KR20220012237A - Systems for additive manufacturing of composite structures - Google Patents

Abstract

An additive manufacturing system (10) for use in manufacturing a structure (12) is disclosed. The additive manufacturing system comprises a support 14, and a print head 16 configured to eject material R+M and operatively connected to the support in a normal travel direction 34 during material ejection and movable by the support. ) may be included. The print head may include a module 22 positioned aft of the ejected material with respect to the normal direction of travel and configured to compress the material and expose the material to curing energy at a tool center point (TCP).

Description

Systems for additive manufacturing of composite structures

Related applications

This application is based on and claims priority to 62/853,610 and 62/981,515 filed on May 28, 2019 and February 25, 2020, respectively, the entire contents of which are hereby incorporated by reference integrally integrated. This application is also a continuation-in-part of U.S. Regular Application No. 16/516,113, filed July 18, 2019, the contents of which are expressly incorporated herein by reference.

technical field

FIELD OF THE INVENTION The present disclosure relates generally to manufacturing systems, and more particularly to systems for additive manufacturing of composite structures.

Continuous fiber 3D printing (also known as CF3D ^® ) involves the use of continuous fibers embedded in a matrix that is ejected from a movable print head. The matrix can be a conventional thermoplastic, powdered metal, liquid resin (eg, UV curable and/or two-part resin), or any combination of these and other known matrices. Upon exiting the print head, a head-mounted cure enhancer (eg, ultraviolet, ultrasonic emitter, heat source, catalyst feeder, etc.) is activated to initiate and/or complete curing of the matrix. This curing occurs almost immediately, allowing unsupported structures to be fabricated in free space. When fibers, particularly continuous fibers, are embedded in a structure, the strength of the structure can be multiplied beyond the matrix-dependent strength. An example of such a technique is disclosed in US Pat. No. 9,511,543 issued December 6, 2016 to Tyler (“the '543 patent”).

Although CF3D ^® provides increased strength compared to manufacturing processes that do not utilize continuous fiber reinforcement, improvements can be made to the structure and/or operation of existing systems. For example, Applicants have discovered that more control over the compression and hardening of the reinforcement can improve reinforcement placement, strength and accuracy. The disclosed additive manufacturing system is uniquely configured to provide these improvements and/or solve other problems of the prior art.

In one aspect, the present disclosure relates to an additive manufacturing system. The additive manufacturing system may include a support and a print head configured to eject material and operatively connected to the support in a normal travel direction during material ejection and movable by the support. The print head may include a module positioned aft of the ejected material with respect to the normal travel direction and configured to compress the material and expose the material to curing energy at a tool center point (TCP).

In another aspect, the present disclosure relates to another additive manufacturing system. Such an additive manufacturing system may include a support and a print head configured to eject material and operatively connected to the support in a normal travel direction during material ejection and movable by the support. The print head may include an outer cover positioned aft of the ejection material with respect to a normal direction of travel and configured to roll over the material, and a source configured to direct curing energy radially outwardly through the outer cover.

In another aspect, the present disclosure relates to a method of additive manufacturing a structure. The method comprises discharging a matrix-wetted continuous stiffener through an outlet of a print head, and pressing the module against the matrix-wetted continuous stiffener after discharging to compress the matrix-wetted continuous stiffener can do. The method may also include directing curing energy radially outwardly into a matrix-wetting continuous reinforcement that is compressed through the module.

