JP6206555B2 - Resin sandwich panel and method for manufacturing resin sandwich panel - Google Patents

Description

The present invention relates to a resin sandwich panel and a method for manufacturing a resin sandwich panel, and more specifically, a resin sandwich panel and a resin sandwich panel that can maintain light weight and high rigidity while firmly fixing an insert. It relates to a manufacturing method.

Conventionally, so-called sandwich panels have been used for various purposes such as transportation equipment for automobiles, aircrafts, etc., building materials, floors for beds, housings for electrical equipment, sports and leisure.
The sandwich panel has two skin material sheets and a core material interposed between both skin material sheets, and the laminated structure of the skin material sheet, the core material and the skin material sheet is a basic form. Depending on the function required for the sandwich panel changes.
For example, an exterior aesthetic is important, such as an interior panel used in a bathroom, but if not so strong, a cosmetic material is applied to the front side skin sheet that has an appearance. In addition, emphasis is placed on the surface properties or the overall molded shape of the decorative material, and in the case of use as a structural material, strength is required from the appearance of appearance.
In this respect, interior parts of transportation equipment such as automobiles and airplanes, especially cargo floor boards, deck boards, rear parcel shelves, etc. for vehicles are required to be lightweight and strong in terms of fuel efficiency. Therefore, a sandwich panel made of resin in which both the skin material sheet and the core material are made of resin has been frequently used.

More specifically, for example, when a resin sandwich panel is used as a cargo floor lid of an automobile, it is used not only for aesthetic appearance but also for placing heavy loads on the cargo floor lid. While rigidity that can withstand the weight of the load (especially bending rigidity) is required, weight reduction is required from the viewpoint of improving fuel efficiency, and it is necessary to overcome technical challenges that are difficult to achieve both high rigidity and light weight. is there.
Therefore, as a resin-made sandwich panel for such applications, a hard resin material with a high Young's modulus is adopted as the skin material sheet, while a core (thickness of the core material) is used as a core material. While increasing the section modulus by widening the gap between both skin sheets as much as possible, as the core material itself, in order to reduce the weight, for example, a foam material is used, or a hollow portion is provided inside, or the surface The thing which provides many hollows in is employ | adopted.
On the other hand, depending on the application, for example, a metal or resin insert is often attached to such a resin sandwich panel as a mounting bracket or a mounting nut, and a large load is applied to the insert. Because of this, it is highly necessary to embed the insert in a resin sandwich panel and fix it firmly.

In such a resin sandwich panel, in order to achieve a weight reduction by providing a gap in the core material, for example, as disclosed in Patent Document 1 and Patent Document 2, a resin is foamed to countless numbers inside. Air bubbles may be provided.
Patent Document 1 and Patent Document 2 are common as sandwich structures for interior material panels such as automobile deck boards or floor panels, and Patent Document 1 discloses a two-piece melted parison between divided molds. Is positioned, and a foamed core material such as polypropylene, which is preformed between two melted parisons, is placed and pressed against a split mold by vacuum or compressed air to be molded.
In Patent Document 2, in the upper and lower divided molds, a pre-formed back side sheet material softened by reheating is placed on the lower mold, and then the back side sheet material is vacuum sucked through the lower mold. And then placing a foamed resin such as polyethylene on the back side sheet material, and re-heating the softened front side sheet material on the foamed resin. It discloses that the sandwich structure is formed by placing and then clamping with vacuum suction through the upper and lower molds. Patent Document 2 further uses, as an alternative to the foamed resin core material, a lattice-shaped structure formed body, a honeycomb structure formed body, or an embossed structure formed body formed in advance by press punching or injection molding, The point which shape | molds a sandwich structure by the same manufacturing method is disclosed.
According to the sandwich panel as described above, it is possible to reduce the weight by forming bubbles by foaming or forming depressions on the surface.

On the other hand, for such a resin sandwich panel, depending on the application, for example, in the case of an interior panel for a vehicle, a clip or a strap is attached to the outer surface to support and fix the interior panel for a vehicle to the vehicle body. A member may be attached by screwing, and Patent Document 3 discloses a technique for firmly fixing a screw to a panel.
That is, in a resin-made sandwich panel, a metal plate is interposed between one thermoplastic resin sheet and the foam core so as to cover a part of the outer surface of the foam core, so that no metal plate is interposed. This eliminates the problem that the screw comes off the foam core.
However, due to the interposition of such a metal plate, the following technical problems exist.
That is, since the metal plate is provided inside the panel, when the screw is passed through the mounting member on the outside of the panel and screwed into the metal plate from the outer surface of the thermoplastic resin sheet, the metal plate is not visible from the outside. It is difficult to determine the position where the screw is screwed in. To avoid this difficulty, if the area of the metal plate is increased, the weight increases, and the effect of achieving weight reduction by the foam core material is offset. End up.

In order to solve this problem, it is considered to fix the mounting member to the outer surface of the thermoplastic resin sheet by using the welding force during molding instead of the screw tightening force. It is done.
For example, conventionally, according to the manufacturing method as disclosed in Patent Document 1 and Patent Document 2, a through-hole extending in the thickness direction of a space sufficient to attach the mounting member is provided to the foam core material. On the other hand, it is conceivable that the attachment member is welded and fixed to one of the skin material sheets while being inserted partway through.
However, due to such welding and fixing, the following technical problems exist.

