Method for molding composite molded article and injection device

Abstract

To provide a molding method capable of molding a composite molded article in which a non-foamable resin and a foamable resin are integrally laminated even with one injection device.SOLUTION: The method for molding a composite molded article of the present invention comprises: a 1A injection step in which a non-foamable resin in a molten state is injected and filled into a molding cavity 15; a first space forming step in which a movable mold 13 is retracted after the 1A injection step to form a first filling space into the molding cavity; a 2A injection step in which a foamable resin in a molten state containing a foaming material is injected and filled into the first filling space; and a 1A bubble expanding step in which the movable mold is retracted after the 2A injection step to expand bubbles in the foamable resin filled by the 2A injection step. In the 2A injection step, the foamable resin in a molten state is injected and filled into the first filling space through the same resin passage 12 as in the 1A injection step, and the foamable resin is formed by injecting the foaming material into the non-foamable resin in a molten state in the process of passing through the resin passage.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for molding a composite molded article in which a non-foamable resin layer and a foamable resin layer are integrally laminated. [Background technology]

[0002] Foam-molded products made of resin containing many fine bubbles are in high demand because they are lightweight yet strong. Among these molded products, not only those made of foamed resin, but also composite molded products obtained by integrally molding non-foamed resin and foamable resin have been proposed. Patent Document 1 proposes that, in order to injection-mold a composite molded product, after injection-molding a non-foamed resin, a movable mold is withdrawn from a fixed mold, a foamable resin is injected, and the movable mold is withdrawn again to expand the foamable resin and form the composite molded product. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-223104 A Summary of the Invention [Problem to be solved by the invention]

[0004] Although Patent Document 1 does not disclose a means for sequentially injecting and filling the non-foamable resin and the foamable resin, if two different injection devices were used to plasticize, measure, and inject the non-foamable resin and the foamable resin, respectively, a large space would be required to install the devices, and the device costs would be high. In addition, a complex control method would be required to operate the two different injection devices in a coordinated manner.

[0005] In view of the above, an object of the present invention is to provide a molding method capable of molding a composite molded product in which a non-foamable resin and a foamable resin are integrally layered, even using a single injection device. [Means for solving the problem]

[0006] The present invention relates to a method for molding a composite molded body in which a non-foamable resin layer and a foamable resin layer are integrally laminated by injecting and filling a molding cavity between a movable mold and a fixed mold with molten resin. The present invention includes a first pattern in which the non-foamable resin is injected first and then the foamable resin, and a second pattern in which the foamable resin is injected first and then the non-foamable resin, which is the opposite of the first pattern. The first and second patterns have in common the following two elements: First element: Non-foaming resin and foaming resin are injected and filled through the same resin passage. Second element: Foamable resin is produced by injecting foaming material into non-foamable resin as it passes through the resin passage.

[0007] The first pattern is, A first injection step A of injecting and filling a molding cavity with a molten non-foaming resin; a first space forming step of forming a first filling space in the molding cavity by retracting the movable mold after the first injection step; A second injection step A of injecting and filling a molten foamable resin containing a foaming material into the first filling space; and a 1A bubble expansion step of expanding the bubbles of the foamable resin filled in the 2A injection step. The 2A injection process in the first pattern is Molten foamable resin is injected and filled into the first filling space through the same resin passage as in the 1A injection process, and foamable resin is produced by injecting a foaming material into the molten non-foamable resin as it passes through the resin passage.

[0008] The second pattern is, a first injection step of injecting a molten foamable resin containing a foaming material into the molding cavity to fill the molding cavity; a 1B bubble expansion step of expanding the bubbles of the foamable resin filled in the 1B injection step; a second space forming step of forming a second filling space in the molding cavity by retracting the movable mold after the first B bubble expanding step; and a 2B injection step of injecting and filling the second filling space with a molten non-foaming resin. The 1B injection step in the second pattern is Molten foamable resin is injected and filled into the molding cavity through the same resin passage as in the 2B injection process, and foamable resin is produced by injecting a foaming material into the molten non-foamable resin passing through the resin passage.

