Injection molding machine and injection molding method for fiber-reinforced resin

Abstract

To provide an injection molding machine for fiber-reinforced resin and an injection molding method for fiber-reinforced resin that can improve productivity and reduce waste materials.SOLUTION: The injection molding machine for fiber-reinforced resin has a heating cylinder 11 for melting resin, a screw 12 inserted into the heating cylinder 11, a hopper for feeding resin into the heating cylinder 11, a feed box 13B for feeding long fibers L into the heating cylinder 11, and an adhesive spraying unit 21 for assisting contact between the molten resin M melted in the heating cylinder 11 and the long fibers L fed into the heating cylinder 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus for injection molding a fiber-reinforced resin and a method for injection molding a fiber-reinforced resin. [Background technology]

[0002] Conventionally, a direct injection molding machine is known in which resin and long fibers are directly fed into a heating cylinder (heating barrel), melt-kneaded, and injection-molded without melt-kneading the resin and long fibers in advance.

[0003] Patent Document 1 describes an apparatus for manufacturing fiber-reinforced plastic molded products, which includes a heating barrel, a screw inserted inside the heating barrel, an injection section provided at the tip side of the screw, a resin feeding section for feeding matrix resin inside the heating barrel, a long fiber feeding section for feeding long fibers inside the heating barrel, and a short fiber feeding section for feeding short fibers shorter than the long fibers inside the heating barrel. Here, in the apparatus for manufacturing fiber-reinforced plastic molded products, the short fiber feeding section is closer to the rear end of the screw than the long fiber feeding section. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-138851 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the manufacturing apparatus for fiber-reinforced plastic molded products described in Patent Document 1, it may be difficult for multiple long fibers to come into contact with the molten resin in the heating barrel, resulting in reduced productivity and increased waste material.

[0006] An object of the present invention is to provide an injection molding apparatus and an injection molding method for fiber reinforced resin that can improve productivity and reduce waste materials. [Means for solving the problem]

[0007] (1) An injection molding apparatus for fiber-reinforced resin comprising: a heating cylinder for melting resin; a screw inserted into the heating cylinder; a resin feeding section for feeding the resin into the heating cylinder; a long fiber feeding section for feeding long fibers into the heating cylinder; and an assist section for assisting contact between the resin molten in the heating cylinder and the long fibers fed into the heating cylinder.

[0008] (2) The fiber-reinforced resin injection molding apparatus according to (1), wherein the long fiber input section is provided downstream of the resin input section.

[0009] (3) The fiber-reinforced resin injection molding apparatus according to (1) or (2), wherein the long fiber input section inputs a plurality of the long fibers into the heating cylinder.

[0010] (4) The fiber-reinforced resin injection molding apparatus according to (3), wherein the assist unit sprays adhesive onto the multiple long fibers fed into the heating cylinder.

[0011] (5) The fiber-reinforced resin injection molding apparatus according to (3), wherein the assist unit ejects hot melt adhesive onto some of the multiple long fibers fed into the heating cylinder.

[0012] (6) The fiber-reinforced resin injection molding device according to any one of (1) to (3), wherein the assist unit ejects compressed air onto the long fibers fed into the heating cylinder.

[0013] (7) The fiber-reinforced resin injection molding apparatus according to any one of (1) to (3), wherein the assist unit guides the long fibers fed into the heating cylinder with a guide plate.

[0014] (8) The fiber-reinforced resin injection molding apparatus according to any one of (1) to (3), wherein the assist section sucks the long fibers and assists contact of the long fibers with the resin molten in the heating cylinder.

[0015] (9) The long fiber input section is provided with a rod-shaped member to which the long fibers can be attached and detached, The fiber-reinforced resin injection molding device according to any one of (1) to (3), wherein the assist unit moves a rod-shaped member to which the long fibers are attached to assist contact with the resin molten in the heating cylinder.

[0016] (10) The fiber-reinforced resin injection molding apparatus according to any one of (1) to (9), wherein the long fiber input section is provided with a conveying member that conveys the long fibers.

[0017] (11) A method for injection molding a fiber-reinforced resin, comprising the steps of: introducing resin into a heating cylinder through which a screw is inserted and melting the resin; introducing long fibers into the heating cylinder; and assisting contact between the resin molten in the heating cylinder and the long fibers introduced into the heating cylinder. Effect of the Invention

