of full-length optical core 110, a second full-length-optical-core end face 114 of full-length optical core 110, opposite first full-length-optical-core end face 112, and a full-length peripheral surface 116 of full-length optical core 110, extending between the first full-length-optical-core end face 112 and the second full-length-optical-core end face 114. In some examples, the at least one full-length optical waveguide is configured such that when electromagnetic radiation 118 enters the full-length optical core 110 via at least one of the first full-length-optical-core end face 112, the second full-length-optical-core end face 114, or the full-length peripheral surface 116, at least a portion of the electromagnetic radiation 118 exits the full-length optical core 110 via full-length peripheral surface 116 to irradiate, in interior volume 182 of feedstock line 100, resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on exterior surface 180 of the feedstock line 100.
In other examples, when the at least one optical structure 101 comprises optical direction modifiers 123, the at least one outer surface comprises a respective outer surface 184 of each of the optical direction modifiers 123. In some examples, each of the optical direction modifiers 123 is configured such that when electromagnetic radiation 118 strikes a respective outer surface 184 from a first direction, at least a portion of the electromagnetic radiation 118 departs the respective outer surface 184 in a second direction that is at an angle to the first direction, to irradiate, in interior volume 182 of the feedstock line 100, resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on exterior surface 180 of feedstock line 100.
Inclusion of the at least one optical structure 101, such as the at least one full-length optical waveguide 102 and/or optical direction modifiers 123, in the feedstock line 100 can facilitate penetration of electromagnetic radiation 118 into the interior volume 182 of the feedstock line 100 for irradiation of resin 124, despite regions of resin 124 being in the shadows of elongate filaments 104 cast by the direct (i.e., line-of-sight) application of electromagnetic radiation 118. In other words, even when the electromagnetic radiation 118 is shielded from directly reaching all regions of resin 124, the at least one optical structure 101 may receive, redirect, disperse and/or scatter electromagnetic radiation 118. For example, the at least one full-length optical waveguide 102 may receive electromagnetic radiation 118 via one or more of its first full-length-optical-core end face 112, its second full-length-optical-core end face 114, or its full-length peripheral surface 116, and disperse electromagnetic radiation 118 via at least its full-length peripheral surface 116 to indirectly reach regions of resin 124. Alternatively or additionally, for example, optical direction modifiers 123 may disperse, scatter, and/or redirect the electromagnetic radiation 118 via its respective outer surfaces 184 to indirectly reach regions of resin 124. As a result, feedstock line 100 may be more easily cured with electromagnetic radiation 118, may be more evenly cured with electromagnetic radiation 118, may be more thoroughly cured with electromagnetic radiation 118, and/or may be more quickly cured with electromagnetic radiation 118. This configuration of feedstock line may be well suited for additive manufacturing of the fused filament fabrication variety, in which feedstock line 100 is dispensed by a print head, or nozzle, and a source of curing energy (e.g., electromagnetic radiation 118) directs the curing energy at feedstock line 100 as it is being dispensed to cure resin 124 in situ.
Elongate filaments 104 additionally or alternatively may be described as reinforcement filaments or fibers, and may be constructed of any suitable material, illustrative and non-exclusive examples of which include (but are not limited to) fibers, carbon fibers, glass fibers, synthetic organic fibers, aramid fibers, natural fibers, wood fibers, boron fibers, silicon-carbide fibers, optical fibers, fiber bundles, fiber tows, fiber weaves, wires, metal wires, conductive wires, and wire bundles.
Feedstock line 100 may include a single configuration, or type, of elongate filaments 104 or may include more than one configuration, or type, of elongate filaments 104.
In some examples, the elongate filaments 104 may individually and collectively extend for the entire, or substantially the entire, feedstock-line length, and thus may be described as continuous elongate filaments or as full-length elongate filaments.
Additionally or alternatively, the elongate filaments 104 may individually extend for only a portion of the feedstock-line length, and thus may be described as partial-length elongate filaments or non-continuous elongate filaments. Examples of partial-length elongate filaments include (but are not limited to) so-called chopped fibers.
Resin 124 may include any suitable material that is configured to be cured, or hardened, as a result of cross-linking of polymer chains, such as responsive to an application of electromagnetic radiation 118. For example, electromagnetic radiation 118, or curing energy, may comprise one or more of ultraviolet light, visible light, infrared light, x-rays, electron beams, and microwaves, and resin 124 may take the form of one or more of a polymer, a resin, a thermoplastic, a thermoset, a photopolymer, an ultra-violet photopolymer, a visible-light photopolymer, an infrared-light photopolymer, and an x-ray photopolymer. As used herein, a photopolymer is a polymer that is configured to be cured in the presence of light, such as one or more of ultra-violet light, visible-light, infrared-light, and x-rays. However, as discussed, inclusion of at least one optical structure 101 in the feedstock line 100 may facilitate the penetration of electromagnetic radiation 118 into the shadows of elongate filaments 104, and thus, in some examples, electromagnetic radiation 118 may be of a wavelength that does not penetrate elongate filaments 104, and resin 124 may be a photopolymer.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 4, 10, 11 and 20, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, elongate filaments 104 are opaque to electromagnetic radiation 118.
The elongate filaments 104 may be selected for strength properties and not for light-transmissivity properties. For example, carbon fibers are often used in fiber-reinforced composite structures, and carbon fibers are opaque to ultra-violet and visible light. Accordingly, elongate filaments 104 that are opaque to electromagnetic radiation 118 may be well suited for inclusion in feedstock line 100, as at least one optical structure 101 may operatively receive electromagnetic radiation 118 and disperse it into the shadows of elongate filaments 104.
Full-length optical waveguide Referring generally to Fig. 1 and particularly to, e.g., Figs. 4 and 5-9, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, at least one optical structure in feedstock line 100 comprises at least one full-length optical waveguide 102. The at least one full-length optical wavelength 102 extends along all of the feedstock-line length. The at least one full-length optical waveguide 102 is covered by resin and is interspersed among elongate filaments 104. The at least one full-length optical waveguide 102 comprises a full-length optical core 110. Full-length optical core 110 comprises a first full-length-optical-core end face 112, a second full-length-optical-core end face 114, an opposite first full-length-optical-core end face 112, and a full-length peripheral surface 116 extending between the first full-length-optical-core end face 112 and the second full-length-optical-core end face 114. In such examples, the core of at least one optical structure 101 comprises the full-length optical core 110 and at least one outer surface of the at least one optical structure 101 comprises the first full-length-optical-core end face 112, the second full-length-optical-core end face 114 and the full-length peripheral surface 116.
The at least one full-length optical waveguide 102 is configured such that when electromagnetic radiation 118 enters the full-length optical core 110 via at least one of first full-length-optical-core end face 112, the second full-length-optical-core end face 114, and the full-length peripheral surface 116, at least a portion of electromagnetic radiation 118 may exit full-length optical core 110 via the full-length peripheral surface 116 to irradiate, in interior volume 182 of feedstock line 100, resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on exterior surface 180 of the feedstock line 100.
Inclusion of the at least one full-length optical waveguide 102 in feedstock line 100 may facilitate penetration of electromagnetic radiation 118 into the interior volume 182 of the feedstock line 100 for irradiation of resin 124, despite regions of resin 124 being in the shadows of elongate filaments 104 cast by the direct (i.e., line-of-sight) application of electromagnetic radiation 118. In other words, even when electromagnetic radiation 118 is shielded from directly reaching all regions of resin 124, the at least one full-length optical waveguide 102 may receive electromagnetic radiation 118 via one or more of its first full-length-optical-core end face 112, its second full-length-optical-core end face 114, and its full-length peripheral surface 116, and disperse electromagnetic radiation 118 via at least its full-length peripheral surface 116 to indirectly reach regions of resin 124. The at least one full-length optical waveguide 102 may thus serve to disperse electromagnetic radiation 118 into the shadows of elongate filaments 104, and may serve to redirect electromagnetic radiation 118 to other optical structures in the feedstock line 100 (such as optical direction modifiers 123 or other full-length optical waveguides) to facilitate penetration of electromagnetic radiation 118 into the shadows of elongate filaments 104. Additionally or alternatively, other optical structures in the feedstock line 100 (such as optical direction modifiers 123) may serve to redirect electromagnetic radiation 118 to the at least one full-length optical waveguide 102 to facilitate penetration of electromagnetic radiation 118 into the shadows of elongate filaments 104 by the at least one full-length optical waveguide 102.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 4 and 5-9, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the feedstock line 100 is configured such that when electromagnetic radiation 118 enters interior volume of the feedstock line 100 via the exterior surface 180 of the feedstock line 100, electromagnetic radiation 118 enters the at least one full-length optical waveguide 102 via at least one of the full-length peripheral surface 116, the first full-length-optical-core end face 112, and the second full-length-optical-core end face 114 of the full-length optical core 110 of the at least one full-length optical waveguide 102.
In other words, in some examples of feedstock line 100, the at least one full-length optical waveguide 102 is positioned within the interior volume 182 of the feedstock line 100 such that the at least one of full-length peripheral surface 116, the first full-length-optical-core end face 112, and the second full-length-optical-core end face 114 is within the line of sight of electromagnetic radiation 118 to receive electromagnetic radiation 118 directed to the exterior surface 180 of the feedstock line 100 and then disperse electromagnetic radiation 118 into the shadows of elongate filaments 104. For example, at least one of the full-length peripheral surface 116, the first full-length-optical-core end face 112, and the second full-length-optical-core end face 114 may be adjacent to exterior surface 180 of the feedstock line 100.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 4 and 5-9, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the at least one full-length optical waveguide 102 is configured such that when electromagnetic radiation 118 enters the first full-length-optical-core end face 112 of the full-length optical core 110, an initial portion of electromagnetic radiation 118 exits the full-length optical core 110 via the full-length peripheral surface 116 and a final portion of electromagnetic radiation 118, remaining in full-length optical core 110 after the initial portion of electromagnetic radiation 118 exits the full-length optical core 110, via the second full-length-optical-core end face 114.
In other words, in some examples of feedstock line 100, if electromagnetic radiation 118 enters the first full-length-optical-core end face 112, it may exit both the full-length peripheral surface 116 and the second full-length-optical-core end face 114, as opposed, for example, to electromagnetic radiation 118 being fully emitted via full-length peripheral surface 116. Such examples of feedstock line 100 may be well suited for additive manufacturing systems and methods in which electromagnetic radiation 118 is directed at the first full-length-optical-core end face 112 as feedstock line 100 is being constructed and as object 136 is being manufactured. That is, an additive manufacturing system may be configured to construct feedstock line 100 while object 136 is being manufactured from feedstock line 100, and while electromagnetic radiation 118 is entering first full-length-optical-core end face 112. In examples where electromagnetic radiation 118 exits not only the full-length peripheral surface 116, but also the second full-length-optical-core end face 114, at least one full-length optical wavelength 102 may ensure that sufficient electromagnetic radiation 118 travels the full length of at least one full-length optical waveguide 102 to operatively cure resin 124 among elongate filaments 104 within the interior volume 182 of the feedstock line 100.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 4 and 5-9, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the at least one full-length optical waveguide 102 is configured such that the initial portion of electromagnetic radiation 118, which exits full-length optical core 110 via full-length peripheral surface 116, may be greater than or equal to the final portion of electromagnetic radiation 118, which exits full-length optical core 110 via the second full-length-optical-core end face 114. In such configurations, the at least one full-length optical wavelength 102 may ensure that a desired amount of electromagnetic radiation 118 exits the full-length optical core 110 via the full-length peripheral surface 116 to operatively cure resin 124 among elongate filaments 104 within interior volume 182 of feedstock line 100, when feedstock line 100 is utilized by an additive manufacturing system or in an additive manufacturing method.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 4, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the at least one full-length optical waveguide 102 is at least one of parallel to, generally parallel to, twisted with, woven with, or braided with the elongate filaments 104.
By the at least one full-length optical waveguide 102 being parallel to or generally parallel to elongate filaments 104, the reinforcing properties of elongate filaments 104 within the feedstock line 100, and thus within object 136, may not be materially affected. By being twisted with, woven with, or braided with elongate filaments 104, the at least one full-length optical waveguide 102 may be interspersed with elongate filaments 104 such that electromagnetic radiation 118, exiting at least one full-length optical waveguide 102, may be delivered to regions of the interior volume 182 that are in the shadows of elongated filaments 104.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 6-8, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the full-length optical core has a full-length-optical-core refractive index and the at least one full-length optical waveguide 102 further comprises full-length-optical-core cladding 154, at least partially covering the full-length optical core 110. The full-length-optical-core cladding 154 comprises at least first full-length-optical-core cladding resin 156, having a full-length-optical-core first-cladding-resin refractive index. The full-length-optical-core cladding 154 may be non-uniform along the at least one full-length optical waveguide 102. For example, full-length peripheral surface 116 may include full-length-peripheral-surface regions 127 devoid of first full-length-optical-core cladding resin 156. Full-length-optical-core refractive index may be greater than the full-length-optical-core first-cladding-resin refractive index.
By full-length-optical-core cladding 154 being non-uniform along the length of the full-length optical waveguide, electromagnetic radiation 118 may be permitted to exit the full-length optical core 110 via the full-length peripheral surface 116.
Moreover, by the first full-length-optical-core cladding resin 156 having a refractive index that is less than that of full-length optical core 110, electromagnetic radiation 118, upon entering full-length optical core 110, may be trapped within the full-length optical core 110 in regions where first full-length-optical-core cladding resin 156 is present and may only exit full-length optical core 110 in regions (such as full-length-peripheral-surface regions 127) where full-length-optical-core first-cladding resin 156 is not present. As a result, the at least one full-length optical waveguide 102 may be constructed to provide a desired amount of electromagnetic radiation 118, exiting various positions along the full-length peripheral surface 116, and may thus be constructed to ensure that a desired amount of electromagnetic radiation 118 penetrates the shadows of elongate filaments 104.
Referring generally to Fig. 1 and particularly to, e.g., Figs, 7 and 8, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the full-length peripheral surface 116 has full-length-peripheral-surface regions 127 devoid of first full-length-optical-core cladding resin 156 and the full-length-optical-core cladding 154 further comprises second full-length-optical-core cladding resin 158, having a full-length-optical-core second-cladding-resin refractive index. Second full-length-optical-core cladding resin 158 covers the full-length-peripheral-surface regions 127 of full-length peripheral surface 116. The full-length-optical-core second-cladding-resin refractive index may be greater than the full-length-optical-core first-cladding-resin refractive index.

By covering full-length-peripheral-surface regions 127 with second full-length-optical-core cladding resin 158, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits the full-length peripheral surface 116. Additionally, or alternatively, with full-length-peripheral-surface regions 127 covered with second full-length-optical-core cladding resin 158, the integrity of the first full-length-optical-core cladding resin 156 may be ensured, such that it is less likely to peel or break off during storage of the at least one full-length optical waveguide 102 and during construction of feedstock line 100.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 8, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the second full-length-optical-core cladding resin 158 also covers the first full-length-optical-core cladding resin 156.
Full-length optical waveguides including second full-length-optical-core cladding resin 158 covering first full-length-optical-core cladding resin 156 may be more easily manufactured, in that full-length optical core 110 with first full-length-optical-core cladding resin 156 simply may be fully coated with second full-length-optical-core cladding resin 158. Additionally or alternatively, the integrity of full-length optical waveguides may be maintained during storage thereof and during construction of feedstock line 100.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 7 and 8, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index. The resin refractive index may be greater than the full-length-optical-core second-cladding-resin refractive index. In examples where second full-length-optical-core cladding resin 158 has a refractive index less than that of resin 124, electromagnetic radiation 118 may be permitted to exit second full-length-optical-core cladding resin 158 to penetrate and cure resin 124 when feedstock line 100 is used to additively manufacture object 136.

Date Recue/Date Received 2022-01-24 , Referring generally to Fig. 1 and particularly to, e.g., Fig. 9, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, full-length peripheral surface 116 has a surface roughness which may be selected such that when electromagnetic radiation 118 enters full-length optical core 110 via at least one of first full-length-optical-core end face 112, second full-length-optical-core end face 114, or full-length peripheral surface 116, at least a portion of electromagnetic radiation 118 exits full-length optical core 110 via full-length peripheral surface 116 to irradiate, in interior volume 182 of feedstock line 100, resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118 incident on exterior surface 180 of feedstock line 100.
In such examples, rather than relying on refractive-index properties of a cladding to ensure desired dispersal of electromagnetic radiation 118 from full-length optical core 110 via full-length peripheral surface 116, the surface roughness of full-length peripheral surface 116 may be selected such that electromagnetic radiation 118 exits full-length optical core 110 at desired amounts along the length of full-length peripheral surface 116. For example, the surface roughness may create regions of internal reflection of electromagnetic radiation 118 within the full-length optical core 110 and may create regions where electromagnetic radiation 118 is permitted to escape full-length optical core 110.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 9, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the at least one full-length optical waveguide 102 is devoid of any cladding that covers full-length optical core 110.
Full-length optical waveguides without any cladding may be less expensive to manufacture than full-length optical waveguides with cladding. Additionally, in such examples, the difference of refractive indexes between a cladding and resin need not be taken into account when selecting resin 124 for feedstock line 100.

