Laminate forming method, laminate forming device, and program

Abstract

This continuous fiber-reinforced resin yarn is provided with: a base material containing a thermoplastic resin; and at least one fiber bundle containing continuous fibers that are impregnated in the base material and extend in the axial direction. The continuous fibers of the fiber bundle are twisted 20 times / m to 100 times / m around the axis of the continuous fiber-reinforced resin yarn. When the fiber bundle is Z-twisted, the shaping path on the shaping surface is a path in which the shaping material is ejected while being bent or bent toward the right side in the forward direction of the shaping direction, and when the fiber bundle is S-twisted, the shaping material is ejected while being bent toward the right side in the forward direction of the shaping direction. The shaping path on the shaping surface is a path in which the shaping material is ejected while being bent or bent toward the left side in front of the shaping direction, and a curved shape or a bent shape is formed.

Description

TECHNICAL FIELD

[0001] The present application relates to a layering molding method, a layering molding apparatus, and a program. BACKGROUND

[0002] As a layering molding apparatus that shapes an object having a three-dimensional shape, a 3D (three-dimensional) printer that adopts a hot-melt layering method of layering a resin in a plasticized state due to heat along a molding route is known. The 3D printer can shape a three-dimensional shape without a mold, a jig, or the like, and can shape an object of a three-dimensional shape that is difficult to form with a conventional injection molding technique.

[0003] For example, a yarn described in Patent Literature 1 is a filament used as a molding material for a 3D printer, and is formed by impregnating a fiber or a fiber bundle in a base material in which a thermoplastic resin is a main component and twisting the same. Thereby, the flexibility of the filament itself is improved, and the handling property is improved. In addition, by twisting the fiber or the fiber bundle in the filament, a molded article molded by the 3D printer using the filament is excellent in impact strength. In this way, the above-described filament can easily form a molded article excellent in impact strength by the 3D printer.

[0004] PRIOR ART DOCUMENT PATENT LITERATURE Patent Literature 1: Japanese Patent Application Publication No. 2021-123026 SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION However, it is known that the filament in which the continuous fiber is reinforced by the number of twists of 10 twists / m to 200 twists / m as shown in Patent Literature 1 can have a possibility that the opening width of the reinforcing fiber decreases or becomes unstable when a molding material obtained by heating and melting the filament is ejected from a nozzle (ejection portion) provided in the head of the 3D printer along the molding route. This is particularly significant in the case where the number of twists imparted to the reinforcing fiber is large, and is particularly significant in a specific shape of the molding route.

[0006] If the opening of the reinforcing fiber is insufficient, the fusion adhesion of the molding materials ejected from the nozzles to each other decreases between the molding routes adjacent to each other, and voids are easily generated. Thereby, the mechanical strength between the lines and between the layers of the molding route decreases, and it is necessary to improve the molding plan and the like so as not to cause such a decrease in the mechanical strength.

[0007] Therefore, an object of the present application is to provide a layering molding method, a layering molding apparatus, and a program that can shape a molded article without causing a decrease in the mechanical strength between the lines and between the layers of the molding route.

[0008] MEANS FOR SOLVING THE PROBLEMS The present application is constituted by the following structure.

[0009] (1) A layering molding method of causing a molding material obtained by heating and melting a continuous fiber-reinforced filament in a linear shape to be ejected from a nozzle along a molding route on a molding surface, and molding a curved shape or a bent shape on the aforementioned molding surface; the aforementioned continuous fiber-reinforced filament has a base material containing a thermoplastic resin and at least one fiber bundle containing continuous fibers impregnated in the aforementioned base material and extending in an axial direction; the aforementioned continuous fibers of the aforementioned fiber bundle are imparted with a twist of 20 twists / m or more and 100 twists / m or less centered on an axial center of the aforementioned continuous fiber-reinforced filament; in a case where the aforementioned fiber bundle is Z-twisted, the aforementioned molding route on the aforementioned molding surface is set to a route in which the aforementioned molding material is caused to be ejected while being curved or bent toward a right side in a forward direction of a molding direction, and in a case where the aforementioned fiber bundle is S-twisted, the aforementioned molding route on the aforementioned molding surface is set to a route in which the aforementioned molding material is caused to be ejected while being curved or bent toward a left side in the forward direction of the molding direction, and the aforementioned curved shape or the aforementioned bent shape is molded.

[0010] (2) A layering molding device having a head that ejects a molding material obtained by heating and melting a continuous fiber-reinforced filament in a linear shape from a nozzle, a drive mechanism that relatively moves the aforementioned nozzle of the aforementioned head with respect to a molding surface, and a control section that drives the aforementioned drive mechanism to cause the aforementioned molding material to be ejected along a set molding route; the aforementioned continuous fiber-reinforced filament has a base material containing a thermoplastic resin and at least one fiber bundle containing continuous fibers impregnated in the aforementioned base material and extending in an axial direction; the aforementioned continuous fibers of the aforementioned fiber bundle are imparted with a twist of 20 twists / m or more and 100 twists / m or less centered on an axial center of the aforementioned continuous fiber-reinforced filament; the aforementioned control section, when molding a curved shape or a bent shape on the aforementioned molding surface, in a case where the aforementioned fiber bundle is Z-twisted, sets the aforementioned molding route on the aforementioned molding surface to a route in which the aforementioned molding material is caused to be ejected while being curved or bent toward a right side in a forward direction of a molding direction, and in a case where the aforementioned fiber bundle is S-twisted, sets the aforementioned molding route on the aforementioned molding surface to a route in which the aforementioned molding material is caused to be ejected while being curved or bent toward a left side in the forward direction of the molding direction, and molds the aforementioned curved shape or the aforementioned bent shape.

[0011] (3) A program that executes the following layering molding step: causing a molding material obtained by heating and melting a continuous fiber-reinforced filament in a linear shape to be ejected from a nozzle along a molding route on a molding surface to mold a curved shape or a bent shape on the aforementioned molding surface; the aforementioned continuous fiber-reinforced filament having a base material containing a thermoplastic resin and at least one fiber bundle containing a continuous fiber impregnated in the aforementioned base material and extending in an axial direction; the aforementioned continuous fiber of the aforementioned fiber bundle being imparted a twist of 20 twists / m or more and 100 twists / m or less with the axis of the aforementioned continuous fiber-reinforced filament as a center; and causing a computer to execute the following steps: in the case where the aforementioned fiber bundle is Z-twisted, setting the aforementioned molding route on the aforementioned molding surface to be a route along which the aforementioned molding material is ejected while being curved or bent toward the right side in the front direction of the molding direction; in the case where the aforementioned fiber bundle is S-twisted, setting the aforementioned molding route on the aforementioned molding surface to be a route along which the aforementioned molding material is ejected while being curved or bent toward the left side in the front direction of the molding direction; and molding the aforementioned curved shape or the aforementioned bent shape.

