JP2013028031A - Method of manufacturing resin molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a resin molded product, which is capable of precisely and easily controlling the thickness of a resin in each layer even when the resin molded product containing a part of a laminate made from the resin of a plurality of layers is manufactured.SOLUTION: The laminate is formed by extruding a sheet like parison in a single layer from each of extruding slits 34 of two T-dies 28 arranged to be adjacent and sticking two single layer sheet like parisons to each other. The thickness of each sheet-like parison is precisely adjusted by the extrusion rate from the sits of the T-dies 28 or the revolution speed of an adjusting roller 30. Therefor, even when the laminate is molded by at least two layers of the resin, the thickness of each layer in the laminate can be independently, precisely and easily adjusted.

Description

  The present invention relates to a method for producing a resin molded article including at least a portion of a laminate of a plurality of layers of resin.

  For example, when manufacturing a resin molded product in which at least one surface of the core material is covered with a multilayer laminate of a plurality of layers of resin, or a hollow resin molded product of such a multilayer laminate, the plurality of resins are used as one of the T-die. A method of extruding and molding as a multilayer resin sheet in a molten state from two extrusion slits is known (see, for example, Patent Document 1).

  Further, as a molding technique previously filed by the present applicant, two molten resin sheets are extruded downward from an extrusion slit, and a reinforcing core material is sandwiched between the two resin sheets and molded by a split mold. (For example, refer to Patent Document 2).

Japanese Patent No. 3804528 WO2009 / 157197

  However, in the method of extruding a plurality of resins as a multilayer resin sheet in a molten state from one extrusion slit of the T die as in Patent Document 1 described above, the plurality of resins are laminated in the resin flow path in the T die. The Rukoto. Therefore, it has been difficult to precisely adjust the thickness of each layer in the extruded multilayer resin sheet.

  Moreover, the thing of the patent document 2 mentioned above was not considered even about manufacturing the multilayer laminated body by resin of a several layer.

  The present invention has been made in view of such a situation, and even when a resin molded product including a laminate portion made of a plurality of layers of resin is manufactured, the thickness of the resin of each layer can be accurately and easily determined. It aims at providing the manufacturing method of the resin molded product which can be controlled.

In order to achieve such an object, a method for producing a resin molded product according to the present invention includes:
An extrusion step of extruding a molten resin sheet from each of at least two extrusion slits;
A molding step of molding the resin sheet by sandwiching the resin sheet with a split mold, and
In the molding step, among the resin sheets extruded in the extrusion step, at least two resin sheets extruded in a single layer are molded in a state of being bonded to each other.

  As described above, according to the present invention, the thickness of the resin of each layer can be accurately and easily controlled even in the case of manufacturing a resin molded product including a portion of a laminate made of a plurality of layers of resin.

It is a longitudinal cross-sectional view which shows the structural example of the resin molded product 100 by 1st Embodiment. It is a 1st figure for demonstrating the example of the manufacturing method by 1st Embodiment. It is a figure which shows typically the structural example of the extrusion apparatus 12 in 1st Embodiment. It is a 2nd figure for demonstrating the example of the manufacturing method by 1st Embodiment. It is a 3rd figure for demonstrating the example of the manufacturing method by 1st Embodiment. It is a longitudinal cross-sectional view which shows the structural example of the resin molded product 200 by 2nd Embodiment. It is a 1st figure for demonstrating the example of the manufacturing method by 2nd Embodiment. It is a 2nd figure for demonstrating the example of the manufacturing method by 2nd Embodiment. It is a longitudinal cross-sectional view which shows the structural example of the resin molded product 300 by 3rd Embodiment. It is a 1st figure for demonstrating the example of the manufacturing method by 3rd Embodiment. It is a 2nd figure for demonstrating the example of the manufacturing method by 3rd Embodiment. It is a 3rd figure for demonstrating the example of the manufacturing method by 3rd Embodiment. It is a 4th figure for demonstrating the example of the manufacturing method by 3rd Embodiment. It is a 5th figure for demonstrating the example of the manufacturing method by 3rd Embodiment. It is a 1st figure for demonstrating the example of the manufacturing method by 4th Embodiment. It is a 2nd figure for demonstrating the example of the manufacturing method by 4th Embodiment. It is a 3rd figure for demonstrating the example of the manufacturing method by 4th Embodiment. It is a longitudinal cross-sectional view which shows the structural example of the resin molded product 400 by 5th Embodiment. It is a figure for demonstrating the example of the manufacturing method by 5th Embodiment. It is a longitudinal cross-sectional view which shows the other structural example of the resin molded products 300 and 400 by 3rd-5th embodiment.

  Next, an embodiment to which a method for producing a resin molded product according to the present invention is applied will be described in detail with reference to the drawings. In addition, the resin molded product which concerns on this invention can be used for various uses, such as a car deck board and a building material, for example.

First, an outline common to the embodiments of the present invention will be described.
FIG. 1 shows a configuration example of a resin molded product 100, and FIGS. 2 and 3 show an example of a method for manufacturing the resin molded product 100.

As shown in FIG. 2, the molding apparatus 10 for a resin molded product used in each embodiment of the present invention includes at least two T dies 28 arranged side by side so that the extrusion slits 34 of each T die are substantially parallel downward. .
The molten resin sheet is extruded as a single layer from each of the extrusion slits 34 of the two T dies 28 arranged so as to be adjacent to each other, and the two single layer molten resin sheets are bonded to form a laminate.

  As will be described later, the thickness of each molten resin sheet can be precisely adjusted by the extrusion speed from the slit of the T-die 28, the rotation speed of the adjustment roller 30, and the like. For this reason, also when shape | molding the laminated body by a resin of at least 2 layers, the thickness of each layer in this laminated body can be adjusted correctly and easily separately.

[First Embodiment]
<Configuration example of resin molded product 100>
Next, a first embodiment of the present invention will be described.
First, a configuration example of a resin molded product 100 molded according to the present embodiment will be described with reference to FIG.

  The resin molded product 100 of this embodiment is a hollow multilayer laminate composed of a resin layer 1 and a resin layer 2 made of different resins. Each resin layer may be a foamed layer or a non-foamed layer, and may be configured using various known resin materials as described later.

  For this reason, for example, the resin layer 2 constituting the outside of the resin molded product 100 is selected by color and gloss, and the resin layer 1 constituting the inside of the resin molded product 100 is made of a material having excellent rigidity. It is possible to make a hollow resin molded article 100 having both the color, gloss and rigidity.