Referring generally to Fig. 1 and particularly to, e.g., Fig. 4, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, the at least one full-length optical waveguide 102 is a plurality of full-length optical waveguides, interspersed among elongate filaments 104.
By including a plurality of full-length optical waveguides, interspersed among elongate filaments 104, such as among a bundle, or tow, of elongate filaments, a desired penetration of electromagnetic radiation 118 into the shadows of elongate filaments 104 may be ensured.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 4, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, elongate filaments 104 are at least one of twisted with, woven with, or braided with the plurality of full-length optical waveguides.
By being twisted with, woven with, or braided with elongate filaments 104, the plurality of full-length optical waveguides may be interspersed with elongate filaments 104 such that electromagnetic radiation 118, exiting the full-length optical waveguides, is delivered to regions of interior volume 182 that are in the shadows of elongated filaments 104.
Optical direction modifiers Referring generally to Fig. 1 and particularly to, e.g., Figs. 10-19, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, at least one optical structure in feedstock line 100 comprises optical direction modifiers 123. Each of optical direction modifiers 123 may extend along only a portion of the feedstock-line length.
Optical direction modifiers 123 are covered by resin 124 and are interspersed among elongate filaments 104. Each of optical direction modifiers 123 has a respective outer surface 184. In such examples, at least one outer surface of at least one optical structure 101 comprises a respective outer surface 184 of each of optical direction modifiers 123.
Each of optical direction modifiers 123 may be configured such that when electromagnetic radiation 118 strikes a respective outer surface 184 from a first direction, at least a portion of electromagnetic radiation 118 departs the respective outer surface 184 in a second direction that is at an angle to the first direction to irradiate, in interior volume 182 of feedstock line 100, resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on exterior surface 180 of feedstock line 100.
Inclusion of optical direction modifiers 123, each extending only along a portion of the feedstock line length, may provide for dispersion of electromagnetic radiation 118 within interior volume 182 for irradiation of resin 124 therein.
Moreover, by being shorter than full-length optical waveguides, optical direction modifiers 123 may more easily extend among elongate filaments 104 of a bundle, or tow, of elongate filaments 104. Further, optical direction modifiers 123 may serve to disperse, or scatter, electromagnetic radiation 118 into the shadows of elongate filaments 104, and may also serve to redirect electromagnetic radiation 118 to at least one other optical structure in feedstock line 100 (such as full-length optical waveguide 102) to facilitate penetration of electromagnetic radiation 118 into the shadows of elongate filaments 104 by at least one other optical structure.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 10 and 12-16, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, optical direction modifiers comprise partial-length optical waveguides 122. Each of partial-length optical waveguides 122 comprises a respective partial-length optical core 138.
Respective partial-length optical cores 138 of each of partial-length optical waveguides comprise a first partial-length-optical-core end face 140, a second partial-length-optical-core end face 142, an opposite first partial-length-optical-core end face 140, and partial-length peripheral surface 144, extending between first partial-length-optical-core end face 140 and second partial-length-optical-core end face 142.
In such examples, the core of at least one optical structure 101 comprises respective partial-length optical cores 138 and the respective outer surfaces 184 of each of the optical direction modifiers 123 comprise first partial-length-optical-core end face 140, second partial-length-optical-core end face 142 and partial-length peripheral surface 144.
Each of the partial-length optical waveguides 122 is configured such that when electromagnetic radiation 118 enters the partial-length optical core 138 via at least one of first partial-length-optical-core end face 140, second partial-length-optical-core end face 142, and partial-length peripheral surface 144, at least a portion of the electromagnetic radiation 118 exits partial-length optical core 138 via partial-length peripheral surface 144 to irradiate, in interior volume 182 of feedstock line 100, resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on exterior surface 180 of feedstock line 100.
In some examples, optical direction modifiers 123 are similar in construction to full-length optical waveguides but are shorter in length. Partial-length optical waveguides 122 may be cost effective to create, such as according to the various methods disclosed herein. By being interspersed among elongate filaments 104, partial-length optical waveguides 122 may directly receive electromagnetic radiation 118 and deliver electromagnetic radiation 118 into the shadows of elongate filaments 104.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 10 and 12-16, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, feedstock line 100 is configured such that when electromagnetic radiation 118 enters interior volume of feedstock line 100 via exterior surface 180 of feedstock line 100, electromagnetic radiation 118 enters at least one of the partial-length optical waveguides 122 via at least one of a partial-length peripheral surface 144, a first partial-length-optical-core end face 140, and a second partial-length-optical-core end face 142 of the at least one of the partial-length optical waveguides 122.
In other words, in some examples of feedstock line 100, partial-length optical waveguides 122 are positioned within interior volume 182 of feedstock line 100 such that at least one of partial-length peripheral surface 144, first partial-length-optical-core end face 140, and second partial-length-optical-core end face 142 is within the line of sight of electromagnetic radiation 118 to receive electromagnetic radiation 118 directed to exterior surface 180 of feedstock line 100 and then disperse, or scatter, electromagnetic radiation 118 within interior volume 182.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 13-16, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, partial-length optical core has a partial-length-optical-core refractive index. Each partial-length optical waveguide 122 further comprises partial-length-optical-core cladding 160, at least partially covering partial-length optical core 138. Partial-length-optical-core cladding 160 comprises at least first partial-length-optical-core cladding resin 162, having a partial-length-optical-core first-cladding-resin refractive index. Partial-length-optical-core cladding 160 may be non-uniform along each of the partial-length optical waveguides 122. For example, partial-length peripheral surface 144 may include partial-length-peripheral-surface regions 129 devoid of first partial-length-optical-core cladding resin 162. The partial-length-optical-core refractive index may be greater than the partial-length-optical-core first-cladding-resin refractive index.
Similar to full-length optical waveguide 102, by being non-uniform along the length of partial-length optical waveguides 122, electromagnetic radiation 118 may be permitted to exit partial-length optical core 138 via partial-length peripheral surface 144. Moreover, by first partial-length-optical-core cladding resin 162 having a refractive index that is less than that of partial-length optical core 138, electromagnetic radiation 118, upon entering partial-length optical core 138, may be trapped within partial-length optical core 138 in the regions where first partial-length-optical-core cladding resin 162 is present and may only exit partial-length optical core 138 in the regions (such as partial-length-peripheral-surface regions 129) where partial-length-optical-core cladding resin 162 is not present. As a result, partial-length optical waveguides 122 may be constructed to provide a desired amount of electromagnetic radiation 118, exiting various positions along partial-length peripheral surface 144, and may thus be constructed to ensure that a desired amount of electromagnetic radiation 118 penetrates the shadows of elongate filaments 104.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 14 and 15, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, partial-length peripheral surface 144 of partial-length optical core 138 of each of partial-length optical waveguides 122 has partial-length-peripheral-surface regions 129 devoid of first partial-length-optical-core cladding resin 162. Partial-length-optical-core cladding 160 further comprises second partial-length-optical-core cladding resin 164, having a partial-length-optical-core second-cladding-resin refractive index. Second partial-length-optical-core cladding resin 164 covers partial-length-peripheral-surface regions 129 of partial-length peripheral surface 144. The partial-length-optical-core second-cladding-resin refractive index may be greater than the partial-length-optical-core first-cladding-resin refractive index.
By covering partial-length-peripheral-surface regions 129 with second partial-length-optical-core cladding resin 164, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits partial-length peripheral surface 144. Additionally or alternatively, with partial-length-peripheral-surface regions 129 covered with second partial-length-optical-core cladding resin 164, the integrity of first partial-length-optical-core cladding resin 162 may be ensured, such that it is less likely to peel or break off during storage of partial-length optical waveguides 122 and during construction of feedstock line 100.

Referring generally to Fig. 1 and particularly to, e.g., Fig. 15, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, second partial-length-optical-core cladding resin 164 also covers first partial-length-optical-core cladding resin 162.
Partial-length optical waveguides 122 including second partial-length-optical-core cladding resin 164 covering the first partial-length-optical-core cladding resin 162 may be more easily manufactured, in that partial-length optical core 138 with first partial-length-optical-core cladding resin 162 simply may be fully coated with second partial-length-optical-core cladding resin 164. Additionally or alternatively, the integrity of partial-length optical waveguides 122 may be maintained during storage thereof and during construction of feedstock line 100.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 14 and 15, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index. The resin refractive index may be greater than the partial-length-optical-core second-cladding-resin refractive index.
In examples where second partial-length-optical-core cladding resin 164 has a refractive index less than that of resin 124, electromagnetic radiation 118 may be permitted to exit second partial-length-optical-core cladding resin 164 to penetrate and cure resin 124 when feedstock line 100 is being used to additively manufacture object 136.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 16, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, partial-length peripheral surface 144 of partial-length optical core 138 of each of the partial-length optical waveguides 122 has a surface roughness that may be selected such that when electromagnetic radiation 118 enters a partial-length optical core 138 via at least one of the first partial-length-optical-core end face 140, the second partial-length-optical-core end face 142, and the partial-length peripheral surface 144, at least a portion of the electromagnetic radiation 118 exits the partial-length optical core 138 via the partial-length peripheral surface 144 to irradiate, in the interior volume 182 of feedstock line 100, resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on the exterior surface 180 of feedstock line 100.
In such examples, rather than relying on refractive-index properties of a cladding to ensure desired dispersal of electromagnetic radiation 118 from partial-length optical core 138 via partial-length peripheral surface 144, the surface roughness of partial-length peripheral surface 144 may be selected such that electromagnetic radiation 118 exits partial-length optical core 138 at desired amounts along the length of partial-length peripheral surface 144. For example, the surface roughness may create regions of internal reflection of electromagnetic radiation 118 within partial-length optical core 138 and may create regions where electromagnetic radiation 118 is permitted to escape partial-length optical core 138.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 16, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, each of partial-length optical waveguides is devoid of any cladding that covers partial-length optical core 138.
Partial-length optical waveguides 122 without any cladding may be less expensive to manufacture than partial-length optical waveguides 122 with cladding.
Additionally, the difference of refractive indexes between a cladding and resin 124 need not be taken into account when selecting resin 124 for feedstock line 100.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 11 and 17-19, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, optical direction modifiers comprise optical direction-modifying particles 186. Optical direction-modifying particles 186 are configured to at least one of reflect, refract, diffract, or Rayleigh-scatter electromagnetic radiation 118, incident on a respective outer surface 184 of any one of the optical direction-modifying particles 186, to disperse, in interior volume 182 of feedstock line 100, electromagnetic radiation 118 to irradiate resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on the exterior surface 180 of the feedstock line 100. In such examples, respective outer surface 184 of each of the optical direction modifiers 123 may comprise respective outer surfaces 184 of each of the optical direction-modifying particles 186.
Inclusion of optical direction-modifying particles 186 that at least one of reflect, refract, diffract, or Rayleigh-scatter electromagnetic radiation 118 may provide for dispersion of electromagnetic radiation 118 within interior volume 182 for irradiation of resin 124 therein. Moreover, because they are particles, optical direction-modifying particles 186 may be more easily positioned among elongate filaments 104 of a bundle, or tow, of elongate filaments 104. In addition, in some examples, they may be generally uniformly spaced throughout resin 124 within the interior volume 182 and may effectively scatter electromagnetic radiation 118 throughout interior volume 182 to penetrate among elongate filaments 104 and into the shadows cast by elongate filaments 104 when feedstock line 100 is being used to additively manufacture object 136. In other examples, optical direction-modifying particles 186 may have a gradient of concentration within interior volume 182.
Optical direction-modifying particles 186 may be of any suitable material, such that they reflect, refract, diffract, or Rayleigh-scatter electromagnetic radiation 118.
As illustrative, non-exclusive examples, optical direction-modifying particles 186 may be made of alumina, silica, or thermoplastic with desired reflective, refractive, diffractive, or Rayleigh-scattering properties in connection with electromagnetic radiation 118.
In some examples of feedstock line 100, a single type, or configuration, of optical direction-modifying particles 186 may be included. In other examples of feedstock line 100, more than one type, or configuration, of optical direction-modifying particles 186 may be included. Different types may be selected to accomplish different functions, and to collectively scatter electromagnetic radiation 118 evenly throughout interior volume 182, including into the shadows of elongate filaments 104. For example, a first type of optical direction-modifying particles 186 may be configured to reflect electromagnetic radiation 118, a second type of optical direction-modifying particles 186 may be configured to refract electromagnetic .. radiation 118, and a third type of optical direction-modifying particles 186 may be configured to diffract electromagnetic radiation 118.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 11, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, each of elongate filaments 104 has a minimum outer dimension. Each of optical direction-modifying particles 186 has a maximum outer dimension that may be less than one-eighth the minimum outer dimension of any one of elongate filaments 104.
By having a maximum outer dimension that is less than one-eighth the minimum outer dimension of elongate filaments 104, optical direction-modifying particles 186 may more easily extend among elongate filaments 104. Moreover, when feedstock line 100 is being constructed (e.g., by system 200 herein or according to method 300 herein), optical direction-modifying particles 186 may more easily flow with resin 124 into a bundle, or tow, of elongate filaments 104.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 11 and 17-19, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, each of optical direction-modifying particles 186 has a maximum outer dimension that may be less than nm, 500 nm, 250 nm, or 200 nm.
Typical reinforcement fibers for composite materials often have a diameter in .. the range of 5 to 8 microns. By having a maximum outer dimension that is less than 1000 nm (1 micron), 500 nm (0.5 micron), 250 nm (0.25 micron), or 200 nm (0.200 micron), optical direction-modifying particles 186 may more easily extend among and/or between typical sizes of elongate filaments 104. Moreover, when feedstock line 100 is being constructed (e.g., by system 200 herein or according to method 300 herein), optical direction-modifying particles 186 may more easily flow with resin 124 into a bundle, or tow, of elongate filaments 104.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 11 and 17-19, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, electromagnetic radiation has a wavelength. Each of optical direction-modifying particles 186 has a minimum outer dimension that may be greater than one-fourth the wavelength of electromagnetic radiation 118.
Selecting a minimum outer dimension of optical direction-modifying particles .. 186 that is greater than one-fourth the wavelength of electromagnetic radiation 118 may ensure that optical direction-modifying particles 186 have the intended effect of causing electromagnetic radiation 118 to reflect, refract, or diffract upon hitting optical direction-modifying particles 186.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 11 and 17-19, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, each of optical direction-modifying particles 186 has a minimum outer dimension that may be greater than or equal to 60 nm or that is greater than or equal to 100 nm.
Ultra-violet light having a wavelength of about 400 nm is often used in connection with ultra-violet photopolymers. Accordingly, when resin 124 comprises or consists of a photopolymer, optical direction-modifying particles 186 having a minimum outer dimension that is greater than or equal to 100 nm may ensure that optical direction-modifying particles 186 have the intended effect of causing electromagnetic radiation 118 to reflect, refract, or diffract upon hitting optical direction-modifying particles 186. However, in other examples, a minimum outer dimension as low as 50 nm may be appropriate.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 11, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, optical direction-modifying particles 186 may comprise less than 10% by weight of resin 124, less than 5% by weight of resin 124, or less than 1% by weight of resin 124 of feedstock line 100.
By limiting optical direction-modifying particles 186 to the referenced threshold percentages, resin 124 may operatively flow among elongate filaments 104 when feedstock line 100 is being constructed (e.g., by system 200 herein or according to method 300 herein). In addition, desired properties of resin 124, feedstock line 100, and ultimately object 136 may not be negatively impacted by the presence of optical direction-modifying particles 186.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 17-19, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, outer surfaces 184 of at least some of optical direction-modifying particles 186 may be faceted.
By being faceted, outer surfaces 184 may effectively scatter electromagnetic radiation 118.
As used herein, "faceted" means having a plurality of planar, or generally planar, surfaces. In some examples of optical direction-modifying particles 186 that are faceted, outer surface 184 may have six or more, eight or more, ten or more, 100 or more, or even 1000 or more generally planar surfaces. Optical direction-modifying particles 186 may be of a material that has a natural crystalline structure that is faceted.
Referring generally to Fig. 1 and particularly to, e.g., Figs. 17-19, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, outer surfaces 184 of at least some of optical direction-modifying particles 186 have a surface roughness that may be selected such that when electromagnetic radiation 118 strikes outer surfaces 184, electromagnetic radiation 118 is scattered in interior volume 182 of feedstock line 100 to irradiate resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on exterior surface 180 of feedstock line 100.

Having a surface roughness selected to scatter electromagnetic radiation 118 may facilitate the operative irradiation of resin 124 throughout interior volume 182, including into the shadows of elongate filaments 104.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 11, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index. At least some of optical direction-modifying particles 186 have a particle refractive index. The particle refractive index may be greater than or less than the resin refractive index.
When optical direction-modifying particles 186 have a refractive index that is different from (e.g., that is at least 0.001 greater or less than) the refractive index of resin 124, electromagnetic radiation 118 incident upon the outer surfaces thereof may leave the respective outer surface 184 at a different angle, and may scatter throughout resin 124, including into the shadows of elongate filaments 104.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 17, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, at least some of optical direction-modifying particles 186 may be spherical.
By being spherical, optical direction-modifying particles 186 may more easily be positioned among elongate filaments 104, and when feedstock line 100 is being constructed (e.g., by system 200 herein or according to method 300 herein), may more easily flow with resin 124 into a bundle, or tow, of elongate filaments 104.
As used herein, "spherical" includes generally spherical and means that such optical direction-modifying particles 186 have a generally uniform aspect ratio, but are not necessarily perfectly spherical. For example, optical direction-modifying particles 186 that are spherical may be faceted, as discussed herein.
Referring generally to Fig. 1 and particularly to, e.g., Fig. 18, in one example, wherein this one example may also include subject matter according to one or more preceding examples described above, at least some of optical direction-modifying particles 186 may be prismatic.