[0012] Effects of the Invention According to the present invention, a molded object can be layering molded without causing a decrease in mechanical strength between lines and between layers of a molding route. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a schematic structural view of a layering molding apparatus of an FDM method.

[0014] Figure 2A is a schematic cross-sectional view of a radial direction of the filament that is orthogonal to the axial direction.

[0015] Figure 2B is a side view of the filament along the axial direction.

[0016] Figure 3 is a schematic structural view of a filament manufacturing apparatus.

[0017] Figure 4A is a view that schematically shows a state in which a molding material obtained by melting the filament is ejected from a nozzle that is not shown onto a molding surface, and is an explanatory view showing a cross section in a vertical direction of the filament.

[0018] Figure 4B is a view that schematically shows a state in which a molding material obtained by melting the filament is ejected from a nozzle that is not shown onto a molding surface, and is a view that shows a cross section in a radial direction of the filament. Figure 4A is a schematic top view shown by a part of a cross section in a top view.

[0019] Figure 5 is an explanatory view that schematically shows a twist direction in a case where the reinforcing fiber of the fiber bundle in the filament is Z-twisted.

[0020] Figure 6is an explanatory diagram schematically showing a twisting direction of the reinforcing fiber of the fiber bundle in the filament in a case where the reinforcing fiber of the fiber bundle in the filament is provided to be S twisted.

[0021] Figure 7 is an explanatory diagram showing a direction in which the reinforcing fiber of the fiber bundle in the build material at the same nozzle position is rotated in its arrangement position with the transport of the filament after being Z twisted.

[0022] Figure 8 is an explanatory diagram showing a direction in which the reinforcing fiber of the fiber bundle in the build material at the same nozzle position is rotated in its arrangement position with the transport of the filament after being S twisted.

[0023] Figure 9 is an explanatory diagram showing a case where the moving direction of the head is clockwise and a case where the moving direction of the head is counterclockwise in a case where the reinforcing fiber is Z twisted.

[0024] Figure 10 is an explanatory diagram showing a case where the moving direction of the head is clockwise and a case where the moving direction of the head is counterclockwise in a case where the reinforcing fiber is S twisted. DETAILED DESCRIPTION

[0025] Hereinafter, an embodiment relating to the present application will be described in detail with reference to the drawings. First, the structure of a 3D printer as a layered object forming apparatus will be simply described. Here, the structure of an FDM (Fused Deposition Modeling) method is exemplified, but is not limited thereto, and other methods can be used.

[0026] <Structure of Layered Object Forming Apparatus> Figure 1 is a schematic structural diagram of a layered object forming apparatus 100 of the FDM method. The layered object forming apparatus 100 is provided with a filament transport section 13 that transports a continuous fiber reinforced resin filament 11 (hereinafter also referred to as a filament), a head 15, a work table 17, a forming drive section 19, and a control section 21.

[0027] The filament transport section 13 is provided with a pair of drive rollers 13a that sandwich the filament 11, and a drive section (not shown) such as a motor that rotationally drives at least one of the drive rollers 13a. The head 15 has a not-shown heating section that heat-fuses the transported filament 11, and a nozzle 15a that discharges the build material obtained by the fusion of the heating section. In addition, although not shown, a cutting section such as a cutter, a laser cutting device, or the like that cuts the reinforcing fiber included in the filament 11 can be provided in the head 15.

[0028] The table 17 has a molding surface 17a configured opposite to the nozzle 15a of the head 15, and stacks the molded object. The molding drive unit 19 relatively moves the head 15 and the table 17, and forms the molding material ejected from the nozzle 15a of the head 15 along a desired route. The table 17 driven by the molding drive unit 19 can also be configured with a two-axis drive mechanism that moves the head 15 in the plane of the molding surface 17a of the table 17, and a lifting mechanism that drives the table 17 up and down to adjust the stacking height, for example. In this configuration, the table 17 and the molding drive unit 19 function as a drive mechanism that relatively moves the nozzle 15a of the head 15 with respect to the molding surface 17a. In addition, the drive mechanism can be a mechanism that moves the head 15 with the table 17 as a fixed side, or a mechanism that moves the table 17 and the head 15 together.

[0029] The control unit 21 has a function of controlling the transport of the wire 11 by the wire transport unit 13 and the relative movement of the head 15 by the drive mechanism, and a function of comprehensively controlling the other units. To the control unit 21, a molding program that controls each unit including the wire transport unit 13 and the molding drive unit 19 is input, and the control unit 21 executes the input molding program, whereby a molded object of a desired shape is stacked and molded.

[0030] The control unit 21 is configured by hardware using an information processing device such as a PC (Personal Computer). Each function of the control unit 21 is realized by a processor such as a CPU (Central Processing Unit), an MPU (Micro Processor Unit), or a dedicated circuit, or a control device that reads out and executes a program stored in a storage device not shown and having a specific function. As the storage device, a memory such as a RAM (Random Access Memory) as a volatile storage area, a ROM (Read Only Memory) as a non-volatile storage area, a HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like can be exemplified. The control unit 21 can also be another computer connected to the stacked molding device 100 via a network or the like from a remote place, in addition to the above-described configuration.

[0031] <Method for manufacturing molded object> In the layered forming apparatus 100 of this structure, the control unit 21 outputs a drive signal to the filament conveying unit 13, which drives the drive roller 13a to rotate, conveying the filament 11 to the head 15 at a specified conveying speed. The head 15 heats the conveyed filament 11 to melt it. Then, the control unit 21 outputs a drive signal to the forming drive unit 19, causing the head 15 and the worktable 17 to move relative to each other, while the forming material melted by the head 15 is ejected from the nozzle 15a.