[0018] According to the present invention, it is possible to provide an injection molding apparatus and an injection molding method for fiber reinforced resin that can improve productivity and reduce waste materials. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a schematic diagram showing an example of a fiber reinforced resin injection molding apparatus according to the present embodiment. [Diagram 2] FIG. 2 is a partially enlarged cross-sectional view of the fiber-reinforced resin injection molding apparatus of FIG. [Diagram 3] 3 is a cross-sectional view for explaining the operation of the adhesive spray unit in FIG. 2. [Figure 4] 3 is a cross-sectional view for explaining the operation of the adhesive spray unit in FIG. 2. [Diagram 5] 2 is a partially enlarged cross-sectional view of a modified example of the fiber-reinforced resin injection molding apparatus of FIG. 1. [Figure 6] 6 is a cross-sectional view for explaining the operation of the hot melt adhesive discharge portion of FIG. 5. FIG. [Figure 7]6 is a cross-sectional view for explaining the operation of the hot melt adhesive discharge portion of FIG. 5. FIG. [Figure 8] 6 is a cross-sectional view for explaining the operation of the hot melt adhesive discharge portion of FIG. 5. FIG. [Figure 9] 2 is a partially enlarged cross-sectional view of a modified example of the fiber-reinforced resin injection molding apparatus of FIG. 1. [Figure 10] 2 is a partially enlarged cross-sectional view of a modified example of the fiber-reinforced resin injection molding apparatus of FIG. 1. [Figure 11] FIG. 11 is a partially enlarged cross-sectional view of a modified example of the fiber-reinforced resin injection molding apparatus of FIG. [Figure 12] 2 is a partially enlarged cross-sectional view of a modified example of the fiber-reinforced resin injection molding apparatus of FIG. 1. [Figure 13] FIG. 13 is a partially enlarged cross-sectional view of a modified example of the fiber-reinforced resin injection molding apparatus of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] [Fiber reinforced resin injection molding equipment] FIG. 1 shows an injection molding machine 10 as an example of an injection molding device for a fiber reinforced resin according to this embodiment.

[0022] The injection molding machine 10 is a direct injection molding machine including a heating cylinder 11 for melting resin and a screw 12 inserted into the heating cylinder 11. The heating cylinder 11 is provided with a hopper 13A as a resin input section for inputting resin into the heating cylinder 11, and an input box 13B as a long fiber input section for inputting a plurality of long fibers into the heating cylinder 11. The resin melted in the heating cylinder 11 is transported from the upstream side to the downstream side of the heating cylinder 11 by the rotation of the screw 12. Although the input box 13B is provided downstream of the hopper 13A, the input box 13B does not have to be provided downstream of the hopper 13A as long as the long fiber input into the heating cylinder 11 can be brought into contact with the resin melted in the heating cylinder 11. A single long fiber may be input from the input box 13B. Furthermore, short fiber may be input together with the resin from the hopper 13A.

[0023] The injection molding machine 10 further includes a nozzle (injection port) 14 for injecting the molten mixture (fiber reinforced resin) produced in the heating cylinder 11, and a mold 15 for molding the molten mixture injected from the nozzle 14. A substantially cone-shaped area capable of accommodating the tip of the screw 12 is formed near the nozzle 14 of the heating cylinder 11. The mold 15 is composed of a fixed mold and a movable mold.

[0024] 2, the injection molding machine 10 is provided with an adhesive spraying unit 21 on the upper surface of the feeding box 13B as an assisting unit that assists contact between the molten resin M melted in the heating cylinder 11 and the long fibers L fed into the heating cylinder 11. The adhesive spraying unit 21 sprays an adhesive A onto the long fibers L. An example of a commercially available product of the adhesive spraying unit 21 is the automatic spray gun SGA-3 series (manufactured by Anest Iwata).

[0025] The injection molding machine 10 includes a plurality of tubes 22 that guide a plurality of long fibers L drawn from a plurality of rovings R to the input box 13B, and an adhesive spraying unit 21 is disposed between adjacent tubes 22 in the input box 13B. At this time, compressed air supply units 23 and 24 are disposed on the upstream and downstream sides of the plurality of tubes 22. The compressed air supply units 23 and 24 are conveying members that supply compressed air to convey the long fibers L vertically upward and vertically downward, respectively. An example of a commercially available product of the compressed air supply units 23 and 24 is Vacuum Flow (manufactured by SMC).

[0026] As shown in Fig. 3, when the adhesive spraying unit 21 sprays the adhesive A onto a plurality of long fibers L fed into the heating cylinder 11, adhesiveness is imparted to the surfaces of the long fibers L. As a result, after adhesion, the plurality of long fibers L come into contact with the molten resin M adhering to the screw 12, and as a result, are wound around the screw 12, as shown in Fig. 4.

[0027] If the adhesive spray section 21 is not installed in the injection molding machine 10, it may be difficult for the multiple long fibers L to come into contact with the molten resin M adhering to the screw 12, resulting in reduced productivity and increased waste material.

[0028] Furthermore, in the injection molding machine 10, if the compressed air supply unit 24 is not provided downstream of the multiple tubes 22, for example, the rotation of the screw 12 is temporarily stopped, multiple long fibers L are manually fed into the heating cylinder 11, and then the rotation of the screw 12 is resumed to wind the multiple long fibers L around the screw 12. At this time, the manual work needs to be repeated until all of the long fibers L fed into the heating cylinder 11 are wound around the screw 12, which reduces productivity and increases waste materials.

