WO2021145818A1 - Procédé et appareil d'impression 3d avec une buse à géométrie variable - Google Patents

Procédé et appareil d'impression 3d avec une buse à géométrie variable Download PDF

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Publication number
WO2021145818A1
WO2021145818A1 PCT/SG2020/050771 SG2020050771W WO2021145818A1 WO 2021145818 A1 WO2021145818 A1 WO 2021145818A1 SG 2020050771 W SG2020050771 W SG 2020050771W WO 2021145818 A1 WO2021145818 A1 WO 2021145818A1
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WIPO (PCT)
Prior art keywords
nozzle
target
extrudate
profile
slidable plates
Prior art date
Application number
PCT/SG2020/050771
Other languages
English (en)
Inventor
Wenxin LAO
Tegoeh TJAHJOWIDODO
Mingyang Li
Original Assignee
Nanyang Technological University
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Publication date
Application filed by Nanyang Technological University filed Critical Nanyang Technological University
Publication of WO2021145818A1 publication Critical patent/WO2021145818A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/10—Processes of additive manufacturing
    • B29C64/106—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
    • B29C64/118—Processes of additive manufacturing using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material using filamentary material being melted, e.g. fused deposition modelling [FDM]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/02—Small extruding apparatus, e.g. handheld, toy or laboratory extruders
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/05—Filamentary, e.g. strands
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/30—Extrusion nozzles or dies
    • B29C48/302—Extrusion nozzles or dies being adjustable, i.e. having adjustable exit sections
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/92—Measuring, controlling or regulating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/20—Apparatus for additive manufacturing; Details thereof or accessories therefor
    • B29C64/205—Means for applying layers
    • B29C64/209—Heads; Nozzles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/30—Auxiliary operations or equipment
    • B29C64/386—Data acquisition or data processing for additive manufacturing
    • B29C64/393—Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y30/00—Apparatus for additive manufacturing; Details thereof or accessories therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y50/00—Data acquisition or data processing for additive manufacturing
    • B33Y50/02—Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes

Definitions

  • the present disclosure relates to methods and apparatus for additive manufacturing.
  • 3D printing also referred to as additive manufacturing
  • 3D printing has the potential to reduce total fabrication time and labor cost.
  • 3D concrete printing 3DCP
  • the geometry of the extrudate often does not follow the shape of the nozzle due to the effects of gravity and material rheological properties.
  • Surface roughness is important as a rough surface tends to wear more rapidly than a smooth surface.
  • stress concentration at the layer interface may reduce the bonding strength between layers of the extrudate. Therefore, there is a need to improve the surface finish quality of 3DCP -printed objects.
  • a 3D printing method and apparatus with a variable-geometry nozzle includes slicing a model of an object into a plurality of primary slices, and further slicing each primary slice into a plurality of thinner secondary slices.
  • a target extrudate profile of the selected primary slice is defined.
  • the method includes predicting a target nozzle shape correlated with the target extrudate profile; and adjusting the nozzle shape such that the nozzle shape adaptively conforms with the target nozzle shape as the nozzle travels along a printing path to deposit an extrudate layer.
  • a nozzle system operable with a nozzle positioning system to deposit an extrudate to form an object based on a model including: a nozzle, the nozzle including a variable-geometry section spaced apart from an outlet lip, the nozzle being coupled to the nozzle positioning system such that the nozzle positioning system is configured to move the nozzle along a printing path defined by the nozzle system; an actuating system operably coupled to controllably position a plurality of slidable plates along respective tracks, the plurality of slidable plates being slidably disposed at the variable-geometry section to define a nozzle shape; at least one processor; and a computer- readable memory coupled to the at least one processor, the computer-readable memory embodying instructions executable by the at least one processor to perform a method including: acquiring a target extrudate profile for a primary slice of the model, the target extrudate profile being approximated based on intersections between a plurality of secondary slicing planes and a cross-
  • the nozzle includes: a nozzle body having an interior wall, the interior wall extending in a longitudinal direction to define a channel terminating at an outlet lip, the outlet lip being disposed in a first transverse plane substantially parallel to the printing path and substantially perpendicular to the longitudinal direction; a side opening disposed at the nozzle body and longitudinally spaced apart from the first transverse plane; and a plurality of slidable plates in slidable engagement with the side opening, each of the plurality of slidable plates including a first end surface disposed to form a part of the interior wall defining a nozzle shape, wherein each of the plurality of slidable plates is in slidable contact with at least one other of the plurality of slidable plates.