[0032] In a structure where the head 15 is fixed and the worktable 17 is movable, the worktable 17 is driven so that the nozzle 15a of the head 15 moves relative to the shape of the object being shaped, following a shaping path created according to the shape of the object. As a result, new shaping material is ejected from the nozzle 15a along the shaping path and layered onto the shaping surface 17a of the worktable 17 or onto the previous layer (already-established layer) of shaping material. This creates an object of the desired shape. The shaping process includes information on the aforementioned shaping path, the conveying speed of the filament 11, and other information on various shaping conditions required for shaping. The control unit 21 reads this information on shaping conditions from the aforementioned shaping process and shapes the object by layering the shaping material in specified steps.

[0033] <Structure of Silk> Next, the structure of the filament 11 used in the above-described layered forming device 100 will be explained.

[0034] Figure 2A This is a schematic cross-sectional view of wire 11 in the radial direction orthogonal to the axial direction. Figure 2B This is a side view of wire 11 along its axial direction. In the following description, the description is simplified or omitted by assigning the same reference numerals to the same parts or parts.

[0035] like Figure 2A and Figure 2B As shown, the filament 11 is a linear resin material used as a shaping material in a 3D printer such as the aforementioned lamination shaping apparatus 100. The filament 11 consists of a fiber bundle 23 containing continuous fibers (hereinafter also referred to as "reinforcing fibers") impregnated with a thermoplastic matrix resin 25, and a matrix resin 27 is formed on the radially outer side of the fiber bundle 23 to cover it at a predetermined thickness. These matrix resins 25 and 27 (hereinafter also referred to as "resin") form the base material of the filament 11. The matrix resins 25 and 27 can be thermoplastic resins, thermosetting resins, photocurable resins, or other resin materials, or a mixture of multiple materials, in addition to thermoplastic resins. The fiber bundle 23 within the filament 11 is arranged along the filament central axis O and is given a twist centered on the filament central axis O.

[0036] The diameter of the filament 11 is preferably 0.5 mm or more and 1 mm or less; the finer the diameter, the more accurately the fine shapes of the object can be reproduced. Furthermore, the fiber bundle 23 preferably contains 1500 to 6000 continuous fibers. In this case, the continuous fibers are arranged at a high density in the object, which can significantly improve the strength of the object. However, the above numerical range is just one example and is not a limitation.

[0037] If the twist rate of the continuous fibers in the fiber bundle 23 along the axial direction of the filament 11 is set to 20 times / m or more and 100 times / m or less, then when forming in the forming direction as described later, a stable fiber opening increase effect and a forming accuracy improvement effect will be achieved. A twist rate more preferably is 25 times / m or more, and even more preferably 30 times / m or more. Furthermore, a twist rate more preferably is 80 times / m or less, and even more preferably 70 times / m or less.

[0038] Among the reinforcing fibers constituting fiber bundle 23, organic fibers such as polyethylene fiber, aramid fiber, and diurnal fiber, as well as inorganic fibers such as boron fiber, glass fiber, carbon fiber, metal fiber, and rock fiber, can be used. In order to improve the bond strength between the resin and the fiber, surface-treated fibers can be used among the reinforcing fibers.

[0039] Fiber bundle 23 can also be like Figure 2A It can be formed by one bundle as shown, but it can also be an aggregate of multiple fiber bundles. In this case, the reinforcing fibers for each fiber bundle can be twisted together or each fiber bundle can be twisted separately.

[0040] Examples of materials for matrix resins 25 and 27, where the main component is a thermoplastic resin, include polyolefin resins such as polypropylene or polyethylene, acrylonitrile-butadiene-styrene resin, polystyrene resin, polyethylene terephthalate, polybutylene terephthalate or polylactic acid, polyester resins such as polyamide resins, aromatic polyamide resins, polyetherimide, polyarylimide, polyaryl ester, polyetheretherketone, polyaryletherketone, polybenzimidazole, polyethersulfone, polysulfone, polyvinylidene fluoride resin, liquid crystal polymers, polycarbonate resins, polyacetal or polyphenylene sulfide, etc.

[0041] These thermoplastic resins can be used alone as a resin, or a thermoplastic resin in which a plurality of resins are mixed can be used in order to improve the heat resistance, heat distortion temperature, heat aging, tensile properties, bending properties, creep properties, compression properties, fatigue properties, impact properties, and sliding properties of the thermoplastic resin. As an example of the thermoplastic resin, polyether ether ketone resin (PEEK) / polytetrafluoroethylene (PTFE), PEEK / polybenzimidazole (PBI), and the like can be given. In addition, the thermoplastic resin can be a material in which short fibers such as carbon fibers and glass fibers, talc, and the like are added to a resin.

[0042] In addition, an antioxidant such as a phenol-based, thioether-based, or phosphite-based antioxidant, an ultraviolet absorber such as a benzotriazole-based or triazine-based ultraviolet absorber, a metal deactivator such as a hydrazide-based or amide-based metal deactivator, and the like can be added to the thermoplastic resin, and the durability of the shaped object can be improved.

[0043] If a plasticizer such as a phthalic acid-based or polyester-based plasticizer is added to the thermoplastic resin, the softness is improved, and the shaping accuracy at the time of shaping and the softness of the shaped object can be improved.

[0044] If a flame retardant such as a halogen-based, phosphate-based, inorganic-based, or intumescent-based flame retardant is added to the thermoplastic resin, the flame retardancy of the shaped object can be improved.

[0045] If a core material such as a phosphate metal salt-based or sorbitol-based core material is added to the thermoplastic resin, the thermal expansion at the time of shaping can be controlled, and the shaping accuracy can be improved.

[0046] If a permanent antistatic agent such as a nonionic-based, anionic-based, or cationic-based permanent antistatic agent is added to the thermoplastic resin, the antistatic properties of the shaped object can be improved.

[0047] By adding a lubricant such as a hydrocarbon-based or metal soap-based lubricant to the thermoplastic resin, the lubricity of the continuous fiber reinforcement filament is improved, and the filament can be smoothly fed at the time of shaping.

[0048] <Method of manufacturing the filament> The reinforcing fiber of the fiber bundle 23 of the filament 11 used in the above-described 3D printer is imparted with a twist, and the orientation angle of the reinforcing fiber is inclined with respect to the axial direction. An example of the method of manufacturing the filament 11 will be described. Note that the structure of the filament manufacturing apparatus shown here is an example, and is not limited thereto.

