Method and apparatus for manufacturing two-color molded products

Abstract

This invention provides a technology to suppress the decrease in yield during the molding of two-color molded products. [Solution] The first slide piece 21 forms the undercut portion 11, and when the first slide piece 21 is released from the mold, the second slide piece 22 supports the seal part 10.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing a two-color molded product.

Background Art

[0002] Generally, a two-color molded product formed by a primary molded product and a secondary molded product is formed by injecting a secondary molding resin into a secondary cavity formed by a movable mold that holds the primary molded product and a secondary molding mold after the primary molded product is molded.

[0003] For example, when it is desired to provide a complex shape such as a hole on the side surface of a molded product, it is common to use a slide piece that is driven in a direction orthogonal to the mold opening and closing direction. In this case, molding is performed with the slide piece advanced, and after molding, the slide piece is retracted and then the mold is opened to take out the molded product.

[0004] Patent Document 1 discloses a configuration for stably operating a slide piece in molding.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, an undercut shape may be formed in the slide piece. In this case, if the molded product formed by the slide piece is an elastic part, when the slide piece is pulled out from the undercut part, the part may be deformed or damaged, or peeling may occur at the interface with the molded product of another resin in two-color molding.

[0007] Figures 14(a) to (c) show the case in which the elastic component 1402 is molded by two-color molding by sliding the slide piece 1401 using the method described in Patent Document 1. As shown in Figure 14(a), the elastic component 1402 is molded by resin injection with the slide piece 1401 inserted into the molded product, and after molding, the slide piece 1401 is pulled out downwards as shown in Figure 14(b). At this time, the elastic component 1402 deforms and separates from the slide piece 1401 due to the undercut portion 1400, but as shown in Figure 14(c), peeling may occur at the interface 1404 between the molded product 1403 molded with a different resin and the elastic component 1402. If peeling occurs at the interface 1404 between the molded product 1403 and the elastic component 1402, the product will not function properly as a two-color molded product, and the yield may decrease.

[0008] Therefore, the present invention provides a technology to suppress the decrease in yield in the molding of two-color molded products. [Means for solving the problem]

[0009] Therefore, the present invention provides a method for manufacturing a two-color molded product, comprising: a first injection step of injecting a first resin into a mold; and a second injection step performed before or after the first injection step of injecting a second resin, which becomes an elastic body after molding, into the mold, wherein the method further comprises: a first slide step after the first and second injection steps of moving a first slide piece, which forms part of the cavity of the mold, in a direction of movement different from the opening and closing direction of the mold; and a second slide step after the first slide step of moving a second slide piece, which forms part of the cavity of the mold, in the direction of movement, wherein the first and second injection steps form an undercut portion with the first slide piece, and the second slide piece restricts the movement of the molded product of the second resin in the direction of movement during the first slide step. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a technique for suppressing a decrease in yield in the molding of two-color molded products. [Brief explanation of the drawing]

[0011] [Figure 1] This is an exploded perspective view of a recording head used in a recording device. [Figure 2] This is a perspective view showing the main body of the circulation unit. [Figure 3] This is a cross-sectional view showing a magnified portion of the main body. [Figure 4] This is a schematic diagram of a typical two-color injection molding machine. [Figure 5] This diagram shows a slide insert used in two-color molding. [Figure 6] This diagram shows the surface of the movable piece that aligns with the fixed piece used for secondary molding. [Figure 7] This is a cross-sectional view of a mold used when forming body parts in secondary molding. [Figure 8] This is a cross-sectional view of a mold used when forming body parts in secondary molding. [Figure 9] This is a cross-sectional view of a mold used when forming body parts in secondary molding. [Figure 10] This is a cross-sectional view of a mold used when forming body parts in secondary molding. [Figure 11] This is a cross-sectional view of a mold used when forming body parts in secondary molding. [Figure 12] This diagram shows the gate position of the sealing component. [Figure 13] This diagram shows a seal component as an example. [Figure 14] This diagram shows the result of molding using a conventional method. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings.