  • a method includes: slicing a model of the object into a plurality of primary slices, each of the plurality of primary slices having a primary slice thickness corresponding to a thickness of an extrudate layer; slicing a selected primary slice into a plurality of secondary slices according to a plurality of secondary slicing planes, the selected primary slice being selected from the plurality of primary slices; and defining a target extrudate profile of the selected primary slice such that the target extrudate profile corresponds to a cross-section of the extrudate layer, wherein the target extrudate profile is defined by a plurality of intersections between the plurality of secondary slicing planes and a cross-section of the selected primary slice.
  • a method of forming a three-dimensional object can be performed by a processor configured to execute instructions embodied by a computer- readable memory coupled to the processor.
  • the method includes: acquiring a target extrudate profile for a nozzle having a nozzle shape; predicting a target nozzle shape correlated with the target extrudate profile; and adjusting the nozzle shape such that the nozzle shape adaptively conforms with the target nozzle shape as the nozzle travels along a printing path to deposit an extrudate layer.
  • FIG. 1 is an exploded view of a nozzle system according to an embodiment of the present disclosure
  • FIG. 2 is a partial sectional view of the nozzle system of Fig. 1;
  • Fig. 3 A is a cross-section of the nozzle of Fig. 1;
  • Fig. 3B is a close-up view of Fig. 3A showing a variable-geometry section of the nozzle;
  • FIG. 4 is a partial cross-sectional view of a nozzle system according to another embodiment
  • FIG. 5 is another perspective view of the nozzle system of Fig. 4;
  • Fig. 6 A schematically illustrates an example of a nozzle shape;
  • Fig. 6B shows another example of the nozzle shape
  • Fig. 7 is a process flow chart of a method according to an embodiment of the present disclosure.
  • FIG. 8 A to Fig. 8C are schematic representations according to the method of
  • Fig. 9 is another process flow chart of the method according to an embodiment of the present disclosure.
  • FIG. 10 schematically illustrates exemplary extrudate profiles obtained according to the method of Fig. 9;
  • Fig. 11 is a schematic representation of a zero-position state nozzle shape and a corresponding extrudate profile
  • Fig. 12 is a schematic block diagram of a nozzle system
  • Fig. 13 is a workflow diagram according to embodiments of the present disclosure.
  • the present disclosure provides a 3D printing method and apparatus with a nozzle (100).
  • the nozzle includes a variable-geometry section (121), and the nozzle is also referred to herein as a variable-geometry nozzle.
  • Embodiments of the nozzle are suitable for use in 3D printing or additive manufacturing in different fields, including but not limited to the fabrication of medical devices, building structures, etc.
  • the nozzle is also not limited to use with any particular type of printing material. Examples of printing materials that may be used with the nozzle include but are not limited to polymers, metals, bio-printing materials, ceramics, concrete, etc.
  • 3D printing a three-dimensional object may be formed by depositing one extrudate layer on another earlier deposited extrudate layer until a desired thickness of the object is achieved. Conventionally, a horizontal deposition is favored so as to permit the material to exit the nozzle in a transverse direction, similar to the final orientation of the extrudate layer.
  • a vertical deposition mode or process would involve the material exiting the nozzle in a longitudinal direction, substantially perpendicular to the final orientation of the extrudate layer. It can be appreciated that, in a vertical deposition process, the material at different parts in a cross-section of the extrudate would travel paths of different lengths and different degrees of curvature, after exiting through the outlet lip and before coming to rest. For this and other reasons, vertical deposition is technically more challenging. Nonetheless, embodiments of the present disclosure have been found to enable the use of vertical deposition to obtain surprisingly significantly improved surface quality and shape compliance.
  • Fig. 1 is an exploded view of a nozzle system (300) in which an actuating system (200) is provided to enable variable geometry of the nozzle (100).
  • the nozzle (100) includes a nozzle body (110) having an interior wall (114) and an exterior wall (115).
  • the interior wall (114) extends in a longitudinal direction (80) to define a channel (112) in the nozzle, such that a material received by the nozzle (100) can be made to flow in the channel (112) until the material exits the nozzle, forming an extrudate.
  • the channel (112) begins at an inlet (117) and extends longitudinally to terminate at an outlet lip (116).
  • the nozzle (100) may be coupled to an adaptor (170) at the inlet to facilitate reception of the material into the channel (112).