[0009] In the first pattern, preferably, The 1A injection process is by injection compression molding.

[0010] In the second pattern, preferably, The 2B injection step is by injection compression molding.

[0011] In the method for molding a composite molded body of the present invention, preferably, The resin passage is provided with a mixing section capable of kneading the resin flow of molten resin passing through the resin passage.

[0012] In the method for molding a composite molded body of the present invention, preferably, The foam core material is injected into the non-foamable resin along with the foaming material.

[0013] The injection device of the present invention comprises: A heating cylinder, a screw that plasticizes the resin raw material supplied to the heating barrel; an injection nozzle having a resin passage for injecting the molten resin plasticized and metered by the screw toward a molding cavity; and a foaming material supplying device capable of supplying a foaming material to the molten resin passing through the resin passage. The foam material supply device is When the molten resin passes through the resin passage, it is possible to select either a foaming resin molding mode in which a foaming material is supplied to the molten resin, or a non-foaming resin molding mode in which a foaming material is not supplied to the molten resin. Effect of the Invention

[0014] According to the present invention, the non-foamable resin and the foamable resin are injected and filled through the same resin passage (first element), and foamable resin is generated by injecting a foaming material into the non-foamable resin as it passes through the resin passage (second element). Therefore, the composite molded body of the present invention only requires one injection device that plasticizes, measures, and injects the non-foamable resin, and one foaming material supply device, which requires less installation space and reduces equipment costs compared to two injection devices. Furthermore, the control of linking one injection device with a foaming material supply device is simpler than the control of linking two injection devices. [Brief description of the drawings]

[0015] [Figure 1] 1 is a diagram showing a schematic configuration of an injection molding machine according to an embodiment; [Diagram 2] 1A to 1C are diagrams illustrating a procedure of a molding method according to an embodiment. [Diagram 3] 2A to 2C are diagrams illustrating the procedure of the molding method according to the embodiment. [Figure 4] FIG. 13 is a diagram showing a modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In this embodiment, to obtain a composite molded product in which non-foamable resin and foamable resin are integrated, an injection molding machine 1 capable of supplying foaming material FA to molten non-foamable resin passing through resin passage 24 of injection nozzle 23 is used. When non-foamable resin is injection molded, foaming material FA is not supplied from injection nozzle 23, but when foamable resin is injection molded, foaming material FA is supplied from injection nozzle 23. The injection molding machine 1 is equipped with a foaming material supplying device 60 capable of supplying foaming material FA from injection nozzle 23.

[0017] [Configuration of injection molding machine 1: See Figure 1] As shown in FIG. 1, the injection molding machine 1 includes a mold section 10, a plasticizing section 20, a foaming material supplying section 30, and a control section 100 that controls the operation of the injection molding machine 1. Hereinafter, the configuration of the injection molding machine 1 will be described, followed by a description of a control procedure performed by the control unit 100. In the injection molding machine 1, a front side (F) and a rear side (R) are defined as shown in FIG.

[0018] [Mold section 10: see Figure 1] The mold section 10 includes a fixed mold 11 whose position is fixed, and a movable mold 13 that can move forward and backward with respect to the fixed mold 11. In a mold clamping state in which the fixed mold 11 and the movable mold 13 are butted against each other, a molding cavity 15 is formed between the fixed mold 11 and the movable mold 13. A resin passage 12 is formed in the fixed mold 11, and molten resin plasticized in the plasticizing section 20 is injected and filled into the molding cavity 15 through the resin passage 12. The mold section 10 is provided with a pressing cylinder 17 that presses the resin filled in the molding cavity 15 toward the movable mold 13. Note that, even if the pressing cylinder 17 is not used, if the resin filled in the molding cavity 15 can move forward (F) together with the movable mold 13 by leaving the fixed mold 11, the pressing cylinder 17 may not be provided. In the mold section 10, the action of the movable mold 13 moving forward (F) away from the fixed mold 11 is called mold opening or retreating, and conversely, the action of the movable mold 13 moving backward (R) towards the fixed mold 11 is called mold closing or advancing.