1 is a schematic diagram of an exemplary disclosed additive manufacturing system.
2, 3, and 4 are isometric, schematic, and cross-sectional views, respectively, of an exemplary disclosed portion of the system of FIG. 1 ;
5 and 6 are cross-sectional views of another exemplary disclosed portion of the system of FIG. 1 ;

1 depicts an exemplary system 10 that may be used to fabricate a composite structure 12 having any desired shape. The system 10 may include a support 14 and a deposition head (“head”) 16 . The head 16 is coupled to the support 14 and can be moved by the support 14 . In the disclosed embodiment of FIG. 1 , the support 14 is a robotic arm capable of moving the head 16 in multiple directions during fabrication of the structure 12 . The support 14 may alternatively be a gantry (eg, overhead-bridge or single-post gantry) or hybrid gantry/arm capable of moving the head 16 in multiple directions during fabrication of the structure 12 . can be implemented Although the support 14 is shown as capable of six-axis movement relative to the structure 12 , the support 14 may be moved in other ways (eg, along and/or around a greater or fewer number of axes). ) it is contemplated that the head 16 can be moved. It is also contemplated that the structure 12 may be associated with one or more axes of movement and may be configured to move independently of and/or in cooperation with the support 14 . In some embodiments, the drive may mechanically couple the head 16 to the support 14 , to move a portion of the head 16 and/or to supply power or material to the head 16 . It may contain cooperating components.

The head 16 may be configured to receive or otherwise include a matrix (denoted M). The matrix can include any type of curable material or combination thereof (eg, a liquid resin such as a zero-volatile organic compound resin, powdered metal, etc.). Exemplary resins include thermosetting resins, single or multi-part epoxy resins, polyester resins, cationic epoxies, acrylated epoxies, urethanes, esters, thermoplastics, photopolymers, polyepoxides, thiols, alkenes, thiol-enes, and the like. include In one embodiment, the matrix inside the head 16 is, for example, by an external device fluidly connected to the head 16 via a corresponding conduit (not shown) (eg, by an extruder, a pump, etc. - not shown). ), (eg, positively and/or negatively). However, in other embodiments, the pressure may be created entirely within the head 16 by a similar type of device. In another embodiment, the matrix may be gravity-fed into and/or through the head 16 . For example, the matrix may be fed into the head 16 with one or more continuous stiffeners (denoted by R) and may be pushed or pulled from the head 16 . In some cases, the matrix inside the head 16 may need to be kept cool and/or dark to inhibit premature cure or otherwise achieve a desired cure rate after ejection. In other cases, the matrix may need to be kept warm and/or illuminated for similar reasons. In any event, the head 16 may be specifically configured to serve these needs (eg, insulated, temperature-controlled, shielded, etc.).

The matrix at least partially coats any number of continuous reinforcements (eg, individual fibers, tows, rovings, socks and/or sheets of continuous material), and some composite with the reinforcements. It may be used to construct part (eg, a wall) of structure 12 . The stiffener may be stored within the head 16 or may be passed through the head 16 . When a plurality of stiffeners are used simultaneously, the stiffeners may be of the same material composition and may be of the same size and cross-sectional shape (eg, round, square, rectangular, etc.) or of different material compositions differing in size and/or cross-sectional shape. The reinforcing material may include, for example, carbon fibers, vegetable fibers, wood fibers, mineral fibers, glass fibers, plastic fibers, metal fibers, optical fibers (eg, tubes), and the like. The term “reinforcement” is meant to include both structural and non-structural (eg, functional) types of continuous material that is at least partially inserted into the matrix ejected from the head 16 .

While the stiffener is inside the head 16 , the stiffener may be at least partially coated with a matrix, the stiffener being delivered to the head 16 and/or the stiffener being dispensed into the head 16 . The matrix, dry (e.g., not dipped) stiffeners, and stiffeners already exposed to the matrix (e.g., pre-soaked stiffeners) can be applied to the head 16 in any manner apparent to those skilled in the art. can be transported to In some embodiments, the filler material (eg, chopped fibers, nanoparticles or tubes, etc.) and/or additives (eg, thermal initiator, UV initiator, etc.) are added before the matrix coats the continuous reinforcement and/or It can then be mixed with the matrix.