  • the outlet lip (116) is disposed in a first transverse plane (60), that is, the nozzle wall (110) terminates at the first transverse plane where an edge of the interior wall (114) defines the outlet lip.
  • the first transverse plane (60) is substantially perpendicular to the longitudinal direction (80).
  • the channel (112) nearer the inlet (117) has a circular cross-section which tapers to a narrower rectangular cross-section nearer the outlet lip (116).
  • the interior wall (114) further includes a variable-geometry section (121) longitudinally spaced apart from the first transverse plane (60), that is, from the outlet lip (116).
  • the variable-geometry section (121) may be disposed nearer the outlet lip (116) than the inlet (117).
  • the channel (112) may be configured with different cross-sectional shapes and sizes.
  • the variable-geometry section is a section of the nozzle that is controllably changeable to define various channel cross- sectional profiles. In this disclosure, the cross-sectional profile of the channel (112) at the variable-geometry section is referred to as a nozzle shape (129).
  • the nozzle shape (129) is defined with respect to a transverse plane (62), in which the transverse plane is substantially parallel to the first transverse plane (60).
  • the variable-geometry section is configured such that the material flowing past the variable-geometry section (121) is shaped thereby, even before the material exits through the outlet lip (116).
  • the variable- geometry section extends longitudinally for a length H (162) such that the volume of material as well as the profile of the material is affected or regulated over a longitudinal distance, even before the material reaches the outlet lip (116).
  • the variable-geometry section is coupled with an actuating system (200) configured to change the nozzle shape (129) at the variable-geometry section.
  • the nozzle (100) may further be coupled to a nozzle positioning system (310).
  • the nozzle positioning system (310) is configured to move the nozzle (100) along a printing path (70), such that the material exiting the outlet lip (116) is deposited as an extrudate layer (90) following the printing path.
  • variable-geometry section (121) may include a plurality of slidable plates (120) slidably disposed thereat, the variable-geometry section (and hence the plurality of slidable plates) being spaced apart from the outlet lip (116).
  • the slidable plates (120) are configured to be in slidable engagement with the nozzle body (110).
  • a side opening (118), such as an opening, may be disposed at the nozzle body (110) such that the plurality of slidable plates (120) are in slidable engagement with the side opening (118).
  • the side opening (118) is longitudinally spaced apart from the first transverse plane (60) or the outlet lip (116) by a lip thickness (111), such that a dynamic seal (119), such as an O-ring, may be disposed between the side opening (118) and the plurality of slidable plates (120).
  • the dynamic seal (119) is configured to prevent significant leakage of material out of the channel (112) at the side opening.
  • Each of the plurality of slidable plates (120) may be configured with two substantially opposing or parallel major surfaces (123) with a first end surface (122) disposed therebetween.
  • the slidable plates (120) may be arranged as a lateral stack (124) with each of the plurality of slidable plates (120) in slidable contact with at least one other of the plurality of slidable plates (120). Adjacent slidable plates (120) contact one another at the respective major surfaces (123), which are configured to permit relative movement while preventing significant leakage of material between the adjacent slidable plates, for example, through the use of tight tolerances.
  • Each of the plurality of slidable plates (120) may be slidable in respective parallel planes or along a first transverse direction (82) independently of one another.
  • the first end surface (122) of each of the plurality of slidable plates is disposed to form a part of the variable-geometry section (121) of the interior wall (114) to define the nozzle shape (129).
  • the plurality of the slidable plates is configured to be positionable at selected positions (125) along respective tracks (84).
  • the slidable plates (120) may be moved relative to the side opening (118) by the actuating system, such that the first end surfaces (122) can be positioned at different displacements or positions (125) relative to the side opening or relative to a fixed part of the inner wall (114).
  • the tracks (84) may be substantially parallel to a first transverse direction (82).
  • a track (84) refers to a path defined by movement of the corresponding slidable plate (120).
  • the first end surfaces (122) of each of the plurality of slidable plates can define a corresponding variable channel width (127) in the first transverse direction, that is, the channel width (127) is measured along the first transverse direction (82).
  • the plurality of slidable plates (120) can define a variable nozzle shape (129), at the variable-geometry section (121) of the nozzle body (110).
  • each of the plurality of slidable plates (120) may be configured with the respective first end surface (122) defining a rectangle having longer edges (162) and shorter edges (163).