By being prismatic, optical direction-modifying particles 186 may be selected to operatively at least one of reflect, refract, or diffract electromagnetic radiation 118, as discussed herein.
Combined optical structures Referring generally to Fig. 1 and particularly to, e.g. Fig. 20, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, at least one optical structure 101 in feedstock line 100 comprises at least one full-length optical wavelength 101 and optical direction modifiers 123. Optical direction modifiers 123 in turn comprise partial-length optical waveguides 122 and optical direction modifying particles 186. At least one full-length optical wavelength 101 and optical direction modifiers 123 are covered by resin 124 and are interspersed among elongate filaments 104.
System Referring generally to Fig. 2 and particularly to, e.g., Figs. 21 and 22, system 200 for creating feedstock line 100 for additive manufacturing of object 136 is disclosed. Feedstock line 100 has a feedstock-line length. System 200 comprises a filament supply 202, a filament separator 210, an optical structure supply 203, a combiner 212, and a resin supply 206.
Filament supply 202 is configured to dispense precursor tow 208, comprising elongate filaments 104.
Filament separator 210 is configured to separate precursor tow 208, dispensed from filament supply 202, into individual ones of elongate filaments 104 or into subsets 214 of elongate filaments 104. Each of subsets 214 of elongate filaments comprises a plurality of elongate filaments 104.
Optical structure supply 203 is configured to dispense at least one optical structure 101. For example, the optical structure supply 203 may comprise full-length-optical-waveguide supply 204 configured to dispense at least one full-length optical waveguide 102. Alternatively or additionally, the optical structure supply 203 may comprise an optical-direction-modifier supply 216 configured to dispense optical direction modifiers 123.
Combiner 212 is configured to combine the individual ones of elongate filaments 104 and at least one optical structure 101, dispensed by optical structure supply 203, or subsets 214 of elongate filaments 104, originating from filament separator 210, and at least one optical structure 101, dispensed by optical structure supply 203, into derivative tow 209 such that the at least one optical structure 101 is interspersed among elongate filaments 104. For example, combiner 212 may be configured to combine the individual ones of elongate filaments 104 and the at least one full-length optical waveguide 102, dispensed by full-length-optical-waveguide supply 204, or subsets 214 of elongate filaments 104, originating from filament separator 210, and at least one full-length optical waveguide 102, dispensed by full-length-optical-waveguide supply 204, into derivative tow 209 such that each of elongate filaments 104 and at least one full-length optical waveguide 102 extend along all of the feedstock-line length and at least one full-length optical waveguide 102 is interspersed among elongate filaments 104. Alternatively or additionally, combiner 212 may be configured to combine the individual ones of elongate filaments 104 and optical direction modifiers 123, dispensed by optical-direction-modifier supply 216, or subsets 214 of elongate filaments 104, originating from filament separator 210 and optical direction modifiers 123, dispensed by optical-direction-modifier supply 216, into derivative tow 209 such that optical direction modifiers 123 are interspersed among elongate filaments 104.
Resin supply 206 is configured to provide resin 124 to be applied to at least one of (i) precursor tow 208, (ii) individual ones of elongate filaments 104 or subsets of elongate filaments 104, (iii) at least one optical structure 101, and (iv) derivative tow 209. For example, resin supply 206 may be configured to provide resin 124 to be applied to at least one of (i) precursor tow 208, dispensed from filament supply 202, (ii) individual ones of elongate filaments 104 or subsets 214 of elongate filaments 104, originating from filament separator 210, (iii) at least one full-length optical waveguide 102, dispensed from full-length-optical-waveguide supply 204, and (iv) derivative tow 209, originating from combiner 212, such that elongate filaments 104 and at least one full-length optical waveguide 102 in derivative tow 209 are covered with resin 124. Alternatively or additionally, resin supply 206 may be configured to provide resin 124 to be applied to at least one of (i) precursor tow 208, dispensed from filament supply 202, (ii) individual ones of elongate filaments 104 or subsets 214 of elongate filaments 104, originating from filament separator 210, (iii) optical direction modifiers 123, dispensed from optical-direction-modifier supply 216, and (iv) derivative tow 209, originating from combiner 212, such that elongate filaments 104 and optical direction modifiers 123 in derivative tow 209 are covered with resin 124.
As discussed, inclusion of at least one optical structure 101 in feedstock line 100 facilitates penetration of electromagnetic radiation 118 into interior volume 182 of feedstock line 100 for irradiation of resin 124, despite regions of resin 124 being in the shadows of elongate filaments 104 cast by the direct (Le., line-of-sight) application of electromagnetic radiation 118. For example, at least one optical structure 101 comprises at least one outer surface and a core. The at least one optical structure 101 may be configured such that when electromagnetic radiation 118 strikes at least one optical structure 101, at least a portion of electromagnetic radiation is reflected by at least one outer surface and/or dispersed by the core, to irradiate resin 124 that, due at least in part to elongate filaments 104, is not directly accessible to electromagnetic radiation 118, incident on exterior surface 108 of the feedstock line 100.
For example, even when electromagnetic radiation 118 is shielded from directly reaching all regions of resin 124, the at least one full-length optical waveguide 102 may receive electromagnetic radiation 118 via one or more of its first full-length-optical-core end face 112, its second full-length-optical-core end face 114, and its full-length peripheral surface 116, and disperse electromagnetic radiation 118 via at least its full-length peripheral surface 116 to indirectly reach regions of resin 124. At least one full-length optical waveguide 102 may thus serve to disperse electromagnetic radiation 118 into the shadows of elongate filaments 104, and may also serve to redirect electromagnetic radiation 118 to optical direction modifiers 123 for penetration into the shadows of elongate filaments 104 by at least one full-length optical waveguide 102. Additionally or alternatively, optical direction modifiers 123 may serve to redirect electromagnetic radiation 118 to at least one full-length optical waveguide 102 for penetration into the shadows of elongate filaments 104 by at least one full-length optical waveguide 102.
As a further example, each optical direction modifier 123 has a respective outer surface 184, and each optical direction modifier 123 is configured such that when electromagnetic radiation 118 strikes outer surface 184 from a first direction, at least a portion of electromagnetic radiation 118 departs the outer surface 184 in a second direction that is at an angle to the first direction. By applying optical direction modifiers 123 to elongate filaments 104 to become part of feedstock line 100 being created by system 200, dispersion of electromagnetic radiation 118 within interior volume 182 for irradiation of resin 124 therein may be achieved when feedstock line 100 is used to additively manufacture object 136. Moreover, as discussed, by being shorter than full-length optical waveguides, optical direction modifiers 123 may more easily extend among elongate filaments 104 within derivative tow 209. Optical direction modifiers 123 may serve to disperse, or scatter, electromagnetic radiation 118 into the shadows of elongate filaments 104, and may further serve to redirect electromagnetic radiation 118 to at least one full-length optical waveguide 102 for penetration of electromagnetic radiation 118 into the shadows of elongate filaments 104 by at least one full-length optical waveguide 102.
Creating feedstock line 100 from precursor tow 208 permits the use of off-the-shelf reinforcement fiber tows. Filament separator 210 separates precursor tow into individual ones of elongate filaments 104 or into subsets 214 of elongate filaments 104, so that at least one optical structure 101, such as at least one full-length optical waveguide 102 and/or optical direction modifiers 123, may be operatively interspersed with elongate filaments 104. Combiner 212 then combines elongate filaments 104 and at least one optical structure 101 into derivative tow 209 to ultimately become feedstock line 100 with resin 124. Resin supply 206 dispenses resin 124 at any suitable location as feedstock line 100 is being created, including one or more of (i) at precursor tow 208 before it is separated into individual ones of elongate filaments 104 or into subsets 214 of elongate filaments 104, (ii) at elongate filaments 104 that have been separated from the precursor tow 208, (iii) at or with least one optical structure 101, such as at or with at least one full-length optical waveguide 102 and/or optical direction modifiers 123, before they are combined with elongate filaments 104, and (iv) at derivative tow 209 after at least one optical structure 101 has been combined with elongate filaments 104.
Precursor tow 208 may take any suitable form depending on the desired properties of feedstock line 100. As mentioned, precursor tow 208 may be (but is not required to be) an off-the-shelf precursor tow, with such examples including tows having 1000, 3000, 6000, 12000, 24000, or 48000 continuous individual fibers within the tow, but other examples also may be used.
Filament separator 210 may take any suitable configuration, such that it is configured to operatively separate precursor tow 208 into individual ones of elongate filaments 104 or subsets 214 of elongate filaments 104. For example, filament separator 210 may comprise at least one of a knife, an air knife, a comb, a mesh, a screen, a series of polished idlers, and other mechanisms known in the art.
Combiner 212 may take any suitable configuration, such that it is configured to operatively combine elongate filaments 104 with at least one optical structure 101.
For example, combiner 212 may be configured to combine elongate filaments 104 with at least one full-length optical waveguide 102 and/or optical direction modifiers 123, such that at least one full-length optical waveguide 102 and/or optical direction modifiers 123 become interspersed among elongate filaments 104. For example, combiner 212 may at least one of twist, weave, braid, or otherwise bundle elongate filaments 104 together with at least one full-length optical waveguide 102.
Combiner 212 also may include a fixator, such as a mesh or screen, through which elongate filaments 104 and/or full-length optical waveguide(s) extend, and which may prevent the twisting, weaving, braiding, or bundling from propagating upstream of combiner 212.
Resin supply 206 may take any suitable configuration, such that it is configured to operatively dispense and apply resin 124 at an operative location. For example, resin supply 206 may be configured to spray or mist resin 124.
Additionally or alternatively, resin supply 206 may include a reservoir or bath of resin 124, through which is pulled at least one of precursor tow 208, individual ones of elongate filaments 104, subsets 214 of elongate filaments 104, full-length optical waveguide(s), and/or derivative tow 209.
In some examples, system 200 may further comprise a chamber 224 between filament separator 210 and combiner 212, and through which individual ones of elongate filaments 104 or subsets 214 of elongate filaments 104 pass as feedstock line 100 is being created. In some such examples, at least one full-length optical waveguide 102 also extends through chamber 224. Moreover, in some examples, resin 124 is applied to at least elongate filaments 104, and in some examples, also to or with at least one full-length optical waveguide 102 or optical direction modifiers 123, in chamber 224.
Referring generally to Fig. 2, elongate filaments 104 are opaque to electromagnetic radiation 118.
As discussed, elongate filaments 104 that are opaque to electromagnetic radiation 118 may be well suited for inclusion in feedstock line 100, as at least one optical structure 101 also included in the feedstock line 100 may operatively receive electromagnetic radiation 118 and disperse electromagnetic radiation 118 into the shadows of elongate filaments 104 when feedstock line 100 is being used to additively manufacture object 136 with in situ curing thereof.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 21 and 22, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, filament separator 210 is configured to impart a first electrical charge to elongate filaments 104 as precursor tow 208 is separated into the individual ones of elongate filaments 104 or into subsets 214 of elongate filaments 104. Resin supply 206 is configured to impart a second electrical charge to resin 124 when resin 124 is applied to at least one of (i) the individual ones of elongate filaments 104 or subsets 214 of elongate filaments 104, originating from filament separator 210, and (ii) derivative tow 209, originating from combiner 212, such that elongate filaments 104 and at least one optical structure 101 (such as at least one full-length optical waveguide 102 and/or optical direction modifiers 123) in derivative tow 209 are covered with resin 124. The second electrical charge and the first electrical charge have opposite polarity.
By imparting a first electrical charge to elongate filaments 104 and by imparting a second opposite charge to resin 124 as it is applied to elongate filaments 104, resin 124 may be electrostatically attracted to elongate filaments 104, which may thereby facilitate wetting of elongate filaments 104 with resin 124.
Full-length optical-waveguide supply Referring generally to Fig. 2 and particularly to, e.g., Figs. 5-9, 21, and 22 in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical structure supply 203 configured to dispense at least one optical structure 101 comprises a full-length-optical-waveguide supply 204 configured to dispense at least one full-length optical waveguide 102. At least one full-length optical waveguide 102 comprises a full-length optical core 110. The full-length optical core 110 comprises a first full-length-optical-core end face 112, a second full-length-optical-core end face 114, an opposite first full-length-optical-core end face 112, and a full-length peripheral surface 116, extending between the first full-length-optical-core end face 112 and the second full-length-optical-core end face 114. In such examples, a core of at least one optical structure 101 comprises full-length optical core 110 and the at least one outer surface of the at least one optical structure 101 comprises first full-length-optical-core end face 112, second full-length-optical-core end face 114, and full-length peripheral surface 116.