[0049] Figure 3 is a schematic structural view of a filament manufacturing apparatus 200.

[0050] The filament manufacturing apparatus 200 includes a fiber material supply section 31, a mixing extruder 33, a resin bath section 35, a cooling section 37, and a twisting section 39.

[0051] The fiber material supply section 31 feeds out one or a plurality of fiber bundles 23 wound in a coil shape at a predetermined speed. The mixing extruder 33 internally has a hollow chamber 33a in which a screw (not shown) having mixing blades is rotatably provided, and melts and plasticizes resin poured from a hopper 33b. The resin bath section 35 impregnates the resin plasticized by the mixing extruder 33 into the fiber bundle 23 fed out from the fiber material supply section 31. The cooling section 37 is provided on the downstream side of the resin bath section 35, and cools the composite 41 fed out from the resin bath section 35. The twisting section 39 imparts twisting around the center of the axis to the fiber bundle 23 mainly before cooling.

[0052] The resin bath section 35 is formed in a cylindrical shape with the axis direction oriented upward. Inside the cylinder, the resin 43 plasticized by the mixing extruder 33 is supplied and stored. The upper end portion of the resin bath section 35 is open, and the fiber bundle 23 guided by the guide roller 45 is drawn in from the opening of the upper end portion with respect to the resin 43 stored in the resin bath section 35.

[0053] Inside the resin bath section 35, a plurality of impregnation rollers (not shown) are rotatably held with the axis oriented in the horizontal direction. The fiber bundle 23 introduced from the opening of the upper end portion of the resin bath section 35 is sequentially mounted on each of the impregnation rollers and is transported to the outlet section 47 provided at the lower end portion of the resin bath section 35. At the outlet section 47, a die 49 is provided which shapes the outer periphery of the filament 11 when the composite 41 of the resin 43 and the fiber bundle 23 is drawn out to the outside of the resin bath section 35. The die 49 can form grooves, ridges, or the like on the outer peripheral surface of the filament 11 depending on the shape of the opening thereof.

[0054] The cooling section 37 is a long-size water tank provided along the direction in which the composite 41 is drawn out from the resin bath section 35, and stores cooling water 51 in the tank. In this cooling section 37, the resin impregnated into the fiber bundle 23 of the composite 41 is cooled in the cooling water 51, and is solidified.

[0055] The twisting section 39 is provided on the downstream side of the cooling section 37, and has an upper and lower pair of drawing rollers 53, 55 which contact each other. The twisting section 39 can employ various mechanisms in addition to the structure of the drawing rollers 53, 55. For example, although not shown, a mechanism can be employed in which a bobbin winding the filament 11 is rotated around the axis of the filament 11.

[0056] The drawing rollers 53, 55 have a function of drawing the fiber bundle 23 from the fiber material supply section 31 into the resin bath section 35, and further drawing the composite 41 from the resin bath section 35 into the cooling section 37 and the twisting section 39. Furthermore, on the downstream side of the twisting section 39, a winding section (not shown) such as a bobbin is provided separately, and the manufactured filament 11 is wound.

[0057] The manufacturing steps of the filament 11 using the filament manufacturing apparatus 200 described above are as follows.

[0058] (Immersion process) The impregnation process is performed by the resin bath 35 of the filament manufacturing apparatus 200. Specifically, resin supplied from the hopper 33b is mixed using a mixing extruder 33, and the molten resin is stored in the resin bath 35. Fiber bundles 23 are supplied to the resin bath 35 from the fiber material supply section 31. Then, the amount of resin impregnation is adjusted by passing the fiber bundles 23 impregnated with molten resin in the resin bath 35 through a mold 49 disposed at the outlet section 47. Through this resin impregnation, a state is achieved where matrix resin exists in the gaps within the fiber bundles 23 and around the radially outer side of the fiber bundles 23. The resulting composite 41 of matrix resin and fiber bundles 23 is cooled using a cooling section 37.

[0059] (Twisting process) In the twisting process, the twisting section 39 twists the fiber bundle 23, which is impregnated with resin in the resin bath section 35. Specifically, while rotating the pull rollers 53 and 55 of the twisting section 39, the composite 41, after passing through the cooling section 37, passes between the pull rollers 53 and 55. As a result, the continuous fibers of the fiber bundle 23 are twisted. By adjusting the tilt angle of the pull rollers 53 and 55 relative to the pulling direction, the number of twists and the twist angle can be adjusted.

[0060] By impregnating a matrix resin 25 containing thermoplastic resin onto a fiber bundle 23 disposed along the central axis O of the filament, a filament 11 is obtained in which the matrix resin 27 is formed on the outer periphery of the radially outer side of the fiber bundle 23 in such a way that the fiber bundle 23 is covered. In addition, when manufacturing the filament 11, the fiber bundles supplied from the multiple fiber material supply sections 31 can be twisted individually or the fiber bundles can be twisted together.

[0061] <Fiber bundle opening state during shaping> When shaping an object using the aforementioned filament 11 by means of thermal melting and lamination, if the twist number of the reinforcing fiber of the fiber bundle 23 is large, the opening width of the fiber bundle 23 ejected from the nozzle 15a is prone to decrease or become unstable depending on the shape of the shaping path.

[0062] Figure 4A , Figure 4B This diagram schematically illustrates how a nozzle (not shown) ejects the molten material from wire 11 onto the shaping surface. Figure 4A This is an explanatory diagram showing the vertical cross-section of wire 11. Figure 4B It is Figure 4A A schematic top view showing a partial cross-section from above. For example... Figure 4AAs shown, filament 11 is released and supplied in the vertical direction, and molten shaping material is sprayed onto the shaping surface 17a along the shaping direction WD. Fiber bundles 23 within the shaping material are as follows... Figure 4B As shown, the fiber is opened to a width W that is wider than the width W0 of the filament 11 before melting.

[0063] When the twist number of the reinforcing fibers in fiber bundle 23 is large, insufficient fiber opening may occur after the shaping material is ejected. In this case, Figure 1 If the bonding between the shaping surface 17a or the substrate of the worktable 17 shown and the shaping material becomes incomplete, or if the reinforcing fibers are unevenly dispersed during shaping, it will affect the strength of the shaped object. Therefore, during shaping, it is preferable to eject the shaping material while untwisting the twisted fiber bundles 23.