First, as shown in FIG. 13, the attachment member is inserted in the middle of the penetration and not only welded and fixed to only one skin sheet, but the attachment member is particularly sensitive to the load in the thickness direction of the sandwich panel. On the other hand, it moved easily, and it was difficult to sufficiently fix the sandwich panel. For example, if a large load is applied to the sandwich panel through the mounting member, the sandwich panel itself may be damaged. Furthermore, when providing a plurality of attachment members, providing the through-holes in the foam core more than necessary causes a reduction in rigidity as a sandwich panel. In this case, if the through hole is too narrow in order to prevent a reduction in rigidity, when the mounting member is inserted into the through hole of the core material, the mounting member interferes with the core material, so that one skin sheet is torn. May cause molding defects. In this case, if the through hole is too narrow in order to prevent a decrease in rigidity, when the insert is inserted into the through hole of the core material, the insert interferes with the core material and one of the skin material sheets may be torn. May cause molding defects.
In this sense, when attaching the mounting member to the resin sandwich panel, while maintaining the light weight and high rigidity as the sandwich panel while firmly fixing the mounting member to the resin sandwich panel, Technically difficult.
In particular, when the insert has a thin plate shape, when the plate surface is attached in a direction orthogonal to the panel surface of the sandwich panel, it is difficult to firmly fix it to the resin sandwich panel.
More specifically, if the plate surface of the insert is surface-bonded to the panel surface of the sandwich panel, the insert does not protrude from the panel surface. For example, the insert protrudes from the side wall of the sandwich panel. When the insert is attached to the sandwich panel, the plate surface must be oriented perpendicular to the panel surface of the sandwich panel, and it is difficult to firmly fix it to the resin sandwich panel. is there.
Second, due to the sandwich panel forming method, it is difficult to obtain a sandwich panel of good quality.
More specifically, as in Patent Document 1 and Patent Document 2, chemical foaming technology or physical foaming technology is generally used to form bubbles by foaming, but in either case, foaming is performed. However, there is no restriction on the molding method for the core material, and it is possible to use extrusion molding, injection molding, blow molding or press molding as in the case of non-foamed core material. Accordingly, particularly in the case of extrusion molding or injection molding, it is difficult to adjust the expansion ratio, and it is difficult to obtain a desired quality.
JP 2006-334801 A JP 2008-247003 A JP 2010-52389 A

In view of the above technical problems, an object of the present invention is to provide a resin sandwich panel and a resin sandwich panel manufacturing method capable of maintaining light weight and high rigidity while firmly fixing an insert.

In order to achieve the above object, the resin sandwich panel of the present invention comprises:
In a sandwich panel having two resin skin sheets and a resin core material that is surface-bonded to both skin sheets in a form sandwiched between both skin sheets,
At least one outer surface of the two resin skin sheets is provided with a recess extending toward the other resin skin sheet,
A plate-like insert that is in close contact with an outer surface portion of one resin skin material sheet that constitutes the recessed portion, and is substantially orthogonal to the outer surface of one resin skin material sheet. A plate-like insert inserted from the outside in the direction is provided,
In the corresponding position of the plate-like insert of the resin core material, a space extending in the thickness direction of the resin core material is provided,
The width of the space is set to be greater than the sum of the plate thickness of the plate-like insert and twice the thickness of one resin skin sheet,
Accordingly, the inner surface portion of one resin skin material sheet constituting the bottom of the recessed portion is joined to the inner surface of the other resin skin material sheet, and the plate-like insert has the recessed portion on the other side. It is set as the structure fixed to the said sandwich panel by joining to the sheet | seat of this.

According to the resin sandwich panel having the above configuration, two resin skin sheets and a resin foam core that is surface-bonded to each of the skin sheets in a form sandwiched between the resin skin sheets. One of the two resin skin layers is provided on the outer surface of at least one of the two resin skin sheets, and has a recess extending toward the other resin skin sheet. A plate-like insert is provided that is in close contact with the outer surface portion of the material sheet, and is inserted from the outside to the outer surface of one resin skin sheet in a direction in which the plate surface is orthogonal to the outer surface. In the corresponding position of the plate insert of the resin foam core material, there is a space large enough not to contact the plate insert, the width of which is the thickness of the plate insert and the thickness of one resin skin sheet. Combined with twice the thickness Since it is provided in a larger form across the thickness direction of the resin foam core material, the inner surface portion of one resin skin sheet constituting the bottom of the recess is the other resin skin material. Bonded to the inner surface of the sheet, the plate-like insert can be fixed to the sandwich panel by bonding the concave part to one resin skin sheet, and the plate-like insert is firmly fixed However, light weight and high rigidity can be maintained.

Further, the space may be constituted by a through hole provided in the resin core material.
Furthermore, the space may be constituted by a notch provided in the resin core material.
Furthermore, the space may be formed by a gap between adjacent core members in the divided resin core member.
In addition, the plate-like insert has an insertion portion that is inserted into the recessed portion, and the insertion portion has an opening, and opposing portions of one of the resin skin sheets that constitute the recessed portion Are preferably joined through the opening.

Furthermore, the plate-like insert further has a protruding portion connected to the insertion portion, and the insertion portion is embedded in the recessed portion and corresponds to the one resin skin material sheet constituting the recessed portion. The recessed portion may be closed by a portion, and the protruding portion may be provided so as to protrude from a side surface of the resin sandwich panel.
Furthermore, a concave portion extending toward the one resin skin material sheet is provided on an outer surface of the corresponding position of the concave portion of the other resin skin material sheet, and the concave portion and the concave portion are provided. Butt-joining may also be used.
In addition, a metallic reinforcement may be provided in a gap between the divided resin cores.