Referring generally to Fig. 2 and particularly to, e.g., Figs. 5-9,21, and 22, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, at least one full-length optical waveguide 102 dispensed by full-length optical waveguide supply 204 is configured such that when electromagnetic radiation 118 enters the full-length optical core 110 via at least one of first full-length-optical-core end face 112, the second full-length-optical-core end face 114, and the full-length peripheral surface 116, at least a portion of the electromagnetic radiation 118 exits the full-length optical core 110 via the full-length peripheral surface 116.
Accordingly, when feedstock line 100 is used to additively manufacture object 136 with in situ curing thereof (i.e., with electromagnetic radiation 118 entering full-length optical core 110), at least a portion of the electromagnetic radiation 118 may be emitted from the full-length optical core 110 at a position that is spaced-apart from where it entered full-length optical core 110. As a result, electromagnetic radiation may be dispersed throughout the interior volume 182 of feedstock line 100 for operative irradiation of resin 124.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 5-9, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, at least one full-length optical waveguide is configured such that when electromagnetic radiation 118 enters the first full-length-optical-core end face 112 of the full-length optical core 110, an initial portion of electromagnetic radiation 118 exits full-length optical core 110 via full-length peripheral surface 116 and a final portion of electromagnetic radiation 118, remaining in full-length optical core 110 after the initial portion of electromagnetic radiation 118 exits full-length optical core 110, exits full-length optical core 110 via second full-length-optical-core end face 114.
In other words, in some examples of feedstock line 100, if electromagnetic radiation 118 enters first full-length-optical-core end face 112, it may exit both the full-length peripheral surface 116 and the second full-length-optical-core end face 114, as opposed, for example, to electromagnetic radiation 118 being fully emitted via full-length peripheral surface 116. As discussed, such examples of feedstock line 100 may be well suited for additive manufacturing systems and methods in which electromagnetic radiation 118 is directed at first full-length-optical-core end face 112 as feedstock line 100 is being constructed and as object 136 is being manufactured.
Referring generally to Fig, 2 and particularly to, e.g., Fig, 5-9, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, at least one full-length optical waveguide is configured such that the initial portion of electromagnetic radiation 118, which exits full-length optical core 110 via full-length peripheral surface 116, may be greater than or equal to the final portion of electromagnetic radiation 118, which exits full-length optical core 110 via second full-length-optical-core end face 114.
As discussed, in such configurations, at least one full-length optical wavelength 102 may ensure that a desired amount of electromagnetic radiation exits full-length optical core 110 via full-length peripheral surface 116 to operatively cure resin 124 among elongate filaments 104 within interior volume 182 of feedstock line 100 when feedstock line 100 is used to additively manufacture object 136.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 6-8, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, the full-length optical core 110 has a full-length-optical-core refractive index and the at least one full-length optical waveguide 102 further comprises full-length-optical-core cladding 154, at least partially covering the full-length optical core 110. The full-length-optical-core cladding 154 comprises at least first full-length-optical-core cladding resin 156, having a full-length-optical-core first-cladding-resin refractive index. The full-length-optical-core cladding 154 may be non-uniform along the at least one full-length optical waveguide 102. For example, full-length peripheral surface 116 may include full-length-peripheral-surface regions 127 devoid of first full-length-optical-core cladding resin 156. The full-length-optical-core refractive index may be greater than the full-length-optical-core first-cladding-resin refractive index.
As discussed, by full-length-optical-core cladding 154 being non-uniform along the length of the full-length optical waveguide, electromagnetic radiation 118 may be permitted to exit the full-length optical core 110 via the full-length peripheral surface 116. Moreover, by the first full-length-optical-core cladding resin 156 having a refractive index that is less than that of full-length optical core 110, electromagnetic radiation 118, upon entering full-length optical core 110, may be trapped within the full-length optical core 110 in regions where first full-length-optical-core cladding resin 156 is present and may only exit full-length optical core 110 in regions (such as full-length-peripheral-surface regions 127) where first full-length-optical-core cladding resin 156 is not present. As a result, the full-length optical waveguide may be constructed to provide a desired amount of electromagnetic radiation 118, exiting various positions along the full-length peripheral surface 116, and may thus be constructed to ensure that a desired amount of electromagnetic radiation 118 penetrates the shadows of elongate filaments 104 when feedstock line 100 is used to additively manufacture object 136.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 7 and 8, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, the full-length peripheral surface has full-length-peripheral-surface regions 127 devoid of first full-length-optical-core cladding resin 156 and the full-length-optical-core cladding 154 further comprises second full-length-optical-core cladding resin 158, having a full-length-optical-core second-cladding-resin refractive index. Second full-length-optical-core cladding resin 158 covers the full-length-peripheral-surface regions 127 of the full-length peripheral surface 116. The full-length-optical-core second-cladding-resin refractive index may be greater than the full-length-optical-core first-cladding-resin refractive index. As discussed, by covering full-length-peripheral-surface regions 127 with second full-length-optical-core cladding resin 158, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits the full-length peripheral surface 116. Additionally or alternatively, with full-length-peripheral-surface regions 127 covered with second full-length-optical-core cladding resin 158, the integrity of the first full-length-optical-core cladding resin 166 may be ensured, such that it is less likely to peel or break off during storage of the at least one full-length optical waveguide 102 and during construction of feedstock line 100.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 8, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, the second full-length-optical-core cladding resin 158 also covers the first full-length-optical-core cladding resin 156.
As discussed, full-length optical waveguides including second full-length-optical-core cladding resin 158 covering first full-length-optical-core cladding resin 156 may be more easily manufactured, in that full-length optical core 110 with first full-length-optical-core cladding resin 156 simply may be fully coated with second full-length-optical-core cladding resin 158. Additionally or alternatively, the integrity of full-length optical waveguides may be maintained during storage thereof and during construction of feedstock line 100.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 7 and 8, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index.
The resin refractive index may be greater than the full-length-optical-core second-cladding-resin refractive index. As discussed, in examples where second full-length-optical-core cladding resin 158 has a refractive index less than that of resin 124, electromagnetic radiation 118 may be permitted to exit second full-length-optical-core cladding resin 158 to penetrate and cure resin 124 when feedstock line 100 is used to additively manufacture object 136.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 9, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, full-length peripheral surface 116 has a surface roughness which may be selected such that when electromagnetic radiation 118 enters full-length optical core 110 via at least one of first full-length-optical-core end face 112, second full-length-optical-core end face 114, and full-length peripheral surface 116, at least a portion of electromagnetic radiation 118 exits full-length optical core 110 via full-length peripheral surface 116.
As discussed, in such examples, rather than relying on refractive-index properties of a cladding to ensure desired dispersal of electromagnetic radiation 118 from full-length optical core 110 via full-length peripheral surface 116, the surface roughness of full-length peripheral surface 116 may be selected such that electromagnetic radiation 118 exits full-length optical core 110 at desired amounts along the length of full-length peripheral surface 116. For example, the surface roughness may create regions of internal reflection of electromagnetic radiation 118 within the full-length optical core 110 and may create regions where electromagnetic radiation 118 is permitted to escape full-length optical core 110.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 9, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, the at least one full-length optical waveguide 102 is devoid of any cladding that covers full-length optical core 110.
As discussed, full-length optical waveguides without any cladding may be less expensive to manufacture than full-length optical waveguides with cladding.
Additionally, in such examples, the difference of refractive indexes between a cladding and resin 124 need not be taken into account when selecting resin 124 for feedstock line 100.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 21 and 22, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, combiner 212 is configured to at least one of twist, weave, or braid the individual ones of elongate filaments 104 and at least one full-length optical waveguide 102, dispensed by full-length-optical-waveguide supply 204, or subsets 214 of elongate filaments 104, originating from filament separator 210, and at least one optical structure 101, dispensed by full-length-optical-waveguide supply 204, into derivative tow 209.
As discussed, by being twisted with, woven with, or braided with elongate filaments 104, at least one full-length optical waveguide 102 may be interspersed with elongate filaments 104 such that electromagnetic radiation 118, exiting the at least one full-length optical waveguide 102, may be delivered to regions of interior volume 182 that are in the shadows of elongate filaments 104 when feedstock line 100 is used to additively manufacture object 136. As an example, combiner 212 may comprise a spool that winds up derivative tow 209 while simultaneously twisting derivative tow 209. Other mechanisms for twisting, weaving, or braiding multi-filament structures, as known in the art, also may be used.
Optical-direction-modifier supply Referring generally to Fig. 2 and particularly to, e.g., Figs. 12-19, 21, and 22, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical structure supply 203 configured to dispense at least one optical structure 101 comprises optical-direction-modifier supply 216 configured to dispense optical direction modifiers 123.
Each optical direction modifier 123 is configured such that when electromagnetic radiation 118 strikes a respective outer surface 184 from a first direction, at least a portion of the electromagnetic radiation 118 departs the respective outer surface 184 in a second direction that is at an angle to the first direction to irradiate resin 124. In such examples, at least one outer surface of the at least one optical structure 101 comprises a respective outer surface 184 of each of optical direction modifiers 123.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 12-16, 21, and 22, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical direction modifiers dispensed by the optical-direction-modifier supply 216 comprise partial-length optical waveguides 122. Each of partial-length optical waveguides 122 comprises a respective partial-length optical core 138. Respective partial-length optical cores 138 of respective partial-length optical waveguides 122 comprise a first partial-length-optical-core end face 140, a second partial-length-optical-core end face 142, opposite first partial-length-optical-core end face 140, and a partial-length peripheral surface 144, extending between the first partial-length-optical-core end face 140 and the second partial-length-optical-core end face 142. In such examples, the core of the at least one optical structure 101 comprises respective partial-length optical core 138, and respective outer surfaces 184 of each of the optical direction modifiers 123 comprise the first partial-length-optical-core end face 140, the second partial-length-optical-core end face 142, and the partial-length peripheral surface 144.
Each of partial-length optical waveguide 122 is configured such that when electromagnetic radiation 118 enters partial-length optical core 138 via at least one of the first partial-length-optical-core end face 140, the second partial-length-optical-core end face 142, and the partial-length peripheral surface 144, at least a portion of electromagnetic radiation 118 exits partial-length optical core 138 via the partial-length peripheral surface 144.
As discussed, in some examples, optical direction modifiers 123 are similar in construction to full-length optical waveguides but are shorter in length.
Further, as discussed, the partial-length optical waveguides 122 may be cost effective to create, such as according to the various methods disclosed here. By being interspersed among elongate filaments 104, the partial-length optical waveguides 122 may directly receive electromagnetic radiation 118 and may deliver electromagnetic radiation 118 into the shadows of elongate filaments 104.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 13-15, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, the partial-length optical core 138 has a partial-length-optical-core refractive index. Each of the partial-length optical waveguides 122 further comprises partial-length-optical-core cladding 160, at least partially covering the partial-length optical core 138. The partial-length-optical-core cladding 160 comprises at least a first partial-length-optical-core cladding resin 162, having a partial-length-optical-core first-cladding-resin refractive index.
The partial-length-optical-core cladding 160 may be non-uniform along each of partial-length optical waveguides 122. For example, the partial-length peripheral surface 144 may include partial-length-peripheral-surface regions 129 devoid of first partial-length-optical-core cladding resin 162. The partial-length-optical-core refractive index may be greater than the partial-length-optical-core first-cladding-resin refractive index.
As discussed, similar to the full-length optical waveguide 102, by partial-length-optical-core cladding 160 being non-uniform along the length of partial-length optical waveguides 122, electromagnetic radiation 118 may be permitted to exit partial-length optical core 138 via partial-length peripheral surface 144.
Moreover, by first partial-length-optical-core cladding resin 162 having a refractive index that is less than that of partial-length optical core 138, electromagnetic radiation 118, upon entering partial-length optical core 138, may be trapped within partial-length optical core 138 in regions where first partial-length-optical-core cladding resin 162 is present and may only exit partial-length optical core 138 in regions (such as partial-length-peripheral-surface regions 129) where first partial-length-optical-core cladding resin 156 is not present. As a result, partial-length optical waveguides 122 may be constructed to provide a desired amount of electromagnetic radiation 118, exiting various positions along partial-length peripheral surface 144, and thus may be constructed to ensure that a desired amount of electromagnetic radiation 118 penetrates the shadows of elongate filaments 104 when feedstock line 100 is being used to additively manufacture object 136.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 14 and 15, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, partial-length peripheral surface 144 of partial-length optical core 138 of each of partial-length optical waveguides 122 has partial-length-peripheral-surface regions 129 devoid of first partial-length-optical-core cladding resin 162. Partial-length-optical-core cladding 160 further comprises second partial-length-optical-core cladding resin 164, having a partial-length-optical-core second-cladding-resin refractive index. Second partial-length-optical-core cladding resin 164 covers partial-length-peripheral-surface regions 129 of partial-length peripheral surface 144. The partial-length-optical-core second-cladding-resin refractive index may be greater than the partial-length-optical-core first-cladding-resin refractive index.
As discussed, by covering partial-length-peripheral-surface regions 129 with second partial-length-optical-core cladding resin 164, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits partial-length peripheral surface 144. Additionally or alternatively, with partial-length-peripheral-surface regions 129 covered with second partial-length-optical-core cladding resin 164, the integrity of first partial-length-optical-core cladding resin 162 may be ensured, such that it is less likely to peel or break off during storage of partial-length optical waveguides 122 and during construction of feedstock line 100.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 15, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, second partial-length-optical-core cladding resin 164 also covers first partial-length-optical-core cladding resin 162.
As discussed, partial-length optical waveguides 122 including second partial-length-optical-core cladding resin 164 covering first partial-length-optical-core cladding resin 162 may be more easily manufactured, in that partial-length optical core 138 with first partial-length-optical-core cladding resin 162 simply may be fully coated with second partial-length-optical-core cladding resin 164.
Additionally or alternatively, the integrity of partial-length optical waveguides 122 may be maintained during storage thereof and during construction of feedstock line 100.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 14 and 15, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index.
The resin refractive index may be greater than the partial-length-optical-core second-cladding-resin refractive index.

Again, in examples where second partial-length-optical-core cladding resin 164 has a refractive index less than that of resin 124, electromagnetic radiation 118 may be permitted to exit second partial-length-optical-core cladding resin 164 to penetrate and cure resin 124 when feedstock line 100 is being used to additively manufacture object 136.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 16, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, partial-length peripheral surface 144 of partial-length optical core 138 of each of partial-length optical waveguides 122 has a surface roughness that may be selected such that when electromagnetic radiation 118 enters partial-length optical core 138 via at least one of first partial-length-optical-core end face 140, second partial-length-optical-core end face 142, and partial-length peripheral surface 144, at least a portion of electromagnetic radiation 118 exits partial-length optical core 138 via partial-length peripheral surface 144.
Again, in such examples, rather than relying on refractive-index properties of a cladding to ensure desired dispersal of electromagnetic radiation 118 from partial-length optical core 138 via partial-length peripheral surface 144, the surface roughness of partial-length peripheral surface 144 may be selected such that electromagnetic radiation 118 exits partial-length optical core 138 at desired .. amounts along the length of partial-length peripheral surface 144. For example, the surface roughness may create regions of internal reflection of electromagnetic radiation 118 within partial-length optical core 138 and may create regions where electromagnetic radiation 118 is permitted to escape partial-length optical core 138.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 16, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, each of partial-length optical waveguides is devoid of any cladding that covers partial-length optical core 138.
Again, partial-length optical waveguides 122 without any cladding may be less expensive to manufacture than partial-length optical waveguides 122 with cladding.

Additionally, the difference in refractive indexes between a cladding and resin 124 need not be taken into account when selecting resin 124 for feedstock line 100.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 17-19, 21, and 22, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical direction modifiers dispensed by the optical direction modifier supply 216 comprise optical direction-modifying particles 186. Optical direction-modifying particles 186 are configured to at least one of reflect, refract, diffract, or Rayleigh-scatter electromagnetic radiation 118, incident on a respective outer surface 184 of any one of optical direction-modifying particles 186 to disperse electromagnetic radiation 118. In such examples, respective outer surface 184 of each of optical direction modifiers 123 comprises respective outer surface 184 of each of optical direction-modifying particles 186.
As discussed, inclusion of optical direction-modifying particles 186 that at least one of reflect, refract, diffract, or Rayleigh-scatter electromagnetic radiation 118 may provide for dispersion of electromagnetic radiation 118 within interior volume 182 for irradiation of resin 124 therein when feedstock line 100 is being used to additively manufacture object 136. Moreover, because they are particles, optical direction-modifying particles 186 may be more easily interspersed among elongate filaments 104 when applied thereto. In addition, in some examples of feedstock line 100, they may be generally uniformly spaced throughout resin 124 within interior volume 182 and may effectively scatter electromagnetic radiation 118 throughout interior volume 182 to penetrate among elongate filaments 104 and into the shadows cast by elongate filaments 104 when feedstock line 100 is being used to additively manufacture object 136. In other examples of feedstock line 100, optical direction-modifying particles 186 may have a gradient of concentration within interior volume Referring generally to Fig. 2 and particularly to, e.g., Figs. 11 and 17-19, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, each of elongate filaments 104 has a minimum outer dimension. Each of the optical direction-modifying particles 186 has a maximum outer dimension that may be less than one-eighth the minimum outer dimension of any one of the elongate filaments 104.
Again, by having a maximum outer dimension that is less than one-eighth the minimum outer dimension of the elongate filaments 104, the optical direction-modifying particles 186 may be easily dispersed between and/or among elongate filaments 104. Moreover, optical direction-modifying particles 186 may more easily flow with resin 124 to operatively disperse the optical direction-modifying particles 186 throughout the feedstock line 100, including into the shadows of elongate filaments 104.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 11 and 17-19, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, each of the optical direction-modifying particles 186 has a maximum outer dimension that may be less than nm, 500 nm, 250 nm, or 200 nm.
As discussed, typical reinforcement fibers for composite materials often have a diameter in the range of 5 to 8 microns. By having a maximum outer dimension that is less than 1000 nm (1 micron), 500 nm (0.5 micron), 250 nm (0.25 micron), or 200 nm (0.200 micron), optical direction-modifying particles 186 may more easily extend between and/or among typical sizes of elongate filaments 104. Moreover, optical direction-modifying particles 186 may more easily flow with resin 124 to operatively disperse optical direction-modifying particles 186 throughout feedstock line 100, including into the shadows of elongate filaments 104.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 11 and 17-19, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, electromagnetic radiation 118 has a wavelength. Each of optical direction-modifying particles 186 has a minimum outer dimension that may be greater than one-fourth the wavelength of electromagnetic radiation 118.

Again, selecting a minimum outer dimension of optical direction-modifying particles 186 that is greater than one-fourth the wavelength of electromagnetic radiation 118 that will be used when additively manufacturing object 136 may ensure that optical direction-modifying particles 186 have the intended effect of causing electromagnetic radiation 118 to reflect, refract, or diffract upon hitting optical direction-modifying particles 186.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 11 and 17-19, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, each of the optical direction-modifying particles 186 has a minimum outer dimension that may be greater than or equal to 50 nm or that is greater than or equal to 100 nm.
As discussed, ultra-violet light having a wavelength of about 400 nm is often used in connection with ultra-violet photopolymers. Accordingly, when resin comprises or consists of a photopolymer, optical direction-modifying particles having a minimum outer dimension that is greater than or equal to 100 nm may ensure that optical direction-modifying particles 186 have the intended effect of causing electromagnetic radiation 118 to reflect, refract, or diffract upon hitting optical direction-modifying particles 186. However, in other examples, a minimum outer dimension as low as 50 nm may be appropriate.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 11, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, in feedstock line 100, optical direction-modifying particles 186 may comprise less than 10% by weight of resin 124, less than 5% by weight of resin 124, or less than 1% by weight of resin 124.
As discussed, by limiting optical direction-modifying particles 186 to the referenced threshold percentages, resin 124 may operatively flow among elongate filaments 104 when combiner 212 combines elongate filaments 104 and optical direction-modifying particles 186 or combines elongate filaments 104, at least one full length optical waveguide 102 and optical direction-modifying particles 186. In addition, desired properties of resin 124, feedstock line 100, and ultimately object 136 may not be negatively impacted by the presence of optical direction-modifying particles 186.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 17-19, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, outer surfaces 184 of at least some of optical direction-modifying particles 186 may be faceted.
Again, by being faceted, outer surfaces 184 may effectively scatter electromagnetic radiation 118.
Referring generally to Fig. 2 and particularly to, e.g., Figs. 17-19, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, outer surfaces 184 of at least some of optical direction-modifying particles 186 have a surface roughness that may be selected such that when electromagnetic radiation 118 strikes outer surfaces 184, electromagnetic radiation 118 is scattered.
As discussed, having a surface roughness selected to scatter electromagnetic radiation 118 may facilitate the operative irradiation of resin 124 throughout feedstock line 100, including into the shadows of elongate filaments 104, when feedstock line 100 is being used to additively manufacture object 136.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 11, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index. At least some of the optical direction-modifying particles 186 have a particle refractive index.
The particle refractive index may be greater than or less than the resin refractive index.
Again, when optical direction-modifying particles 186 have a refractive index that is different from the refractive index of resin 124, electromagnetic radiation 118 incident upon the respective outer surfaces 184 thereof may leave the respective outer surfaces 184 at a different angle, and may scatter throughout resin 124, including into the shadows of elongate filaments 104.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 17, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, at least some of optical direction-modifying particles 186 may be spherical.
Again, by being spherical, optical direction-modifying particles 186 may more easily be positioned among elongate filaments 104 and may more easily flow with resin 124 as combiner 212 combines elongate filaments 104 and optical direction-modifying particles 186.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 18, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, at least some of optical direction-modifying particles 186 may be prismatic.
Again, by being prismatic, optical direction-modifying particles 186 may be selected to operatively at least one of reflect, refract, or diffract electromagnetic radiation 118, as discussed herein.
Referring generally to Fig. 2 and particularly to, e.g., Fig. 22, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical-direction-modifier supply 216 and resin supply 206 together form combined supply 222, configured to dispense optical direction modifiers 123 together with resin 124.
That is, combined supply 222 may dispense optical direction modifiers 123 in a volume of resin 124. Stated differently, optical direction modifiers 123 may be suspended within resin 124. By using combined supply 222, even dispersion of optical direction modifiers 123 may be ensured, and a less-expensive system may be constructed. For example, combined supply 222 may spray or mist resin and optical direction modifiers 123 together to apply them to elongate filaments 104, or elongate filaments 104 may be pulled through a bath of resin 124 with optical direction modifiers 123 suspended therein.
Method Referring generally to, e.g., Figs. 21 and 22, and particularly to Fig. 23, a method 300 of creating feedstock line 100 for additive manufacturing of object 136 is disclosed. Feedstock line 100 has a feedstock-line length.
Method 300 comprises a step of (block 302) separating precursor tow 208, comprising elongate filaments 104, into individual ones of elongate filaments 104 or into subsets 214 of elongate filaments 104. Each of subsets 214 of elongate filaments 104 comprises a plurality of elongate filaments 104.
Method 300 also comprises a step of (block 304) combining individual ones of elongate filaments 104 or subsets 214 of elongate filaments 104 with at least one optical structure 101. For example, the step of block 304 may comprise a step of (block 305) combining the individual ones of elongate filaments 104 and at least one full-length optical waveguide 102 or subsets 214 of elongate filaments 104 and at least one full-length optical waveguide 102 into derivative tow 209 so that each of elongate filaments 104 and at least one full-length optical waveguide 102 extends along all of the feedstock-line length and at least one full-length optical waveguide 102 is interspersed among elongate filaments 104. Alternatively or additionally, the step of block 304 may comprise a step of (block 316) combining optical direction modifiers 123 and the individual ones of elongate filaments 104 or combining optical direction modifiers 123 and subsets 214 of elongate filaments 104 such that optical direction modifiers 123 are interspersed among elongate filaments 104.
Method 300 further comprises a step of (block 306) applying resin 124 to cover elongate filaments 104 and at least one optical structure 101 combined with the elongate filaments 104 such that elongate filaments 104 and at least one optical structure 101 are covered by resin 124 in derivative tow 209. For example, the step of block 306 may comprise a step of (block 307) applying resin 124 to cover elongate filaments 104 and at least one full-length optical waveguide 102 such that elongate filaments 104 and at least one full-length optical waveguide 102 are covered by resin 124 in derivative tow 209. Alternatively or additionally, the step of block 306 may comprise a step of (block 318) applying resin 124 to cover elongate filaments 104 and optical direction modifiers 123 such that elongate filaments and optical direction modifiers 123 are covered by resin 124 in derivative tow 209.
As discussed in connection with system 200, creating feedstock line 100 from precursor tow 208 may permit the use of off-the-shelf reinforcement fiber tows. By separating precursor tow 208 into individual ones of elongate filaments 104 or into subsets 214 of elongate filaments 104, at least one optical structure 101 (such as at least one full-length optical waveguide 102 and/or optical direction modifiers 123) may be operatively interspersed with elongate filaments 104. Covering elongate filaments 104 and at least one optical structure 101 with resin 124 may ensure that elongate filaments 104 and at least one optical structure 101 are wetted and have suitable integrity for additively manufacturing object 136.
Referring generally to, e.g., Figs. 21 and 22, and particularly to Fig. 23, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, in some implementations of method 300, the step of (block 306) applying resin 124 to cover elongate filaments 104 and at least one optical structure 101 such that elongate filaments 104 and at least one optical structure 101 are covered by resin 124 in derivative tow 209 may be performed at least one of before or after the step of (block 302) separating precursor tow 208 into the individual ones of elongate filaments 104 or into subsets 214 of elongate filaments 104.
Applying resin 124 before precursor tow 208 is separated may enable a corresponding system (e.g., system 200 herein) to regulate the amount of resin on each individual one of elongate filaments 104 or individual subsets 214 of elongate filaments 104. For example, when a screen or mesh is used to separate precursor tow 208, the screen or mesh may effectively scrape away excess resin 124 leaving only a desired amount on each individual one of elongate filaments or individual subsets 214 of elongate filaments 104 for subsequent combination with at least one optical structure 101 to create feedstock line 100.
On the other hand, applying resin 124 after precursor tow 208 is separated may enable a sufficient amount of resin 124 to fully wet elongate filaments 104 and at least one optical structure 101.
In some implementations of method 300, resin 124 may be applied both before and after precursor tow 208 is separated.
Referring generally to, e.g., Figs. 21 and 22, and particularly to Fig. 23, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, in some embodiments of method 300, the step of (block 306) applying resin 124 to cover elongate filaments 104 and at least one optical structure 101, such that elongate filaments 104 and at least one optical structure 101 are covered by resin 124 in derivative tow 209, is performed at least one of before or after the step of (block 304) combining the individual ones of elongate filaments 104 and at least one optical structure 101 or subsets 214 of elongate filaments 104 and at least one optical structure 101 into derivative tow 209.
For example, in examples where at least one optical structure 101 comprises at least one full-length optical waveguide 102, applying resin 124 before elongate filaments 104 and at least one full-length optical waveguide 102 are combined may enable a sufficient amount of resin 124 to fully wet elongate filaments 104 and at least one full-length optical waveguide(s). Alternatively, applying resin 124 after elongate filaments 104 and full-length optical waveguide(s) are combined into derivative tow 209 may ensure that feedstock line 100 has the overall desired amount of resin 124 therein.
In some implementations of method 300, resin 124 may be applied both before and after elongate filaments 104 and at least one optical structure 101 are combined.
Referring generally to, e.g., Figs. 21 and 22, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, according to method 300, elongate filaments 104 are opaque to electromagnetic radiation 118. Again, elongate filaments 104 that are opaque to electromagnetic radiation 118 may be well suited for inclusion in feedstock line 100, as at least one optical structure 101 also included in the feedstock line 100 (such as at least one full-length optical waveguide 102 and/or optical direction modifiers 123) may operatively receive electromagnetic radiation 118 and disperse it into the shadows of elongate filaments 104 when feedstock line 100 is being used to add itively manufacture object 136 with in situ curing thereof.
Referring generally to, e.g., Figs. 21 and 22, and particularly to Fig. 23, according to one example of method 300, the step of (block 302) separating precursor tow 208 into individual ones of elongate filaments 104 or into subsets 214 of elongate filaments 104 comprises a step of (block 308) imparting a first electrical charge to elongate filaments 104. In such examples, the step of (block 306) applying resin 124 to cover elongate filaments 104 and at least one optical structure (such as at least one full-length optical waveguide 102 and/or optical direction modifiers 123) such that elongate filaments 104 and at least one optical structure 101 are covered by resin 124 in derivative tow 209 comprises a step of (block 310) imparting a second electrical charge to resin 124. The second electrical charge and the first electrical charge have opposite signs.
As discussed in connection with system 200, by imparting a first electrical charge to elongate filaments 104 and by imparting a second opposite charge to resin 124 as it is applied to elongate filaments 104, resin 124 may be electrostatically attracted to elongate filaments 104, which may thereby facilitate wetting of elongate filaments 104 with resin 124.
Full-length optical waveguide Referring generally to, e.g., Figs. 2 and 5-8, in one example according to method 300, wherein this one example may include subject matter according to one or more preceding examples described above, according to method 300, at least one optical structure 101 comprises at least one full-length optical waveguide 102. At least one waveguide 102 comprises full-length optical core 110. Full-length optical core 110 comprises first full-length-optical-core end face 112, second full-length-optical-core end face 114, opposite first full-length-optical-core end face 112, and full-length peripheral surface 116, extending between first full-length-optical-core end face 112 and second full-length-optical-core end face 114. In such examples, core of at least one optical structure 101 comprises full-length optical core 110 and at least one outer surface of at least one optical structure 101 comprises first full-length-optical-core end face 112, second full-length-optical-core end face 114, and full-length peripheral surface 116.
As discussed, inclusion of at least one full-length optical waveguide 102 in feedstock line 100 may facilitate penetration of electromagnetic radiation 118 into interior volume 182 of feedstock line 100 for irradiation of resin 124, despite regions of resin 124 being in the shadows of elongate filaments 104 cast by the direct (i.e., line-of-sight) application of electromagnetic radiation 118.
Referring generally to, e.g., Figs. 2 and 5-8, in one example according to method 300, wherein this one example may include subject matter according to one or more preceding examples described above, at least one full-length optical waveguide 102 is configured such that when electromagnetic radiation 118 enters full-length optical core 110 via at least one of first full-length-optical-core end face 112, second full-length-optical-core end face 114, and full-length peripheral surface 116, at least a portion of electromagnetic radiation 118 exits full-length optical core 110 via full-length peripheral surface 116.
Again, when feedstock line 100 is used to additively manufacture object 136 with in situ curing thereof (i.e., with electromagnetic radiation 118 entering full-length optical core 110), at least a portion of electromagnetic radiation 118 may be emitted from full-length optical core 110 at a position that is spaced-apart from where electromagnetic radiation 118 entered full-length optical core 110. As a result, electromagnetic radiation 118 may be dispersed throughout interior volume 182 of feedstock line 100 for operative irradiation of resin 124.