  • the plurality of slidable plates (120) may be disposed such that the longer edges (162) are substantially parallel to the longitudinal direction (80), such that the length of the longer edges (162) defines a longitudinal length H of the variable- geometry section (121).
  • Each of the shorter edges (163) has a thickness dimension Wl, configured to allow for a desired number of the slidable plates (120) to be disposed in one side opening, resulting in a corresponding degree of freedom for configuring the nozzle shape (129).
  • Each stack (124) of the slidable plates (120) forms a collective thickness of W2 (164) which contributes towards defining the thickness (95) of the extrudate layer (90).
  • the longer edges (162) of the first end surface (122) allows a longer path during which the material can conform to the nozzle shape (129). The result is a more consistent and predictable extrudate layer.
  • material flowing in the channel (112) is subject to a shaping effect of the variable-geometry section over the longitudinal length of the variable- geometry section, providing a controllable volume of the material as well as a controllable cross-sectional profile to the extrudate layer.
  • the nozzle (100) may be operable with various types of actuating systems (for example, pneumatic actuating systems, electro-hydraulic systems, etc.) configured to controllably position each of the plurality of slidable plates along respective tracks, without going beyond the scope of the present disclosure.
  • the actuating system (200) described herein is therefore a non-limiting example.
  • the actuating system (200) may include a stepper motor (140) for each slidable plate (120), coupled to allow relatively small adjustments to the position of the slidable plate (120) along a corresponding track (84).
  • a circular motion of a linear-motion pin (148) driven by the stepper motor (140) may be translated into a linear movement of bars (144) by a cam mechanism (142).
  • the cam mechanism (142) may include the linear-motion pin (148) engaged with a slotted plate (146).
  • the bars (144) connect a corresponding slidable plate (120) to the slotted plate (146), such that linear motion of the slotted plate (146) in the first transverse direction (82) causes the bars (144) to drive the slidable plate in linear movement along a corresponding track (84) parallel to the first transverse direction.
  • a guiding plate (150) having a plurality of apertures may be provided for guiding the linear movement of the bars (144).
  • a second seal (119a) may be provided between the nozzle body (110) and the guiding plate (150) to prevent significant leakage of materials out of the channel (112).
  • Part of the actuating system (200) may be disposed in a modular housing (130). Opposing sides of the modular housing (130) may be spaced apart to accommodate the slotted plates (146). The opposing sides of the modular housing (130) may be configured with guiding slots (132), such that opposing ends of each slotted plate (146) are received in the corresponding guiding slots (132) and prevented from tilting during movement. Each guiding slot (132) may provide abutment walls (133) to act as displacement limits for the slotted plates (146).
  • the guiding slots (132) are oriented in the first transverse direction (82) so that the slotted plates (146) and the sliding plates (120) are constrained to move in linear or translational motion in the first transverse direction (82).
  • the slidable plates (120) may thus be independently positioned or collectively positioned by controlling the stepper motors (140).
  • a sensor assembly (160) may be provided to detect the respective positions of the slidable plates (120), that is, to determine the respective positions or displacements of the first end surfaces relative to the interior wall (114).
  • the sensor assembly (160) may include a plurality of position sensors disposed at modular housing (130).
  • the position sensors (162) may be configured to detect the positions of the slotted plates (146), and thereby determine the respective positions or displacements of the first end surfaces (122) relative to the interior wall (114).
  • the sensor assembly (160) may be configured to determine the respective positions of the plurality of slidable plates (120) with reference to a zero position (90) as shown in Fig. 6A and Fig. 6B.
  • the zero position (90) of a slidable plate (120) may be defined as one in which the first end surface (122) is substantially flushed with the rest of the adjacent interior wall (114).
  • the zero position (90) may alternatively be defined as one in which the slidable plate 120 is retracted into the nozzle body (110) or the side opening (118) until the slotted plate (146) abuts the abutment wall (133).
  • a zero-position state may be described as the configuration or nozzle shape in which the channel (112) has the largest possible width dimensions.
  • the nozzle (100) may be configured to be symmetrical about a longitudinal axis (80) of the nozzle (100), such that more than one surface of the extrudate layer (90) may be shaped by the variable-geometry section (121), such as shown in Fig. 6A.
  • the nozzle (100) may include more than one side opening (118) disposed in the nozzle body (110), with each of the side openings (118) being in slidable engagement with a corresponding stack (124) of slidable plates, that is, with a corresponding plurality of slidable plates (120).
  • Each of the plurality of slidable plates is configured to be positionable at selected positions (125) along respective tracks (84).