[0064] The opening state of fiber bundle 23 varies depending on the twist number of the reinforcing fibers of the original fiber bundle 23 and the orientation of the forming route (forming direction). Among the twisting directions, Z twist and S twist are generally known.

[0065] Figure 5 This is an explanatory diagram schematically showing the twisting direction when the reinforcing fibers of the fiber bundle 23 within the filament 11 are twisted in a Z-shape. Figure 6 This diagram schematically illustrates the twisting direction when the reinforcing fibers of the fiber bundle 23 within the filament 11 are twisted in an S-shape. Figure 5 , Figure 6 The state in which the three long fibers are twisted in a spiral along the central axis O of the filament is represented together with the layers L1 to L6 of each cross section along the length direction of the filament 11 (fiber bundle 23).

[0066] exist Figure 5 In the case of Z-twist shown, the nozzle 15a in the vertical direction can be considered as being in front of the wire conveying direction FD. Figure 1 The extrusion side of the filament 11. In this case, if the filament 11 is fed to the nozzle 15a, the reinforcing fiber at the position of the nozzle 15a rotates to the left. That is, as the filament 11 is fed to the nozzle 15a, layers L1 to L6 of the filament 11 are arranged sequentially from the extrusion position of the nozzle 15a. In this case, if we focus on a specific fiber F, when the fiber F reaches the position of the nozzle 15a from the position of the fiber F in layer L1 as the filament 11 is fed, the position of the fiber F moves counterclockwise. Then, if the feeding of the filament 11 progresses to layers L3 to L6, the arrangement of the fibers F in each layer rotates counterclockwise around the filament central axis O.

[0067] Similarly, in Figure 6In the case of S-twisting of the reinforcing fiber of the fiber bundle 23, the arrangement of the fiber F in each layer is rotated in the clockwise direction with the center axis O of the filament 11 as the center along with the conveyance of the filament 11.

[0068] Figure 7 is an explanatory view showing the direction in which the reinforcing fiber of the fiber bundle 23 at the same nozzle position is rotated in its arrangement position along with the conveyance of the filament 11 in the case of Z-twisting of the reinforcing fiber. Figure 8 is an explanatory view showing the direction in which the reinforcing fiber of the fiber bundle 23 at the same nozzle position is rotated in its arrangement position along with the conveyance of the filament 11 in the case of S-twisting of the reinforcing fiber.

[0069] In the case of Z-twisting of the reinforcing fiber of the fiber bundle 23 as shown in Figure 7 , the twisted reinforcing fiber is continuously supplied in the position of the nozzle 15a while being rotated in the counterclockwise direction along with the conveyance of the filament 11. Further, in the case of S-twisting as shown in Figure 8 , the twisted reinforcing fiber of the fiber bundle 23 is continuously supplied in the position of the nozzle 15a while being rotated in the clockwise direction along with the conveyance of the filament 11.

[0070] The reinforcing fiber twisted as described above is supplied from the nozzle 15a while being rotated at the time of molding. Next, the relationship between the direction of rotation (twisting direction) of the reinforcing fiber and the molding direction WD will be described.

[0071] Figure 9 is an explanatory view showing the case where the moving direction of the head 15 is the clockwise (bending to the right side) molding route PS_R and the case where it is the counterclockwise (bending to the left side) molding route PS_L in the case of Z-twisting of the reinforcing fiber. In the case of Z-twisting, in the molding direction of the molding route PS_L, since the bending is made in the same direction as the direction of twisting of the reinforcing fiber (counterclockwise), the twisting of the reinforcing fiber is difficult to be released, and thus the fiber opening is difficult. On the other hand, in the molding direction of the molding route PS_R, since the bending is made in the direction opposite to the direction of twisting of the reinforcing fiber (counterclockwise), the twisting of the reinforcing fiber is easily released. Therefore, in the case of Z-twisting, if the molding direction is set to the direction of the molding route PS_R, the good fiber opening state shown in Figure 4B is easily obtained.

[0072] Figure 10is a view showing a case where the moving direction of the head 15 is clockwise (bending to the right side) in the case of S-twisted reinforcing fiber, and a case where the moving direction of the head 15 is counterclockwise (bending to the left side) in the case of S-twisted reinforcing fiber. In the case of S-twisted reinforcing fiber, in the molding direction of the molding route PS_R, since the fiber is bent in the same direction as the twisting direction (clockwise) of the reinforcing fiber, the twisting of the reinforcing fiber is difficult to be released, and thus the fiber is difficult to be separated. On the other hand, in the molding direction of the molding route PS_L, since the fiber is bent in the opposite direction to the twisting direction (clockwise) of the reinforcing fiber, the twisting of the reinforcing fiber is easily released. Therefore, in the case of S-twisted reinforcing fiber, if the molding direction is set to the direction of the molding route PS_L, the good separated state shown in FIG. 6 is easily obtained. Figure 4B

[0073] The curvature radius of the bend of the molding route is preferably set to be larger than the width W0 of the molding material (the width of the fiber bundle 23) so that the molding materials discharged from the nozzles 15a do not overlap each other. For example, the curvature radius of the bend of the molding route is preferably 1.5 mm or more, more preferably 2 mm or more, and still more preferably 2.5 mm or more. Further, the upper limit of the curvature radius is a value at which the molding materials do not overlap each other. In addition, in the present specification, the "bend" is expressed as "bend" in the case where the length of the bent portion of the molding route is very short, but in either case, the preferred molding direction becomes the same direction. Figure 4B

[0074] That is, the control section 21 sets the molding route in which the fiber bundle 23 is bent or bent to the left side while the molding material is discharged toward the front direction of the molding direction on the molding surface 17a in the case of Z-twisted reinforcing fiber, and sets the molding route in which the fiber bundle 23 is bent or bent to the right side while the molding material is discharged toward the front direction of the molding direction on the molding surface 17a in the case of S-twisted reinforcing fiber. In this way, the molding curved shape or the bent shape is formed. The control section 21 can set the above-described molding route according to the used yarn 11, or can set the molding program in advance so as to switch the above-described molding route according to the used yarn 11.