Referring generally to, e.g., Figs. 2 and 5-9, in one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, at least one full-length optical waveguide is configured such that when electromagnetic radiation 118 enters first full-length-optical-core end face 112 of full-length optical core 110, an initial portion of electromagnetic radiation 118 exits full-length optical core 110 via full-length peripheral surface 116 and a final portion of electromagnetic radiation 118, remaining in full-length optical core 110 after the initial portion of electromagnetic radiation 118 exits full-length optical core 110, exits full-length optical core 110 via second full-length-optical-core end face 114.
As discussed, in some examples of feedstock line 100, if electromagnetic radiation 118 enters first full-length-optical-core end face 112, it may exit both full-length peripheral surface 116 and second full-length-optical-core end face 114, as opposed, for example, to electromagnetic radiation 118 being fully emitted via full-length peripheral surface 116. Such examples of feedstock line 100 may be well suited for additive manufacturing systems and methods in which electromagnetic radiation 118 is directed at first full-length-optical-core end face 112 as feedstock line 100 is being constructed and as object 136 is being manufactured.
Referring generally to, e.g., Figs. 2 and 5-9, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, at least one full-length optical waveguide 102 is configured such that the initial portion of electromagnetic radiation 118, which exits full-length optical core 110 via full-length peripheral surface 116, may be greater than or equal to the final portion of electromagnetic radiation 118, which exits full-length optical core 110 via second full-length-optical-core end face 114.
Again, in such configurations of full-length optical waveguide 102, at least one full-length optical wavelength 102 may ensure that a desired amount of electromagnetic radiation 118 exits full-length optical core 110 via full-length peripheral surface 116 to operatively cure resin 124 among elongate filaments within interior volume 182 of feedstock line 100 when feedstock line 100 is used to additively manufacture object 136.
Referring generally to, e.g., Figs. 2 and 6-8, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, full-length optical core 110 has a full-length-optical-core refractive index. At least one full-length optical waveguide 102 further comprises full-length-optical-core cladding 154, at least partially covering full-length optical core 110. Full-length-optical-core cladding 154 comprises at least first full-length-optical-core cladding resin 156, having a full-length-optical-core first-cladding-resin refractive index. Full-length-optical-core cladding 154 may be non-uniform along at least one full-length optical waveguide 102. For example, full-length peripheral surface 116 may include full-length-peripheral-surface regions 127 devoid of first full-length-optical-core cladding resin 156. The full-length-optical-core refractive index may be greater than the full-length-optical-core first-cladding-resin refractive index.
Again, by full-length-optical-core cladding 154 being non-uniform along the length of the full-length optical waveguide, electromagnetic radiation 118 may be permitted to exit full-length optical core 110 via full-length peripheral surface 116.
Moreover, by first full-length-optical-core cladding resin 156 having a refractive index that is less than that of full-length optical core 110, electromagnetic radiation 118, upon entering full-length optical core 110, may be trapped within full-length optical core 110 in the regions where first full-length-optical-core cladding resin 156 is present and may only exit full length optical core 110 in the regions (such as full-length-peripheral-surface regions 127) where first full-length-optical-core cladding resin 156 is not present. As a result, at least one full-length optical waveguide 102 may be constructed to provide a desired amount of electromagnetic radiation 118, exiting various positions along full-length peripheral surface 116, and may thus be constructed to ensure that a desired amount of electromagnetic radiation 118 penetrates the shadows of elongate filaments 104 when feedstock line 100 is used to additively manufacture object 136.
Referring generally to, e.g., Figs. 7 and 8, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, full-length peripheral surface 116 has full-length-peripheral-surface regions 127 devoid of first full-length-optical-core cladding resin 156. Full-length-optical-core cladding 154 further comprises second full-length-optical-core cladding resin 158, having a full-length-optical-core second-cladding-resin refractive index. Second full-length-optical-core cladding resin 158 covers full-length-peripheral-surface regions 127 of full-length peripheral surface 116. The full-length-optical-core second-cladding-resin refractive index may be greater than the full-length-optical-core first-cladding-resin refractive index.
Again, by covering full-length-peripheral-surface regions 127 with second full-length-optical-core cladding resin 158, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits full-length peripheral surface 116. Additionally or alternatively, with full-length-peripheral-surface regions 127 covered with second full-length-optical-core cladding resin 158, the integrity of first full-length-optical-core cladding resin 156 may be ensured, such that it is less likely to peel or break off during storage of at least one full-length optical waveguide 102 and during implementation of method 300.
Referring generally to, e.g., Fig. 8, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, second full-length-optical-core cladding resin 158 also covers first full-length-optical-core cladding resin 156.
As discussed, full-length optical waveguides including second full-length-optical-core cladding resin 158 covering first full-length-optical-core cladding resin 156, may be more easily manufactured, in that full-length optical core 110 with first full-length-optical-core cladding resin 156 simply may be fully coated with second full-length-optical-core cladding resin 158. Additionally or alternatively, the integrity of full-length optical waveguides may be maintained during storage thereof and during implementation of method 300.
Referring generally to, e.g., Figs. 7 and 8, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index.
The resin refractive index may be greater than the full-length-optical-core second-cladding-resin refractive index. As discussed, in examples where second full-length-optical-core cladding resin 158 has a refractive index less than that of resin 124, electromagnetic radiation 118 may be permitted to exit second full-length-optical-core cladding resin 158 to penetrate and cure resin 124 when feedstock line 100 is used to additively manufacture object 136.
Referring generally to, e.g., Fig. 9, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, full-length peripheral surface 116 has a surface roughness which may be selected such that when electromagnetic radiation 118 enters full-length optical core 110 via at least one of first full-length-optical-core end face 112, second full-length-optical-core end face 114, and full-length peripheral surface 116, at least a portion of electromagnetic radiation 118 exits full-length optical core 110 via full-length peripheral surface 116. As discussed, in such .. examples, rather than relying on refractive-index properties of a cladding to ensure desired dispersal of electromagnetic radiation 118 from full-length optical core 110 via full-length peripheral surface 116, the surface roughness of full-length peripheral surface 116 may be selected such that electromagnetic radiation 118 exits full-length optical core 110 at desired amounts along the length of full-length peripheral surface 116. For example, the surface roughness may create regions of internal reflection of electromagnetic radiation 118 within full-length optical core 110 and may create regions where electromagnetic radiation 118 is permitted to escape full-length optical core 110.

, Referring generally to, e.g., Fig. 9, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, at least one full-length optical waveguide is devoid of any cladding that covers full-length optical core 110.
As discussed, full-length optical waveguides without any cladding may be less expensive to manufacture than full-length optical waveguides with cladding.
Additionally, in such examples, the difference of refractive indexes between a cladding and resin 124 need not be taken into account when selecting resin 124 for feedstock line 100.
Referring generally to, e.g., Figs. 21 and 22, and particularly to Fig. 23, according to one example of method 300, when at least one optical structure comprises at least one full-length optical waveguide 102, the step of (block 305) combining the individual ones of elongate filaments 104 and at least one full-length optical waveguide 102 or subsets 214 of elongate filaments 104 and at least one full-length optical waveguide 102 into derivative tow 209 comprises a step of (block 312) at least one of twisting, weaving, or braiding the individual ones of elongate filaments 104 and at least one full-length optical waveguide 102, or subsets 214 of elongate filaments 104 and at least one full-length optical waveguide 102, into derivative tow 209.
Again, by being twisted with, woven with, or braided with elongate filaments 104, at least one full-length optical waveguide 102 may be interspersed with elongate filaments 104 such that electromagnetic radiation 118, exiting at least one full-length optical waveguide 102, may be delivered to regions of interior volume 182 that are in the shadows of elongated filaments 104 when feedstock line 100 is used to additively manufacture object 136.
Optical direction modifiers Referring generally to, e.g., Figs. 12-19, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, at least one optical structure 101 comprises optical direction modifiers 123. Each of optical direction modifiers 123 has respective outer surface 184, and in such examples, at least one outer surface of at least one optical structure 101 comprises respective outer surface 184 of each of optical direction modifiers 123.
Each of optical direction modifiers 123 is configured such that when electromagnetic radiation 118 strikes outer surface 184 from a first direction, at least a portion of electromagnetic radiation 118 departs outer surface 184 in a second direction that is at an angle to the first direction.
Inclusion of optical direction modifiers 123, each extending only along a portion of the feedstock line length, may provide for dispersion of electromagnetic radiation 118 within interior volume 182 of feedstock line 100 for irrigation of resin 124 therein.
Referring generally to, e.g., Figs. 12-16, optical direction modifiers 123 comprise partial-length optical waveguides 122. Each of partial-length optical waveguides 122 comprises a respective partial-length optical core 138.
Respective partial-length optical core 138 of each of partial-length optical waveguides comprises first partial-length-optical-core end face 140, second partial-length-optical-core end face 142, opposite first partial-length-optical-core end face 140, and partial-length peripheral surface 144, extending between first partial-length-optical-core end face 140 and second partial-length-optical-core end face 142. In such examples, core of at least one optical structure 101 comprises respective partial-length optical core 138 and respective outer surface 184 of each of optical direction modifiers 123 comprises first partial-length-optical-core end face 140, second partial-length-optical-core end face 142, and partial-length peripheral surface 144.
Each of partial-length optical waveguides 122 is configured such that when electromagnetic radiation 118 enters partial-length optical core 138 via at least one of first partial-length-optical-core end face 140, second partial-length-optical-core end face 142, and partial-length peripheral surface 144, at least a portion of electromagnetic radiation 118 exits partial-length optical core 138 via partial-length peripheral surface 144.
In some examples of method 300, optical direction modifiers 123 are similar in construction to full-length optical waveguides but are shorter in length. As discussed, partial-length optical waveguides 122 may be cost effective to create, such as according to the various methods disclosed here. Moreover, by being interspersed among elongate filaments 104, partial-length optical waveguides 122 may directly receive electromagnetic radiation 118 and deliver electromagnetic radiation 118 into the shadows of elongate filaments 104.
Referring generally to, e.g., Figs. 13-15, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, partial-length optical core 138 has a partial-length-optical-core refractive index. Each of partial-length optical waveguides 122 further comprises partial-length-optical-core cladding 160, at least partially covering partial-length optical core 138. Partial-length-optical-core cladding 160 comprises at least first partial-length-optical-core cladding resin 162, having a partial-length-optical-core first-cladding-resin refractive index. Partial-length-optical-core cladding 160 may be non-uniform along each of partial-length optical waveguides 122.
For example, partial-length peripheral surface 144 may include partial-length-peripheral-surface regions 129 devoid of first partial-length-optical-core cladding resin 162.
Partial-length-optical-core refractive index may be greater than the partial-length-optical-core first-cladding-resin refractive index.
Again, similar to full-length optical waveguide 102, by partial-length-optical-core cladding 160 being non-uniform along the length of partial-length optical waveguides 122, electromagnetic radiation 118 may be permitted to exit partial-length optical core 138 via partial-length peripheral surface 144. Moreover, by first partial-length-optical-core cladding resin 162 having a refractive index that is less than that of partial-length optical core 138, electromagnetic radiation 118, upon entering partial-length optical core 138, may be trapped within partial-length optical core 138 in the regions where first partial-length-optical-core cladding resin 162 is present and may only exit partial-length optical core 138 in the regions (such as partial-length-peripheral-surface regions 129) where partial-length-optical-core cladding resin 162 is not present. As a result, partial-length optical waveguides 122 may be constructed to provide a desired amount of electromagnetic radiation 118, exiting various positions along partial-length peripheral surface 144, and may thus be constructed to ensure that a desired amount of electromagnetic radiation penetrates the shadows of elongate filaments 104 when feedstock line 100 is being used to additively manufacture object 136.
Referring generally to, e.g., Figs. 14 and 15, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, partial-length peripheral surface of partial-length optical core 138 of each of partial-length optical waveguides 122 has partial-length-peripheral-surface regions 129 devoid of first partial-length-optical-core cladding resin 162. Partial-length-optical-core cladding 160 further comprises second partial-length-optical-core cladding resin 164, having a partial-length-optical-core second-cladding-resin refractive index. Second partial-length-optical-core cladding resin 164 covers partial-length-peripheral-surface regions 129 of partial-length peripheral surface 144. The partial-length-optical-core second-cladding-resin refractive index may be greater than the partial-length-optical-core first-cladding-resin refractive index.
As discussed, by covering partial-length-peripheral-surface regions 129 with second partial-length-optical-core cladding resin 164, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits partial-length peripheral surface 144. Additionally or alternatively, with partial-length-peripheral-surface regions 129 covered with second partial-length-optical-core cladding resin 164, the integrity of first partial-length-optical-core cladding resin 162 may be ensured, such that it is less likely to peel or break off during storage of partial-length optical waveguides 122 and during implementation of method 300.