[0029] The adhesive A is not particularly limited as long as it can be sprayed onto the long fibers L and can impart adhesion to the surface of the long fibers L. Commercially available products of the adhesive A include, for example, Super G Spray Z (manufactured by Konishi) and RQ-NVN2 (manufactured by Aica Kogyo).

[0030] The resin constituting the molten resin M is not particularly limited, but may be, for example, polyimide.

[0031] The fibers constituting the long fibers L and the short fibers are not particularly limited, but examples thereof include glass fibers, carbon fibers, and aramid fibers.

[0032] The fibers constituting the long fibers L and the short fibers may be the same or different.

[0033] In the injection molding machine 10, instead of providing the adhesive spray unit 21 on the top surface of the input box 13B, a hot melt adhesive discharge unit 51 may be provided on the upstream side of the input box 13B with respect to the rotation direction of the screw 12 (see FIG. 5). The hot melt adhesive discharge unit 51 discharges the hot melt adhesive H onto some of the multiple long fibers L. In this case, an example of a commercially available hot melt adhesive discharge unit 51 is the electric hot melt gun TE-m12 (manufactured by SANYO LIFE MATERIALS).

[0034] As shown in Fig. 6, when the hot melt adhesive discharge part 51 discharges the hot melt adhesive H at a discharge angle α onto some of the multiple long fibers L fed into the heating cylinder 11, the long fibers L bonded by the hot melt adhesive H come into contact with the molten resin M adhering to the screw 12, and as a result, start to wind around the screw 12, as shown in Fig. 7. Next, as shown in Fig. 8, the remaining parts of the long fibers L are guided by the long fibers L that have started to wind around the screw 12 to come into contact with the molten resin M adhering to the screw 12, and as a result, the multiple long fibers L wind around the screw 12.

[0035] The material constituting the hot melt adhesive H is not particularly limited as long as it is capable of adhering a portion of the long fibers L, but examples thereof include polyamide, polyolefin, ethylene vinyl acetate copolymer, and acrylic resin.

[0036] The viscosity of the hot melt adhesive H is not particularly limited as long as it can be discharged onto a portion of the long fibers L, but is, for example, 1000 cps or more and 17000 cps or less.

[0037] The discharge angle α is not particularly limited as long as it is possible to bond a portion of the long fibers L, and is, for example, 25° or more and 45° or less.

[0038] In the injection molding machine 10, instead of providing the adhesive spray unit 21 on the top surface of the feeding box 13B, a compressed air discharge unit 91 may be provided on the upstream side of the feeding box 13B with respect to the rotation direction of the screw 12 (see FIG. 9). The compressed air discharge unit 91 discharges compressed air C to the multiple long fibers L. In this case, an example of a commercially available compressed air discharge unit 91 is the rechargeable air duster AS001GZ (manufactured by Makita).

[0039] When the compressed air discharge section 91 discharges compressed air C at a discharge angle β toward multiple long fibers L fed into the heating cylinder 11, the multiple long fibers L are guided by the compressed air C to come into contact with the molten resin M adhering to the screw 12, and as a result, they are wrapped around the screw 12.

[0040] The discharge angle β is not particularly limited as long as the plurality of long fibers L can come into contact with the molten resin M, and is, for example, 25° or more and 45° or less.

[0041] In the injection molding machine 10, instead of providing the adhesive spraying unit 21 on the upper surface of the feeding box 13B, a guide plate 101 may be provided on the upstream side of the feeding box 13B with respect to the rotation direction of the screw 12 at an inclination angle γ (see FIG. 10). The guide plate 101 guides the multiple long fibers L. A movable guide plate capable of moving in the inclined direction may be used as the guide plate 101.

[0042] When a plurality of long fibers L are fed into the heating cylinder 11 , the plurality of long fibers L are guided by the guide plate 101 so as to come into contact with the molten resin M adhering to the screw 12 , and as a result, are wound around the screw 12 .

[0043] The inclination angle γ is not particularly limited as long as the multiple long fibers L can come into contact with the molten resin M, but is, for example, 15° or more and 45° or less.

[0044] In Fig. 10, an electric rotary roller 111 may be provided instead of the compressed air supply unit 24 (see Fig. 11). The electric rotary roller 111 is a conveying member that conveys the long fibers L vertically downward by rotating. The electric rotary roller 111 may be applied to an injection molding machine 10 other than that shown in Fig. 10.