[0075] For example, the operator determines or a sensor or the like automatically determines whether the yarn 11 used in the laminated molding apparatus 100 is Z-twisted or S-twisted. The determination result is input to the control section 21. The control section 21 sets the molding route of the preferred molding direction according to the determination result. Specifically, the control section 21 can selectively use a certain molding route to perform molding by preparing the molding route in the case of Z-twisted reinforcing fiber and the molding route in the case of S-twisted reinforcing fiber in the molding program in advance, respectively. Embodiment

[0076] ​​Here, using a plurality of filaments having different structures, molding was performed along a molding route that was curved in the same direction as the twisting direction of the reinforcing fiber of the fiber bundle and the opposite direction thereof. Then, the opening width of the reinforcing fiber in the filament-shaped molded material, and the circularity of the circular molded article produced in a circular molding route were evaluated. The structures of the respective filaments and the evaluation results thereof are shown in Table 1.

[0077] [Table 1]

[0078] In Test Examples Al, A2, and Test Example Bl, as the thermoplastic resin, UBE Nilon (registered trademark) 1010X1 (manufactured by UBE Incorporated) was used, and as the reinforcing fiber, one fiber bundle composed of 1500 of TAIRYFIL TC-33 (manufactured by FORMOSA PLASTICS CORPORATION) was used, and a fiber-reinforced resin filament (cross-sectional diameter 0.5 mm) having a fiber content of 40 mass% was produced.

[0079] In the production of the fiber-reinforced resin filament, a filament production device 200 as shown in FIG. 1 was used. The fiber material was impregnated in the thermoplastic resin in a molten state, and by adjusting the inclination angle of the pulling direction of the pair of pulling rollers 53, 55 of the twisting portion 39 with respect to the composite 41, the twisting angle θ (refer to FIG. 2) and the number of twists N per 1 m in the above-described composite 41 were respectively set. Figure 1 Figure 1 In the production of the fiber-reinforced resin filament, a filament production device 200 as shown in FIG. 1 was used. The fiber material was impregnated in the thermoplastic resin in a molten state, and by adjusting the inclination angle of the pulling direction of the pair of pulling rollers 53, 55 of the twisting portion 39 with respect to the composite 41, the twisting angle θ (refer to FIG. 2) and the number of twists N per 1 m in the above-described composite 41 were respectively set.

[0080] In Test Example Al, twisting was imparted in such a manner that the twisting angle θ was 3° and the number of twists N was 33 times / m, in Test Example A2, twisting was imparted in such a manner that the twisting angle θ was 7° and the number of twists N was 78 times / m, and in Test Example Bl, twisting was imparted in such a manner that the twisting angle θ was 10° and the number of twists N was 112 times / m. In this way, the filaments of Test Examples Al, A2, and Test Example Bl were formed.

[0081] In Test Examples Al, A2, and Test Example Bl, as the thermoplastic resin, UBE Nilon (registered trademark) 1010X1 (manufactured by UBE Incorporated) was used, and as the reinforcing fiber, one fiber bundle composed of 1500 of TAIRYFIL TC-33 (manufactured by FORMOSA PLASTICS CORPORATION) was used, and a fiber-reinforced resin filament (cross-sectional diameter 0.5 mm) having a fiber content of 40 mass% was produced.

[0082] In addition, by adjusting the inclination angle of the pulling direction of the pair of pulling rollers 53, 55 with respect to the composite 41, the above-described twisting angle θ and the number of twists N in the composite 41 were respectively set.

[0083] ​In test example A3, a twist angle θ of 3° and a twist number N of 24 twists / m were applied. In test example A4, a twist angle θ of 7° and a twist number N of 56 twists / m were applied. In test example B2, a twist angle θ of 13° and a twist number N of 105 twists / m were applied. In this way, the filaments of test examples A3, A4, and B2 were formed.

[0084] In Test Examples A5, A6, and B3, the same thermoplastic resin and filament manufacturing apparatus 200 as in Test Examples A1, A2, and B1 were used. A fiber bundle consisting of 6000 PYROFIL (registered trademark) TR50S 6L (manufactured by Mitsubishi Chemical Corporation) fibers was used as the reinforcing fiber. This produced a fiber-reinforced resin filament (1 mm cross-sectional diameter) with a fiber content of 40% by mass.

[0085] Furthermore, similarly to the above, the twist angle θ and twist number N in the composite 41 are respectively set. In test example A5, a twist angle θ of 6° and a twist number N of 33 times / m are given; in test example A6, a twist angle θ of 10° and a twist number N of 56 times / m are given; and in test example B3, a twist angle θ of 20° and a twist number N of 116 times / m are given. In this way, the filaments of test examples A5, A6, and B3 are formed.

[0086] (Evaluation of fiber opening ability) Use the various silks obtained as Figure 1 The filament used in the 3D printer, as shown, produces a single-layer model under conditions of a nozzle temperature of 260°C, a stage temperature of 60°C, and a printing speed of 5 mm / sec. This model is created using a curved model (modeling path) with a circular shape and a radius of 5 mm. Regarding the fiber opening width of the reinforcing fibers, the circular model created on the modeling surface is photographed using a laser microscope, and measurements are taken based on the photographed images. Specifically, using image processing software, the radial width of the reinforcing fibers within the model is measured at multiple locations along the circumference of the model, and the average value is set as the fiber opening width. Then, the fiber opening width is compared along each modeling direction (printing direction) of the clockwise or counterclockwise curved modeling path. If an increase in fiber opening width is confirmed due to setting the modeling direction as the direction of release of the twisting of the reinforcing fibers, the direction superiority is indicated as "yes"; otherwise, the direction superiority is indicated as "no".

[0087] Further, in a case where the curvature radius of the curved shape of the shaping route is, for example, smaller than 2.5 mm, which is a radius of 1 / 2 of the diameter of the filament, the reproducibility of the shape of the curved shape model set decreases because the curvature radius of the shaping route is too close to the width of the opening. Therefore, the evaluation is limited to a case where the curvature radius of the curved shape (bend) of the shaping route is larger than the diameter of the filament. Further, the maximum width that can be taken by the width of opening corresponds to the entire width of the shaping material on the shaping surface when the shaping material obtained by heat melting the base resin 25, 27 included in the filament 11 is ejected from the nozzle 15a and expands on the shaping surface in a direction orthogonal to the shaping direction.