In order to achieve the above object, a method for producing a resin sandwich panel of the present invention comprises:
A method for forming a sandwich panel having a resin core material interposed between two resin skin sheets, using two molten thermoplastic resin sheets,
A plate-like insert fixed to the sandwich panel and a cavity of one mold are provided with a recess that opens toward the other mold and into which the plate-like insert is inserted in a direction substantially perpendicular to the cavity. The pair of split molds and the width orthogonal to the plate surface are set to be equal to or greater than the sum of the plate thickness of the plate-like insert and twice the thickness of one molten thermoplastic resin sheet. Preparing a resin core having a space extending in a direction;
In a form that protrudes around the annular pinch-off portion formed at the peripheral edge of the cavity of each of the pair of split molds, two molten thermoplastic resin sheets are placed between the pair of split molds. The stage of placement;
A sealed space is formed between the at least one mold and the corresponding thermoplastic resin sheet, and air is decompressed from the sealed space, so that the thermoplastic resin sheet is sucked and applied along the cavity. The sheet is formed on the thermoplastic resin sheet while forming a recess recessed toward the other split mold in accordance with the plate-like insert that is inserted into the recess in advance and protrudes from the cavity. Welding the projecting outer surface of the insert to the recess;
Positioning the space of the preformed resin core disposed between the two molten thermoplastic resin sheets with respect to the recessed portion, and passing the recessed portion through the space, The pair of split molds are moved to the mold clamping position, and the inner surfaces of the two thermoplastic resin sheets are welded along the pinch-off portions of the pair of molds, thereby making two strips of thermoplastic resin. While integrating the peripheral portions of the sheet and welding the inner surface of the thermoplastic resin sheet and the corresponding surface of the resin core material, the other thermoplastic resin is connected to the bottom of the recessed portion via the space. Having the step of welding to the inner surface of the sheet made of
Thereby, the plate-like insert is firmly fixed to the resin sandwich panel.

Further, it is preferable that the resin core material is pressed and welded to the thermoplastic resin sheet formed by suction before clamping the pair of split molds.
Further, the plate-like insert has an insertion portion that is inserted into the recessed portion, and the insertion portion has an opening,
In the suction step, the portions of the thermoplastic resin sheets that are pressed against the projecting outer surface of the plate-like insert and that form a recessed portion are in the opening and welded to each other through the opening. It is good.
Further, the depressurizing step includes a step of moving an outer frame that is externally fitted to a peripheral edge of the at least one divided mold in a mold clamping direction toward an outer surface of the corresponding thermoplastic resin sheet. And it is good to comprise sealed space with the outer surface of the said sheet | seat made from a thermoplastic resin, the internal peripheral surface of the said outer frame, and each cavity of a pair of said division mold.
Furthermore, the one and / or the other thermoplastic resin sheet may be preformed in advance and reheated to be in a molten state.
In addition, it is preferable to have a step of extruding the one and the other molten thermoplastic resin sheet downward between the pair of split molds in a form of hanging downward.

Further, the thermoplastic resin sheet may be formed into two sheets by extruding a molten cylindrical parison and cutting the cylindrical parison along the extrusion direction at least at two locations during extrusion. Good.
Furthermore, the resin core material may be a foamed resin having a predetermined expansion ratio.

It is a fragmentary perspective view around the plate-shaped insert 40 of the resin sandwich panel 10 according to the embodiment of the present invention. FIG. 2 is a sectional view taken along line AA in FIG. 1. 1 is a perspective view of a plate-like insert 40 of a resin sandwich panel 10 according to an embodiment of the present invention. It is a top view which shows the relationship between the foaming core material 13 and the plate-shaped insert 40 of the resin sandwich panel 10 which concerns on embodiment of this invention. It is a top view which shows the relationship between the foaming core material 13 of the resin sandwich panel 10 and the plate-shaped insert 40 which concern on the modification of this invention. It is a top view which shows the relationship between the foaming core material 13 of the resin sandwich panel 10 and the plate-shaped insert 40 which concern on the further modification of this invention. It is a figure similar to FIG. 1 of the resin sandwich panel 10 which concerns on the modification of this invention. The outline of the shaping | molding apparatus of the resin sandwich panel 10 which concerns on embodiment of this invention is shown, and in the shaping | molding process of the resin sandwich panel 10 which concerns on embodiment of this invention, the sheet | seats P1 and P2 made of thermoplastic resin are divided | segmented. It is a figure which shows the state arrange | positioned between metal mold | dies. FIG. 5 is a schematic side view showing a state in which the mold of the split mold 73 is in contact with the side surface of the thermoplastic resin sheet P1 in the molding process of the resin sandwich panel 10 according to the embodiment of the present invention. FIG. 3 is a schematic partial cross-sectional view showing a state in which a thermoplastic resin sheet P1 is shaped in the molding process of the resin sandwich panel 10 according to the embodiment of the present invention. It is a figure which shows the state which clamped the division mold 73 in the formation process of the resin sandwich panel 10 which concerns on embodiment of this invention. It is a figure which shows the state which open | released the division mold 73 in the formation process of the resin sandwich panel 10 which concerns on embodiment of this invention. It is a fragmentary sectional view around the plate-like insert 40 of the conventional resin sandwich panel 10.

Embodiments of the resin sandwich panel and the method for producing such a sandwich panel according to the present invention will be described below in detail with reference to the drawings.

The sandwich panel 10 according to the present invention is a structural member resistant to bending rigidity or bending buckling for automobiles, aircrafts, vehicles / ships, building materials, housings for various electrical equipment, bed floors, sports / leisure. Can be suitably used. In particular, it can improve fuel efficiency from the viewpoint of weight reduction as a structural member for automobiles, specifically, interior panels such as cargo floor boards, deck boards, rear parcel shelves, roof panels, door trims, and other doors. It contributes to weight reduction as a structural member such as an inner panel, platform, hardtop, sunroof, bonnet, bumper, floor spacer, devia pad, etc. The shape of the sandwich panel 10 can be appropriately determined according to the purpose of the product. .

In the present embodiment, the sandwich panel 10 will be described below by taking as an example a case where the sandwich panel 10 is used for a cargo floor lid of an automobile that is required to be lightweight and highly rigid.

As shown in FIG. 1 and FIG. 2, such a sandwich panel 10 has a foaming property that is interposed between the front side skin material sheet 12A, the back side skin material sheet 12B, and both skin material sheets 12A and 12B. The foamed core material 13 and a decorative material sheet 14 bonded to the outer surface of the front surface skin sheet 12A. The sandwich panel 10 includes a decorative material sheet 14 and a front surface skin material sheet. It is a laminated structure of 12A, the foam core material 13, and the back surface skin sheet 12B.