[0019] Although not shown in the figure, the fixed mold 11 is attached to the fixed platen, and the movable mold 13 is attached to the movable platen. A plurality of tie bars are provided between the fixed platen and the movable platen to connect them, and the mold is closed or opened by applying pressure from, for example, a hydraulic cylinder between the fixed platen and the movable platen via the tie bars.

[0020] [Plasticization section 20: see Figure 1] The plasticizing section 20 includes a cylindrical heating cylinder 21, an injection nozzle 23 provided at the front end of the heating cylinder 21, a screw 25 rotatably provided inside the heating cylinder 21, and a heater 27 wound around the heating cylinder 21. Pellet-shaped raw material resin is supplied to the inside of the heating cylinder 21 through a raw material inlet (not shown) provided in the heating cylinder 21. The heater 27 heats the resin inside the heating cylinder 21 according to an instruction from the control unit 100. The heating cylinder 21 is fixed in position, and the screw 25 can move forward or backward inside the heating cylinder 21 and can rotate forward or backward. The injection nozzle 23 has a resin passage 24 penetrating therethrough in the front-rear direction, and the plasticized molten resin is injected and filled into the resin passage 12 through the resin passage 24. The screw 25 includes a screw shaft 25A and a spiral flight 25B formed around the screw shaft 25A. The raw resin becomes a plasticized molten resin while being transported through the screw groove between the screw shaft 25A and the flight 25B.

[0021] Although not shown, the plasticizing unit 20 includes a drive device for moving the screw 25 forward or backward, and a drive device for rotating the screw 25 forward or backward. These drive devices include, for example, electric motors, and perform necessary operations according to instructions from the control unit 100.

[0022] [Foaming material supply section 30: see FIG. 1] The foaming material supply unit 30 operates according to instructions from the control unit 100, and supplies the foaming material FA to the molten resin MR transported through the resin passage 24. When a foamable resin is injection molded, the foaming material FA is injected into the non-foamable resin passing through the resin passage 24, thereby generating the foamable resin.

[0023] The foaming material supplying section 30 includes a valve device 40 that can select between an open position (ON) that allows the supply of the foaming material FA and a closed position (OFF) that blocks the supply of the foaming material FA, and a valve drive device 50 that alternates between the open position (ON) and the closed position (OFF) of the valve device 40. The foaming material supplying section 30 includes a foaming material supplying device 60 that supplies the foaming material FA toward the valve device 40.

[0024] There is no limitation on the resin that can be used in this embodiment, and a wide range of thermoplastic resins can be used. There are two types of foaming materials: chemical foaming materials and physical foaming materials. Either type of foaming material can be used in the present invention. As the chemical foaming material, a substance that decomposes when heated to generate gas, such as azodicarboxylic acid amide, can be used. As the physical foaming material, an inert gas such as nitrogen or carbon dioxide, or a low-boiling liquid such as water, a solvent, an alcohol, or an ether can be used.

[0025] [Valve device 40] The valve device 40 has a poppet-shaped structure and includes a valve box 41 that is integral with the injection nozzle 23 and has a flow path 42 formed therein, a valve element 43 that moves up and down the flow path 42 of the valve box 41, and a valve seat 45 that faces the flow path 42 and against which the tip of the valve element 43 abuts. The valve device 40 shown in Fig. 1 is in the closed position (OFF) where the valve element 43 abuts against the valve seat 45 and the flow path 42 is blocked at the valve seat 45. When molding a non-foamable resin, the valve device 40 is in the closed position (OFF), and the supply and injection of the foaming material FA into the molten resin MR through the resin passage 24 is prevented.