One or more cure intensifiers (eg, ultraviolet, ultrasonic emitters, lasers, heaters, catalyst dispensers, etc.) 18 proximate (eg, within, on, and/or adjacent to head 16 ) ) and is configured to improve the curing rate and/or quality of the matrix as it is ejected from the head 16 . The cure enhancer 18 is controlled to selectively expose portions of the structure 12 to energy (eg, ultraviolet light, electromagnetic radiation, vibration, heat, chemical catalysts, etc.) during material ejection and formation of the structure 12 . can be Energy triggers a chemical reaction to occur within the matrix, increases the rate of the chemical reaction, sinters the matrix, cures the matrix, solidifies the matrix, polymerizes the matrix, or otherwise ejects from the head 16 . Allow the matrix to cure. The amount of energy generated by the cure enhancer 18 may be sufficient to cure the matrix before the structure 12 grows axially beyond a predetermined length from the head 16 . In one embodiment, the structure 12 is at least partially (eg, fully) cured before the axial growth length equals the outer diameter of the matrix-coated reinforcement.

The matrix and/or stiffener may be ejected together from the head 16 through any number of different modes of operation. In a first exemplary mode of operation, matrix and/or stiffeners are extruded (e.g., from head 16) as head 16 is moved by support 14 to create features of structure 12. , pushed under pressure and/or mechanical force). In the second exemplary mode of operation, at least the stiffener is pulled from the head 16 , so that a tensile stress is created in the stiffener during ejection. In this second mode of operation, the matrix may adhere to the stiffener, thereby also being pulled from the head 16 along with the stiffener and/or the matrix may be ejected from the head 16 under pressure along with the pulled stiffener. In a second mode of operation in which the stiffener is pulled from the head 16, the resulting tension of the stiffener increases the strength of the structure 12 after hardening of the matrix (eg, by stiffener alignment, anti-buckling, equalizing stiffener loading, etc.). Also, the longer length of the unsupported structure 12 results in a more linear trajectory. That is, the tension of the reinforcement remaining after curing of the matrix may act against gravity (eg, directly and/or indirectly by creating a moment against gravity) to provide support for the support 12 . .

The stiffener may be pulled from the head 16 as a result of the head 16 being moved by the support 14 away from an anchor point (eg, a print bed, an existing surface of the structure 12, a fixture, etc.). For example, when structure formation begins, a length of matrix-dipped reinforcement can be pulled and/or pushed from the head 16 , deposited relative to the anchor point, and at least partially cured so that the ejected material is anchored to the anchor. glued (or otherwise coupled) to the point. The head 16 may then be moved away from the anchor point, and the relative movement may cause the stiffener to be pulled away from the head 16 . As will be described in more detail below, movement of the stiffener through the head 16 may optionally be supported via one or more internal feeding mechanisms, if desired. However, the ejection velocity of the stiffener from the head 16 may be primarily a result of relative movement between the head 16 and the anchor point, such that tension is created within the stiffener. As discussed above, the anchor point may be moved away from the head 16 instead of or in addition to the head 16 being moved away from the anchor point.

The head 16 may include, among other things, an outlet 22 and a matrix reservoir 24 located upstream of the outlet 22 . In one example, outlet 22 is a single-channel outlet configured to discharge a composite material having a generally circular, tubular, or rectangular cross-section. However, the configuration of the head 16 allows the outlet 22 to be exchanged for another outlet that discharges multiple channels of composite material having the same or different shapes (eg, planar or sheet-like cross-sections, multi-track cross-sections, etc.). can Fibers, tubes, and/or other stiffeners may pass through the matrix reservoir 24 (eg, via one or more internal wetting mechanisms 26 positioned within the reservoir 24 ) and be wetted with the matrix prior to ejection. (eg, at least partially coated or embedded and/or fully saturated).