<Example of manufacturing method of resin molded product 100>
Next, an example of a method for manufacturing the resin molded product 100 of the present embodiment will be described with reference to FIGS. 2-5 is a figure explaining the example of the manufacturing method of the resin molded product 100 by this embodiment.

  As shown in FIGS. 2 and 3, the resin molded product molding apparatus 10 used in the present embodiment includes an extrusion apparatus 12 (12 a, 12 b) and a mold clamping apparatus 14 disposed below the extrusion apparatus 12. Configured.

  The extrusion apparatus 12 (12a, 12b) is arranged so that the two molten resin sheets P1 and P2 are arranged side by side, and the two molten resin sheets are inserted into the extrusion slits 34 (34a) of each T die 28 (28a, 28b). To 34b), and the thickness and the like are adjusted by the adjusting roller 30. The molten resin sheets P1 and P2 thus extruded are sandwiched and clamped by split molds 50A and 50B described later.

  Since the two extrusion apparatuses 12 (12a, 12b) have the same configuration, one extrusion apparatus 12 will be described with reference to FIG. In FIG. 2, only the T die 28 and the adjustment roller 30 are shown in the configuration of the extrusion device 12, and the other configurations are omitted.

  The extrusion device 12 includes a cylinder 18 provided with a hopper 16, a screw (not shown) provided in the cylinder 18, a hydraulic motor 20 connected to the screw, an accumulator 24 in which the cylinder 18 communicates with the inside, A plunger 26 provided in the accumulator 24, a T die 28, and a pair of adjustment rollers 30 are configured.

  Resin pellets fed from the hopper 16 are melted and kneaded in the cylinder 18 by the rotation of the screw by the hydraulic motor 20, and the molten resin is transferred to the accumulator 24 and stored in a certain amount. The molten resin is sent toward the die 28. In this way, a continuous molten resin sheet made of molten resin is pushed out from the extrusion slit 34 at the lower end of the T die 28 and sent downward while being pinched by a pair of adjusting rollers 30 arranged at intervals. , And is suspended between the split molds 50A and 50B.

  The T die 28 is provided with a die bolt 46 for adjusting the slit interval of the extrusion slit 34. In addition to the mechanical mechanism using the die bolt 46, the slit interval adjusting mechanism may include various other known adjusting mechanisms.

  With such a configuration, as will be described in detail later, the divided molds 50A and 50B in a state where the molten resin sheet P has a uniform thickness in the vertical direction (extrusion direction) from the extrusion slits 34 of the two T dies 28. It is arranged between.

The extrusion capability of the extrusion device 12 may be appropriately selected from the viewpoint of the size of the resin molded product to be molded, the draw-down of each molten resin sheet P, or the prevention of neck-in occurrence. Taking a specific example from a practical viewpoint, the amount of extrusion per shot in the intermittent extrusion is preferably 1 to 10 kg, and the extrusion rate of the resin from the extrusion slit 34 is several hundred kg / hour or more, more preferably 700 kg. / Hour or more. In addition, from the viewpoint of preventing the draw-down of each molten resin sheet P or the occurrence of neck-in, the extrusion process of the molten resin sheet P is preferably performed in as short a time as possible, depending on the type of resin, MFR value, and melt tension value. However, for example, the extrusion process should be completed within 40 seconds, preferably within 10 to 20 seconds. For this reason, the unit area and the amount of extrusion per unit time from the extrusion slit 34 of the thermoplastic resin are, for example, 50 kg / hour cm ² or more, preferably 150 kg / hour cm ² or more.

  By feeding the molten resin sheet P sandwiched between the pair of adjustment rollers 30 downward by the rotation of the pair of adjustment rollers 30, it is possible to stretch and thin the molten sheet-like resin. For this reason, by adjusting the relationship between the extrusion speed of the extruded sheet-like resin and the delivery speed of the molten resin sheet P by the pair of adjustment rollers 30, it is possible to prevent the occurrence of drawdown or neck-in. . For this reason, it is possible to reduce the restrictions on the type of resin, particularly the MFR value and melt tension value, or the extrusion amount per unit time.

  As shown in FIG. 3, the extrusion slit 34 provided in the T die 28 is arranged vertically downward, and the continuous sheet-like molten resin extruded from the extrusion slit 34 is vertically suspended from the extrusion slit 34 in the vertical direction. It is sent downwards. Since the interval between the extrusion slits 34 can be adjusted, even if the sheet-like resin to be extruded is various types such as a foamed layer and a non-foamed layer by adjusting the slit interval, there are various preset values. Can correspond to various thicknesses.

  As a thermoplastic resin for constituting such a sheet-like resin, for example, a polyolefin resin such as a polypropylene resin can be applied. However, when the molten resin sheet is a foamed layer, the thermoplastic resin constituting the foamed layer is preferably one having propylene alone, specifically, a propylene homopolymer, an ethylene-propylene block copolymer. Preferably there is. Thereby, since melt tension becomes high, it can make it easy to foam the sheet-like resin by a foamed layer, and can also make a bubble cell easy to equalize | homogenize.

  The propylene homopolymer having a long chain branched structure is preferably a propylene homopolymer having a weight average branching index of 0.9 or less. The weight average branching index is represented by v1 / v2, where v1 is the intrinsic viscosity of the branched polyolefin and v2 is the intrinsic viscosity of a linear polyolefin having the same weight average molecular weight as the branched polyolefin.

Moreover, it is preferable to use the polypropylene resin in the range whose melt tension (MT) in 230 degreeC is 30-350 mN as a thermoplastic resin for comprising the sheet-like resin extruded. Here, MT means melt tension.
When the molten resin sheet is a foam layer, if the MT of the thermoplastic resin constituting the foam layer is within the range of 30 to 350 mN, the polypropylene resin exhibits strain-hardening properties and a high foaming ratio can be obtained. . In addition, MT uses a melt tension tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and extrudes a strand from an orifice having a diameter of 2.095 mm and a length of 8 mm at a preheating temperature of 230 ° C. and an extrusion speed of 5.7 mm / min. Is a tension when the roller is wound around a roller having a diameter of 50 mm at a winding speed of 100 rpm.