[0045] In the injection molding machine 10, instead of providing the compressed air supply unit 24 and providing the feeding box 13B in the heating cylinder 11, a feeding port 121 may be formed and a suction unit 122 for assisting contact between the resin molten in the heating cylinder 11 and the long fibers L fed into the heating cylinder 11 may be provided in the heating cylinder 11 (see FIG. 12). In the suction unit 122, a suction path 122a is formed downstream of the heating cylinder 11 with respect to the feeding port 121, and the long fibers L are sucked by a suction pump 122b. At this time, the long fibers L are sucked vertically upward in the suction path 122a and vertically downward in the feeding port 121. Therefore, the multiple long fibers L are sucked from the feeding port 121 toward the suction path 122a in the space between the heating cylinder 11 and the screw 12, and come into contact with the molten resin M attached to the screw 12.

[0046] In Fig. 12, instead of providing the suction section 122 on the heating cylinder 11, a rod-shaped member 131 to which the long fibers L can be detachably attached may be provided at the inlet 121 (see Fig. 13). The rod-shaped member 131 is supported by a support member 132 and can be moved vertically by, for example, a motor. At this time, when the rod-shaped member 131 to which the long fibers L are attached is moved vertically downward, it comes into contact with the molten resin M adhering to the screw 12. On the other hand, when the rod-shaped member 131 is moved vertically upward, the long fibers that have come into contact with the molten resin M are detached from the rod-shaped member 131.

[0047] The rod-shaped member 131 is not particularly limited as long as the long fiber L can be attached and detached. For example, the tip may be provided with heat-resistant rubber, or a recess may be formed in the tip.

[0048] [Method of fiber-reinforced resin injection molding] The fiber-reinforced resin injection molding method of the present embodiment includes the steps of feeding a resin into a heating cylinder through which a screw is inserted and melting the resin, feeding long fibers into the heating cylinder, and assisting contact between the resin melted in the heating cylinder and the long fibers fed into the heating cylinder. Here, the fiber-reinforced resin injection molding method of the present embodiment can be carried out using the fiber-reinforced resin injection molding device of the present embodiment.

[0049] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and the above embodiment may be modified as appropriate within the scope of the present invention. For example, any of the adhesive spray unit 21, the hot melt adhesive discharge unit 51, the compressed air discharge unit 91, and the guide plate 101 may be used in combination. [Explanation of symbols]

[0050] 10 injection molding machine 11 Heating cylinder 12 Screw 13A Hopper 13B Input Box 14 Nozzles 15 Mold 21 Adhesive spray section 22 Tube 23, 24 Compressed air supply section 51 Hot melt adhesive discharge section 91 Compressed air discharge section 101 Guide plate 111 Electric rotating roller 121 Inlet 122 Suction part 121a Suction path 121c Suction Pump 131 Rod-shaped member 132 Support member A Adhesive C. Compressed air H Hot melt adhesive L Long Fiber M Molten Resin R Roving

Claims

1. A heating cylinder for melting the resin; A screw inserted into the heating cylinder; a resin supply unit that supplies the resin to the heating cylinder; a long fiber input section for inputting long fibers into the heating cylinder; an assist unit that assists contact between the resin molten in the heating cylinder and the long fibers introduced into the heating cylinder.

2. 2. The fiber reinforced resin injection molding apparatus according to claim 1, wherein the long fiber input section is provided downstream of the resin input section.

3. 3. The fiber-reinforced resin injection molding apparatus according to claim 1, wherein the long fiber input unit inputs a plurality of the long fibers into the heating cylinder.

4. The fiber reinforced resin injection molding device according to claim 3 , wherein the assist unit sprays an adhesive onto the plurality of long fibers fed into the heating cylinder.

5. The fiber reinforced resin injection molding device according to claim 3 , wherein the assist unit ejects the hot melt adhesive onto some of the plurality of long fibers fed into the heating cylinder.

6. 3. The fiber-reinforced resin injection molding apparatus according to claim 1, wherein the assist unit ejects compressed air onto the long fibers fed into the heating cylinder.

7. 3. The fiber-reinforced resin injection molding apparatus according to claim 1, wherein the assist section guides the long fibers fed into the heating cylinder with a guide plate.

8. 3. The fiber-reinforced resin injection molding device according to claim 1, wherein the assist section sucks the long fibers to assist contact of the long fibers with the resin molten in the heating cylinder.

9. a rod-shaped member to which the long fibers can be detachably attached is provided in the long fiber input section, 3. The fiber-reinforced resin injection molding apparatus according to claim 1, wherein the assist section moves a rod-shaped member to which the long fibers are attached, to assist contact with the resin molten in the heating cylinder.

10. 3. The fiber-reinforced resin injection molding apparatus according to claim 1, wherein the long fiber input section is provided with a conveying member that conveys the long fibers.

11. A step of pouring resin into a heating cylinder through which a screw is inserted and melting the resin; feeding long fibers into the heating cylinder; and assisting contact between the resin molten in the heating cylinder and the long fibers introduced into the heating cylinder.

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