The plate-like insert 40 will be described. The plate-like insert 40 is a jig attached to the sandwich panel 10 from the outside. For example, the plate-like insert 40 is used to fix a separate member to the sandwich panel 10. There is a need to be firmly fixed to the sandwich panel 10.
As shown in FIG. 3, the plate-like insert 40 is made of plate-like metal, and a main body portion 42 protruding from the side surface of the back-side skin material sheet 12B to which the plate-like insert 40 is attached, and the back-side skin material sheet. And an insertion portion 46 to be inserted into a recessed portion 44 (described later) provided on the outer surface 41 of 12B. The plate-like insert 40 is inserted into the outer surface 41 of the back-side skin material sheet 12B in a direction substantially orthogonal to the outer surface 41 of the back-side skin material sheet 12B constituting the recessed portion 44. Is done. The main body portion 42 is provided with a recess 48 for mounting a separate member to fix the separate member using, for example, the plate-like insert 40, and the insertion portion 46 is obliquely connected to the main body portion 42. The insertion portion 46 has an opening 52, and opposing portions of the back surface skin sheet 12B constituting the recessed portion 44 are joined to each other through the opening 52, whereby the plate-like insert 40 is connected to the back surface side. It is designed to be more firmly fixed to the skin material sheet 12B. The shape or size of the opening 52 may be determined from such a viewpoint in relation to the plate thickness of the plate-like insert 40, that is, the depth of the opening 52.

The depth of the insertion portion 46 is such that when the sandwich panel 10 is formed, the recessed portion 44 of the back side skin material sheet 12B formed thereby can be abutted and welded to the inner surface 43 of the front side skin material sheet 12A. In this sense, a welding surface 45 is formed at the tapered distal end portion of the insertion portion 46, and the width thereof, that is, the plate thickness of the plate-like insert 40, is determined by the back surface skin sheet 12B. What is necessary is just to determine from the viewpoint that the recess 44 is sufficiently abutted and welded to the inner surface 43 of the front side skin material sheet 12 </ b> A, whereby the plate-like insert 40 is firmly fixed to the sandwich panel 10.
The insertion portion 46 is embedded in the recessed portion 44, and the recessed portion 44 is closed by a corresponding portion of the back surface skin sheet 12B constituting the recessed portion 44, and the main body portion 42 is formed of the resin sandwich panel 10. It is provided so as to protrude from the side wall, which is advantageous, for example, for adhering the decorative material 14 not only to the front side skin sheet 12A but also to the back side skin sheet 12B.
As described above, the plate-like insert 40 is inserted from the outside into the back-side skin material sheet 12B in a form in close contact with the outer peripheral surface portion of the back-side skin material sheet 12B constituting the recessed portion 44.

A through hole 50, which is a space that does not contact the plate-like insert 40, extends in the thickness direction of the resin-made foam core 13 at a position corresponding to the plate-like insert 40 of the resin-made foam core 13. Thus, the portion of the inner surface 47 of the back side skin material sheet 12B constituting the bottom of the recessed portion 44 is joined to the inner surface 43 of the front side skin material sheet 12A through the through hole 50. The plate-like insert 40 is firmly fixed to the sandwich panel 10 by joining the recessed portion 44 to the front surface skin sheet 12A which is the other sheet.

More specifically, the shape of the through hole 50 is a rectangular parallelepiped, and the axis of the through hole is provided so as to be orthogonal to the back surface skin sheet 12B. The shape of the through-hole 50 may be determined according to the shape of the plate-like insert 40, and a molten thermoplastic resin sheet P1 constituting the back-side skin material sheet 12B that covers the outer peripheral surface of the plate-like insert 40. May be determined from the viewpoint of preventing the molten thermoplastic resin sheet P1 from being torn and causing poor molding by contacting the through hole 50 of the foam core 13. In particular, when a plurality of plate-like inserts 40 are provided for the sandwich panel 10 and a plurality of through holes 50 are provided for the foam core member 13 for that purpose, each of the through-holes is provided from the viewpoint of ensuring high rigidity of the sandwich panel 10. The size of the hole 50 is preferably as small as possible, and the size of the through hole 50 may be determined so that the plate-like insert 40 is easily inserted without contact and does not cause a decrease in rigidity.
More specifically, as shown in FIG. 2, the width X of the space is set to be larger than the sum of the plate thickness t1 of the plate-like insert 40 and twice the thickness t2 of the back surface skin sheet 12B. When molding the resin sandwich panel 10 (described later), when the plate-like insert 40 is inserted into the through hole 50, the back-side skin material sheet 12B that is in close contact with the outer peripheral surface of the plate-like insert 40 is configured. The molten thermoplastic resin sheet P <b> 1 does not come into contact with the inner peripheral surface of the through hole 50.
The position where the space is provided may be determined according to the position where the plate-like insert 40 is provided in the sandwich panel 10. As a modification, as shown in FIGS. 4 to 6, the space is provided in the resin foam core 13. Alternatively, the space may be formed by a gap 58 between the adjacent foam cores 13 in the divided resin foam core 13. In this case, a metal reinforcement (not shown) may be provided in the gap 58 between the divided resin foam cores 13, thereby ensuring the rigidity of the sandwich panel 10. It is.