[0026] [Valve drive mechanism 50] The valve drive device 50 supplies the working fluid to the valve device 40, thereby causing the valve device 40 to operate between an open position (ON) and a closed position (OFF). The valve drive device 50 includes a fluid pressure cylinder 51, a fluid storage tank 55 that stores the working fluid to be supplied to the fluid pressure cylinder 51, and a hydraulic oil flow path 57 that connects the fluid storage tank 55 and the fluid pressure cylinder 51. The fluid in the fluid pressure cylinder 51 is either a liquid or a gas, and hydraulic pressure or air pressure is used as the driving fluid pressure. The fluid pressure cylinder 51 includes a cylinder tube 52 fixed to the valve box 41 and having a fluid chamber 53 provided therein, and a piston 54 capable of moving up and down the fluid chamber 53 of the cylinder tube 52. The fluid chamber 53 is divided into a first fluid chamber 53A and a second fluid chamber 53B by the piston 54. The piston 54 is fixed to the valve body 43, which also serves as the rod of the fluid pressure cylinder 51. When hydraulic fluid is supplied to the first fluid chamber 53A, the piston 54 is pushed down, causing the valve body 43 to abut against the valve seat 45, thereby moving the fluid pressure cylinder 51 to a closed position (OFF) where the valve body 43 is abutted against the valve seat 45, and when hydraulic fluid is supplied to the second fluid chamber 53B, the fluid pressure cylinder 51 is pushed up, causing the valve body 43 to move away from the valve seat 45, thereby moving the fluid pressure cylinder 51 to an open position (ON).

[0027] The hydraulic oil flow path 57 includes a 1-1 flow path 57A1 having one end connected to the fluid storage tank 55 and the other end connected to the flow path switching valve 58, a 1-2 flow path 57A2 having one end connected to the flow path switching valve 58 and the other end connected to the first fluid chamber 53A, a 2-1 flow path 57B1 having one end connected to the fluid storage tank 55 and the other end connected to the flow path switching valve 58, and a 2-2 flow path 57B2 having one end connected to the flow path switching valve 58 and the other end connected to the second fluid chamber 53B. The flow path switching valve 58 is provided between the 1-1 flow path 57A1 and the 1-2 flow path 57A2 and between the 2-1 flow path 57B1 and the 2-2 flow path 57B2. A hydraulic fluid pump 59 for supplying the hydraulic fluid WF from the fluid storage tank 55 to the fluid pressure cylinder 51 is provided in the 1-1 flow path 57A1.

[0028] [Foam material supply device 60] The foaming material supplying device 60 includes a foaming material storage tank 61 that stores foaming material FA to be injected into molten resin MR made of non-foamable resin, and a foaming material flow path 63 that connects the foaming material storage tank 61 to the flow path 42 of the valve device 40. The foaming material supplying device 60 includes a foaming material pump 65 provided in the foaming material flow path 63 for supplying the foaming material FA from the foaming material storage tank 61 toward the flow path 42 of the valve device 40, and an on-off valve 67 provided in the foaming material flow path 63 downstream of the foaming material pump 65.

[0029] When the foaming material FA is injected into the molten resin MR to generate a foamable resin, the on-off valve 67 is opened (ON) and the foaming material pump 65 is driven (ON). Then, the foaming material FA stored in the foaming material storage tank 61 is supplied to the flow path 42 of the valve device 40 through the foaming material flow path 63. If the valve body 43 of the valve device 40 is in the open position (ON) away from the valve seat 45, the foaming material FA is injected into the molten resin MR consisting of a non-foaming resin transported through the resin passage 24. In this way, the non-foaming resin passing through the resin passage 24 changes its nature to a foaming resin. When molding a non-foamable resin, the on-off valve 67 is closed (OFF), and the driving of the foaming material pump 65 is stopped.

[0030] [Molding procedure: see Figures 2 and 3] The following describes a procedure for obtaining a composite molded product in which a non-foamable resin layer (L1) and a foamable resin layer (L2) are integrated by injection molding using an injection molding machine 1. The following describes an example of a procedure for a first pattern in which a non-foamable resin is molded first, and then a foamable resin is molded.

[0031] [Non-foaming resin molding mode (Fig. 2(a))] In order to mold the non-foaming resin first, the valve device 40 is in the closed position (OFF), and although not shown, the on-off valve 67 is closed (OFF), and the drive of the foaming material pump 65 is stopped (OFF). This state is called the non-foaming resin molding mode in the injection molding machine 1. In the non-foaming resin molding mode, the fixed mold 11 and the movable mold 13 are, for example, most closed, and the distance D between the fixed mold 11 and the movable mold 13 in the molding cavity 15 is set to the minimum D1. The volume of the molding cavity 15 is also at its minimum at this point.