  • two side openings (118) are disposed substantially opposite one another.
  • Actuators (140) such as stepper motors or linear motors, may be provided and operatively coupled to respective slidable plates (120) to move the slidable plates (120).
  • Each of the plurality of slidable plates (120) may be configured to be positionable at selected positions (125) along respective tracks, such that the slidable plates (120) may be independently positioned or collectively positioned.
  • the tracks (84) may be substantially parallel to the first transverse direction (82).
  • nozzle shape (129) definable by the slidable plates (120) in different positions are schematically illustrated in Fig. 6A and Fig. 6B.
  • the inner wall may be described as having a leading face (114a) and a trailing face (114b), relative to a printing direction (71).
  • the leading face (114a) travels ahead of the trailing face (114b) to deposit the extrudate layer (90).
  • the material defined by the leading face (114a) corresponds to a first surface (94a) of the extrudate layer (90), and the material defined by the trailing face (114b) corresponds to a second surface (94b) of the extrudate layer (90).
  • the first surface (94a) can be in contact with a previously deposited extrudate layer.
  • a thickness (95) of the extrudate layer (90) can be defined between the first surface (94a) and the second surface (94b).
  • the nozzle (100) used in a vertical deposition process can be configured such that material that is shaped by the plurality of slidable plates (120) forms corresponding surfaces of the extrudate layer (90), and thereby the corresponding surfaces of the object formed.
  • the nozzle (100) may also be used to define at least one surface of the extrudate layer (90).
  • the nozzle shape (129) at the variable-geometry section may be other than rectangular in shape.
  • the nozzle shape (129) may alternatively be configured with a circular cross- section, a square cross-section, a polygonal cross-section, etc.
  • the nozzle (100) may be configured with more than two side openings (118), in which each side opening is provided with a corresponding plurality of plates (120).
  • the outlet lip (116) may also be configured in different shapes, and preferably no smaller than the nozzle shape (129) at the variable-geometry section, such that the outlet lip does not interfere with the profile or shape of the material as it passes through the outlet lip.
  • embodiments of the present disclosure include a method (400) (Fig. 7) of forming a three-dimensional object in which the method can be performed by a processor configured to execute instructions embodied by a computer- readably memory coupled to the processor.
  • the method (400) includes slicing (410) a model (600) of the object into a plurality of primary slices (610) using a plurality of primary slicing planes (612).
  • the model (600) represents a target surface geometry (such as an outer surface geometry) of a three-dimensional object to be fabricated by 3D printing.
  • Each primary slice (610) (defined between two neighboring primary slicing planes) represents a single printing layer obtained in one pass of the nozzle, that is, an extrudate layer (90).
  • Primary slicing planes (612) are defined as parallel planes with adjacent primary slicing planes spaced apart by a primary slice distance equivalent to a thickness of the extrudate layer, such that, each of the plurality of primary slices has a primary slice thickness (614) corresponding to a thickness (95) of the extrudate layer (90), which in this case also corresponds to the collective thickness (164) of a stack (124) of the slidable plates.
  • the corresponding primary slice is further sliced into thinner secondary slices (620).
  • the method includes slicing (420) a selected primary slice (610) into a plurality of secondary slices (620) according to a plurality of secondary slicing planes (622), in which the selected primary slice (610) is selected from the plurality of primary slices.
  • Each of the plurality of secondary slices (620) has a secondary slice thickness (624), where the plurality of secondary slice thickness (624) collectively corresponds to the primary slice thickness (614).
  • the method further includes defining (430) a target extrudate profile (650) of the selected primary slice such that the target extrudate profile (650) corresponds to a cross-section of the extrudate layer (90).
  • the target extrudate profile is defined by a plurality of intersections (660) between the plurality of secondary slicing planes (622) and a cross-section (673) of the selected primary slice.
  • the target extrudate profile (650) can be used as a basis for controllably adjusting the nozzle shape (129) at the variable-geometry section (121) of the nozzle.
  • the plurality of primary slices (610) and the plurality of secondary slices (620) may be substantially parallel to a transverse plane (60), in which the transverse plane (60) is substantially parallel to the printing path or printing trajectories of the same primary slice (610).
  • the method may further include determining multiple trajectory points (670) for the extrudate layer (90), in which each of the multiple trajectory points corresponds to an intersection between an outer surface of the selected primary slice (or a surface geometry as described by the model) and a cross-section plane (672).