The outlet 22 may take different forms. In one example, guide or nozzle 30 is located downstream of wetting mechanism 26 and compressor 32 (eg, as indicated by arrow 34 , normal travel of head 16 during material ejection) direction) along the nozzle 30 . Either the nozzle 30 or the compressor 32 functions as the tool center point (TCP) of the head 16 to form the matrix prior to and/or during curing when exposed to energy by the cure enhancer(s) 18 . - It is contemplated that the wet stiffener(s) can be attached in any desired location. It is also contemplated that in some embodiments, the nozzle 30 may be omitted. Finally, it is contemplated that the TCP of the head 16 need not necessarily be associated with the nozzle 30 or the compressor 32, but may instead be a location of curing energy exposure separate from these locations. TCP may also switch locations in some applications.

One or more controllers 28 may be provided and communicatively coupled with support 14 and head 16 . Each controller 28 may implement a single processor or multiple processors that are programmed and/or configured to control the operation of system 10 . Controller 28 may include one or more general purpose or special purpose processors or microprocessors. Controller 28 may further include or be associated with memory for storing data such as, for example, design limits, performance characteristics, operating instructions, tool paths, and corresponding parameters of each component of system 10 . can A variety of other known circuits may be associated with the controller 28 including power supply circuits, signal-conditioning circuits, solenoid driver circuits, communication circuits, and other suitable circuits. Controller 28 may also communicate with other components of system 10 via wired and/or wireless transmissions.

One or more maps may be stored in the memory of controller 28 and used during fabrication of structure 12 . Each of these maps may contain a set of data in the form of lookup tables, graphs, and/or equations. In the disclosed embodiment, the map is the head 16 required by the controller 28 to generate the desired geometry (eg, size, shape, material composition, performance parameters, and/or contour) of the structure 12 . .

2 , 3 and 4 , the coin intensifier(s) 18 and compressor 32 may be integrated into a module 54 that may perform both hardening and compression functions. As shown in these figures, the module 54 transmits curing energy (e.g. For example, a source 168 configured to direct light), a distributor 170 positioned about a shaft 164 and one or more covers (eg, It may be a free-standing assembly of a plurality of components including an inner compliant cover 172 and/or an outer protective cover 174 . Energy directed axially to shaft 164 is coupled to optics (eg, baffles, lenses, mirrors, polished bores or end walls, etc.) 176 and shaft 164 located at the inner end of shaft 164 . It may be dispensed, focused and/or redirected radially outwardly by one or more radial passageways 177 (shown only in FIG. 4 ) formed therein. The energy may pass through one or more axially extending circumferential slots 178 of the distributor 170 and then through an associated cover(s), the associated cover(s) comprising: energy (eg, with a wavelength of about 405 nm) It may be at least partially transparent (eg, about 70-100% transparent) to the same light energy at a wavelength of about 350 - 450 nm). In some embodiments, one or more of the slots 178 may be equipped with a transparent spacer 180 to help support the cover(s). In some embodiments, spacer 180 itself may be optics that function to focus, amplify, distribute, and/or collimate energy from source 168 .

In some applications, module 54 (eg, the outer surface of cover 174 ) may form the TCP of head 16 . In such applications, the head 16 may be nozzleless. Thus, the TCP of the head 16 is axially between the outer surface of the cover 174 and the active surface of the structure 12 (eg, where the module 54 pushes the wetting-stiffener onto the surface). It may correspond to an oriented line of contact. The contact line may move, for example, as the head 16 is tilted with respect to the printing surface and/or with respect to the direction of travel (eg, when printing in free space) by the support 14 (see FIG. 1 ). It should be noted that there is

In one embodiment, the outer cover 174 may be made of a low friction material (eg, polytetrafluoroethylene - PTFE, fluorinated ethylene propylene - FEP, etc.). In one example, FEP may be used for the outer cover 174 due to its greater transparency compared to PTFE.