[0013] FIG. 1 is an exploded perspective view of a recording head 100 used in a recording apparatus. The recording head 100 is connected to a recording apparatus main body via a main body connection member 2, and ink supplied from the recording apparatus main body to the recording head 100 is distributed for each color by a flow path member 3 via a circulation unit 1 and ejected from a recording element substrate 5. The circulation unit 1 is housed inside the flow path member 3 and covered by an upper surface cover 8. The presence of the circulation unit 1 enables ink circulation through the circulation unit 1, the flow path member 2, and the recording element substrate 5. Ink is supplied to a recording element substrate 5 supported by a support member 4 and covered by a lower surface cover 6, and the supplied ink is ejected based on a signal supplied from an electric wiring substrate 7. In the present disclosure, the circulation unit 1 of the recording head 100 is molded by two-color molding.

[0014] FIG. 2 is a perspective view showing a main body portion 101 constituting the circulation unit 1. The main body portion 101 is composed of a body component 9 and an elastic seal component 10, and four seal components 10 are incorporated in the body component 9. The four seal components 10 function to suppress ink leakage at connection ports for supplying and recovering ink between the main body connection member 2 or the flow path member 3 and the circulation unit 1.

[0015] FIG. 3 is a cross-sectional view showing an enlarged part of the main body portion 101. A ring-shaped seal component 10 is incorporated inside an opening formed in the body component 9. The circulation unit 1 is incorporated into the recording head 100 by inserting a connection portion of the main body connection member 2 or the flow path member 3 inside the body component 9 through the opening of the seal component 10. At this time, the seal component 10 needs to ensure sealing performance by elastic force in order to prevent leakage of fluids such as ink. Therefore, it is common to employ a member that can be injection-molded and has elasticity, such as an elastomer. With this configuration, fastening members such as screws can be reduced as much as possible, enabling miniaturization of the recording head 100.

[0016] While it is possible to mold the body part 9 and then incorporate an elastic O-ring as a sealing part, this would require equipment for incorporating the O-ring, and there is a possibility of problems such as contamination by foreign matter during assembly or deterioration of sealing performance due to foreign matter. Therefore, by molding the body part 9 and the sealing part 10 using two-color molding, the process can be completed within the same mold, thus eliminating the aforementioned concerns. In particular, for products that handle liquids, such as recording heads, there are significant material constraints on the components that come into contact with the ink, and the requirements for sealing performance are high. For this reason, material-based solutions are difficult to implement, and it is necessary to address these issues through manufacturing methods.

[0017] In the two-color molding shown in Figure 3, when removing the molded product, it is necessary to pull out a slide piece (not shown) located in the undercut portion 11 to the left in the figure while compressing the seal component 10. In Figure 3, the undercut portion corresponds to the space (enclosed by the dashed line) that is located inside the body component 9 and is larger than the inner circumference of the seal component 10. When removing the slide piece (not shown) located in the undercut portion 11, the slide piece in the undercut portion 11 deforms the seal component 10 as it passes through the inner circumference of the seal component 10. In this case, there is a risk that the slide piece may damage the seal component 10 or that the compatible portion between the body component 9 and the seal component 10 may peel off. If peeling occurs at the interface between the body component 9 and the seal component 10, liquid leakage will occur from the peeled portion, impairing the function of the circulation unit 1.

[0018] Here, using Figure 4, a conventional two-color injection molding machine will be described. The mold has a fixed mold 12 and a movable mold 13 that can be opened and closed. Primary molding is performed by clamping the mold with a fixed primary molding piece 14 attached to the fixed mold 12 and a movable mold piece 15 attached to the movable mold 13 facing the fixed mold 12, and injecting the primary molding resin from the first gate 16. After primary molding, when the mold opens, separating the fixed mold 12 and the movable mold 13 in the opening and closing direction, the primary molded product is held by the movable mold piece 15. After that, the movable mold 13 is moved to the secondary molding section, the mold is closed again, and secondary molding is performed by injecting the secondary molding resin from the second gate 18 using the secondary molding fixed mold piece 17 and the movable mold piece 15.

[0019] This method is merely one example. Here, the movable piece 15 is shown moving parallel to the vertical direction in the diagram, but a configuration in which the movable mold to which the movable piece 15 is attached rotates relative to the fixed mold is also widely known. As long as the piece moves within the mold, it can also be moved linearly on the mold using an air cylinder or the like. Furthermore, there are various methods, such as enabling primary and secondary molding at multiple locations and providing a piece for each, allowing primary and secondary molding to proceed simultaneously at each location.