The foam core 13 is formed of a resin to which a foaming agent is added. Examples of the resin that forms the foamed core material 13 include polyolefins (for example, polypropylene and high-density polyethylene) that are homopolymers or copolymers of olefins such as ethylene, propylene, butene, isoprenepentene, and methylpentene, polyamide, and polystyrene. , Acrylic derivatives such as polyvinyl chloride, polyacrylonitrile, ethylene-ethyl acrylate copolymer, polycarbonate, vinyl acetate copolymers such as ethylene-vinyl acetate copolymer, terpolymers such as ionomer, ethylene-propylene-dienes, Examples include acrylonitrile-styrene copolymer, ABS resin, polyphenylene oxide, polyacetal, phenol resin, polymethacrylimide, and polyetherimide. In addition, these may be used individually by 1 type, or may mix and use 2 or more types. In particular, by making the foam core material 13 and the skin material sheet 12 the same material, they can be bonded by heat welding without using a solvent or the like. The foam core material 13 may contain an additive. Examples of the additive include silica, mica, talc, calcium carbonate, glass fiber, carbon fiber, and other inorganic fillers, plasticizers, stabilizers, colorants, An antistatic agent, a flame retardant, a foaming agent, etc. are mentioned.

  As the foaming agent used in the present invention, any of physical foaming agents, chemical foaming agents and mixtures thereof may be used. As physical foaming agents, inorganic physical foaming agents such as air, carbon dioxide, nitrogen gas, and water, and organic physical foaming agents such as butane, pentane, hexane, dichloromethane, dichloroethane, and their supercritical fluids are used. be able to. As the supercritical fluid, carbon dioxide, nitrogen or the like is preferably used. If nitrogen is used, the critical temperature is 149.1 ° C. and the critical pressure is 3.4 MPa or more. If carbon dioxide is used, the critical temperature is 31 ° C. and the critical pressure is 7 It is obtained by setting it to 4 MPa or more.

The outer surface 41 of the back surface skin sheet 12B is provided with a recessed portion 44 extending toward the front surface skin sheet 12A. As will be described later, when the sandwich panel 10 is molded, the plate-like insert 40 is fitted in the cavity recess 75 provided in one cavity 74A of the split mold 73, whereby the back-side skin material The melted thermoplastic resin sheet P1 forming the sheet 12B is vacuum-sucked toward the one cavity 74A, and the recessed portion 44 having a shape along the outer peripheral surface of the insertion portion 46 of the plate-like insert 40 is formed. It depends.

As a modification, as shown in FIG. 7, the outer surface 47 at a corresponding position of the recessed portion 44 of the front surface skin sheet 12A is provided with a recess 48 extending toward the back surface skin sheet 12B. The recess 44 and the recess 48 may be butt-joined. This is because if the thickness of the foam core 13 is large and the concave portion 44 that extends over the entire thickness of the foam core 13 is provided only on the back surface skin sheet 12B, the blow ratio of the molten thermoplastic resin sheet P is high. It is useful to prevent such a situation by providing a recess in both the resin skin sheets 12 when it becomes too thin and a thin wall portion is formed, resulting in a decrease in rigidity and possibly tearing. is there.

The skin material sheet 12 is made of a sheet formed of polypropylene, engineering plastics, olefin resin, or the like. From the viewpoint of ensuring the rigidity of the sandwich panel 10 as a whole, particularly the bending rigidity, by ensuring the space between the skin sheet sheets 12 provided on both sides of the foam core material 13, that is, the bulk (thickness) of the foam core material 13. As the rigidity of the skin sheet 12, a material that is at least higher than the rigidity of the foam core 13 is required. The skin material sheet 12 constitutes an upper surface wall and a lower surface wall of the sandwich panel 10, and preferably, the end of the skin material sheet 12 a and the skin material sheet 12 b are welded and integrated by a pinch-off portion on the outer periphery of the sandwich panel 10. . A gap (not shown) is formed between the outer peripheral side wall of the sandwich panel 10 and the outer periphery of the foam core member 13, whereby the sandwich is formed by the difference in thermal shrinkage between the skin material sheet 12 and the foam core member 13 after molding. The deformation of the panel 10 can be prevented.

More specifically, the skin material sheet 12 is preferably made of a resin material having a high melt tension from the viewpoint of preventing the occurrence of variations in thickness due to drawdown, neck-in, or the like. In order to improve transferability and followability, it is preferable to use a resin material with high fluidity.
Specifically, it is a polyolefin (for example, polypropylene, high density polyethylene) which is a homopolymer or copolymer of olefins such as ethylene, propylene, butene, isoprene pentene, methyl pentene, etc., and has an MFR (JIS K) at 230 ° C. Measured at a test temperature of 230 ° C. and a test load of 2.16 kg according to −7210) of 3.0 g / 10 min or less, more preferably from 0.3 to 1.5 g / 10 min, or acrylonitrile butadiene styrene Amorphous resin such as copolymer, polystyrene, high impact polystyrene (HIPS resin), acrylonitrile / styrene copolymer (AS resin), MFR at 200 ° C. (test temperature 200 ° C. according to JIS K-7210) , Measured at a test load of 2.16 kg) is 3.0-60 g / 10 min. Preferably, the melt tension at 230 ° C. is 30 to 50 g / 10 min (using a melt tension tester manufactured by Toyo Seiki Seisakusho Co., Ltd., a preheating temperature of 230 ° C., an extrusion speed of 5.7 mm / min, a diameter of 2.095 mm, A strand is extruded from an orifice having a length of 8 mm, and a tension when the strand is wound around a roller having a diameter of 50 mm at a winding speed of 100 rpm is 50 mN or more, preferably 120 mN or more.

Further, in order to prevent the skin material sheet 12 from being cracked by impact, it is preferable that a hydrogenated styrene-based thermoplastic elastomer is added in a range of less than 30 wt%, preferably less than 15 wt%. Specifically, a styrene-ethylene / butylene-styrene block copolymer, a styrene-ethylene / propylene-styrene block copolymer, a hydrogenated styrene-butadiene rubber and a mixture thereof are suitable as the hydrogenated styrene-based thermoplastic elastomer. The styrene content is less than 30 wt%, preferably less than 20 wt%, and the MFR at 230 ° C. (measured at a test temperature of 230 ° C. and a test load of 2.16 kg according to JIS K-7210) is 1.0 to 10 g / 10. Minute, preferably 5.0 g / 10 min or less and 1.0 g / 10 min or more.