The conformability of the inner cover 172 may allow for adequate bonding and compressive forces to the stiffener without requiring great precision in positioning the module 54 . The conformability of the inner cover 172 may also result in a flat point in the area of engagement with the structure 12 (see FIG. 6 ). These flat points can help the matrix-wetting stiffener disengage from the module 54 and attach only to the structure 12 , and also help the stiffener lie flatter with respect to the lower layers of the structure 12 . can be Additionally, the conformability of the inner cover 172 allows the cutting device (described in more detail below with reference to FIGS. 5 and 6 ) to push the distance to the module 54 , thereby improving cutting performance. The outer cover 174 may need to be replaced periodically due to engagement with the cutting device. In one embodiment, the inner cover 172 may have a hardness of about 20 - 50 A-Shore (eg, about 40 A-Shore), and the outer cover 174 increases life during cutting It may have a greater hardness (eg, at least 5-10% greater than the hardness of the inner cover 172 ) in order to increase the hardness of the inner cover 172 . Since the thickness of the outer cover 174 may be less than the thickness of the inner cover 172 , the conformability of the inner cover 172 may still be effective through the stiffer outer cover 174 . For example, the outer cover 174 may be about 1/5 - 1/25 of the thickness of the inner cover 172 . In some embodiments, the outer cover 174 may have lower friction than the inner cover 172 , which may help prevent unwanted sticking of the matrix-wetting reinforcement to the module 54 .

Because energy may be directed through the module 54 to the matrix-wetting reinforcement, curing may be possible in TCP (eg, immediately before, directly above, and/or immediately after). It is considered that sufficient hardening can occur to secure the stiffener prior to that, provided little, if any, movement of the stiffener away from the TCP position occurs. This can improve the placement accuracy of the reinforcement. Further, the matrix may only be cured on the external surface (eg, sufficient to fix and/or maintain a desired shape) or the matrix may be exposed only to energy from the source 168 (with additional or no external environmental exposure). It is contemplated that it can be through-hardened through In the preceding case, additional energy exposure (eg, oven baking, autoclave heating, etc.) may be required after completion of structure 12 .

In one embodiment, the geometry of the distributor 170 may be selected to focus energy from the source 168 only on the TCP (ie, with respect to the location and orientation of the radial passageway 177 ). For example, the geometry allows energy from the source 168 to pass through only one slot 178 located closest to (eg, to TCP) the TCP, while the energy is more from the TCP at a given time. Passing through other distant slots 178 may be prohibited. A thicker walled distributor with a narrower slot 178 can create a more focused exposed area. In the disclosed example, the slot 178 may have an axial length of about 0-2 times the width of the stiffener passing through the distributor 170 .

5 and 6 show another module 200 which in particular incorporates curing and compression functions. Like module 54 of FIGS. 2-4 , module 200 of FIGS. 5 and 6 includes a shaft 164 rotatably connected to the remainder of head 16 via bearings 166 , and curing energy a source 168 that axially directs (eg, energy from an ultraviolet, laser, or other curing energy source 202 ) to the shaft 164 . Energy may be redirected radially outwardly to the TCP of head 16 via inner and outer covers 172 , 174 through optics 176 located at the inner end of shaft 164 and passageway 177 . In one embodiment, the TCP is located axially center of the distributor 170 (shown in FIG. 5 ). However, it is contemplated that the TCP may be positioned closer to the end of the dispenser 170 if desired.

Like module 54 , module 200 may be configured to contain energy dissipation and loss when passing radially outward through inner and outer covers 172 , 174 . However, module 200 may do this without using divider 170 , slot 178 , and spacer 180 . Instead, the inner and/or outer covers 172 , 174 of the module 200 may be segmented via one or more dividers 184 . Dividers 184 may be generally planar, clocked at regular intervals from each other, and oriented through the axis of compression device 150 . Divider 184 may extend radially inwardly through outer and inner covers 174 , 172 , but may terminate at or short on shaft 164 . Divider 184 may be fabricated, coated, colored, or implanted with a material configured to block or reflect energy from source 168 towards the TCP. Any number of dividers 184 may be used to create as many discrete energy-transmission channels (eg, arcuate segments between adjacent dividers 184 ) as desired. In addition to divider 184 , one or more dividers 186 lying in a plane oriented at an angle generally orthogonal or oblique to the axis of shaft 164 further focus energy from source 168 in some embodiments. It is contemplated that it can be used to (eg, axially direct energy towards a TCP). In some applications, the spacing between dividers 184 and/or 186 may be adjusted during material ejection to selectively change and focus cure path parameters.