  In addition, in this embodiment, the expansion ratio is the density of the thermoplastic resin used in the molding method of this embodiment described later, and the apparent density of each resin layer wall surface of the resin molded product 100 obtained by the molding method of this embodiment. The value divided by was taken as the expansion ratio.

  Moreover, it is preferable that the melt flow rate (MFR) in 230 degreeC is 1-10 as for the thermoplastic resin for comprising the sheet-like resin extruded. Here, MFR is a value measured according to JIS K-7210. When the MFR is less than 1, it tends to be difficult to increase the extrusion speed as compared with the case where the MFR is in the range of 1 to 10. When the MFR exceeds 10, the MFR is in the range of 1 to 10. Compared with the case where it exists, there exists a tendency for blow molding to become difficult by generation | occurrence | production of a drawdown etc.

  When the molten resin sheet is a foamed layer, an elastomer having a styrene unit in which hydrogen is added in the molecule can be used as the styrene-based elastomer mixed in the foamed layer. For example, hydrogenated elastomers such as styrene-ethylene / butylene-styrene block copolymer, styrene-ethylene / propylene-styrene block copolymer, styrene-butadiene random copolymer, and the like are applicable. The blending ratio of the styrenic elastomer is preferably in the range of less than 40 wt% with respect to the thermoplastic resin from the viewpoint of moldability. In addition, the content of styrene in the styrene-based elastomer is preferably less than 30 wt%, more preferably less than 20 wt%, from the viewpoint of impact strength at low temperatures.

  In addition, as the polyethylene to be mixed in the foam layer, those having a density of 0.91 g / cm 3 or less are applicable from the viewpoint of impact strength at low temperatures. In particular, it is preferable to use linear ultra-low density polyethylene polymerized by a metallocene catalyst. The blending ratio of the low density polyethylene is preferably in the range of less than 40 wt% with respect to the above-described thermoplastic resin from the viewpoint of rigidity and heat resistance.

  In addition to the styrene-based elastomer, low-density polyethylene, and foaming agent described above, a nucleating agent, a coloring agent, and the like can be added to the base resin constituting the foamed layer.

  Examples of the foaming agent include inorganic foaming agents such as air, carbon dioxide gas, nitrogen gas, and water, or organic foaming agents such as butane, pentane, hexane, dichloromethane, and dichloroethane. Among these, it is preferable to use air, carbon dioxide gas or nitrogen gas as the foaming agent. In this case, there is no mixing of organic substances, and there is no decrease in durability or the like.

  Examples of the foaming method include a method using a supercritical fluid. In this case, it is preferable to make carbon dioxide gas or nitrogen gas into a supercritical state and foam the base resin constituting the foam layer. If this supercritical fluid method is used, foaming can be performed uniformly and reliably. The nitrogen supercritical fluid is obtained by setting nitrogen to a critical temperature of 149.1 ° C. and a critical pressure of 3.4 MPa or more, and the carbon dioxide supercritical fluid is carbon dioxide to a critical temperature of 31 ° C. and a critical pressure. It is obtained by setting it to 7.4 MPa or more.

The pair of adjusting rollers 30 shown in FIGS. 2 and 3 are arranged below the extrusion slit 34, and the rotation axes of the rollers are arranged parallel to each other and almost horizontally.
As shown in FIGS. 2 and 3, the pair of adjustment rollers 30 are arranged so as to be line-symmetric with respect to the molten resin sheet extruded in a form that hangs downward from the extrusion slit 34.

  The diameter of each roller and the axial length of the roller may be appropriately set according to the extrusion speed of the extruded sheet-like resin, the length and width of the sheet in the extrusion direction, the type of resin, and the like. For example, the roller diameter is preferably in the range of 50 to 300 mm, and the molten resin sheet is wound around the roller even if the roller curvature is too large or too small in contact with the molten resin sheet. Cause.

  The outer surface of each of the pair of adjustment rollers 30 is provided with uneven texture. The uneven texture is preferably provided on the outer surface so as to be evenly distributed over the entire surface in contact with the sheet resin, and the depth and density of the uneven texture are smoothed by the pair of adjusting rollers 30. In order to prevent the slippage between the outer surface of each of the pair of adjustment rollers 30 and the surface of the corresponding sheet-like resin, the distance may be determined appropriately. Such uneven texture is formed by, for example, a conventionally known sand blasting process, and in a blasting machine, for example, a roughness of about 60 is adopted.

  One of the pair of adjusting rollers 30 is a rotation driving roller 30A, and the other is a rotation driven roller 30B. The rotation by a drive source (not shown) is transmitted to the rotation driving roller 30A, and also to the rotation driving roller 30B. Configured to be communicated.

By transmitting the rotational driving force of the rotational driving roller 30A to the rotational driving roller 30B in this way, it is possible to sandwich the molten resin sheet between the two rollers and send them out downward with the rotational speeds of the two rollers matched. Become.
The details of the drive mechanism of the pair of adjustment rollers 30 are the same as those of a known configuration, and the description thereof is omitted.

  The rotational speed of the rotational drive roller 30A is the difference in relative speed between the extrusion speed at which the sheet-like resin is extruded from the extrusion slit 34 and the delivery speed at which the molten resin sheet P is delivered downward by the rotation of the pair of adjusting rollers 30. It is determined by a method of adjusting according to the extrusion speed of the resin-like resin.

  For example, when a molten resin sheet having a length of 2000 mm is fed in the feeding direction in 15 seconds using a pair of adjusting rollers 30 having a diameter of 100 mm, the feeding speed of the molten resin sheets P1 and P2 by the roller is about 6 per shot for 15 seconds. The rotation speed of the roller can be calculated to be about 25.5 rpm. By raising and lowering the rotational speed of the rotational drive roller 30A, the delivery speed of each molten resin sheet P1, P2 can be easily adjusted.

  The pair of adjusting rollers 30 is made of metal, for example, aluminum, and each of the pair of adjusting rollers 30 has surface temperature adjusting means (not used) for adjusting the surface temperature of the rollers according to the temperature of the molten sheet-like resin. (Shown) is attached. By adjusting the temperature in this manner, heat exchange is performed so that the surface of each roller is not excessively heated by the sandwiched molten sheet-like resin.