   Furthermore, the skin material sheet 12 may contain an additive in the same manner as the foamed core material 13, and examples of the additive include silica, mica, talc, calcium carbonate, glass fiber, carbon fiber and other inorganic fillers, Examples include plasticizers, stabilizers, colorants, antistatic agents, flame retardants, and foaming agents. Specifically, silica, mica, glass fiber or the like is added in an amount of 50 wt% or less, preferably 30 to 40 wt%, based on the molding resin.

In the case where the decorative material sheet 14 is provided on the surface of the skin material sheet 12, the decorative material sheet 14 is an object that improves appearance, decoration, and contacts with the molded product (for example, in the case of a cargo floor board, placed on the upper surface of the board). Configured for the purpose of protecting the baggage, etc.). As the material of the decorative material sheet 14, a fiber skin material sheet-like skin material, a film-like skin material, or the like is applied. As the material of such a fiber skin material, synthetic fibers such as polyester, polypropylene, polyamide, polyurethane, acrylic and vinylon, semi-synthetic fibers such as acetate and rayon, regenerated fibers such as viscose rayon and copper ammonia rayon, cotton, hemp, Examples thereof include natural fibers such as wool and silk, or blended fibers thereof.

Next, an apparatus and a method for molding the resin sandwich panel 10 having the above configuration using a mold will be described.
As shown in FIG. 8, the molding device 60 of the resin sandwich panel 10 includes an extrusion device 62 and a mold clamping device 64 disposed below the extrusion device 62, and is in a molten state extruded from the extrusion device 62. The thermoplastic resin sheet P is sent to the mold clamping device 64, and the mold clamping device 64 molds the molten thermoplastic resin sheet P.

  The extruding device 62 is a conventionally known type, and detailed description thereof is omitted. However, a cylinder 66 provided with a hopper 65, a screw (not shown) provided in the cylinder 66, and a screw are connected to the screw. A hydraulic motor 68, an accumulator 70 that communicates with the inside of the cylinder 66, and a plunger 72 provided in the accumulator 70. The molten resin is melted and kneaded by the rotation of the resin, and the molten resin is transferred to the accumulator chamber and stored in a certain amount. The plunger 72 is driven to feed the molten resin toward the T die 71 and continuously through the die slit (not shown). A sheet-like thermoplastic resin sheet P is extruded and spaced apart. While being pinched by the pair of rollers 79, it is sent downward and is suspended between the split molds 73. Thereby, the sheet-like thermoplastic resin sheet P is disposed between the split molds 73 without being wrinkled or loosened.

The extrusion capability of the extrusion device 62 is appropriately selected from the viewpoints of the size of the front side skin material sheet 12A and the back side skin material sheet 12B to be molded, and the prevention of the drawdown of the thermoplastic resin sheet P. More specifically, from a practical viewpoint, the extrusion rate of the resin from the die slit is several hundred kg / hour or more, more preferably 700 kg / hour or more. Further, from the viewpoint of preventing the drawdown of the thermoplastic resin sheet P, the extrusion process of the thermoplastic resin sheet P is preferably as short as possible and generally depends on the type of resin and the MFR value. Should be completed within 40 seconds, more preferably within 30 seconds. For this reason, the extrusion area per unit area and unit time of the thermoplastic resin from the die slit is 50 kg / hour cm ² or more, more preferably 60 kg / hour cm ² or more.

  The die slit 75 is arranged vertically downward, and the thermoplastic resin sheet P pushed out from the die slit 75 is sent vertically downward in a form that hangs down from the die slit 75 as it is. By making the width of the die slit variable, it is possible to change the thickness of the continuous sheet-like thermoplastic resin sheet P.

  On the other hand, the mold clamping device 64 is also a conventionally known type like the extrusion device 62, and detailed description thereof will be omitted. A mold driving device that moves between an open position and a closed position in a direction substantially orthogonal to the supply direction of the plastic resin sheet P;

  The two divided molds 73 are arranged with the cavities 74 facing each other, and are arranged so that the cavities 74 are directed substantially in the vertical direction. The surface of each cavity 74 is in accordance with the outer shape and the surface shape of the front side skin material sheet 12A and the back side skin material sheet 12B which are molded based on the molten sheet-like thermoplastic resin sheet P. An uneven portion is provided.

  In each of the two divided molds 73, a pinch-off portion 76 is formed around the cavity 74. The pinch-off portion 76 is formed in an annular shape around the cavity 74 and protrudes toward the opposing mold 73. To do. As a result, when the two divided molds 73 are clamped, the tip portions of the respective pinch-off portions 76 come into contact with each other so that the parting line PL is formed at the periphery of the molten thermoplastic resin sheet P. I have to.

  A cavity recess 75 for fitting the main body 42 of the plate-like insert 40 is formed in the cavity 74A of one mold 73A of the split mold 73 for shaping the molten sheet-like thermoplastic resin sheet P1. The cavity recess 75 is formed so that the sheet-like thermoplastic resin sheet P1 is a cavity when the molten sheet-like thermoplastic resin sheet P1 forming the back surface sheet 12B is suction-molded toward the cavity 74A. It is pressed against the outer peripheral surface of the insertion portion 46 of the plate-like insert 40 projecting from 74A so as to form the recess 44 and not to flow into the gap between the cavity recess 75 and the main body 42. The main body 42 of the insert 40 is fitted with no gap.

  A mold 81 is slidably fitted around the outer periphery of the divided mold 73A, and the mold 81 can be moved relative to the mold 73A by a mold moving device (not shown). More specifically, the mold 81 can contact one side 83 of the thermoplastic resin sheet P1 disposed between the molds 73 by protruding toward the mold 73B with respect to the mold 73A. It is.