[0088] (Evaluation of Shaping Precision) With respect to the shaped object whose opening property was evaluated as described above, the roundness of the outer periphery and the inner periphery of the circular shape was calculated using the aforementioned laser microscope and image processing software, respectively, and the average of the inner periphery and the outer periphery was found. The average of the roundness found was compared between a case where the shaping direction (printing direction) was curved clockwise and a case where the shaping direction was curved counterclockwise, and the shaping precision was evaluated in accordance with the magnitude of the deviation from the circular track (circular shaping route) set. The direction superiority was expressed as "Yes" in a case where the improvement effect of the shaping precision resulting from setting the shaping direction to the direction of release of the twist of the reinforcing fiber was confirmed, and the direction superiority was expressed as "No" in a case where the improvement effect of the shaping precision was not confirmed.

[0089] (Evaluation Results) As a result, in Test Examples Al to A5 and Test Examples Bl to B3, the measurement result in the shaping direction curved in the direction of release of the twist was larger than the measurement result in the shaping direction curved in the direction of the twist with respect to the width of opening. With respect to the roundness, in Test Examples Al to A5, the measurement result in the shaping direction curved in the direction of release of the twist was larger than the measurement result in the shaping direction curved in the direction of the twist. On the other hand, in Test Examples Bl to B3, the measurement result in the shaping direction curved in the direction of release of the twist was smaller than the measurement result in the shaping direction curved in the direction of the twist.

[0090] According to the results described above, in a case where the filament is shaped in a curved shape or a bent shape in which the twist of the reinforcing fiber of the fiber bundle is imparted 20 times or more and 100 times or less per 1 m, as in Test Examples Al to A6, the opening property can be improved without decreasing the shaping precision by shaping in a direction curved or bent in a direction opposite to the direction of the twist of the reinforcing fiber of the fiber bundle of the filament. That is, the adhesion of the shaped materials to each other after being shaped by the shaping routes adjacent to each other is improved, the adhesion between the layers is also improved in a case where the shaped body is a multilayer structure, and it is shown that the strength of the shaped object can be suppressed from decreasing while maintaining a high shape precision.

[0091] The present application is not limited to the above-described embodiments, and various modifications, applications, and changes of the configurations of the embodiments, which are made by those skilled in the art based on the description of the present specification and known technologies, are intended to be included in the scope of the present application.

[0092] As described above, the following matters are disclosed in the present specification.

[0093] (1) A layering molding method of causing a molding material obtained by heating and melting a continuous fiber-reinforced filament in a linear shape to be discharged from a nozzle along a molding route on a molding surface, and molding a curved shape or a bent shape on the aforementioned molding surface; the aforementioned continuous fiber-reinforced filament has a base material containing a thermoplastic resin and at least one fiber bundle containing continuous fibers impregnated in the aforementioned base material and extending in an axial direction; the aforementioned continuous fibers of the aforementioned fiber bundle are twisted at 20 times / m or more and 100 times / m or less with the center of the axis of the aforementioned continuous fiber-reinforced filament; in a case where the aforementioned fiber bundle is Z-twisted, the aforementioned molding route on the aforementioned molding surface is set to a route in which the aforementioned molding material is discharged while being curved or bent toward the right side in a forward direction of a molding direction; in a case where the aforementioned fiber bundle is S-twisted, the aforementioned molding route on the aforementioned molding surface is set to a route in which the aforementioned molding material is discharged while being curved or bent toward the left side in the forward direction of the molding direction, and the aforementioned curved shape or the aforementioned bent shape is molded.

[0094] According to the layering molding method, when molding is performed by using a molding material obtained by melting a continuous fiber-reinforced filament having a fiber bundle, the opening property can be improved without causing a decrease in molding accuracy by molding in a direction opposite to the twisting direction of the continuous fibers of the fiber bundle. In particular, if the number of twists of the continuous fibers is 20 times / m or more and 100 times / m or less, the effect becomes significant. As a result, the adhesion between adjacent molding materials can be improved, and a decrease in the strength of the molded article can be suppressed.

[0095] (2) The layering molding method according to (1), wherein a radius of curvature of the curved shape or the bent shape is larger than a width of the aforementioned molding material, which is orthogonal to the molding direction, that is discharged onto the aforementioned molding surface.

[0096] According to the layering molding method, the molding material discharged from the nozzle does not overlap, and a high molding accuracy can be maintained.

[0097] (3) The layering molding method according to (1) or (2), wherein the aforementioned fiber bundle contains 1500 or more and 6000 or less continuous fibers.

[0098] According to the layering molding method, since the continuous fibers are arranged at a high density in the molded article, the strength of the molded article can be sufficiently improved.

[0099] (4) The layered molding method according to any one of (1) to (3), wherein the continuous fiber-reinforced filament has a diameter of 0.5 mm or more and 1 mm or less.

[0100] According to the layered molding method, a fine shape of a molded object can be accurately reproduced.

[0101] (5) A layered molding apparatus comprising a head that ejects a molded material obtained by heating and melting a continuous fiber-reinforced filament in a thread form from a nozzle, a drive mechanism that relatively moves the nozzle of the head with respect to a molding surface, and a control section that drives the drive mechanism to cause the molded material to be ejected along a set molding route; the continuous fiber-reinforced filament includes a base material including a thermoplastic resin and at least one fiber bundle including continuous fibers that are impregnated in the base material and extend in an axial direction; the continuous fibers of the fiber bundle are twisted at 20 twists / m or more and 100 twists / m or less around an axial center of the continuous fiber-reinforced filament; and when the control section molds a curved shape or a bent shape on the molding surface, in a case where the fiber bundle is Z-twisted, the control section sets the molding route on the molding surface so as to be curved or bent to a right side in a forward direction of a molding direction while causing the molded material to be ejected, and in a case where the fiber bundle is S-twisted, the control section sets the molding route on the molding surface so as to be curved or bent to a left side in the forward direction of the molding direction while causing the molded material to be ejected, and molds the curved shape or the bent shape.

[0102] According to the layered molding apparatus, when molding is performed by using a molded material obtained by melting a continuous fiber-reinforced filament having a fiber bundle, the opening property can be improved without degrading the molding accuracy by molding in a direction opposite to a twisting direction of the continuous fibers of the fiber bundle. In particular, if the number of twists of the continuous fibers is 20 twists / m or more and 100 twists / m or less, the effect becomes significant. As a result, the adhesion between adjacent molded materials can be improved, and the strength of the molded object can be suppressed from being degraded.