[0020] Figure 5 shows the movement of the slide piece after secondary molding in the two-color molding of this embodiment. In the figure, the fixed and movable molds are omitted, and only the slide piece inside the mold is shown in a simplified manner. In this embodiment, a first slide piece 21 and a second slide piece 22 are provided. Figure 5(a) shows the state in which the body part 9 and the seal part 10 have been molded with the first slide piece 21 and the second slide piece 22 inserted. Figure 5(b) shows the state after Figure 5(a), with the first slide piece 21 removed in the α direction. In this embodiment, the seal part 10 is molded using the first slide piece 21 and the second slide piece 22. The first slide piece 21 and the second slide piece 22 form part of the cavity in the mold. The first slide piece 21 and the second slide piece 22 are configured to be individually slid in the α direction (multi-stage sliding) (movable). Here, after secondary molding, the first slide piece 21 is slid out in the α direction, and then the second slide piece 22 is slid in the α direction.

[0021] When the first slide piece 21 is slid, the second slide piece 22 partially supports the seal component 10, thereby suppressing deformation of the seal component 10 in the α direction. When the first slide piece 21 slides in the α direction, a force in the α direction acts on the seal component 10 from the first slide piece 21 as the portion of the first slide piece 21 at the undercut portion 11 passes through the seal component 10. This causes a force to act on the mating portion 500 of the body component 9 and the seal component 10 in a direction that peels the seal component 10 away from the body component 9. However, the second slide piece 22 restricts the movement of the seal component 10 in the α direction, thereby suppressing the force acting on the mating portion 500. This suppresses deformation of the seal component 10 when the first slide piece 21 is withdrawn and prevents peeling at the mating portion 500 between the body component 9 and the seal component 10. Once the sliding of the first slide piece 21 is complete, the sliding of the second slide piece 22 in the α direction is started. Since the second slide piece 22 is not located in an undercut position and is only in contact with the seal part 10, it can slide without deforming the seal part 10.

[0022] Figure 6 is a perspective view showing the joint surface between the movable mold 13 and the fixed mold 12 in the manufacturing apparatus 600 of this embodiment. In the manufacturing apparatus 600, multiple slides are provided on the side that is not in the mold opening / closing direction in order to form complex shapes such as holes. The manufacturing apparatus 600 is equipped with a normal slide 19 and a multi-stage slide 20. The normal slide 19 performs a normal (single-stage) slide, and the multi-stage slide 20 performs a multi-stage slide (two stages in this embodiment). The multi-stage slide 20 includes a first slide piece 21 that forms the undercut portion 11 and a second slide piece 22 that forms other shapes. The first slide piece 21 and the second slide piece 22 can slide independently in a multi-stage slide. In Figure 6, there are two multi-stage slides 20, but here we will focus on one of the multi-stage slides 20 (located on the left side in the figure) and explain the movement of the slide at each operating timing in a series of injection molding sequences in each cross-section.

[0023] Figures 7 to 11 are enlarged views illustrating the movement of the multi-stage slide 20 during secondary molding. Figures 7 to 11 show the same part but at different timings of secondary molding. In each figure, (a) is a cross-sectional view at A in Figure 6, and (b) is a cross-sectional view at B in Figure 6. Figures 7 to 11 also show cross-sections at various timings when the sealing part 10 is formed in primary molding and then the body part 9 is formed in secondary molding. Here, an example of forming the sealing part 10 in primary molding is described, but the body part 9 may be formed in primary molding and the sealing part 10 in secondary molding.

[0024] Figures 7(a) and 7(b) show the state when mold clamping has started in secondary molding. The figures show the state in which the lower movable mold 13 moves toward the upper fixed mold 12. More specifically, these are cross-sections at the moment when the second angular cam 24 provided on the fixed mold 12 contacts the second slide piece 22 provided on the movable mold 13 during operation. Here, an angular cam is a part that has an inclined portion at its tip relative to the opening and closing direction of the mold, and the inclined portion of the angular cam allows the movement of the slide piece of the movable mold. On the other hand, the portion of the angular cam parallel to the opening and closing direction of the mold holds the slide piece. When the distance between the fixed side piece 17 and the movable side piece 15 for secondary molding shortens due to the mold clamping operation, the inclined portion of the second angular cam 24 causes the first slide piece 21 and the second slide piece 22 to start moving in the -α direction.