Referring generally to, e.g., Fig. 15, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, second partial-length-optical-core cladding resin 164 also covers first partial-length-optical-core cladding resin 162.
As discussed, partial-length optical waveguides 122 including second partial-length-optical-core cladding resin 164 covering first partial-length-optical-core cladding resin 162 may be more easily manufactured, in that partial-length optical core 138 with first partial-length-optical-core cladding resin 162 simply may be fully coated with second partial-length-optical-core cladding resin 164.
Additionally or alternatively, the integrity of partial-length optical waveguides 122 may be maintained during storage thereof and during implementation of method 300.
Referring generally to, e.g., Figs. 14 and 15, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index.
The resin refractive index may be greater than the partial-length-optical-core second-cladding-resin refractive index.
Again, because second partial-length-optical-core cladding resin 164 has a refractive index less than that of resin 124, electromagnetic radiation 118 may be permitted to exit second partial-length-optical-core cladding resin 164 to penetrate and cure resin 124 when feedstock line 100 is being used to additively manufacture object 136.
Referring generally to, e.g., Fig. 16, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, partial-length peripheral surface 144 of partial-length optical core 138 of each of partial-length optical waveguides 122 has a surface roughness that may be selected such that when electromagnetic radiation 118 enters partial-length optical core 138 via at least one of first partial-length-optical-core end face 140, second partial-length-optical-core end face 142, and partial-length peripheral surface 144, at least a portion of electromagnetic radiation 118 exits partial-length optical core 138 via partial-length peripheral surface 144.
As discussed, in such examples, rather than relying on refractive-index properties of a cladding to ensure desired dispersal of electromagnetic radiation 118 from partial-length optical core 138 via partial-length peripheral surface 144, the surface roughness of partial-length peripheral surface 144 may be selected such that electromagnetic radiation 118 exits partial-length optical core 138 at desired amounts along the length of partial-length peripheral surface 144. Again, the surface roughness may create regions of internal reflection of electromagnetic radiation 118 within partial-length optical core 138 and may create regions where electromagnetic radiation 118 is permitted to escape partial-length optical core 138.
Referring generally to, e.g., Fig. 16, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, each of partial-length optical waveguides is devoid of any cladding that covers partial-length optical core 138.
As discussed, partial-length optical waveguides 122 without any cladding may be less expensive to manufacture than partial-length optical waveguides 122 with cladding. Additionally, the difference of refractive indexes between a cladding and resin 124 need not be taken into account when selecting resin 124 for feedstock line 100.
Referring generally to, e.g., Figs. 17-19, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, optical direction modifiers 123 comprise optical direction-modifying particles 186. Optical direction-modifying particles 186 are configured to at least one of reflect, refract, diffract, or Rayleigh-scatter electromagnetic radiation 118, incident on a respective outer surface 184 of any one of optical direction-modifying particles 186, to disperse electromagnetic radiation 118. In such examples, respective outer surface 184 of each of optical direction modifiers 123 comprises respective outer surface 184 of each of optical direction-modifying particles 186.
Again, inclusion of optical direction-modifying particles 186 that at least one of reflect, refract, diffract, or Rayleigh-scatter electromagnetic radiation 118 may provide for further dispersion of electromagnetic radiation 118 within interior volume 182 for irradiation of resin 124 therein when feedstock line 100 is being used to additively manufacture object 136. Moreover, because they are particles, optical direction-modifying particles 186 may be more easily interspersed among elongate filaments 104 when applied thereto. In addition, in some examples of feedstock line 100, they may be generally uniformly spaced throughout resin 124 within interior volume 182 and may effectively scatter electromagnetic radiation 118 throughout interior volume 182 to penetrate among elongate filaments 104 and into the shadows cast by elongate filaments 104 when feedstock line 100 is being used to additively manufacture object 136. In other examples of feedstock line 100, optical direction-modifying particles 186 may have a gradient of concentration within interior volume 182.
Referring generally to, e.g., Figs. 11 and 17-19, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, each of elongate filaments 104 has a minimum outer dimension. Each of optical direction-modifying particles 186 has a maximum outer dimension that may be less than one-eighth the minimum outer dimension of any one of elongate filaments 104.
Again, by having a maximum outer dimension that is less than one-eighth the minimum outer dimension of elongate filaments 104, optical direction-modifying particles 186 may be easily dispersed between and/or among elongate filaments 104. Moreover, optical direction-modifying particles 186 may more easily flow with resin 124 to operatively disperse optical direction-modifying particles 186 throughout feedstock line 100, including into the shadows of elongate filaments 104.

Referring generally to, e.g., Figs. 17-19, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, each of optical direction-modifying particles 186 has a maximum outer dimension that may be less than 1000 nm, 500 nm, 250 nm, or 200 nm. As discussed, typical reinforcement fibers for composite materials often have a diameter in the range of 6 to 8 microns. By having a maximum outer dimension that is less than 1000 nm (1 micron), 500 nm (0.5 micron), 250 nm (0.25 micron), or 200 nm (0.200 micron), optical direction-modifying particles 186 may more easily extend between and/or among typical sizes of elongate filaments 104.
Moreover, optical direction-modifying particles 186 may more easily flow with resin 124 to operatively disperse optical direction-modifying particles 186 throughout feedstock line 100, including into the shadows of elongate filaments 104.
Referring generally to, e.g., Figs. 17-19, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, electromagnetic radiation 118 has a wavelength. Each of optical direction-modifying particles 186 has a minimum outer dimension that may be greater than one-fourth the wavelength of electromagnetic radiation 118.
Again, selecting a minimum outer dimension of optical direction-modifying particles 186 that is greater than one-fourth the wavelength of electromagnetic radiation 118 that will be used when additively manufacturing object 136 may ensure that optical direction-modifying particles 186 have the intended effect of causing electromagnetic radiation 118 to reflect, refract, or diffract upon hitting optical direction-modifying particles 186.
Referring generally to, e.g., Figs. 17-19, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, each of optical direction-modifying particles 186 has a minimum outer dimension that may be greater than or equal to 50 nm or that is greater than or equal to 100 nm.

As discussed, ultra-violet light having a wavelength of about 400 nm is often used in connection with ultra-violet photopolymers. Accordingly, when resin comprises or consists of a photopolymer, optical direction-modifying particles having a minimum outer dimension that is greater than or equal to 100 nm may ensure that optical direction-modifying particles 186 have the intended effect of causing electromagnetic radiation 118 to reflect, refract, or diffract upon hitting optical direction-modifying particles 186. However, in other examples, a minimum outer dimension as low as 50 nm may be appropriate.
Referring generally to, e.g., Fig. 11, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, in feedstock line 100, optical direction-modifying particles 186 may comprise less than 10% by weight of resin 124, less than 5% by weight of resin 124, or less than 1% by weight of resin 124.
As discussed, by limiting optical direction-modifying particles 186 to the referenced threshold percentages, resin 124 may operatively flow among elongate filaments 104 when elongate filaments 104 and optical direction-modifying particles 186 are being combined or when elongate filaments 104, at least one full length optical waveguide 102, and optical direction-modifying particles 186 are being combined to create feedstock line 100. In addition, desired properties of resin 124, feedstock line 100, and ultimately object 136 may not be negatively impacted by the presence of optical direction-modifying particles 186.
Referring generally to, e.g., Figs. 17-19, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, outer surfaces 184 of at least some of optical direction-modifying particles 186 may be faceted.
Again, by being faceted, outer surfaces 184 may effectively scatter electromagnetic radiation 118.
Referring generally to, e.g., Figs. 17-19, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, outer surfaces 184 of at least some of optical direction-modifying particles 186 have a surface roughness that is selected such that when electromagnetic radiation 118 strikes outer surfaces 184, electromagnetic radiation 118 is scattered.
As discussed, having a surface roughness selected to scatter electromagnetic radiation 118 may facilitate the operative irradiation of resin 124 throughout feedstock line 100, including into the shadows of elongate filaments 104, when feedstock line 100 is being used to additively manufacture object 136.
Referring generally to, e.g., Fig. 11, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, resin 124 has a resin refractive index. At least some of optical direction-modifying particles 186 have a particle refractive index. The particle refractive index may be greater than or less than the resin refractive index.
Again, when optical direction-modifying particles 186 have a refractive index that is different from the refractive index of resin 124, electromagnetic radiation 118 incident upon the outer surfaces thereof may leave the outer surfaces at a different angle, and may scatter throughout resin 124, including into the shadows of elongate filaments 104.
Referring generally to, e.g., Fig. 17, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, at least some of optical direction-modifying particles 186 may be spherical.
Again, by being spherical, optical direction-modifying particles 186 may more easily be positioned among elongate filaments 104 and may more easily flow with resin 124 as elongate filaments 104 and optical direction-modifying particles 186 are being combined.
Referring generally to, e.g., Fig. 18, according to one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, at least some of optical direction-modifying particles 186 may be prismatic.
Again, by being prismatic, optical direction-modifying particles 186 may be selected to operatively at least one of reflect, refract, or diffract electromagnetic radiation 118, as discussed herein.
Referring generally to, e.g., Fig. 2, and particularly to Fig. 23, in accordance with one example of method 300, wherein this one example may include subject matter according to one or more preceding examples described above, when the at least one optical structure 101 comprises optical direction modifiers 123, the step of (block 316) combining optical direction modifiers 123 with individual ones of elongate filaments 104 or subsets 214 of elongate filaments 104 comprises a step of (block 314) applying optical direction modifiers 123 to the individual ones of elongate filaments 104 or to subsets 214 of elongate filaments 104. According to some examples of method 300, the step of (block 314) applying optical direction modifiers 123 to the individual ones of elongate filaments 104 or to subsets 214 of elongate filaments 104 may occur at least one of before and after the step of (block 305) combining the individual ones of elongate filaments 104 and at least one full-length optical waveguide 102 or subsets 214 of elongate filaments 104 and at least one full-length optical waveguide 102 into derivative tow 209, such that the step of (block 314) applying optical direction modifiers 123 comprises combining optical direction modifiers 123 with at least one full-length optical waveguide 102 and elongate filaments 1041nt0 derivative tow 209 or such that the step of (block 305) combining individual ones of elongate filaments 104 or subsets 214 of elongate filaments and at least one full-length optical waveguide 102 comprises combining at least one full-length optical waveguide 102 with elongate filaments 104 and optical direction modifiers 123 into derivative tow 209.
Also, in some examples of method 300, the step of (block 306) applying resin 124 to cover elongate filaments 104 and at least one optical structure 101 combined with the elongate filaments 104 such that elongate filaments 104 and at least one optical structure 101 are covered by resin 124 in derivative tow 209 may comprise a step of (block 318) applying resin 124 to cover optical direction modifiers 123 in derivative tow 209. Further, according to some examples of method 300, the step of (block 318) applying resin 124 to cover optical direction modifiers 123 in derivative tow 209 is performed at least one of before and after the step of (block 305) combining elongate filaments 104 and at least one full-length optical waveguide 102, such that resin 124 is applied to cover optical direction modifiers 123, elongate filaments 104 and at least one full-length optical waveguide 102 for example.
As discussed, by applying optical direction modifiers 123 to elongate filaments 104 to become part of feedstock line 100, dispersion of electromagnetic radiation 118 within interior volume 182 for irradiation of resin 124 therein may be achieved when feedstock line 100 is used to additively manufacture object 136.
Moreover, again, by being shorter than full-length optical waveguides, optical direction modifiers 123 may more easily extend among elongate filaments 104 within derivative tow 209. Optical direction modifiers 123 may serve to disperse, or scatter, electromagnetic radiation 118 into the shadows of elongate filaments 104, and may also serve to redirect electromagnetic radiation 118 to at least one full-length optical waveguide 102 for penetration into the shadows of elongate filaments 104 by at least one full-length optical waveguide 102.
Optical waveguide Referring generally to Fig. 3 and particularly to, e.g., Figs. 24-28, an optical waveguide 108 is disclosed. Full-length optical waveguides and partial-length optical waveguides, such as at least one full-length optical waveguides 102 and partial-length optical waveguides 122, are examples of optical waveguides, such as optical waveguide 108. Optical waveguide 108 may thus be an example of at least one optical structure 101.
Referring generally to Fig. 3 and particularly to, e.g., Figs. 24-28, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical waveguide 108 comprises optical core 146, comprising first end face 148, second end face 150, opposite first end face 148, and peripheral surface 152, extending between first end face 148 and second end face 150. In such examples, core of at least one optical structure comprises optical core 146 and at least one outer surface of at least one optical structure 101 comprises first end face 148, second end face 150, and peripheral surface 152.
Optical waveguide 108 is configured such that when electromagnetic radiation 118 enters optical core 146 via at least one of first end face 148, second end face 150, and peripheral surface 152, at least a portion of electromagnetic radiation 118 exits optical core 146 via peripheral surface 152.
Because optical waveguide 108 is configured for electromagnetic radiation to enter optical core 146 via any one of first end face 148, second end face 150, or peripheral surface 152 and then exit optical core 146 via peripheral surface 152, optical waveguide 108 may be well suited for inclusion in a photopolymer resin (e.g., resin 124 herein) of a feedstock line (e.g., feedstock line 100 here) that also includes reinforcing fibers (e.g., elongate filaments 104 herein) and that is used to additively manufacture an object (e.g., object 136 herein). More specifically, inclusion of at least one optical waveguide 108 in such a feedstock line may facilitate penetration of electromagnetic radiation 118 into the interior volume of the feedstock line for irradiation of the resin, despite regions of the resin being in the shadows of the reinforcing fibers cast by the direct (i.e., line-of-sight) application of electromagnetic radiation 118. In other words, even when electromagnetic radiation 118 is shielded from directly reaching all regions of the resin, at least one optical waveguide 108 may receive electromagnetic radiation 118 via one or more of first end face 148, second end face 150, or peripheral surface 152, and may disperse electromagnetic radiation 118 via at least peripheral surface 152 to indirectly reach regions of the resin. As a result, the feedstock line may be more easily cured with electromagnetic radiation 118, may be more evenly cured with electromagnetic radiation 118, may be more thoroughly cured with electromagnetic radiation 118, and/or may be more quickly cured with electromagnetic radiation 118. Such a configuration of feedstock line may be well suited for additive manufacturing of the fused filament fabrication variety, in which the feedstock line is dispensed by a print head, or nozzle, and a source of curing energy (e.g., electromagnetic radiation 118) directs the curing energy at the feedstock line as it is being dispensed to cure the resin in situ.
Referring generally to Fig. 3 and particularly to, e.g., Figs. 24-28, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical waveguide 108 is configured such that when electromagnetic radiation 118 enters first end face 148 of optical core 146, an initial portion of electromagnetic radiation 118 exits optical core 146 via peripheral surface 152 and a final portion of electromagnetic radiation 118, remaining in optical core 146 after the initial portion of electromagnetic radiation 118 exits optical core 146, exits optical core 146 via second end face 150.
That is, when electromagnetic radiation 118 enters first end face 148, it may exit both peripheral surface 152 and second end face 150, as opposed, for example, to electromagnetic radiation 118 being fully emitted via peripheral surface 152. Such examples of optical waveguide 108 may be well suited for inclusion in feedstock lines with additive manufacturing systems and methods in which electromagnetic radiation 118 is directed at first end face 148 as the feedstock line is being constructed and as an object is being manufactured. That is, an additive manufacturing system may be configured to construct a feedstock line while the object is being manufactured from the feedstock line, and while electromagnetic radiation 118 is entering first end face 148. Because electromagnetic radiation 118 exits not only peripheral surface 152, but also second end face 150, it may be ensured that sufficient electromagnetic radiation 118 travels the full length of optical waveguide 108 to operatively cure the resin of the feedstock line that is in the shadows of the reinforcing fibers.
Referring generally to Fig. 3 and particularly to, e.g., Figs. 24-28, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical waveguide 108 is configured such that the initial portion of electromagnetic radiation 118, which exits optical core 146 via peripheral surface 152, may be greater than or equal to the final portion of electromagnetic radiation 118, which exits optical core 146 via second end face 150.
In such configurations, it may be ensured that a desired amount of electromagnetic radiation 118 exits optical core 146 via peripheral surface 152 to operatively cure the resin of a feedstock line that is in the shadows of the reinforcing fibers, when the feedstock line is utilized by an additive manufacturing system or in an additive manufacturing method for example.
Referring generally to Fig. 3 and particularly to, e.g., Figs. 25-27, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical core 146 has an optical-core refractive index. Optical waveguide 108 further comprises cladding 120, at least partially covering optical core 146. Cladding 120 comprises at least first resin 132, having a first-resin refractive index. Cladding 120 may be non-uniform along optical waveguide 108. For example, peripheral surface 152 may include regions 130 where first resin 132 is not present. The optical-core refractive index may be greater than the first-resin refractive index.
By cladding 120 being non-uniform along the length of optical waveguide 108, electromagnetic radiation 118 may be permitted to exit optical core 146 via peripheral surface 152. Moreover, by first resin 132 having a refractive index that is less than that of optical core 146, electromagnetic radiation 118, upon entering optical core 146, may be trapped within optical core 146 in the regions where first resin 132 is present and may only exit optical core 146 in the regions (such as regions 130) where first resin 132 is not present. As a result, optical waveguide 108 may be constructed to provide a desired amount of electromagnetic radiation 118, exiting various positions along peripheral surface 152, and may thus be constructed as to ensure that a desired amount of electromagnetic radiation 118 penetrates the shadows of reinforcing fibers when optical waveguide 108 is included in a feedstock line that is used to additively manufacture an object.