  • the method includes acquiring the target extrudate profile (650) for at least one trajectory point selected from the multiple trajectory points (670).
  • the cross-section plane (672) is defined as a plane that is substantially perpendicular to the plurality of primary slices.
  • the cross-section plane (672) at a trajectory point is also defined as a plane that is substantially perpendicular to the nozzle’s direction of movement at the trajectory point.
  • the cross-section plane (672) may be defined with reference to coordinates of the trajectory point (670) and a normal vector (674) pointing in the direction of travel of the nozzle.
  • the intersection of the cross- section plane (672) and the outer surface of the selected primary slice (610) defines a corresponding target extrudate profile (650) associated with the trajectory point (670).
  • the method may include defining the target extrudate profile (650) for at least one trajectory point selected from the multiple trajectory points.
  • the “ideal” or “exact” cross-section geometry (690) of the extrudate layer (90) will have a correspondingly curved profile since it is based on the model.
  • the term “target extrudate profile” refers to an approximation of the “ideal” or “exact” cross-sectional geometry.
  • the target extrudate profile (650) can be acquired by using a stepped or “staircase” profile to approximate a curved profile.
  • each primary slice (610) is further sliced into a corresponding five secondary slices (620).
  • a reference point (intersection) (660) is taken from each intersection of the primary slice geometry (690) and the extrudate cross-section plane (672). An approximation of the exact cross- sectional geometry of the extrudate layer is derived from the reference points (660).
  • one extrudate layer (90) deposited for a curved surface is expected to have a side surface configured with steps. There is no layer interface between adjacent steps since the steps are formed as part of the same extrudate layer.
  • a stepped profile is traditionally avoided when the desired surface geometry is curved.
  • the target extrudate profile (650) is intentionally defined as a stepped profile by using discrete width variations to approximate the exact cross-sectional geometry.
  • the method may include generating a printing path from the multiple trajectory points (670) for all of the plurality of primary slices (600) required to form the object.
  • the method may include storing the printing path such that each of the multiple trajectory points (670) is associated with the corresponding target extrudate profile (650).
  • the method may include correlating the target extrudate profile (650) with a target nozzle shape (700).
  • the correlation may be based on a machine learning model.
  • the machine learning model may be configured such that it is trained to provide the target extrudate profile (650) based on input parameters associated with the target nozzle shape (700) and a flow ratio of a selected material. Examples of input parameters include environmental factors such as temperature and humidity, selected material property such as viscosity and composition, etc.
  • the method may include acquiring a target nozzle shape (700) for the nozzle, based on the target extrudate profile (650), in which the nozzle has a nozzle shape that is adjustable to conform with the target nozzle shape (700).
  • the target nozzle shape (700) may be acquired based on a database and/or calculations or analysis.
  • embodiments of the present disclosure includes a method (500) of forming a three-dimensional object.
  • the method may be performed by a processor configured to execute instructions embodied by a computer- readably memory coupled to the processor.
  • the method (500) includes acquiring (510) a target extrudate profile (650) for a nozzle having a nozzle shape (such as by the method described above), and predicting (520) a target nozzle shape (700) correlated with the target extrudate profile (650).
  • the method includes adjusting (530) the nozzle shape such that the nozzle shape adaptively conforms with the target nozzle shape (700) as the nozzle travels along a printing path to deposit an extrudate layer.
  • the target nozzle shape can be varied accordingly for the different extrudate layers.
  • the resulting object can thus be formed by extrudate layers in which the actual extrudate profile differs from one extrudate layer to another extrudate layer.
  • the target nozzle shape can also be varied from one trajectory point to another trajectory point for the same extrudate layer.
  • the resulting object can thus be formed by at least one extrudate layer in which the actual extrudate profile varies along the same extrudate layer.
  • the method may further include depositing an extrudate layer (90) characterised by a stepped surface (98), the stepped surface defining different widths along a thickness (95) of the extrudate layer such that the stepped surface (98) approximates a curved surface, in which the curved surface is characterised by different curvatures along the printing path.
  • the method may further include actuating a plurality of slidable plates (120) configured to vary respective transverse widths (127) of the channel cross-section, such that the extrudate layer is characterised by different widths along a thickness (t) of the extrudate layer, in which the thickness (t) of the extrudate layer corresponds to a collective thickness (W2) of the plurality of slidable plates.
  • a current position of the nozzle (100) may be determined, for example, by sensing and/or calculations.