[0025] Figures 8(a) and 8(b) show cross-sections at the point when the mold clamping has progressed further from Figure 7 and the first angular cam 23 has contacted the claw component 25 of the first slide piece 21. The claw component 25 has a structure that retracts to avoid obstructing the movement of parts moving in the mold clamping direction, but does not retract to parts moving in the mold opening direction. Therefore, the first angular cam 23 prevents the first slide piece 21 from moving in the mold clamping direction, but it does move in the mold opening direction. The inclined portion of the second angular cam 24 has caused the first slide piece 21 and the second slide piece 22 to move in the -α direction, and at this point they have finished moving and are held by the straight portion (parallel portion parallel to the opening and closing direction) of the second angular cam 24.

[0026] Figures 9(a) and (b) show cross-sections at the time when mold clamping is complete. Upon completion of mold clamping, the inclined portion of the first angular cam 23 comes into contact with the inclined portion of the first slide piece 21, and the first angular cam 23 and the second angular cam 24 hold the first slide piece 21 and the second slide piece 22 in place. In this state, secondary molding (molding of the body part 9) is performed to complete the two-color molded product.

[0027] Figures 10(a) and (b) show cross-sections at the time when the mold opening is started after the completion of secondary molding, the first angular cam 23 contacts the claw part 25 of the first slide piece 21, and the first slide piece 21 is moved in the α direction. As mentioned above, when the mold is opened, the claw part 25 is fixed, so the claw part 25 slides along the inclined part of the first angular cam 23, causing the first slide piece 21 to move in the α direction and retract from the part forming the undercut. At this time, the second slide piece 22 is held in place by the straight part of the second angular cam 24, preventing it from moving and holding the seal part 10 from deforming. Therefore, it is possible to suppress deformation of the seal part 10 in the α direction when the first slide piece 21 comes out of the undercut part 11 (see Figure 3), thereby preventing damage to the seal part 10 and peeling of the compatible part 500 (see Figure 5) between the body part 9 and the seal part 10.

[0028] Figures 11(a) and (b) show cross-sections at the time when mold opening is complete. The inclined portion of the second angular cam 24 moves the second slide piece 22 in the α direction, and when mold opening is complete, the first slide piece 21 and the second slide piece 22 return to their initial positions. After the next primary molding is performed, the above sequence is repeated to produce a two-color molded product.

[0029] In a circulation unit 1 like the one in this embodiment, the seal component 10 is generally made of elastomer, and the body component 9 is made of a wide variety of resins, such as polypropylene. When the resin of the body component 9 comes into contact with the seal component 10 molded in the primary molding process, they tend to bond strongly due to thermal compatibility and the anchoring effect at the contact point. On the other hand, the molding difficulty tends to increase, such as the resin of the body component 9 seeping into the interior of the seal component 10. These tendencies become stronger the higher the melting temperature of the body component 9 is compared to the melting temperature of the material of the seal component 10.

[0030] In contrast, when the body part 9 is molded in primary molding and the seal part 10 is molded in secondary molding, the body part 9 has already cooled to some extent and has a smooth surface by the time of secondary molding, so the bonding strength with the seal part 10 tends to be weaker. Also, since elastomer materials generally have a low melting point, resin inflow into the body part 9 is often minimal, so the molding difficulty tends to be low.

[0031] The order in which molded products are formed in primary and secondary molding depends on the type of molding resin, molding conditions, part shape, and required bonding strength, and should therefore be selected appropriately. Furthermore, although this embodiment describes a configuration in which the slide piece moves perpendicular to the mold opening and closing direction (in the direction of movement), it is not limited to this. The driving direction of the slide piece can be other than perpendicular to the mold opening and closing direction, and it is also possible to arrange the two-color molded section at an angle on the side of the product.

[0032] Figure 12 shows the gate 26 position of the seal component 10 in this embodiment. In this embodiment, the seal component 10 is molded by injecting resin in the mold opening direction, which is the vertical direction in the figure.

[0033] Due to the mold's configuration, it is easy to place the gate on the side of the ring shape, in the direction in which the resin is injected in the mold opening direction, which is also advantageous for the product. In terms of the flow of molded resin, the inner circumference of the ring shape is filled first, and the outer circumference is the final part to be filled. Generally, slight filling defects called welds are prone to occur in the final filling area of ​​the resin. In other words, with the method of this embodiment, welds are likely to form on the outer circumference of the seal part 10.