6 also shows the module 200 further having a cutting function. For example, a cutting mechanism 188 may be incorporated into the module 200 in some embodiments. The cutting mechanism 188 may include components that cooperate to clamp, cut, and/or supply stiffener during and/or after the printing operation. These components include, among other things, a bar 190 pivotally mounted at an axial end opposite the shaft 164 , a blade 192 attached to the outer rail 194 of the bar 190 , and a radius one or more actuators (eg, linear actuators at each end of the shaft 164 ) 196 configured to selectively extend and retract the outer rail 194 in a direction.

During operation, the stiffener may be ejected through the nozzle 30 and at least partially wrapped around the outer cover 174 of the module 200 from the TCP to the nip point. The curing energy may pass axially to the compression module 200 and then be redirected radially outward to cure the matrix coating the reinforcement in the TCP. When it is desired to cut the stiffener (eg, at the end of a printing pass), actuator(s) 196 are activated by controller 28 (see FIG. 1 ) to cause bar 190 to move radially inward. can make it shrink. This action may cause the stiffener to pinch between the outer rail 194 and the outer cover 174, thereby clamping the stiffener in the position shown in FIG. During retraction and clamping of the bar 190 , the blade 192 is forced through the stiffener and against the outer cover 174 , thereby cutting the stiffener.

The bar 190 can remain in the clamped position during the start of the next printing pass and can be rotated together due to engagement with the outer cover 174 of the module 200 . This rotation may serve to pull the stiffener away from the head 16 (eg, out through the nozzle 30 to prepare it for printing) and may continue until the outer rail 194 reaches the TCP. At this point, the bar 190 can be pushed and/or released to move radially outwardly back, causing the rail 194 to rotate back to the outlet of the nozzle 30 . It is contemplated that the return of the rail 194 may be facilitated with other actuators (not shown) and/or springs 198 as desired. With this configuration, not only clamping and cutting of the stiffener is provided, but also the guidance of the cut stiffener to the TCP can be facilitated.

Industrial Applicability

The disclosed systems can be used to fabricate composite structures having any desired cross-sectional shape and length. The composite structure may include any number of different fibers of the same or different types and of the same or different diameters, and any number of different matrices of the same or different configuration. The operation of the system 10 is described in detail below.

At the start of a manufacturing event, information regarding the desired structure 12 is sent to the system 10 (eg, to the controller 28 responsible for regulating the operation of the support 14 and/or head 16 ). can be loaded. This information includes, among other things, size (eg diameter, wall thickness, length, etc.), contour (eg trajectory, surface normal, etc.), surface features (eg ridge size, location, thickness, length, flange), among others. size, location, thickness, length, etc.), connection geometry (e.g., location and size of couplings, tee, splice, etc.), stiffener selection, matrix selection, discharge location, cut location, It may include hardening specifications, compression specifications, and the like. It should be noted that this information may alternatively or additionally be loaded into the system 10 at other times and/or continuously during a manufacturing event if desired. Based on the component information, one or more different stiffeners and/or matrix materials may be installed and/or continuously supplied to the system 10 .

To install the reinforcement, individual fibers, tows and/or ribbons may pass through matrix reservoir 24 and outlet 22 (eg, through features of nozzle 30 and under the compressor (32)). In some embodiments, the stiffener may also need to be connected to a pulling machine (not shown) and/or a mounting fixture (eg, anchor point). Installation of the matrix material may include filling the head 16 (eg, the wetting mechanism 26 of the reservoir 24 ) and/or coupling of an extruder (not shown) to the head 16 .