  • Embodiments of the method includes adjusting the nozzle shape (129) at the variable-geometry section (121) at the same time as the nozzle (100) is travelling along the printing path.
  • the method may include determining a nearest trajectory point (670) relative to the current location of the nozzle, and acquiring a predictive target extrudate profile (650) associated with the nearest trajectory point (670), such that the target nozzle shape (700) acquired is one correlated to the predictive target extrudate profile (650).
  • the current position of the nozzle may be one that does not exactly coincide with any of the multiple trajectory points stored.
  • the method may then involve using the target extrudate profile (650) associated with the nearest trajectory point as the basis for adjusting the nozzle shape.
  • the method may use the closest trajectory point yet to be traversed by the nozzle as the basis for predicting a target extrudate profile (650).
  • the nozzle system (300) includes a computing device having at least one processor (302) and a computer-readable memory (304) coupled to the at least one processor, in which the computer-readable memory is configured to embody instructions executable by the processor.
  • the nozzle system (300) may be coupled with a nozzle positioning system (310) such that the nozzle positioning system can move the nozzle (100) along the printing path.
  • the nozzle system further includes an actuating system (200) coupled to control the adjustable elements of the variable-geometry section and to configure the nozzle shape.
  • the nozzle system is configured such that the nozzle positioning system (310) and the actuating system (200) work cooperatively and simultaneously when the nozzle system is depositing an extrudate to form an object.
  • a nozzle system (900) is configured to perform a method, in which the method includes: i) acquiring a target extrudate profile for a primary slice of the model, the target extrudate profile being approximated based on intersections between a plurality of secondary slicing planes and a cross-section of the primary slice of the model; ii) based on the target extrudate profile, acquiring a target nozzle shape from a machine learning model; and iii) positioning the plurality of slidable plates at respective selected positions along the respective tracks such that the nozzle shape corresponds to the target nozzle shape; and forming a corresponding extrudate layer.
  • the number of secondary slicing planes is selected to produce a number of secondary slices corresponding to a number of the slidable plates.
  • the method may also include: iv) for each of multiple trajectory points along the printing path, acquiring and storing the target extrudate profile; and v) sending commands to the actuating system, wherein the commands are configured to position the plurality of slidable plates to provide the nozzle shape corresponding to each of the multiple trajectory points. Further, the method may also include: vi) locating a current position of the nozzle; and controllably positioning the plurality of slidable plates to provide the nozzle shape corresponding to the target extrudate profile associated with a trajectory point nearest to the current position.
  • Fig. 13 is a workflow diagram of a working prototype, according to embodiments of the present disclosure.
  • a model of an object may be developed in the form of a computer-aided drawing (CAD) model (902).
  • the nozzle system (900) is configured to define both the printing paths and the target extrudate geometry at multiple trajectory points.
  • the model is first sliced using a number of spaced apart primary planes, and each primary plane is further sliced using a plurality of secondary planes.
  • the primary planes are spaced 15 millimeters (mm) apart
  • the secondary planes are spaced 3 mm part (3 mm resolution), with the primary planes and the secondary planes being horizontally disposed.
  • variable-geometry section of the nozzle includes two side openings, each of which is slidably engaged with a stack of five slidable plates. The result is a nozzle with ten degrees of freedom for the configuration of the nozzle shape.
  • the leading face and the trailing face of the channel are spaced 15 mm apart such that the thickness of one extrudate layer is correspondingly 15 mm, with a maximum channel width of 38 mm.
  • the printing paths are loaded to a robot controller (922) of a robotic arm (924) which forms part of the nozzle positioning system (310).
  • the target extrudate profiles (950) are loaded to a computing device which stores a nozzle-extrudate correlation database (940).
  • the nozzle- extrudate correlation database may be compiled through training a machine learning model.
  • the nozzle-extrudate correlation database is configured to associate target extrudate profiles with corresponding nozzle shapes.
  • the robot controller (922) controls the robotic arm (924) such that the nozzle is moved along the printing path.
  • the nozzle may be coupled to the robotic arm by an end-effector of the robotic arm.
  • a real-time position of the end-effector (930) may be recorded by position sensors (926) and sent as feedback to the robot controller (922).
  • Part of the nozzle system may reside in a remote computing device connected to the robot controller by an ethernet port, such that the real-time position can be published via a server to the processor (970).
  • the nozzle system calculates a current position of the nozzle.
  • the nozzle system (300) is thus configurable for use with different types of nozzle positioning systems.