Referring generally to Fig. 3 and particularly to, e.g., Figs. 26 and 27, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, peripheral surface 152 has regions devoid of first resin 132. Cladding 120 further comprises second resin 134, having a second-resin refractive index. Second resin 134 contacts regions 130 of peripheral surface 152. The second-resin refractive index may be greater than the first-resin refractive index.
By covering regions 130 with second resin 134, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits peripheral surface 152. Additionally or alternatively, with regions 130 covered with second resin 134, the integrity of first resin 132 may be ensured, such that it is less likely to peel or break off during storage of optical waveguide 108 and during construction of an associated feedstock line.
Referring generally to Fig. 3 and particularly to, e.g., Fig. 27, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, second resin 134 covers first resin 132.
Optical waveguides including second resin 134 covering first resin 132 may be more easily manufactured, in that optical core 146 with first resin 132 simply may be fully coated with second resin 134. Additionally or alternatively, the integrity of optical waveguides may be maintained during storage thereof and during construction of an associated feedstock line.
Referring generally to Fig. 3 and particularly to, e.g., Fig. 28, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, peripheral surface 152 has a surface roughness that may be selected such that when electromagnetic radiation 118 enters optical core 146 via at least one of first end face 148, second end face 150, and peripheral surface 152, at least a portion of electromagnetic radiation 118 exits optical core 146 via peripheral surface 152.

In such examples, rather than relying on refractive index properties of a cladding to ensure desired dispersal of electromagnetic radiation 118 from optical core 146 via peripheral surface 152, the surface roughness of peripheral surface 152 may be selected such that electromagnetic radiation 118 exits optical core 146 at desired amounts along the length of peripheral surface 152. For example, the surface roughness may create regions of internal reflection of electromagnetic radiation 118 within optical core 146 and may create regions where electromagnetic radiation 118 is permitted to escape optical core 146.
Referring generally to Fig. 3 and particularly to, e.g., Fig. 28, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, optical waveguide 108 is devoid of any cladding that covers optical core 146.
Optical waveguides without any cladding may be less expensive to manufacture than optical waveguides with cladding. Additionally, in such examples, the difference of refractive indexes between a cladding and a resin of a feedstock line need not be taken into account when selecting the resin for the feedstock line.
Referring generally to, e.g., Figs. 25 and 29, and particularly to Fig. 30, method 400 of modifying optical fiber 126 to create optical waveguide 108 is disclosed. Optical fiber 126 comprises optical core 146, having an optical-core refractive index, and cladding 120, comprising at least first resin 132, having a first-resin refractive index that is less than the optical-core refractive index.
Cladding 120 covers peripheral surface 152 of optical core 146 and extends between first end face 148 and second end face 150 of optical core 146.
In one example, wherein this one example may include subject matter according to one or more preceding examples described above, method 400 comprises a step of (block 402) removing portions 128 of cladding 120 to expose regions 130 of peripheral surface 152, such that at least a portion of electromagnetic radiation 118, entering optical core 146 via at least one of first end face 148, second end face 150, or peripheral surface 152, may exit optical core 146 via regions 130 of peripheral surface 152.
Method 400 may provide an inexpensive process for creating optical waveguide 108. For example, an off-the-shelf cladded optical fiber may be used as optical fiber 126, and portions 128 of cladding 120 may be removed at regions that are appropriately spaced apart to result in the desired functions of optical waveguide 108, discussed herein.
Any suitable process may be utilized to remove portion 128 of cladding 120, including, for example, mechanical processes, chemical processes, thermal processes (e.g., utilizing a laser), etc.
Referring generally to, e.g., Figs. 26 and 27, and particularly to Fig. 30, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, method 400 further comprises a step of (block 404) applying second resin 134 to contact regions 130 of peripheral surface 152. Second resin 134 has a second-resin refractive index which may be greater than the first-resin refractive index.
As discussed, by covering regions 130 with second resin 134, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits peripheral surface 152. Additionally or alternatively, with regions covered with second resin 134, the integrity of first resin 132 may be ensured, such that it is less likely to peel or break off during storage of optical waveguide 108 and during construction of an associated feedstock line.
Referring generally to, e.g., Fig. 27, and particularly to Fig. 30, according one example of method 400, wherein this one example may include subject matter according to one or more preceding examples described above, the step of (block 404) applying second resin 134 to contact regions 130 of peripheral surface comprises (block 406) covering first resin 132 with second resin 134.

Applying second resin 134 such that it also covers first resin 132 may be an easier and less-expensive process than applying second resin 134 only to contact and cover regions 130.
Referring generally to, e.g., Figs. 24 and 25, and particularly to Fig. 31, method 500 of modifying optical core 146 to create optical waveguide 108 is disclosed. Optical core 146 comprises first end face 148, second end face 150, opposite first end face 148, and peripheral surface 152, extending between first end face 148 and second end face 160.
In one example, wherein this one example may include subject matter according to one or more preceding examples described above, method 500 comprises a step of (block 502) applying first resin 132 to peripheral surface 152 of optical core 146. The first resin 132 may be applied in a non-uniform manner such that regions 130 of peripheral surface 152 remain uncovered by first resin 132. First resin 132 has a first-resin refractive index. Optical core 146 has an optical-core refractive index which may be greater than the first-resin refractive index.
At least a portion of electromagnetic radiation 118, entering optical core 146 via at least one of first end face 148, second end face 150, or peripheral surface 152, may exit optical core 146 via peripheral surface 152.
Method 500 may provide an inexpensive process for creating optical waveguide 108. For example, an off-the-shelf non-cladded optical fiber may be used as optical core 146, and first resin 132 may be applied to peripheral surface thereof.
Any suitable process for applying first resin 132 may be used, including, for example spraying, misting, or splattering first resin 132 on peripheral surface 152, such that regions 130 of peripheral surface 152 remain uncovered by first resin 132.
Referring generally to, e.g., Figs. 26 and 27, and particularly to Fig. 31, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, method SOO further comprises a step of (block 504) applying second resin 134 to contact regions 130 of peripheral surface 152 to create, with first resin 132, cladding 120 that covers peripheral surface 152 of optical core 146. Second resin 134 has a second-resin refractive index which may be greater than the first-resin refractive index.
Similar to method 400, by covering regions 130 with second resin 134, a desired refractive index thereof may be selected to optimize how electromagnetic radiation 118 exits peripheral surface 152. Additionally or alternatively, with regions 130 covered with second resin 134, the integrity of first resin 132 may be ensured, such that it is less likely to peel or break off during storage of optical waveguide 108 and during construction of an associated feedstock line.
Referring generally to, e.g., Fig. 27, and particularly to Fig. 31, according to one example of method 500, wherein this one example may include subject matter according to one or more preceding examples described above, the step of (block 504) applying second resin 134 to contact regions 130 of peripheral surface comprises (block 506) covering first resin 132 with second resin 134.
Again, applying second resin 134 such that it also covers first resin 132 may be an easier and less-expensive process than applying second resin 134 only to contact and cover regions 130.
Referring generally to, e.g., Fig. 28, and particularly to Fig. 32, method 600 of modifying optical core 146 to create optical waveguide 108 is disclosed.
Optical core 146 comprises first end face 148, second end face 150, opposite first end face 148, and peripheral surface 152, extending between first end face 148 and second end face 150.
In one example, wherein this one example may include subject matter according to one or more preceding examples described above, method 600 comprises a step of (block 602) increasing surface roughness of all or portions of peripheral surface 152 of optical core 146 so that at least a portion of electromagnetic radiation 118, entering optical core 146 via at least one of first end face 148, second end face 150, or peripheral surface 152, exits optical core 146 via peripheral surface 152.

Method 600 may provide an inexpensive process for creating optical waveguide 108. For example, an off-the-shelf non-cladded optical fiber may be used as optical core 146, and peripheral surface 152 thereof may be roughened.
Any suitable process for increasing surface roughness of peripheral surface may be used including, for example, mechanical processes, chemical processes, thermal processes (e.g., utilizing a laser), etc.
Referring generally to, e.g., Fig. 28, and particularly to Fig. 32, in one example, wherein this one example may include subject matter according to one or more preceding examples described above, method 600 further comprises a step of (block 604) applying cladding 120 to cover peripheral surface 152. Optical core 146 has an optical-core refractive index. Cladding 120 has a cladding refractive index.
The optical-core refractive index may be less than the cladding refractive index.
By applying cladding 120 to cover peripheral surface 152, the integrity of the surface roughness of peripheral surface 152 may be maintained, and selecting a cladding refractive index that is less than the optical-core refractive index may ensure that electromagnetic radiation 118 can operatively exit optical core 146 at desired locations as a result of the surface roughness of peripheral surface 152.
Examples of the present disclosure may be described in the context of aircraft manufacturing and service method 1100 as shown in Fig. 33 and aircraft 1102 as shown in Fig. 34. During pre-production, illustrative method 1100 may include specification and design (block 1104) of aircraft 1102 and material procurement (block 1106). During production, component and subassembly manufacturing (block 1108) and system integration (block 1110) of aircraft 1102 may take place.
Thereafter, aircraft 1102 may go through certification and delivery (block 1112) to be placed in service (block 1114). While in service, aircraft 1102 may be scheduled for routine maintenance and service (block 1116). Routine maintenance and service may include modification, reconfiguration, refurbishment, etc. of one or more systems of aircraft 1102.

Each of the processes of illustrative method 1100 may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include, without limitation, any number of aircraft manufacturers and major-system subcontractors; a third party may include, without limitation, any number of vendors, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.
As shown in Fig. 34, aircraft 1102 produced by illustrative method 1100 may include airframe 1118 with a plurality of high-level systems 1120 and interior 1122.
Examples of high-level systems 1120 include one or more of propulsion system 1124, electrical system 1126, hydraulic system 1128, and environmental system 1130. Any number of other systems may be included. Although an aerospace example is shown, the principles disclosed herein may be applied to other industries, such as the automotive industry. Accordingly, in addition to aircraft 1102, the principles disclosed herein may apply to other vehicles, e.g., land vehicles, marine vehicles, space vehicles, etc.
Apparatus(es) and method(s) shown or described herein may be employed during any one or more of the stages of the manufacturing and service method 1100.
For example, components or subassemblies corresponding to component and subassembly manufacturing (block 1108) may be fabricated or manufactured in a manner similar to components or subassemblies produced while aircraft 1102 is in service (block 1114). Also, one or more examples of the apparatus(es), method(s), or combination thereof may be utilized during production stages 1108 and 1110, for example, by substantially expediting assembly of or reducing the cost of aircraft 1102. Similarly, one or more examples of the apparatus or method realizations, or a combination thereof, may be utilized, for example and without limitation, while aircraft 1102 is in service (block 1114) and/or during maintenance and service (block 1116).

Different examples of the apparatus(es) and method(s) disclosed herein include a variety of components, features, and functionalities. It should be understood that the various examples of the apparatus(es) and method(s) disclosed herein may include any of the components, features, and functionalities of any of the other examples of the apparatus(es) and method(s) disclosed herein in any combination, and all of such possibilities are intended to be within the scope of the present disclosure.
Many modifications of examples set forth herein will come to mind to one skilled in the art to which the present disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.

Therefore, it is to be understood that the present disclosure is not to be limited to the specific examples illustrated and that modifications and other examples are intended to be included within the scope of the teachings herein. Moreover, although the foregoing description and the associated drawings describe examples of the present disclosure in the context of certain illustrative combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative implementations without departing from the scope of the teachings herein.

Date Recue/Date Received 2022-01-24

Claims

EMBODIMENTS IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS
CLAIMED ARE DEFINED AS FOLLOWS:

1. A feedstock line for additive manufacturing of an object, the feedstock line having a feedstock-line length and an exterior surface, defining an interior volume of the feedstock line, and comprising:
elongate filaments, extending along at least a portion of the feedstock-line length;
a resin, covering the elongate filaments; and optical direction modifiers, each extending along only a portion of the feedstock-line length, wherein:
the optical direction modifiers are covered by the resin and are interspersed among the elongate filaments;
each of the optical direction modifiers has an outer surface;
each of the optical direction modifiers is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a first portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first direction to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line;
the optical direction modifiers comprise partial-length optical waveguides;

Date Recue/Date Received 2022-07-25 each of the partial-length optical waveguides comprises a partial-length optical core;
the partial-length optical core of each of the partial-length optical waveguides comprises a first partial-length-optical-core end face, a second partial-length-optical-core end face, opposite the first partial-length-optical-core end face, and a partial-length peripheral surface, extending between the first partial-length-optical-core end face and the second partial-length-optical-core end face; and each of the partial-length optical waveguides is configured such that when the electromagnetic radiation enters the partial-length optical core via at least one of the first partial-length-optical-core end face, the second partial-length-optical-core end face, or the partial-length peripheral surface, at least a second portion of the electromagnetic radiation exits the partial-length optical core via the partial-length peripheral surface to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.

2. The feedstock line according to claim 1, wherein the elongate filaments are opaque to the electromagnetic radiation.

3. The feedstock line according to claim 1, wherein the feedstock line is configured such that when the electromagnetic radiation enters the interior volume of the feedstock line via the exterior surface of the feedstock line, the electromagnetic radiation enters at least one of the partial-length optical waveguides via at least one of the partial-length peripheral surface, the first partial-length-optical-core Date Recue/Date Received 2022-07-25 end face, or the second partial-length-optical-core end face of at least the one of the partial-length optical waveguides.

4. The feedstock line according to claim 1, wherein:
the partial-length optical core has a partial-length-optical-core refractive index;
each of the partial-length optical waveguides further comprises a partial-length-optical-core cladding, at least partially covering the partial-length optical core;
the partial-length-optical-core cladding comprises at least a first partial-length-optical-core cladding resin, having a partial-length-optical-core first-cladding-resin refractive index;
the partial-length-optical-core cladding is non-uniform along each of the partial-length optical waveguides; and the partial-length-optical-core refractive index is greater than the partial-length-optical-core first-cladding-resin refractive index.

5. The feedstock line according to claim 4, wherein:
the partial-length peripheral surface of the partial-length optical core of each of the partial-length optical waveguides has partial-length-peripheral-surface regions devoid of the first partial-length-optical-core cladding resin;
the partial-length-optical-core cladding further comprises a second partial-length-optical-core cladding resin, having a partiakength-optical-core second-cladding-resin refractive index;

Date Recue/Date Received 2022-07-25 the second partial-length-optical-core cladding resin covers the partial-length-peripheral-surface regions of the partial-length peripheral surface; and the partial-length-optical-core second-cladding-resin refractive index is greater than the partial-length-optical-core first-cladding-resin refractive index.

6. The feedstock line according to claim 5, wherein the second partial-length-optical-core cladding resin also covers the first partial-length-optical-core cladding resin.

7. The feedstock line according to claim 5, wherein:
the resin covering the elongate filaments has a resin refractive index;
and the resin refractive index is greater than the partial-length-optical-core second-cladding-resin refractive index.

8. The feedstock line according to claim 1, wherein the partial-length peripheral surface of the partial-length optical core of each of the partial-length optical waveguides has a surface roughness that is selected such that when electromagnetic radiation enters the partial-length optical core via at least one of the first partial-length-optical-core end face, the second partial-length-optical-core end face, or the partial-length peripheral surface, at least the second portion of the electromagnetic radiation exits the partial-length optical core via the partial-length peripheral surface to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.
Date Recue/Date Received 2022-07-25

9. The feedstock line according to claim 8, wherein the partial-length optical core of each of the partial-length optical waveguides is uncladded.

10. The feedstock line according to claim 1, wherein:
the optical direction modifiers further comprise optical direction-modifying particles, having outer surfaces; and the optical direction-modifying particles are configured to at least one of reflect, refract, diffract, or Rayleigh-scatter the electromagnetic radiation, incident on any one of the outer surfaces of the optical direction-modifying particles, to disperse, in the interior volume of the feedstock line, the electromagnetic radiation to irradiate the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.

11. The feedstock line according to claim 10, wherein:
each of the elongate filaments has a minimum outer dimension; and each of the optical direction-modifying particles has a maximum outer dimension that is less than one-eighth the minimum outer dimension of any one of the elongate filaments.

12. The feedstock line according to claim 10, wherein each of the optical direction-modifying particles has a maximum outer dimension that is less than 1000 nm.

13. The feedstock line according to claim 10, wherein:
the electromagnetic radiation has a wavelength; and Date Recue/Date Received 2022-07-25 each of the optical direction-modifying particles has a minimum outer dimension that is greater than one-fourth the wavelength of the electromagnetic radiation.

14. The feedstock line according to claim 10, wherein each of the optical direction-modifying particles has a minimum outer dimension that is greater than or equal to 50 nm.

15. The feedstock line according to claim 10, wherein the optical direction-modifying particles comprise less than 10% by weight of the resin.

16. The feedstock line according to claim 10, wherein the outer surfaces of at least some of the optical direction-modifying particles are faceted.

17. The feedstock line according to claim 10, wherein the outer surfaces of at least some of the optical direction-modifying particles have a surface roughness that is selected such that when electromagnetic radiation strikes the outer surfaces, the electromagnetic radiation is scattered in the interior volume of the feedstock line to irradiate the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.

18. The feedstock line according to claim 10, wherein:
the resin has a resin refractive index;
at least some of the optical direction-modifying particles have a particle refractive index; and wherein the particle refractive index is greater than or less than the resin refractive index.

19. The feedstock line according to claim 10, wherein at least some of the optical direction-modifying particles are prismatic.

Date Recue/Date Received 2022-07-25

20. The feedstock line according to claim 1, further comprising:
at least one full-length optical waveguide, extending along all of the feedstock-line length, wherein:
at least the one full-length optical waveguide is covered by the resin and is interspersed among the elongate filaments;
at least the one full-length optical waveguide comprises a full-length optical core;
the full-length optical core comprises a first full-length-optical-core end face, a second full-length-optical-core end face, opposite the first full-length-optical-core end face, and a full-length peripheral surface, extending between the first full-length-optical-core end face and the second full-length-optical-core end face; and at least the one full-length optical waveguide is configured such that when the electromagnetic radiation enters the full-length optical core via at least one of the first full-length-optical-core end face, the second full-length-optical-core end face, or the full-length peripheral surface, at least the second portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.