The interval between the pair of adjusting rollers 30 is set so that the lowermost portion of the sheet-shaped resin is wider than the thickness of the supplied sheet-shaped resin before the lowermost portion of the sheet-shaped resin is supplied to the position of the adjusting roller 30, It is supplied between the adjusting rollers 30. Thereafter, the gap between the pair of adjustment rollers 30 is narrowed at a predetermined timing, the sheet-like resin is sandwiched between the pair of adjustment rollers 30, and the molten resin sheet P is sent out downward by the rotation of the rollers.
Note that the interval between the pair of adjustment rollers 30 may be adjusted to an appropriate interval before the lowermost portion of the sheet-shaped resin is supplied to the position of the adjustment roller 30. Further, the gap between the pair of adjustment rollers 30 may be fixed, and the force sandwiched between the pair of adjustment rollers 30 may be constant. In this case, the sheet is wound between the pair of adjustment rollers 30, so that the roller interval is automatically expanded to a predetermined interval.

  As described above, by adjusting the extrusion speed of the sheet-shaped resin from the extrusion slit 34 and the distance between the pair of adjustment rollers 30, the rotation speed, the temperature, and the like, the extruded molten resin sheets P 1 and P 2 are not foamed layers. Even if it is based on various resin materials such as a foam layer, each molten resin sheet can be accurately adjusted to a predetermined thickness for each molten resin sheet. Moreover, it can operate smoothly without causing drawdown or neck-in.

  The mold clamping device 14 is substantially orthogonal to the supply direction (extrusion direction) of the divided molds 50A and 50B and the split molds 50A and 50B, which are divided into two divided types, and the molten resin sheets P1 and P2. And a mold driving device (not shown) that moves between an open position and a closed position in the direction.

As shown in FIG. 2, the split molds 50A and 50B, which are two split types, are arranged with the cavity surfaces 51A and 51B facing each other, and the bottom surfaces of the respective cavity surfaces 51A and 51B are substantially vertical. It is arranged to face. The surface of each cavity surface 51A, 51B may be provided with uneven portions according to the outer shape and surface shape of the molded product formed from the molten resin sheets P1, P2.
In the present embodiment, a case where the bottom surfaces of the cavity surfaces 51A and 51B are flat surfaces without unevenness will be described as an example.

  In addition, pinch-off portions 52A and 52B are formed around the cavity surfaces 51A and 51B for the two divided molds 50A and 50B, respectively. The pinch-off portions 52A and 52B are formed in an annular shape around the cavity surfaces 51A and 51B, and project toward the opposing split molds. As a result, when the molds 50A and 50B that are divided into two types are clamped, the tips of the respective pinch-off parts 52A and 52B come into contact with each other and the peripheral edges of the molten resin sheets P1 and P2 sandwiched therebetween A parting line is formed on the surface.

The two divided molds 50A and 50B are respectively driven by a mold driving device (not shown) and are suspended from the respective extrusion slits 34 between the two divided molds 50A and 50B in the open position. All the molten resin sheets thus made can be arranged. Further, in the closed position, the two split molds 50A and 50B are brought close to a predetermined position where a parting line is formed on the periphery of the molten resin sheet at the pinch-off portions 52A and 52B of the two split molds 50A and 50B. The annular pinch-off portions 52A and 52B form a sealed space in the two divided molds 50A and 50B.
The details of the mold driving device are the same as those in the prior art, and a description thereof will be omitted.

  In the present embodiment, a hole 55A is provided inside the split mold 50A, and the air blower (not shown) communicates with the cavity surface 51A. For this reason, air from a blower means (not shown) is blown in the horizontal direction (direction substantially perpendicular to the extrusion direction) as a blow.

  Further, a vacuum suction chamber 53B is provided inside the split mold 50B of the present embodiment, and the vacuum suction chamber 53B is configured to communicate with the cavity surface 51B through the suction hole 54B. For this reason, the inside of the vacuum suction chamber 53B is decompressed by a decompression unit (not shown), and the molten resin sheet is adsorbed toward the cavity surface 51B by sucking from the vacuum suction chamber 53B through the suction hole 54B. The shape is along the outer surface of 51B.

With the molding apparatus 10 as described above, as shown in FIG. 2, the molten resin sheet P1 that forms the resin layer 1 from the extrusion slit 34a of the T-die 28a is single while the split molds 50A and 50B are in the open position. The thickness and the feeding speed are accurately adjusted by the pair of adjusting rollers 30Aa and 30Ba.
Further, the molten resin sheet P2 forming the resin layer 2 is extruded as a single layer from the extrusion slit 34b of the T die 28b, and the thickness and the feeding speed are accurately adjusted by the pair of adjusting rollers 30Ab and 30Bb.

  When each of the molten resin sheets P1 to P3 is pushed out and hung down to a predetermined position below, as shown in FIG. 4, the mold clamping device 14 moves the divided molds 50A and 50B and immediately before closing, that is, pinch off. The part 52A is brought into contact with the molten resin sheet P1, and the pinch-off part 52B is moved to a position in contact with the molten resin sheet P2.

  Next, as shown in FIG. 5, air is blown from the split mold 50A in the thickness direction of the molten resin sheets P1 and P2 (a direction substantially perpendicular to the extrusion direction), and at the same time, sucked from the split mold 50B to the cavity surface 51B. To do. That is, the pressure of one space (cavity surface 51A side) is made higher than the pressure of the other space (cavity surface 51B side) across the molten resin sheet, so that the molten resin sheets P1 and P2 are formed on the cavity surface in the split mold. It moves to the 51B side and shape | molds by the said cavity surface 51B.

At this time, in the split mold 50A, air is blown from the cavity surface 51A by sending air for blowing from a blower (not shown) into the hole 55A.
Further, in the divided mold 50B, the inside of the vacuum suction chamber 53B is decompressed by a decompression means (not shown), and suction is performed from the vacuum suction chamber 53B through the suction hole 54B, whereby the molten resin sheet P1 is directed toward the cavity surface 51B. , P2 is adsorbed.
As a result, the molten resin sheets P1 and P2 are adhered to each other, and the molten resin sheet laminate that has been adhered to form a laminate is adsorbed to the cavity surface 51B.

When the molten resin sheets P1 and P2 thus formed as a laminated body are adsorbed to the cavity surface 51B, the mold clamping device 14 moves the split molds 50A and 50B to the closed position. After mold-clamping, a molded resin product having a shape corresponding to the shape of the cavity surface 51B of the split mold 50B is molded, then the split molds 50A and 50B are opened, and the molded resin molded product is taken out and parting is performed. Remove burrs formed around the line.
Each time the molten resin is intermittently extruded from each extrusion slit 34 (34a, 34b), the resin molded product 100 can be molded one after another by repeating the above-described steps.