[0032] [First injection process: Figure 2(b)] In the non-foaming resin molding mode, the plasticizing section 20 plasticizes and weighs the molten resin MR, and transports the molten resin MR toward the molding cavity 15. The molten resin MR passes through the resin passage 24 of the injection nozzle 23 and the resin passage 12 of the fixed mold 11 in this order, and is injected and filled into the molding cavity 15. After the molten resin MR is filled into the molding cavity 15, the necessary pressure is applied. A skin layer is formed on the outer peripheral surface of the molten resin MR filled into the molding cavity 15. The non-foaming resin layer L1 molded with the non-foaming resin is disposed on the side that requires design among the front and back of the composite molded body. The foaming resin layer L2 molded later is formed by integrating the skin layer of the foaming resin layer L2 and the skin layer of the non-foaming resin layer L1 by bonding.

[0033] In the first injection step, injection compression can be preferably applied. In the injection compression, the fixed mold 11 and the movable mold 13 are not completely closed, the molten resin MR is injected into the molding cavity 15, and the fixed mold 11 and the movable mold 13 are completely closed during the injection or after the injection and filling are completed. By applying injection compression, the non-foaming resin layer molded in the first injection step can be easily thinned, so that the effect of reducing the weight of the composite molded body by foam molding can be fully enjoyed.

[0034] [Filling space formation process: Figure 2(c)] After the first injection step, the movable mold 13 is moved backward to expand the interval D of the molding cavity 15. Before the movable mold 13 is moved backward, the molding cavity 15 is filled with the molten resin MR injected in the first injection step, and there is no space inside the molding cavity 15. However, as the movable mold 13 is moved backward, a new first filling space 16 for the next second injection step is formed. The first filling space 16 caused by the moving mold 13 moving backward is formed between the non-foaming resin layer L1 formed in the first injection step and the fixed mold 11. In other words, the non-foaming resin layer L1 moves backward together with the movable mold 13 while remaining attached to the movable mold 13. At this time, the pressing cylinder 17 moves forward to press the non-foaming resin layer L1 against the movable mold 13, so that the non-foaming resin layer L1 is maintained in a state of being attached to the movable mold 13. The volume of the first filling space 16, that is, the amount of movement of the movable mold 13 is determined according to the thickness of the foaming resin layer to be formed in the second injection step. The distance between the fixed mold 11 and the movable mold 13 in the molding cavity 15 is expanded from D1 to D2.

[0035] [Second injection process: Figure 3(d)] A second injection process is performed in which the molten resin MR into which the foaming material FA has been injected is injected to fill the first filling space 16 formed in the filling space forming process. The second injection step is performed under the following conditions. Valve device 40: Valve body 43 open position (ON) Valve drive device 50 (flow path switching valve 58): connects 1-1 flow path 57A1 and 1-2 flow path 57A2, and connects 2-1 flow path 57B1 and 2-2 flow path 57B2 Foaming material supply device 60: Open / close valve 67 open (ON) Foaming material pump 65 driven

[0036] Since the foaming material supplying device 60 is in the operating state as described above, the foaming material FA is supplied from the flow path 42 of the valve device 40 to the molten resin MR being transported through the resin passage 24. The foaming material FA is contained in the molten resin MR in the resin passage 24 on the mold section 10 side from the valve device 40, and the molten resin MR into which the foaming material FA has been injected is injected through the resin passage 12 and filled into the first filling space 16. The foaming material FA foams as bubbles in the molten resin MR, and the molten resin MR constitutes the foamable resin layer L2.

[0037] The second injection step can begin after the necessary first fill space 16 has been formed, or can begin at the same time that the formation of the first fill space 16 begins.