21.
The feedstock line according to claim 20, wherein the feedstock line is configured such that when the electromagnetic radiation enters the interior Date Recue/Date Received 2022-07-25 volume of the feedstock line via the exterior surface of the feedstock line, the electromagnetic radiation enters at least the one full-length optical waveguide via at least one of the full-length peripheral surface, the first full-length-optical-core end face, or the second full-length-optical-core end face.

22. The feedstock line according to claim 20, wherein at least the one full-length optical waveguide is configured such that when the electromagnetic radiation enters the first full-length-optical-core end face of the full-length optical core, an initial portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface and a final portion of the electromagnetic radiation, remaining in the full-length optical core after the initial portion of the electromagnetic radiation exits the full-length optical core, exits the full-length optical core via the second full-length-optical-core end face.

23. The feedstock line according to claim 20, wherein at least the one full-length optical waveguide is at least one of parallel to, generally parallel to, twisted with, woven with, or braided with the elongate filaments.

24. The feedstock line according to claim 20, wherein:
the full-length optical core has a full-length-optical-core refractive index;
at least the one full-length optical waveguide further comprises a full-length-optical-core cladding at least partially covering the full-length optical core;
the full-length-optical-core cladding comprises at least a first full-length-optical-core cladding resin, having a full-length-optical-core first-cladding-resin refractive index;
the full-length-optical-core cladding is non-uniform along at least the one full-length optical waveguide; and Date Recue/Date Received 2022-07-25 the full-length-optical-core refractive index is greater than the full-length-optical-core first-cladding-resin refractive index.

25. The feedstock line according to claim 24, wherein:
the full-length peripheral surface has full-length-peripheral-surface regions devoid of the first full-length-optical-core cladding resin;
the full-length-optical-core cladding further comprises a second full-length-optical-core cladding resin, having a full-length-optical-core second-cladding-resin refractive index;
the second full-length-optical-core cladding resin covers the full-length-peripheral-surface regions of the full-length peripheral surface; and the full-length-optical-core second-cladding-resin refractive index is greater than the full-length-optical-core first-cladding-resin refractive index.

26. The feedstock line according to claim 25, wherein the second full-length-optical-core cladding resin also covers the first full-length-optical-core cladding resin.

27. The feedstock line according to claim 25, wherein:
the resin covering the elongate filaments has a resin refractive index;
and the resin refractive index is greater than the full-length-optical-core second-cladding-resin refractive index.

28. The feedstock line according to claim 20, wherein the full-length peripheral surface has a surface roughness that is selected such that when the electromagnetic radiation enters the full-length optical core via at least one of the first full-length-optical-core end face, the second full-length-optical-core end Date Recue/Date Received 2022-07-25 face, or the full-length peripheral surface, at least the second portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface to irradiate, in the interior volume of the feedstock line, the resin that, due at least in part to the elongate filaments, is not directly accessible to the electromagnetic radiation, incident on the exterior surface of the feedstock line.

29. The feedstock line according to claim 28, wherein the full-length optical core of the at least the one full-length optical waveguide is uncladded.

30. The feedstock line according to claim 20, wherein at least the one full-length optical waveguide is a plurality of full-length optical waveguides, interspersed among the elongate filaments.

31. The feedstock line according to claim 30, wherein the elongate filaments are at least one of twisted with, woven with, or braided with the plurality of full-length optical waveguides.

32. The feedstock line according to claim 22, wherein at least the one full-length optical waveguide is configured such that the initial portion of the electromagnetic radiation, which exits the full-length optical core via the full-length peripheral surface, is greater than or equal to the final portion of the electromagnetic radiation, which exits the full-length optical core via the second full-length-optical-core end face.

33. A system for creating a feedstock line for additive manufacturing of an object, the feedstock line having a feedstock-line length, the system comprising:
a filament supply, configured to dispense a precursor tow, comprising elongate filaments;
a filament separator, configured to separate the precursor tow, dispensed from the filament supply, into individual ones of the elongate Date Recue/Date Received 2022-07-25 filaments or into subsets of the elongate filaments, wherein each of the subsets comprises a plurality of the elongate filaments;
a full-length-optical-waveguide supply, configured to dispense at least one full-length optical waveguide;
an optical-direction-modifier supply, configured to dispense optical direction modifiers to be applied to the individual ones of the elongate filaments or the subsets of the elongate filaments, originating from the filament separator, and wherein each of the optical direction modifiers has an outer surface and is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a first portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first direction;
a combiner, configured to combine the individual ones of the elongate filaments with the optical direction modifiers and at least the one full-length optical waveguide, dispensed by the full-length-optical-waveguide supply, or the subsets of the elongate filaments, originating from the filament separator, and at least the one full-length optical waveguide, dispensed by the full-length-optical-waveguide supply, into a derivative tow so that each of the elongate filaments and at least the one full-length optical waveguide extend along all of the feedstock-line length and at least the one full-length optical waveguide and the optical direction modifiers are interspersed among the elongate filaments; and a resin supply, configured to provide a resin to be applied to at least the elongate filaments, the optical direction modifiers, and the at least the one full-length optical waveguide in the derivative tow such that the elongate filaments, the optical direction modifiers, and the at least one full-length optical waveguide in the derivative tow are covered with the resin.

Date Recue/Date Received 2022-07-25

34. The system according to claim 33, wherein the elongate filaments are opaque to the electromagnetic radiation.

35. The system according to claim 33, wherein:
at least the one full-length optical waveguide comprises a full-length optical core;
the full-length optical core comprises a first full-length-optical-core end face, a second full-length-optical-core end face, opposite the first full-length-optical-core end face, and a full-length peripheral surface, extending between the first full-length-optical-core end face and the second full-length-optical-core end face; and at least the one full-length optical waveguide is configured such that when the electromagnetic radiation enters the full-length optical core via at least one of the first full-length-optical-core end face, the second full-length-optical-core end face, or the full-length peripheral surface, at least a second portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface.

36. The system according to claim 35, wherein at least the one full-length optical waveguide is configured such that when the electromagnetic radiation enters the first full-length-optical-core end face of the full-length optical core, an initial portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface and a final portion of the electromagnetic radiation, remaining in the full-length optical core after the initial portion of the electromagnetic radiation exits the full-length optical core, exits the full-length optical core via the second full-length-optical-core end face.

37. The system according to claim 35, wherein:
the full-length optical core has a full-length-optical-core refractive index;

Date Recue/Date Received 2022-07-25 at least the one full-length optical waveguide further comprises a full-length-optical-core cladding, at least partially covering the full-length optical core;
the full-length-optical-core cladding comprises at least a first full-length-optical-core cladding resin, having a full-length-optical-core first-cladding-resin refractive index;
the full-length-optical-core cladding is non-uniform along at least the one full-length optical waveguide; and the full-length-optical-core refractive index is greater than the full-length-optical-core first-cladding-resin refractive index.

38. The system according to claim 37, wherein:
the full-length peripheral surface has full-length-peripheral-surface regions devoid of the first full-length-optical-core cladding resin;
the full-length-optical-core cladding further comprises a second full-length-optical-core cladding resin, having a full-length-optical-core second-cladding-resin refractive index;
the second full-length-optical-core cladding resin covers the full-length-peripheral-surface regions of the full-length peripheral surface; and the full-length-optical-core second-cladding-resin refractive index is greater than the full-length-optical-core first-cladding-resin refractive index.

39. The system according to claim 38, wherein the second full-length-optical-core cladding resin also covers the first full-length-optical-core cladding resin.

40. The system according to claim 38, wherein:

Date Recue/Date Received 2022-07-25 the resin provided by the resin supply has a resin refractive index; and the resin refractive index is greater than the full-length-optical-core second-cladding-resin refractive index.

41. The system according to claim 35, wherein the full-length peripheral surface has a surface roughness that is selected such that when the electromagnetic radiation enters the full-length optical core via at least one of the first full-length-optical-core end face, the second full-length-optical-core end face, or the full-length peripheral surface, the at least a first portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface.

42. The system according to claim 41, wherein the full-length optical core of the at least the one full-length optical waveguide is uncladded.

43. The system according to claim 33, wherein:
the filament separator is configured to impart a first electrical charge to the elongate filaments as the precursor tow is separated into the individual ones of the elongate filaments or into the subsets of the elongate filaments;
the resin supply is configured to impart a second electrical charge to the resin when the resin is applied to at least one of the individual ones of the elongate filaments or the subsets of the elongate filaments and originating from the filament separator, or the derivative tow, originating from the combiner, such that the elongate filaments and at least the one full-length optical waveguide in the derivative tow are covered with the resin; and the second electrical charge and the first electrical charge have opposite signs.

Date Recue/Date Received 2022-07-25

44. The system according to claim 33, wherein the combiner is configured to at least one of twist, weave, or braid the individual ones of the elongate filaments and at least the one full-length optical waveguide, dispensed by the full-length-optical-waveguide supply, or the subsets of the elongate filaments, originating from the filament separator, and at least the one full-length optical waveguide, dispensed by the full-length-optical-waveguide supply, into the derivative tow.

45. The system according to claim 33, wherein:
the optical direction modifiers comprise partial-length optical waveguides;
each of the partial-length optical waveguides comprises a partial-length optical core;
the partial-length optical core of each of the partial-length optical waveguides comprises a first partial-length-optical-core end face, a second partial-length-optical-core end face, opposite the first partial-length-optical-core end face, and a partial-length peripheral surface, extending between the first partial-length-optical-core end face and the second partial-length-optical-core end face; and each of the partial-length optical waveguides is configured such that when the electromagnetic radiation enters the partial-length optical core via at least one of the first partial-length-optical-core end face, the second partial-length-optical-core end face, or the partial-length peripheral surface, at least a second portion of the electromagnetic radiation exits the partial-length optical core via the partial-length peripheral surface.

46. The system according to claim 33, wherein:

Date Recue/Date Received 2022-07-25 the optical direction modifiers comprise optical direction-modifying particles; and the optical direction-modifying particles are configured to at least one of reflect, refract, diffract, or Rayleigh-scatter the electromagnetic radiation, incident on an outer surface of any one of the optical direction-modifying particles to disperse the electromagnetic radiation.

47. The system according to claim 46, wherein:
each of the elongate filaments has a minimum outer dimension; and each of the optical direction-modifying particles has a maximum outer dimension that is less than one-eighth the minimum outer dimension of any one of the elongate filaments.

48. The system according to claim 46, wherein each of the optical direction-modifying particles has a minimum outer dimension that is greater than or equal to 50 nm.

49.
The system according to claim 46, wherein in the feedstock line, the optical direction-modifying particles comprise less than 10% by weight of the resin.

50. The system according to claim 33 wherein the optical-direction-modifier supply and the resin supply together form a combined supply, configured to dispense the optical direction modifiers together with the resin.

51. A
method of creating a feedstock line for additive manufacturing of an object, the feedstock line having a feedstock-line length, the method comprising steps of:
separating a precursor tow, comprising elongate filaments, into individual ones of the elongate filaments or into subsets of the elongate Date Recue/Date Received 2022-07-25 filaments, wherein each of the subsets comprises a plurality of the elongate filaments;
applying optical direction modifiers to the individual ones of the elongate filaments or to the subsets of the elongate filaments, and wherein each of the optical direction modifiers has an outer surface and is configured such that when electromagnetic radiation strikes the outer surface from a first direction, at least a first portion of the electromagnetic radiation departs the outer surface in a second direction that is at an angle to the first direction;
combining the individual ones of the elongate filaments, the optical direction modifiers, and at least one full-length optical waveguide or the subsets of the elongate filaments and at least the one full-length optical waveguide into a derivative tow so that each of the elongate filaments and at least the one full-length optical waveguide extends along all of the feedstock-line length and at least the one full-length optical waveguide and the optical direction modifiers are interspersed among the elongate filaments; and applying a resin to cover the elongate filaments, the optical direction modifiers and the at least the one full-length optical waveguide such that the elongate filaments, the optical direction modifiers, and the at least the one full-length optical waveguide are covered by the resin in the derivative tow.

52. The method according to claim 51, wherein:
at least the one full-length optical waveguide comprises a full-length optical core;
the full-length optical core comprises a first full-length-optical-core end face, a second full-length-optical-core end face, opposite the first full-Date Recue/Date Received 2022-07-25 length-optical-core end face, and a full-length peripheral surface, extending between the first full-length-optical-core end face and the second full-length-optical-core end face; and at least the one full-length optical waveguide is configured such that when the electromagnetic radiation enters the full-length optical core via at least one of the first full-length-optical-core end face, the second full-length-optical-core end face, or the full-length peripheral surface, at least a second portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface.

53. The method according to claim 52, wherein at least the one full-length optical waveguide is configured such that when the electromagnetic radiation enters the first full-length-optical-core end face of the full-length optical core, an initial portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface and a final portion of the electromagnetic radiation, remaining in the full-length optical core after the initial portion of the electromagnetic radiation exits the full-length optical core, exits the full-length optical core via the second full-length-optical-core end face.

54. The method according to claim 53, wherein at least the one full-length optical waveguide is configured such that the initial portion of the electromagnetic radiation, which exits the full-length optical core via the full-length peripheral surface, is greater than or equal to the final portion of the electromagnetic radiation, which exits the full-length optical core via the second full-length-optical-core end face.

55. The method according to claim 52, wherein:
the full-length optical core has a full-length-optical-core refractive index;

Date Recue/Date Received 2022-07-25 at least the one full-length optical waveguide further comprises a full-length-optical-core cladding, at least partially covering the full-length optical core;
the full-length-optical-core cladding comprises at least a first full-length-optical-core cladding resin, having a full-length-optical-core first-cladding-resin refractive index;
the full-length-optical-core cladding is non-uniform along at least the one full-length optical waveguide; and the full-length-optical-core refractive index is greater than the full-length-optical-core first-cladding-resin refractive index.

56. The method according to claim 55, wherein:
the full-length peripheral surface has full-length-peripheral-surface regions devoid of the first full-length-optical-core cladding resin;
the full-length-optical-core cladding further comprises a second full-length-optical-core cladding resin, having a full-length-optical-core second-cladding-resin refractive index;
the second full-length-optical-core cladding resin covers the full-length-peripheral-surface regions of the full-length peripheral surface; and the full-length-optical-core second-cladding-resin refractive index is greater than the full-length-optical-core first-cladding-resin refractive index.

57. The method according to claim 56, wherein the second full-length-optical-core cladding resin also covers the first full-length-optical-core cladding resin.

58. The method according to claim 56, wherein:

Date Recue/Date Received 2022-07-25 the resin covering the elongate filaments has a resin refractive index;
and the resin refractive index is greater than the full-length-optical-core second-cladding-resin refractive index.

59.
The method according to claim 52, wherein the full-length peripheral surface has a surface roughness that is selected such that when the electromagnetic radiation enters the full-length optical core via at least one of the first full-length-optical-core end face, the second full-length-optical-core end face, or the full-length peripheral surface, at least the second portion of the electromagnetic radiation exits the full-length optical core via the full-length peripheral surface.

60. The method according to claim 59, wherein the full-length optical core of the at least the one full-length optical waveguide is uncladded.

61. The method according to claim 51, wherein:
the step of separating the precursor tow into the individual ones of the elongate filaments or into the subsets of the elongate filaments comprises imparting a first electrical charge to the elongate filaments;
the step of applying the resin to cover the elongate filaments and at least the one full-length optical waveguide such that the elongate filaments and at least the one full-length optical waveguide are covered by the resin in the derivative tow comprises imparting a second electrical charge to the resin; and the second electrical charge and the first electrical charge have opposite signs.

62. The method according to claim 51, wherein the step of combining the individual ones of the elongate filaments and at least the one full-length optical waveguide or the subsets of the elongate filaments and at least the one full-length optical Date Recue/Date Received 2022-07-25 waveguide into the derivative tow comprises at least one of twisting, weaving, or braiding the individual ones of the elongate filaments and at least the one full-length optical waveguide, or the subsets of the elongate filaments and at least the one full-length optical waveguide, into the derivative tow.

63. The method according to claim 52, wherein:
the optical direction modifiers comprise partial-length optical waveguides;
each of the partial-length optical waveguides comprises a partial-length optical core;
the partial-length optical core of each of the partial-length optical waveguides comprises a first partial-length-optical-core end face, a second partial-length-optical-core end face, opposite the first partial-length-optical-core end face, and a partial-length peripheral surface, extending between the first partial-length-optical-core end face and the second partial-length-optical-core end face; and each of the partial-length optical waveguides is configured such that when the electromagnetic radiation enters the partial-length optical core via at least one of the first partial-length-optical-core end face, the second partial-length-optical-core end face, or the partial-length peripheral surface, at least the second portion of the electromagnetic radiation exits the partial-length optical core via the partial-length peripheral surface.

64. The method according to claim 51, wherein:
the optical direction modifiers comprise optical direction-modifying particles; and Date Recue/Date Received 2022-07-25 the optical direction-modifying particles are configured to at least one of reflect, refract, diffract, or Rayleigh-scatter the electromagnetic radiation, incident on an outer surface of any one of the optical direction-modifying particles, to disperse the electromagnetic radiation.

65. The method according to claim 64, wherein:
each of the elongate filaments has a minimum outer dimension; and each of the optical direction-modifying particles has a maximum outer dimension that is less than one-eighth the minimum outer dimension of any one of the elongate filaments.

66. The method according to claim 64, wherein each of the optical direction-modifying particles has a minimum outer dimension that is greater than or equal to 50 nm.

67. The method according to claim 64, wherein in the feedstock line, the optical direction-modifying particles comprise less than 10% by weight of the resin.

68. The system according to claim 35, wherein the full-length-optical-waveguide supply comprises at least the one full-length optical waveguide.

Date Recue/Date Received 2022-07-25