<Effect of the manufacturing method of this embodiment>
As described above, in the present embodiment, the two molten resin sheets P1 and P2 are extruded from the extrusion devices 12a and 12b provided for each. That is, the thickness of the sheet-like resin extruded from the extrusion slits 34a and 34b is adjusted by the adjusting roller 30 provided individually, and is suspended between the divided molds 50A and 50B.
For this reason, even when manufacturing a resin molded product with a laminate in which the molten resin sheets P1 and P2 are bonded to each other, the thickness of each layer constituting the laminate can be adjusted accurately and easily. For this reason, also when manufacturing the resin molded product 100 by the laminated body on which the resin layers 1 and 2 were laminated | stacked, the thickness of each resin layer can be controlled correctly and easily.

  Furthermore, since two molten resin sheets P1 and P2 are bonded in a molten state to form a laminated body, even if compared with a manufacturing method in which two types of resins are laminated inside a T die and extruded as a multilayer resin sheet, The adhesive strength between the layers constituting the body can be set to the same strength.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

In the first embodiment described above, two molten resin sheets are extruded and suspended, and are adsorbed to the divided mold 50B by blowing and suction, and are bonded to each other.
In the second embodiment, instead of such an operation, first, two molten resin sheets are extruded and suspended, and then clamped with the split molds 50A and 50B in which the core material 4 is arranged, thereby two sheets are clamped. A molten resin sheet is bonded to form a laminate.
Description of the same components as those in the first embodiment described above is omitted.

<Configuration example of resin molded product 200>
First, a configuration example of the resin molded product 200 molded according to the present embodiment will be described with reference to FIG.

The resin molded product 200 of the present embodiment has a configuration in which substantially half of the plate-like core material 4 is covered with a multilayer laminate including the resin layer 1 and the resin layer 2 made of different resins. The resin layer 2 constitutes the outside of the multilayer laminate, and the resin layer 1 constitutes the inside of the multilayer laminate.
Each resin layer may be a foamed layer or a non-foamed layer, and may be configured using various known resin materials as described above.

  The core material 4 may be made of various resin materials such as foam and non-foam, or may be made of a metal material. Thus, the core material 4 can be made of an arbitrary material formed in advance.

<Example of manufacturing method of resin molded product 200>
Next, an example of a method for manufacturing the resin molded product 200 of the present embodiment will be described with reference to FIGS. 7-8 is a figure explaining the example of the manufacturing method of the resin molded product 200 by this embodiment.

  First, as shown in FIG. 7, the core material 4 is attached to the cavity surface 51A of the split mold 50A of the present embodiment. The method of attaching the core material 4 may be various methods such as a method of removing the suction disk from the core material 4 after pressing with a manipulator having the suction disk.

Next, as shown in FIG. 7, between the split molds 50A and 50B at the open position, the molten resin sheet P1 forming the resin layer 1 is extruded from the extrusion slit 34a of the T die 28a as a single layer, The adjustment rollers 30Aa and 30Ba adjust the thickness and the feeding speed accurately.
Further, the molten resin sheet P2 forming the resin layer 2 is extruded as a single layer from the extrusion slit 34b of the T die 28b, and the thickness and the feeding speed are accurately adjusted by the pair of adjusting rollers 30Ab and 30Bb.

Next, as shown in FIG. 8, the mold clamping device 14 moves the divided molds 50 </ b> A and 50 </ b> B and closes them to the closed position.
At this time, the molten resin sheets P1, P2 suspended between the divided molds 50A, 50B are pressure-bonded between the core material 4 and the cavity surface 51B of the divided mold 50B, and between the molten resin sheets P1, P2. Are bonded to each other, and the molten resin sheet P1 and the core material 4 are bonded to each other.

  In addition, when there is a possibility that an air pool may remain between the molten resin sheet P2 and the cavity surface 51B depending on the shape of the cavity surface 51B of the divided mold 50B, the decompression means (not illustrated) By decompressing the inside of the vacuum suction chamber 53B and sucking from the vacuum suction chamber 53B through the suction hole 54B, it is possible to eliminate even if there is air accumulation.

<Effect of the manufacturing method of this embodiment>
As described above, in the present embodiment, the two molten resin sheets P1 and P2 suspended between the divided molds 50A and 50B are pressure-bonded between the core material 4 and the cavity surface 51B of the divided mold 50B. .
For this reason, the effect similar to 1st Embodiment mentioned above is acquired, and the laminated body with which the molten resin sheets P1 and P2 were mutually adhere | attached, and the core material 4 can also be adhere | attached. For this reason, also when manufacturing the resin molded product 200 which coat | covered about half of the core material 4 with the laminated body in which the resin layers 1 and 2 were laminated | stacked, the thickness of each resin layer in a laminated body is controlled accurately and easily. can do.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.

In the second embodiment described above, the molds are clamped and molded by the split molds 50A and 50B in which the core material 4 is disposed in a state where the two molten resin sheets are suspended.
In the third embodiment, instead of such an operation, the molten resin sheets are sucked one by one with the split molds 50A and 50B, and then one molten resin sheet and the core material 4 are clamped. It is a thing.
A description of the same components as those in the first and second embodiments described above will be omitted.

<Configuration example of resin molded product 300>
First, a configuration example of a resin molded product 300 molded according to the present embodiment will be described with reference to FIG.

In the resin molded product 300 of the present embodiment, approximately half of the plate-like core material 4 is covered with a single resin layer 1 and the remaining approximately half is a multilayer composed of a resin layer 2 and a resin layer 3 made of different resins. It is the structure covered with the laminated body. The resin layer 3 constitutes the outside of the multilayer laminate, and the resin layer 2 constitutes the inside of the multilayer laminate.
Each resin layer may be a foamed layer or a non-foamed layer, and may be configured using various known resin materials as described above.

  The core material 4 may be made of various resin materials such as foam and non-foam, or may be made of a metal material. Thus, the core material 4 can be made of an arbitrary material formed in advance.

<Example of manufacturing method of resin molded product 300>
Next, an example of a method for manufacturing the resin molded product 300 of the present embodiment will be described with reference to FIGS. 10-14 is a figure explaining the example of the manufacturing method of the resin molded product 300 by this embodiment.