[0034] If weld material forms on the inner circumference of the sealing part 10, a gap will be created between it and the mating part that is pressed against it, potentially leading to a deterioration in sealing performance and a risk of leakage. Therefore, by placing the gate on the ring-shaped side surface of the sealing part 10, as in this embodiment, weld material is less likely to form on the inner circumference, reducing the likelihood of defects.

[0035] Figure 13 shows a seal component with a different gate position than that of this embodiment, as a comparative example. When manufacturing a seal component as a single unit, the gate 26 is usually arranged as shown in Figure 13. In this case, the resin flow on the outer and inner circumferences of the seal component tends to occur almost simultaneously, and weld lines are more likely to form on the inner circumference as well.

[0036] In this embodiment, we have described a multi-stage slide in which two slide pieces are slid in stages, but the invention is not limited to this, and a configuration in which even more slide pieces are slid in stages is also possible.

[0037] In this way, the first slide piece 21 forms the undercut portion 11, and when the first slide piece 21 is released from the mold, the elastic sealing part 10 is supported by the second slide piece 22. This provides a technology that suppresses a decrease in yield in the molding of two-color molded products.

[0038] This embodiment includes the following methods and configurations.

[0039] (Method 1) A first injection step in which the first resin is injected into a molding die, A second injection step, performed before or after the first injection step, in which a second resin, which becomes an elastic body after molding, is injected into the molding die, A method for manufacturing a two-color molded product, A first sliding step is performed after the first injection step and the second injection step, in which a first slide piece, which forms part of the cavity of the molding die, is moved in a direction different from the opening and closing direction of the molding die, The process further includes a second sliding step, in which a second slide piece, which forms part of the cavity of the molding die, is moved in the direction of movement, after the first sliding step. The first injection step and the second injection step form an undercut portion on the first slide piece. A method for manufacturing a two-color molded product, characterized in that, during the first sliding step, the movement of the molded product of the second resin in the direction of movement is restricted by the second slide piece.

[0040] (Method 2) The molding die comprises a first mold having the first slide piece and the second slide piece, and a second mold provided opposite the first mold. In the first sliding step, as the first mold and the second mold separate in the opening and closing direction, the first slide piece moves in the moving direction due to the action of the first angular cam provided on the second mold. In the second sliding step, the second slide piece moves in the moving direction due to the action of a second angular cam provided on the second mold as the first mold and the second mold separate in the opening and closing direction, according to the method for manufacturing a two-color molded product as described in Method 1.

[0041] (Method 3) In the first sliding step, the inclined portion of the first angular cam and the inclined portion of the first slide piece slide against each other, causing the first slide piece to move. The method for manufacturing a two-color molded product according to Method 2, wherein in the second sliding step, the inclined portion of the second angular cam and the inclined portion of the second slide piece slide against each other, thereby moving the second slide piece.

[0042] (Method 4) When the first mold and the second mold are closed, The first slide piece is held by the inclined portion of the first angular cam with respect to the opening and closing direction, The method for manufacturing a two-color molded article according to method 2 or 3, wherein the second slide piece is held by the portion of the second angular cam parallel to the opening and closing direction.

[0043] (Method 5) The first slide piece is equipped with a claw component that contacts the inclined portion of the first angular cam when the first mold and the second mold are opened. The method for manufacturing a two-color molded product according to any one of methods 2 to 4, wherein the first slide piece moves by sliding between the inclined portion and the claw component.

[0044] (Method 6) A method for producing a two-color molded article according to any one of methods 1 to 5 using an elastomer as the second resin.

[0045] (Method 7) The method for manufacturing a two-color molded product according to method 6, in which a sealing component is formed by the second resin and a body portion is formed by the first resin.

[0046] (Method 8) A method for manufacturing a two-color molded product according to method 7, wherein the second injection step is performed after the first injection step.

[0047] (Method 9) A method for manufacturing a two-color molded product according to method 7, in which the first injection step is performed after the second injection step.

[0048] (Method 10) A method for manufacturing a two-color molded product according to method 7, in which a gate for injecting the second resin is arranged on the side surface of the ring-shaped sealing component.