[0038] [Bubble expansion process: Figure 3(e)] After the second injection step, a bubble expansion step is carried out to expand the diameter of the bubbles contained in the foamable resin layer L2. The bubble expansion step is carried out by retracting the movable mold 13 by a predetermined amount. The retraction amount is set in advance. After the bubble expansion step is continued for a predetermined time, the mold is opened and the molded composite molding is removed. Incidentally, instead of retracting movable die 13, the expansion of the air bubbles may be achieved by filling the molding cavity 15 with an amount of molten resin equal to its volume and generating and expanding the air bubbles by the amount of contraction of the resin due to solidification while maintaining the position of movable die 13, or by filling the molding cavity 15 with an amount of molten resin less than its volume and expanding the air bubbles generated when the molten resin flows due to the foaming pressure and filling is completed. Alternatively, when the foaming pressure is so high that movable die 13 is pushed back by the foaming pressure, the air bubbles may be expanded while controlling the retraction of movable die 13 by applying a retraction resistance to the movable platen supporting movable die 13. As described above, in the bubble expansion process, there are cases where the movable mold 13 retreats and cases where the movable mold 13 maintains its position. When the movable mold 13 retreats, there are cases where it retreats due to the application of an external force and cases where it retreats due to an internal force called foaming pressure.

[0039] [Effects of the embodiment] According to this embodiment, for example, the resins that form the non-foamable resin layer L1 that forms the design surface and the foamable resin layer L2 can be plasticized in the same plasticization section 20, so one plasticization section 20 is sufficient, the space required to install the injection molding machine 1 can be reduced, and the cost of the injection molding machine 1 is only that for one plasticization section 20, which contributes to reducing the cost of the injection molding machine 1.

[0040] For example, the non-foamed resin layer L1 that forms the design surface can be easily made thin by injection compression molding, thereby maximizing the effect of reducing the weight of the composite molded body integrated with the foamed resin layer L2 by foam molding.

[0041] Although a preferred embodiment of the present invention has been described, it is possible to select and / or change the configurations described in the above embodiment or to change them to other configurations as appropriate without departing from the spirit of the present invention.

[0042] [Mixing structure: see Figure 4] In this embodiment, a mixing mechanism 28 can be provided inside the injection nozzle 23. The mixing mechanism 28 is provided at least downstream (D) of the valve device 40 to which the foaming material FA is supplied, so as to surround the resin passage 24. As long as the mixing mechanism 28 has a function of improving the mixed state of the molten resin MR containing the foaming material FA passing through the resin passage 24, a specific kneading means is not limited. As an example, the molten resin MR containing the foaming material FA passes through the mixing mechanism 28 while undergoing a phase change in the flow. Therefore, the dispersion state of the foaming material FA in the molten resin MR is improved. The phase change of the flow here refers to the radial or circumferential position of the injection nozzle 23 changing with the flow of the molten resin MR. For example, this corresponds to the molten resin MR flowing on the radial inside of the injection nozzle 23 and the molten resin MR flowing on the radial outside being moved forward (F) such that the molten resin MR flowing on the radial inside and the molten resin MR flowing on the radial outside are moved forward.

[0043] In the present embodiment, since the foaming core material can be injected into the molten resin together with the foaming material, it is effective in making the foam bubbles finer. The foaming core material can be inorganic particles such as talc, silica, mica, etc.

[0044] The embodiment described above is based on the first pattern of the present invention, but the present invention also includes a second pattern in which the foamable resin is injected first and then the non-foamable resin is injected, which is the opposite of the first pattern. The second pattern is executed in the following procedure. In the following procedure, in the first injection step, the molten foamable resin is injected and filled into the molding cavity 15 through the same resin passage 24 as in the second injection step, and the foamable resin is generated by injecting a foaming material into the molten non-foamable resin passing through the resin passage 24. The second filled section formed in the second pattern corresponds to the first filled section (16) in the first pattern.

[0045] First injection step: A foamable resin is injected and filled. Air bubble expansion step: The movable mold 13 is moved backward to expand the air bubbles of the foamable resin filled in the injection step. Space forming step: After the air bubble expanding step, the movable mold 13 is moved backward to form a second filling space in the molding cavity. Second injection step: A molten non-foaming resin is injected to fill the second filling space.