  The molding apparatus 10 in the present embodiment includes the above-described extrusion apparatuses 12 (12a to 12c), and the extrusion slits 34 (34a to 34c) of the three T dies 28 (28a to 28c) are substantially parallel downward. They are arranged side by side.

  First, as shown in FIG. 10, the molten resin sheet P1 forming the resin layer 1 is extruded as a single layer from the extrusion slit 34a of the T die 28a between the split molds 50A and 50B in the open position, Thickness and delivery speed are accurately adjusted by the adjustment rollers 30Aa and 30Ba.

  Next, as shown in FIG. 11, the mold clamping device 14 moves the split mold 50A to a position where the pinch-off portion 52A contacts the molten resin sheet P1. Then, the inside of the vacuum suction chamber 53A of the split mold 50A is depressurized by a decompression means (not shown), and the molten resin sheet P1 is drawn toward the cavity surface 51A by sucking from the vacuum suction chamber 53A through the suction hole 54A. Adsorb.

  Next, as shown in FIG. 12, the core material 4 is pressed in the horizontal direction and adhered to the molten resin sheet P1 adsorbed on the cavity surface 51A. The method of pressing the core material 4 may be various methods such as a method of pressing the core material 4 with a manipulator having a suction disk and then removing the suction disk from the core material 4.

  The molten resin sheet P3 forming the resin layer 3 is extruded as a single layer from the extrusion slit 34c of the T die 28c between the split molds 50A and 50B in the open position, and the pair of adjusting rollers 30Ac and 30Bc Thickness and delivery speed are adjusted accurately.

  Next, as shown in FIG. 13, the mold clamping device 14 moves the split mold 50B to a position where the pinch-off portion 52B contacts the molten resin sheet P3. Then, the inside of the vacuum suction chamber 53B of the divided mold 50B is decompressed by a decompression means (not shown), and the molten resin sheet P3 is drawn toward the cavity surface 51B by sucking from the vacuum suction chamber 53B through the suction hole 54B. Adsorb.

  And between the split molds 50A and 50B in the open position, the molten resin sheet P2 forming the resin layer 2 is extruded as a single layer from the extrusion slit 34b of the T die 28b, and a pair of adjusting rollers 30Ab and 30Bb Thickness and delivery speed are adjusted accurately.

Next, as shown in FIG. 14, the mold clamping device 14 moves the split molds 50 </ b> A and 50 </ b> B and closes them to the closed position.
At this time, the molten resin sheet P2 suspended between the divided molds 50A and 50B is pressure-bonded between the molten resin sheet P3 adsorbed on the cavity surface 51B of the divided mold 50B and the core material 4. The molten resin sheets P2 and P3 are bonded to each other, and the molten resin sheet P2 and the core material 4 are bonded to each other.

  When molding by clamping in this way, if there is a possibility that an air pool may remain between the molten resin sheet P3 and the cavity surface 51B due to the shape of the cavity surface 51B of the split mold 50B, the split mold 50B It is good also as performing air venting by well-known methods, such as inserting the pipe for air venting from the provided hole for air venting (not shown).

<Effect of the manufacturing method of this embodiment>
As described above, in the present embodiment, after the molten resin sheets P1 and P3 are sucked by the divided molds 50A and 50B, the molten resin sheet P2 and the core material 4 are clamped.
In this way, the molten resin sheet P1 is arranged on one side with respect to the core material 4, and the molten resin sheets P2 and P3 are arranged on the other side and molded, so that approximately half of the plate-like core material 4 is formed. Can be molded with the resin layer 1 covered with the multilayer laminate including the resin layers 2 and 3 and the other approximately half of the remaining half. And about this manufacturing method, the effect similar to 1st, 2nd embodiment mentioned above can be acquired.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described.

In the above-described third embodiment, the molten resin sheets are sucked one by one by the split molds 50A and 50B, and then one molten resin sheet and the core material 4 are clamped and molded.
In the fourth embodiment, instead of such an operation, the molten resin sheets P2 and P3 that are on the same side with respect to the core material 4 are bonded to each other by the pressure rollers 40A and 40B, and then divided by the split molds 50A and 50B, respectively. Suction is performed, and the core material 4 is arranged and clamped.
Description of the same components as those in the first to third embodiments described above will be omitted.

<Example of manufacturing method of resin molded product 300>
Next, an example of a method for manufacturing the resin molded product 300 according to the present embodiment will be described with reference to FIGS. 15-17 is a figure explaining the example of the manufacturing method of the resin molded product 300 by this embodiment.

  In the present embodiment, the extrusion device 12 includes a pair of pressure rollers 40A and 40B, and the pressure rollers 40A and 40B allow the molten resin sheets P2 and P3 that are on the same side to the core material 4 to adhere to each other. After the layered molten resin sheet laminate is formed, it is adsorbed to the split mold 50B.

  In the present embodiment, since the molten resin sheets P2 and P3 are sandwiched between the pair of pressure rollers 40A and 40B, the molten resin sheets can be continuously bonded in a wide area and formed 2 The thickness of the molten resin sheet laminate of the layers can also be made constant.

Here, the pressure of the pressure rollers 40A and 40B when the molten resin sheets P2 and P3 are sandwiched between the pressure rollers 40A and 40B may be a pressure that does not change the apparent density of the resin molded product 300 that is the final molded product. preferable. That is, for example, when any one of the molten resin sheets P2 and P3 is a foam layer, it is preferable that the pressure is such that the foaming ratio of the foam layer is not reduced, and in particular, the bubbles in the foam layer are not crushed as much as possible. Specifically, it is preferably 1 kg / cm ² or less. Thereby, even if any one of the molten resin sheets P2 and P3 is a foam layer, the bubbles in the foam layer are not easily crushed, so that the apparent density in the resin molded product 300 as the final molded product is hardly changed. Thus, a two-layer molten resin sheet laminate can be formed.

  Further, when sandwiching the molten resin sheets P2 and P3 with the pressure rollers 40A and 40B, in order to prevent wrinkles from occurring on the surface of the two-layer molten resin sheet laminate to be formed, the molten resin sheets P2 and P3 are placed before the sandwiching. It is preferable to perform pre-blow. In this case, a method such as blowing pre-blow air from the T dies 28b and 28c into the molten resin sheets P2 and P3 can be used.