  • the nozzle system is configured to acquire a target extrudate shape based on the current position of the nozzle. This may include determining the current position of the nozzle with respect to the traj ectory points, and performing a look-up in the nozzle-extrudate correlation database to acquire a target extrudate shape.
  • the nozzle-extrudate correlation database may reside at a local processor, such as one coupled to the actuating system.
  • the nozzle system may be configured to find a target nozzle shape (960) corresponding to a best approximation of the desired extrudate profile.
  • the target nozzle shape is converted into data and/or commands, and the commands are sent to the motor controller (972) of the actuating system.
  • the nozzle shape (channel cross-section) is adjusted accordingly (974). This process is repeated automatically during the printing process.

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  • Chemical & Material Sciences (AREA)
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  • Optics & Photonics (AREA)
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  • Clinical Laboratory Science (AREA)

Abstract

L'invention concerne un procédé et un appareil d'impression 3D avec une buse à géométrie variable. Le procédé consiste à trancher un modèle d'un objet en une pluralité de tranches primaires, puis à trancher chaque tranche primaire en une pluralité de tranches secondaires plus minces. Un profil d'extrudat cible de la tranche primaire sélectionnée est défini. Le procédé comprend la prédiction d'une forme de buse cible corrélée au profil d'extrudat cible ; et l'ajustement de la forme de buse de telle sorte que la forme de buse se conforme de manière adaptative à la forme de buse cible lorsque la buse se déplace le long d'un trajet d'impression pour déposer une couche d'extrudat.
PCT/SG2020/050771 2020-01-17 2020-12-22 Procédé et appareil d'impression 3d avec une buse à géométrie variable WO2021145818A1 (fr)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230031400A1 (en) * 2021-07-27 2023-02-02 Saudi Arabian Oil Company Fast layered extrusion for additive manufacturing
WO2023025857A1 (fr) * 2021-08-25 2023-03-02 Saint-Gobain Weber France Contrôle d'impression 3d
EP4364927A1 (fr) 2022-11-04 2024-05-08 Centre national de la recherche scientifique Buse pour impression 3d, système de commande de ladite buse et dispositif d'impression 3d comprenant ledit système

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030011100A1 (en) * 2000-02-02 2003-01-16 Mikio Fukumura Flat die, and moldings producing method using the same
CN106945264A (zh) * 2017-03-23 2017-07-14 湖北工业大学 一种线阵喷射式fdm三维打印喷头及打印方法
CN107856271A (zh) * 2017-12-21 2018-03-30 深圳市沃尔核材股份有限公司 一种挤出装置
CN108237690A (zh) * 2017-07-01 2018-07-03 六安永贞匠道机电科技有限公司 同步高精度控制3d打印机喷口截面的控制机构
CN110253856A (zh) * 2019-07-05 2019-09-20 浙江大学 一种用于制备微纳结构的变截面微分化活字式口模

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030011100A1 (en) * 2000-02-02 2003-01-16 Mikio Fukumura Flat die, and moldings producing method using the same
CN106945264A (zh) * 2017-03-23 2017-07-14 湖北工业大学 一种线阵喷射式fdm三维打印喷头及打印方法
CN108237690A (zh) * 2017-07-01 2018-07-03 六安永贞匠道机电科技有限公司 同步高精度控制3d打印机喷口截面的控制机构
CN107856271A (zh) * 2017-12-21 2018-03-30 深圳市沃尔核材股份有限公司 一种挤出装置
CN110253856A (zh) * 2019-07-05 2019-09-20 浙江大学 一种用于制备微纳结构的变截面微分化活字式口模

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230031400A1 (en) * 2021-07-27 2023-02-02 Saudi Arabian Oil Company Fast layered extrusion for additive manufacturing
WO2023025857A1 (fr) * 2021-08-25 2023-03-02 Saint-Gobain Weber France Contrôle d'impression 3d
FR3126333A1 (fr) * 2021-08-25 2023-03-03 Saint-Gobain Weber France contrôle d’impression 3D
EP4364927A1 (fr) 2022-11-04 2024-05-08 Centre national de la recherche scientifique Buse pour impression 3d, système de commande de ladite buse et dispositif d'impression 3d comprenant ledit système
WO2024094869A1 (fr) 2022-11-04 2024-05-10 Centre National De La Recherche Scientifique Buse pour impression 3d, système de commande de ladite buse

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