  As shown in FIG. 10, a vacuum suction chamber 85 is provided inside the split mold 73 </ b> A. The vacuum suction chamber 85 communicates with the cavity 74 </ b> A through the suction hole 87, and the suction hole 87 extends from the vacuum suction chamber 85. The sheet P1 made of the thermoplastic resin is adsorbed toward the cavity 74A and is shaped into a shape along the outer surface of the cavity 74A.

  The mold driving device is the same as the conventional one, and the description thereof is omitted. However, the two divided molds 73 are each driven by the mold driving device, and in the open position, the two divided molds are used. 73, two continuous sheet-like thermoplastic resin sheets P1 and 2 in a molten state can be arranged with a space between each other, and in one closed position, the pinch-off portions of the two split molds 73 76 abuts and the annular pinch-off portions 76 abut each other so that a sealed space is formed in the two split molds 73. As for the movement of each mold 73 from the open position to the closed position, the closed position is the position of the center line of the two continuous sheet-like thermoplastic resin sheets P1 and 2 in the molten state. It is driven by the mold driving device so as to move toward the position.

Next, a method for forming the resin sandwich panel 10 using the above-described forming apparatus will be described.
The foam core material 13 in which the through hole 50 is formed is prepared in advance, and the plate-like insert 40 is fitted into the cavity concave portion 75 of the cavity 74A so that the insertion portion 64 of the plate-like insert 40 faces the other mold 73B. It arrange | positions so that it may protrude from the cavity 74A. Further, the decorative material 14 is placed in the cavity 74B.
Next, as shown in FIG. 8, the thermoplastic resin sheets P1 and P2 in the molten state are extruded vertically downward from the corresponding die slits 75 to correspond to the two continuous sheet-like thermoplastic resin sheets P1 and P2. The sheet is supplied between the two divided molds 73 so as to protrude from the pinch-off portion 76.
In addition, since the thermoplastic resin sheet P1 that forms the recessed portion 44 has a higher blow ratio than the planar thermoplastic resin sheet P2 that does not form the recessed portion 44, in consideration thereof, When extruding from the die slit 75, the thickness of the thermoplastic resin sheet P1 may be set larger than the thickness of the thermoplastic resin sheet P2.

  Next, as shown in FIG. 9, the mold frame 81 of the split mold 73A is moved toward the thermoplastic resin sheet P1 with respect to the split mold 73A so as to contact the side surface 83 of the thermoplastic resin sheet P1. Make contact. As a result, a sealed space 84 is formed by the side surface 83 of the thermoplastic resin sheet P1, the inner peripheral surface of the mold 81, and the cavity 73A.

  Next, as shown in FIG. 10, by sucking the air in the sealed space 84 from the vacuum suction chamber 85 through the suction hole 87, the thermoplastic resin sheet P1 is adsorbed to the cavity 74A, thereby The thermoplastic resin sheet P1 is shaped into a shape along the surface of the cavity 74A. More specifically, in accordance with the plate-like insert 40 that is fitted in the cavity recess 75 in advance and protrudes from the cavity 74A with respect to the thermoplastic resin sheet P1, the recess 44 that is recessed toward the other split mold 73B. The insertion portion 46 of the plate-like insert 40 is welded to the recessed portion 44. In this case, the portions of the thermoplastic resin sheet P1 facing each other that form the recesses are welded to each other through the opening 52 of the insertion portion 46, and thus the opening 52 of the plate-like insert 40 is formed. By passing the thermoplastic resin sheet P1 through, the plate-like insert 40 can be more firmly fixed to the thermoplastic resin sheet P1.

Next, the foam core material 13 is disposed between the two thermoplastic resin sheets P1 and 2 in parallel with both sheets, and, for example, using a known manipulator or the like, the through hole 50 of the foam core material 13 is formed. The position is adjusted with respect to the position of the formed recessed portion 44, and the recessed portion 44 is made to pass through the through hole 50 so that the recessed portion 44 that is the molten thermoplastic resin sheet P <b> 1 does not contact the through hole 50. The surface of the foamed core material 13 is pressed against the inner surface of the thermoplastic resin sheet P1 while being passed through. In this sense, it is advantageous to dispose the foamed core material 13 at the stage where the recessed portion 44 is formed because the target position of the through hole 50 can be easily set.
In particular, the width X perpendicular to the plate surface of the through hole 50 is exactly the sum of the plate thickness t1 of the plate-like insert 40 and twice the thickness of the molten thermoplastic resin sheet P1. As long as the thickness of the thermoplastic resin sheet P1 is set, the portion of the thermoplastic resin sheet P1 that forms the recessed portion 44 is inevitably thinned by suction molding. It is possible to reliably prevent the molten thermoplastic resin sheet P1 from coming into contact with the inner peripheral surface of the through-hole 50 when it is inserted into the through hole 50 to cause molding defects and, in some cases, tearing.

  Next, as shown in FIG. 11, in the state where the thermoplastic resin sheet P1 is sucked and held in a state where the mold 81 that is in contact with the outer surface 83 of the thermoplastic resin sheet P1 is held as it is, The molds 73A and 73B are moved toward each other until the pinch-off portions 76A and B come into contact with each other, and the molds are clamped.

More specifically, the pair of split molds 73 are moved to the mold clamping position, and the inner surfaces of the two thermoplastic resin sheets P1, 2 are welded along the pinch-off portions of the pair of molds 73. As a result, the peripheral portions of the two thermoplastic resin sheets P1 and P2 are integrated with each other, and the foamed resin is welded and fixed to the inner surface of the thermoplastic resin sheet P2 and the thermoplastic resin sheet P1. While welding the corresponding surface of the core material 13 and the decorative material 14 being welded to the thermoplastic resin sheet P <b> 2, the other thermoplastic resin is made through the through hole 50 through the welding surface 45 at the bottom of the recessed portion 44. The insert 40, which is welded to the inner surface of the sheet P2 and is firmly fixed to the thermoplastic resin sheet P1, is welded and fixed to the thermoplastic resin sheet P2 by the thermoplastic resin sheet P1. Sun It is firmly fixed to the Deutsch panel 10.
The extruded thermoplastic resin sheet P may be formed into a sheet by crushing the molten cylindrical parison, and the thermoplastic resin sheet P is extruded from the molten cylindrical parison, The cylindrical parison may be cut along the extrusion direction at least at two places during extrusion to form two sheets.