Further, when the molten resin sheets P2 and P3 are sandwiched between the pressure rollers 40A and 40B, it is preferable to suck air between the molten resin sheets P2 and P3 from the T dies 28b and 28c. Thereby, when molten resin sheet P2, P3 mutually adhere | attaches, it can prevent suitably that an air clogging generate | occur | produces on the adhesion surface.
When the pre-blow air is blown from the T dies 28b and 28c and the air between the molten resin sheets P2 and P3 is sucked, the blowing process and the suction process are dynamically changed. There is a need to.

Further, before the molten resin sheets P2 and P3 are supplied, the pressure rollers 40A and 40B are separated from each other by a distance between the pair of pressure rollers 40A and 40B, and the molten resin sheets P2 and P3 are pushed out to a predetermined length. At this point, the molten resin sheets are brought close to a distance set in advance as a distance for bonding them.
By doing in this way, the operation | movement from the start of extrusion to formation of the molten resin sheet laminated body of 2 layers can be advanced smoothly.

  Thus, as shown in FIG. 15, the molten resin sheets P2 and P3 on the same side with respect to the core material 4 are melted into two layers by the pressure rollers 40A and 40B in a state where the divided molds 50A and 50B are in the open position. It is formed as a resin sheet laminate and is suspended to a predetermined length between the divided molds 50A and 50B.

  Further, the molten resin sheet P1 on the opposite side to the core material 4 is extruded as a single layer from the extrusion slit 34a of the T die 28a, and the thickness and the feeding speed are accurately adjusted by the pair of adjustment rollers 30Aa and 30Ba. The

Next, as shown in FIG. 16, the mold clamping device 14 moves the split mold 50 </ b> A to a position where the pinch-off part 52 </ b> A contacts the molten resin sheet P <b> 1. Move to a position where it contacts the sheet P3.
Then, for each of the divided molds 50A and 50B, the inside of the vacuum suction chambers 53A and 53B is decompressed by a decompression means (not shown), and suction is performed from the vacuum suction chambers 53A and 53B through the suction holes 54A and 54B. Thus, the molten resin sheet P1 is adsorbed toward the cavity surface 51A, and the two-layered molten resin sheet laminate (molten resin sheets P2 and P3) is adsorbed toward the cavity surface 51B.

  Next, as shown in FIG. 17, the core material 4 is pressed in the horizontal direction and bonded to the molten resin sheet P1 adsorbed on the cavity surface 51A. The method of pressing the core material 4 may be various methods such as a method of pressing the core material 4 with a manipulator having a suction disk and then removing the suction disk from the core material 4.

Then, the mold clamping device 14 moves the divided molds 50A and 50B and closes them to the closed position.
At this time, the core material 4 and the two-layer molten resin sheet laminate adsorbed on the cavity surface 51 </ b> B are pressure-bonded and bonded on the surface of the core material 4.

<Effect of the manufacturing method of this embodiment>
As described above, in the present embodiment, the molten resin sheets P2 and P3 on the same side with respect to the core material 4 are bonded to each other by the pressure rollers 40A and 40B, and then the molten resin sheet laminate and the molten resin sheet P1. The mold is clamped so as to sandwich the core material 4 therebetween.
Thus, the molten resin sheets P2 and P3 bonded to each other by the pressure rollers 40A and 40B are arranged on one side with respect to the core material 4, and the molten resin sheet P1 is arranged on the other side and molded. In addition to obtaining the same effects as those of the first to third embodiments described above, the possibility of air trapping between the molten resin sheets P2 and P3 can be further reduced, and the mold is more stable. Tightening can be done.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described.

In the fourth embodiment described above, the mold is clamped so that the core material 4 is sandwiched between the molten resin sheet laminate and the molten resin sheet P1 laminated by the pressure rollers 40A and 40B.
In the fifth embodiment, instead of such an operation, the core material 4 is not sandwiched and finished in a hollow shape.
Description of the same components as those in the first to fourth embodiments described above will be omitted.

<Configuration example of resin molded product 400>
First, a configuration example of a resin molded product 400 molded according to the present embodiment will be described with reference to FIG.

The resin molded product 400 of the present embodiment is a multilayer laminate in which approximately half in the thickness direction is covered with a single resin layer 1 and the remaining approximately half in the thickness direction is composed of a resin layer 2 and a resin layer 3 made of different resins. It becomes the hollow multilayer laminated body covered with. The resin layer 3 constitutes the outer side in the multilayer laminate portion, and the resin layer 2 constitutes the inner side in the multilayer laminate portion.
Each resin layer may be a foamed layer or a non-foamed layer, and may be configured using various known resin materials as described above.

<Example of manufacturing method of resin molded product 400>
Next, an example of a method for manufacturing the resin molded product 400 according to the present embodiment will be described with reference to FIG. FIG. 19 is a diagram for explaining an example of a method for producing the resin molded product 400 according to the present embodiment.

In the present embodiment, similarly to the steps described with reference to FIGS. 15 and 16 in the fourth embodiment described above, the pair of pressure-bonding rollers 40A and 40B causes the molten resin sheets P2 and P3 on the same side to the hollow portion. Are bonded to each other to form a two-layer molten resin sheet laminate, and then adsorbed to the split mold 50B.
Further, the molten resin sheet P1 on the opposite side to the hollow portion is adsorbed to the split mold 50A.

  Next, as shown in FIG. 19, the mold clamping device 14 moves the split molds 50A and 50B to close them to the closed position.

  In this way, when forming by mold clamping, there is a possibility that the hollow portion may not be finished finely in a shape along the shape of the cavity surfaces 51A and 51B depending on conditions such as the shape of the cavity surfaces 51A and 51B of the split molds 50A and 50B. In that case, air may be fed into the hollow portion and blown by a known method such as inserting a pipe from a pipe insertion hole (not shown) provided in the split molds 50A and 50B.

<Effect of the manufacturing method of this embodiment>
As described above, in the present embodiment, the molten resin sheets P2 and P3 that are on the same side with respect to the hollow portion are bonded to each other by the pressure rollers 40A and 40B, and then the molten resin sheet laminate is attached to the split mold 50B. In addition, the molten resin sheet P1 is adsorbed to the split mold 50A. In this way, by clamping the mold in a state of being adsorbed to the divided molds 50A and 50B, approximately half of the periphery of the hollow portion in the plate-shaped resin molded product 400 is covered with the resin layer 1, and the remaining approximately half is resin. The resin molded product 400 covered with the multilayer laminate including the layers 2 and 3 can be molded.
According to the present embodiment, even in such a manufacturing method, the same effect as that of the first embodiment described above can be obtained for the laminate portion of the resin layers 2 and 3.