The component information can then be used to control the operation of the system 10 . For example, as the support 14 selectively moves (eg, based on the known mechanics of the support 14 and/or the known geometry of the structure 12 ), the in-situ wetting stiffener may It can be pulled and/or pushed from the outlet 22 of the head 16 , thereby producing the resulting support 12 as desired.

The operating parameters of the support 14 , the cure enhancer(s) 18 , the compressor 32 , the modules 54 and/or 200 , and/or other components of the system 10 are determined by the desired configuration of the structure 12 . It can be adjusted in real time during material ejection to provide bonding, strength, tension, geometry and other characteristics. Once the structure 12 has grown to a desired length, the structure 12 may be cut in the system 10 .

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed system. For example, components of system 10 (eg, distributor 170 , covers 172 and 174 , spacers 180 , dividers 184 and 186 , etc.) are described and shown as separate components. However, it is contemplated that two or more components of system 10 may alternatively be integrated if desired. The specification and examples are to be considered illustrative only, the true scope of which is intended to be defined by the following claims and their equivalents.

Claims (15)

An additive manufacturing system (10) comprising:
support 14; and
a print head (16) configured to eject material (R+M) and operatively connected to and movable by the support in a normal direction of travel (34) during material ejection;
The print head is positioned aft of the ejected material with respect to the normal travel direction, and a module 22 configured to compress the material and expose the material to curing energy at a tool center point (TCP). comprising, an additive manufacturing system. The method of claim 1,
The module is
an outer cover (174) configured to roll over the material during compression; and
and a source (168) configured to direct the curing energy radially outward through the outer cover. 3. The method of claim 2,
the module includes a shaft (164) to which the outer cover is mounted;
and the source is configured to direct the curing energy axially to the shaft and then radially outwardly through the passageway (177) of the shaft and through the outer cover. 4. The method of claim 3,
and optics (176) mounted to the interior of the shaft and configured to redirect the axially directed curing energy radially outward of the shaft. 4. The method of claim 3,
and a slotted distributor (170) disposed between the shaft and the outer cover. 6. The method of claim 5,
the slotted dispenser includes a plurality of axially oriented slots (178);
wherein the module further comprises a spacer (180) at least partially transparent to the curing energy disposed within each of the plurality of axially oriented slots. 6. The method of claim 5,
and an inner cover (172) disposed between the slotted dispenser and the outer cover, the inner cover being more compliant than the outer cover. 8. The method of claim 7,
wherein each of the inner cover and the outer cover is at least partially transparent. According to claim 1,
and the module is rotatably connected to the remainder of the print head via at least one bearing. According to claim 1,
and at least one divider (184) aligned with the axis of the module and configured to focus the curing energy on an arcuate segment of the module. 11. The method of claim 10,
and at least one divider (186) extending radially outwardly through the module and configured to focus the curing energy in an axial direction of the module. According to claim 1,
The module is
an outer cover (174) configured to roll over the material during compression;
an arm (190) extending radially outwardly past the outer cover;
a bar (194) connected to the distal end of the arm and extending in the axial direction of the module; and
and an actuator (196) coupled to the arm and configured to selectively pull the bar radially inward relative to the outer cover. 13. The method of claim 12,
and a cutting device (192) operatively connected to the bar. A method of additive manufacturing a structure (12) comprising:
discharging a matrix-wetted continuous reinforcement (R+M) through the outlet (30) of the print head (16);
pressing the module (22) against the matrix-wet continuous reinforcement after ejection to compress the matrix-wet continuous reinforcement; and
directing curing energy radially outwardly to the matrix-wetting continuous reinforcement being compressed through the module. 15. The method of claim 14,
and at least one of axially and radially focusing the curing energy to a tool center point (TCP) of the print head.

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