[0049] (Composition 1) A mold that can be opened and closed, A first injection means for injecting the first resin into the molding die, A second injection means for injecting a second resin, which becomes an elastic body after molding, into the molding die, A slide piece is provided so as to be movable in a direction different from the opening and closing direction of the molding die, and forms part of the cavity of the molding die, A manufacturing apparatus for two-color molded products, comprising: The slide piece includes a first slide piece that forms an undercut portion by molding, and a second slide piece that restricts the movement of the second resin molded product in the direction of movement when the first slide piece is released from the mold. A two-color molded product manufacturing apparatus characterized in that, after the injection of the first resin and the injection of the second resin, the first slide piece is demolded, and then the second slide piece is demolded. [Explanation of symbols]

[0050] 9 Body parts 10 sealing parts 11 Undercut section 21. First slide piece 22. Second slide piece 23 First Angular Coma 24 Second Angular Coma 25 Claw parts 100 recording heads

Claims

1. A first injection step in which the first resin is injected into a molding die, A second injection step is performed before or after the first injection step, in which a second resin, which becomes an elastic body after molding, is injected into the molding die. A method for manufacturing a two-color molded product, A first sliding step is performed after the first injection step and the second injection step, in which a first slide piece forming part of the cavity of the molding die is moved in a direction different from the opening and closing direction of the molding die, The process further includes a second sliding step, in which a second slide piece, which forms part of the cavity of the molding die, is moved in the direction of movement, after the first sliding step. The first injection step and the second injection step form an undercut portion with the first slide piece. A method for manufacturing a two-color molded product, characterized in that, during the first sliding step, the movement of the molded product of the second resin in the direction of movement is restricted by the second slide piece.

2. The molding die comprises a first mold having the first slide piece and the second slide piece, and a second mold provided opposite the first mold. In the first sliding step, as the first mold and the second mold separate in the opening and closing direction, the first slide piece moves in the moving direction due to the action of the first angular cam provided on the second mold. The method for manufacturing a two-color molded product according to claim 1, wherein in the second sliding step, as the first mold and the second mold separate in the opening and closing direction, the second slide piece moves in the moving direction due to the action of the second angular cam provided on the second mold.

3. In the first sliding step, the inclined portion of the first angular cam and the inclined portion of the first slide piece slide against each other, causing the first slide piece to move. The method for manufacturing a two-color molded product according to claim 2, wherein in the second sliding step, the inclined portion of the second angular cam and the inclined portion of the second slide piece slide against each other, thereby moving the second slide piece.

4. When the first mold and the second mold are closed, The first slide piece is held by the inclined portion of the first angular cam with respect to the opening and closing direction, The method for manufacturing a two-color molded product according to claim 2, wherein the second slide piece is held by the portion of the second angular cam parallel to the opening and closing direction.

5. The first slide piece is equipped with a claw component that contacts the inclined portion of the first angular cam when the first mold and the second mold are opened. The method for manufacturing a two-color molded product according to claim 2, wherein the first slide piece moves by sliding between the inclined portion and the claw component.

6. A method for manufacturing a two-color molded article according to claim 1, wherein an elastomer is used as the second resin.

7. The method for manufacturing a two-color molded product according to claim 6, wherein a sealing component is formed by the second resin and a body portion is formed by the first resin.

8. The method for manufacturing a two-color molded product according to claim 7, wherein the second injection step is performed after the first injection step.

9. The method for manufacturing a two-color molded product according to claim 7, wherein the first injection step is performed after the second injection step.

10. The method for manufacturing a two-color molded product according to claim 7, wherein a gate for injecting the second resin is arranged on the side surface of the ring-shaped sealing component.

11. A mold that can be opened and closed, A first injection means for injecting the first resin into the molding die, A second injection means for injecting a second resin, which becomes an elastic body after molding, into the molding die, A slide piece is provided so as to be movable in a direction different from the opening and closing direction of the molding die, and forms part of the cavity of the molding die, A manufacturing apparatus for two-color molded products, comprising: The slide piece includes a first slide piece that forms an undercut portion by molding, and a second slide piece that restricts the movement of the second resin molded product in the direction of movement when the first slide piece is released from the mold. A manufacturing apparatus for two-color molded products, characterized in that, after the injection of the first resin and the injection of the second resin, the first slide piece is demolded, and then the second slide piece is demolded.

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