[0103] (6) A program that executes the following layering molding step: causing a molding material obtained by heating and melting a continuous fiber-reinforced filament to be ejected from a nozzle along a molding route on a molding surface to mold a curved shape or a bent shape on the molding surface; the continuous fiber-reinforced filament having a base material including a thermoplastic resin and at least one fiber bundle including a continuous fiber impregnated in the base material and extending in an axial direction; the continuous fiber of the fiber bundle being twisted at 20 twists / m or more and 100 twists / m or less around the axis of the continuous fiber-reinforced filament; and causing a computer to execute the following steps: in a case where the fiber bundle is Z-twisted, setting the molding route on the molding surface to be a route along which the molding material is ejected while being curved or bent to the right in a forward direction of a molding direction; in a case where the fiber bundle is S-twisted, setting the molding route on the molding surface to be a route along which the molding material is ejected while being curved or bent to the left in the forward direction of the molding direction; and molding the curved shape or the bent shape.

[0104] According to the program, when molding is performed using a molding material obtained by melting a continuous fiber-reinforced filament having a fiber bundle, the fiber opening property can be improved without degrading the molding accuracy by molding in a direction opposite to the twisting direction of the continuous fiber of the fiber bundle. In particular, if the number of twists of the continuous fiber is 20 twists / m or more and 100 twists / m or less, the effect becomes significant. As a result, the adhesion between adjacent molding materials can be improved, and the strength of the molded article can be suppressed from degrading.

[0105] In addition, the present application is based on Japanese Patent Application (Japanese Patent Application No. 2023-103557) filed on June 23, 2023, the content of which is incorporated herein by reference in its entirety.

[0106] Explanation of Reference Signs 11 Filament (continuous fiber-reinforced resin filament) 13 Filament conveying section 13a Drive roller 15 Head 15a Nozzle 17 Work table 17a Molding surface 19 Shaping drive section 21 Control section 23 Fiber bundle 25 Base resin 27 Base resin 31 Fiber material supply section 33 Homogenizing extruder 33a Chamber 33b Hopper 35 Resin bath section 37 cooling section 39 twisting section 41 composite body 43 resin 45 guide roller 47 outlet section 49 mold 51 cooling water 53, 55 pulling roller 100 layering molding apparatus 200 filament manufacturing apparatus

Claims

1. A layering molding method of causing a molding material obtained by heating and melting a continuous fiber-reinforced filament in a linear shape to be ejected from a nozzle along a molding route on a molding surface, and molding a curved shape or a bent shape on the molding surface, characterized in that the continuous fiber-reinforced filament has a base material containing a thermoplastic resin and at least one fiber bundle containing continuous fibers impregnated in the base material and extending in an axial direction; the continuous fibers of the fiber bundle are twisted at 20 twists / m or more and 100 twists / m or less around a center axis of the continuous fiber-reinforced filament; in a case where the fiber bundle is twisted in a Z twist, the molding route on the molding surface is set to a route in which the molding material is caused to be ejected while being curved or bent to a right side in a forward direction of a molding direction, and in a case where the fiber bundle is twisted in an S twist, the molding route on the molding surface is set to a route in which the molding material is caused to be ejected while being curved or bent to a left side in the forward direction of the molding direction, and the curved shape or the bent shape is molded.

2. The layering molding method according to claim 1, characterized in that a radius of curvature of the curved shape or the bent shape is larger than a width of the molding material in a direction orthogonal to the molding direction, which is ejected onto the molding surface.

3. The layering molding method according to claim 1 or 2, characterized in that the fiber bundle contains 1,500 or more continuous fibers and 6,000 or less continuous fibers.

4. The layering molding method according to claim 1 or 2, characterized in that a diameter of the continuous fiber-reinforced filament is 0.5 mm or more and 1 mm or less.

5. A layering molding apparatus provided with a head that ejects a molding material obtained by heating and melting a continuous fiber-reinforced filament in a linear shape from a nozzle, a drive mechanism that relatively moves the nozzle of the head with respect to a molding surface, and a control section that drives the drive mechanism to cause the molding material to be ejected along a set molding route, characterized in that the continuous fiber-reinforced filament has a base material containing a thermoplastic resin and at least one fiber bundle containing continuous fibers impregnated in the base material and extending in an axial direction; the continuous fibers of the fiber bundle are twisted at 20 twists / m or more and 100 twists / m or less around a center axis of the continuous fiber-reinforced filament; and the control section, when molding a curved shape or a bent shape on the molding surface, sets the molding route on the molding surface to a route in which the molding material is caused to be ejected while being curved or bent to a right side in a forward direction of a molding direction in a case where the fiber bundle is twisted in a Z twist, and sets the molding route on the molding surface to a route in which the molding material is caused to be ejected while being curved or bent to a left side in the forward direction of the molding direction in a case where the fiber bundle is twisted in an S twist, and molds the curved shape or the bent shape.

6. A program that executes a layering molding step of causing a molding material obtained by heating and melting a continuous fiber-reinforced filament in a linear shape to be ejected from a nozzle along a molding route on a molding surface, and molding a curved shape or a bent shape on the molding surface, characterized in that ​ ​ ​ ​ ​ ​ ​ ​ ​ The aforementioned continuous fiber-reinforced yarn has a base material containing a thermoplastic resin and at least one fiber bundle containing continuous fibers impregnated in the aforementioned base material and extending in the axial direction; The aforementioned continuous fiber of the aforementioned fiber bundle is twisted at 20 twists / m or more and 100 twists / m or less around the axis of the aforementioned continuous fiber-reinforced yarn; The computer is caused to execute the following steps: in the case where the aforementioned fiber bundle is Z-twisted, the aforementioned shaping route on the aforementioned shaping surface is set to a route in which the aforementioned shaping material is ejected while being bent or folded to the right side in the forward direction of the shaping direction, and in the case where the aforementioned fiber bundle is S-twisted, the aforementioned shaping route on the aforementioned shaping surface is set to a route in which the aforementioned shaping material is ejected while being bent or folded to the left side in the forward direction of the shaping direction, and the aforementioned bent shape or the aforementioned folded shape is shaped.

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