[About each embodiment]
Each of the above-described embodiments is a preferred embodiment of the present invention, and the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

  For example, the shape of the cavity surfaces 51A and 51B of the split molds 50A and 50B is not limited to the above-described embodiment. For example, the cavity surface on which the core material is not disposed may have an arbitrary shape such as a shape having irregularities.

  Moreover, about the 3rd, 4th embodiment mentioned above, by adjusting suitably the height of the uneven | corrugated shape in the cavity surface of split mold 50A, 50B, as shown, for example to FIG. 20 (a) (b), Even if it is a case where the resin molded product 300 containing the part where all the molten resin sheets inserted | pinched is crushed is molded, this invention can be applied similarly. In this case, the core material 4 may be processed in advance according to the shape in which all the molten resin sheets are crushed. Moreover, when the core material 4 is a material with low hardness, such as a foam, the core material 4 may be crushed by clamping with the divided molds 50A and 50B.

  Moreover, when molding the resin molded product 300 including a portion where all the molten resin sheets sandwiched in this way are crushed, for example, as shown in FIG. 20 (a), either one of the divided molds 50A and 50B is used. The cavity surface may have a shape including irregularities, and as illustrated in FIG. 20B, both cavity surfaces of the split molds 50A and 50B may have a shape including irregularities.

Further, the fifth embodiment described above is also sandwiched as shown in FIGS. 20C and 20D, for example, by appropriately adjusting the height of the concavo-convex shape on the cavity surfaces of the split molds 50A and 50B. The present invention can be similarly applied even when a hollow resin molded product 400 including a portion where all the molten resin sheets are crushed is formed.
Also in this case, for example, as shown in FIG. 20 (c), one of the cavity surfaces of the divided molds 50A and 50B may have a shape including irregularities, as illustrated in FIG. 20 (d). The cavity surfaces of the split molds 50A and 50B may have a shape including irregularities.

  Further, also in the second embodiment described above, the resin molded product 200 having a shape in which the core material 4 is discontinuously arranged is formed by appropriately adjusting the height of the uneven shape on the cavity surface of the split mold. Even in this case, the present invention can be similarly applied. Also in this case, the core material 4 may be processed in advance according to the shape in which all the molten resin sheets are crushed, and the core material 4 is crushed by clamping with the divided molds 50A and 50B. May be.

  In each of the above-described embodiments, the cavity surface is macroscopically concave for both the pair of split molds 50A and 50B. However, the present invention is not limited to this shape. The present invention can be similarly realized even when the concave surface and the other cavity surface are convex.

  Moreover, in each embodiment mentioned above, the case where a pair of split metal mold | die 50A, 50B was used was demonstrated. However, the number of divisions of the divided mold is not limited to two, and the present invention can be similarly realized even when a divided mold divided into an arbitrary number is used.

  Further, the number of T dies is not limited to the number exemplified in each of the above-described embodiments, and may be any number depending on the shape of the target molded product. That is, as long as at least two adjacent single-layer molten resin sheets are bonded together, the number of the molten resin sheets to be arranged is not limited and may be an arbitrary number.

  Moreover, the structure of the extrusion apparatus 12 is not limited to the structure of embodiment mentioned above, As long as the molten resin sheet can be extruded, it may be arbitrary structures.

100, 200, 300, 400 Resin molded product 1, 2, 3 Resin layer P1, P2, P3 Molten resin sheet 10 Molding device 12 Extruding device 14 Clamping device 16 Hopper 18 Cylinder 20 Hydraulic motor 24 Accumulator 26 Plunger 28 T-die 30A, 30B Adjustment roller 34 Extrusion slit 40A, 40B Pressure roller 50A, 50B Split mold 51A, 51B Cavity surface 52A, 52B Pinch-off part 53A, 53B Vacuum suction chamber 54A, 54B Suction hole 55A, 55B Hole

Claims (9)

An extrusion step of extruding a molten resin sheet from each of at least two extrusion slits;
A molding step of molding the resin sheet by sandwiching the resin sheet with a split mold, and
In the molding step, of the resin sheet extruded in the extrusion step, at least two resin sheets extruded in a single layer are molded in a state of being bonded to each other. Production method.   The method for producing a resin molded product according to claim 1, wherein the at least two resin sheets extruded in the single layer are bonded to each other when being molded in the molding step.   3. The resin molded product according to claim 2, wherein in the molding step, all of the resin sheets sandwiched between split molds are blown from one surface side and sucked from the other surface side. 4. Production method. In the molding step, the resin sheet extruded in the extrusion step and the core material are sandwiched and molded by the split mold,
The at least two resin sheets extruded in the single layer are arranged on the same side with respect to the core material in a direction substantially perpendicular to the extrusion direction when sandwiched between the split molds. The manufacturing method of the resin molded product of Claim 2. In the extrusion step, a molten resin sheet is extruded from each of at least three extrusion slits,
In the molding step, at least two resin sheets extruded in the single layer are disposed on one side with respect to the core material, and at least one resin sheet is disposed on the other side with respect to the core material. The method for producing a resin molded product according to claim 4, wherein:   The at least two resin sheets extruded in the single layer are pressed by a pressure roller in a direction substantially perpendicular to the extrusion direction after being extruded, and are bonded to each other before the molding step. The manufacturing method of the resin molded product of Claim 1. In the extrusion step, a molten resin sheet is extruded from each of at least three extrusion slits,
In the molding step, the resin sheet extruded in the extrusion step and the core material are sandwiched and molded by the split mold,
At least two resin sheets crimped by the pressure roller are disposed on one side with respect to the core material, and at least one resin sheet is disposed on the other side with respect to the core material. The manufacturing method of the resin molded product of Claim 6.   7. The method of manufacturing a resin molded product according to claim 6, wherein in the molding step, the at least two resin sheets bonded together are sucked from at least one of the divided molds. In the extrusion step, a molten resin sheet is extruded from each of at least three extrusion slits,
In the molding step, at least two resin sheets pressure-bonded by the pressure roller are adsorbed to the split mold so as to be arranged on one side with respect to the hollow portion, and at least one resin sheet is placed in the hollow portion. The method for producing a resin molded product according to claim 8, wherein the mold is adsorbed to the split mold so as to be disposed on the other side.

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