[0046] In addition, in the present invention, a non-foaming resin may be injected after the first pattern. If this pattern is the third pattern, the molded product formed by the third pattern can have a non-foaming resin layer on both the front and back sides, so that both the front and back sides can be designed surfaces. [Explanation of symbols]

[0047] 1 injection molding machine 10. Mold Department 11 Fixed mold 12 Resin passage 13 Movable mold 15 Molding Cavity 16 1st filling space 17 Pressing cylinder 20 Plasticization Section 21 Heating cylinder 23 Injection nozzle 24 Resin passage 25 Screw 25A screw shaft 25B Flight 27 Heater 28 Mixing mechanism 40 Valve gear 41 Valve box 42 Flow Path 43 Valve body 45 Valve seat 50 Valve drive mechanism 51 Fluid pressure cylinder 52 Cylinder tube 53 Fluid chamber 53A 1st fluid chamber 53B 2nd fluid chamber 54 Piston 55 Fluid storage tank 57 Hydraulic oil flow path 57A1 No. 1-1 flow channel 57A2 1st-2nd flow channel 57B1 No. 2-1 flow channel 57B2 No. 2-2 Channel 58 Flow path switching valve 59 Hydraulic Fluid Pump 60 Foam material supply device 61 Foam storage tank MR Melt Resin FA foam material

Claims

1. A method for molding a composite molded body in which a non-foamable resin layer and a foamable resin layer are integrally laminated by injecting and filling a molding cavity between a movable mold and a fixed mold, comprising the steps of: a first injection step of injecting and filling the molding cavity with a molten non-foamable resin; a first space forming step of retracting the movable mold after the first A injection step to form a first filling space in the molding cavity; A second injection step A of injecting and filling the first filling space with a molten foamable resin containing a foaming material; a first A bubble expansion step of expanding the bubbles of the foamable resin filled in the second A injection step, The second injection step is The foamable resin in a molten state is injected and filled into the first filling space through the same resin passage as in the first A injection step, and the foaming material is injected into the non-foamable resin in a molten state during the process of passing through the resin passage, thereby generating the foamable resin. A method for forming a composite compact.

2. A method for molding a composite molded body in which a non-foamable resin layer and a foamable resin layer are integrally laminated by injecting and filling a molding cavity between a movable mold and a fixed mold, comprising the steps of: A first injection step B of injecting and filling the molding cavity with a molten foamable resin containing a foaming material; a first B bubble expansion step of expanding the bubbles of the foamable resin filled in the first B injection step; a second space forming step of retracting the movable mold after the first B bubble expanding step to form a second filling space in the molding cavity; a second B injection step of injecting and filling the second filling space with a molten non-foamable resin, The first injection step is The foamable resin in a molten state is injected and filled into the molding cavity through the same resin passage as in the second B injection step, and the foamable resin is generated by injecting the foaming material into the non-foamable resin in a molten state passing through the resin passage. A method for forming a composite compact.

3. The first injection step is performed by injection compression molding. A method for molding the composite molded article according to claim 1.

4. The second B injection step is performed by injection compression molding. A method for molding the composite molded article according to claim 2.

5. The resin passage is provided with a mixing section that kneads the molten resin passing through the resin passage. A method for molding the composite molded product according to any one of claims 1 to 4.

6. Injecting a foam core material into the non-foamable resin together with the foaming material; A method for molding the composite molded product according to any one of claims 1 to 4.

7. A heating cylinder, A screw for plasticizing the resin raw material supplied to the heating barrel; an injection nozzle having a resin passage for injecting the molten resin plasticized and metered by the screw toward a molding cavity; a foaming material supplying device capable of supplying a foaming material to the molten resin passing through the resin passage, The foaming material supply device is An injection device that is capable of selecting either a foaming resin molding mode in which the foaming material is supplied to the molten resin as the molten resin passes through the resin passage, or a non-foaming resin molding mode in which the foaming material is not supplied to the molten resin.

Images