Next, as shown in FIG. 12, the two divided molds 73 are opened, the completed resin sandwich panel 10 is separated from the cavity 74, and burrs formed around the parting line PL are removed.
Thus, the molding of the resin sandwich panel 10 is completed.

  As described above, each time the molten thermoplastic resin is intermittently extruded, it is possible to efficiently form the resin sandwich panel 10 one after another by repeating the above-described steps. Thus, it is possible to intermittently extrude the thermoplastic resin sheets P1 and P2 in a molten state, and shape the extruded thermoplastic resin sheets P1 and P2 into a predetermined shape using a mold 73.

According to the resin sandwich panel 10 having the above-described configuration, two resin skin sheets and a resin foam core material that is surface-bonded to both skin sheets in a form sandwiched between both skin sheets. 13 is provided on the outer surface of at least one back side skin material sheet 12B of the two resin skin material sheets with a recessed portion 44 extending toward the front side skin material sheet 12A, In a form in close contact with the outer surface portion of the back side skin material sheet 12B constituting the recessed portion 44, the plate surface is oriented in a direction orthogonal to the outer surface from the outside with respect to the outer surface of the back side skin material sheet 12B A plate-like insert 40 to be inserted is provided, and at a position corresponding to the plate-like insert 40 of the resin foam core material 13, there is a space large enough not to contact the plate-like insert 40, and its width is plate-like. insert Since it is provided over the thickness direction of the resin foam core material 13 in a form larger than the sum of the plate thickness of 40 and twice the thickness of the back surface skin sheet 12B, the bottom of the recessed portion 44 is configured. The portion of the inner surface of the back-side skin material sheet 12B to be joined is joined to the inner surface of the front-side skin material sheet 12A, and the plate-like insert 40 has the recess 44 joined to the back-side skin material sheet 12B. Thus, it is possible to be fixed to the sandwich panel 10, and it is possible to maintain lightness and high rigidity while firmly fixing the plate-like insert 40.

The embodiments of the present invention have been described in detail above, but various modifications or changes can be made by those skilled in the art without departing from the scope of the present invention.
For example, in the present embodiment, the thermoplastic resin sheets P1 and P2 in a molten state extruded from the extrusion slit are directly formed. However, the present invention is not limited thereto, and one and / or the other thermoplastic resin sheet P1 is used. , P2 may be preformed in advance and reheated into a molten state.
Moreover, in this embodiment, although the case where the single plate-like insert 40 was provided was demonstrated, it is not limited to it, For example, the some plate-like insert 40 is on a straight line at intervals in the longitudinal direction of a sandwich. In that case, the size of the through hole 50, the notch 56 or the gap 58 provided in the foam core 13 is inserted from the viewpoint of preventing the rigidity from being lowered. As small as possible, it is preferable that the interference is as small as possible.

Furthermore, in the present embodiment, it has been described that the split mold is clamped after being pressed against one thermoplastic resin sheet P1 formed by suction molding the foam core 13 and then fixed thereto. The foamed core material 13 is positioned between the two thermoplastic resin sheets P1 and P2, and the foamed core material 13 is fixed to the both thermoplastic resin sheets P1 and P2 by clamping the divided molds. In this case, it is necessary to clamp the mold while passing the recessed portion 44 of the thermoplastic resin sheet P1 so as not to contact the through hole 50 of the foam core 13.
Furthermore, in the present embodiment, the case where the decorative material is provided only on the back surface side thermoplastic resin sheet P has been described, but the present invention is not limited thereto, and the front surface side thermoplastic resin sheet P is also provided. A decorative material may be provided, and in that case, the plate-like insert 40 may be provided so as to protrude obliquely outward from the side surface of the sandwich panel 10.

In addition, in the present embodiment, when the sandwich panel 10 is formed, the plate-like insert 40 is placed in the mold cavity and between the two molten thermoplastic resin sheets P of the foam core 13. With respect to the timing of each of the arrangements, the former is described as before the thermoplastic resin sheet P in the molten state of the two strips is arranged in the split mold, and the latter is after the suction molding of the thermoplastic resin sheet P. However, the present invention is not limited thereto, and the plate-like insert 40 may be installed until the molten thermoplastic resin sheet P on the side where the plate-like insert 40 is provided is sucked and molded. May be arranged before the split mold 73 is clamped, and may be before the suction molding of the thermoplastic resin sheet P.

P Thermoplastic resin sheet PL Parting line 10 Resin sandwich panel 12A Front side skin sheet 12B Back side skin sheet 13 Foam core material 14 Cosmetic material 40 Plate insert 41 Outer surface 42 Main body 43 Inner surface 44 recessed portion 45 welding surface 46 insertion portion 47 outer surface 48 recessed portion 50 through hole 56 notch 58 gap 75 cavity recessed portion 60 molding device for resin sandwich panel 62 extrusion device 64 mold clamping device 65 hopper 66 cylinder 68 hydraulic motor 70 accumulator 72 Plunger 73 Mold 74 Cavity 75 Die slit 76 Pinch-off part 80 Projection body 81 Mold frame 85 Vacuum suction chamber 87 Suction hole

Claims (20)

In a sandwich panel having two resin skin sheets and a resin core material that is surface-bonded to both skin sheets in a form sandwiched between both skin sheets,
At least one outer surface of the two resin skin sheets is provided with a recess extending toward the other resin skin sheet,
An insert having a plate surface, wherein the plate surface is in close contact with a portion of the outer surface of one resin skin material sheet constituting the recessed portion, and the plate surface is placed against the outer surface of one resin skin material sheet. An insert that is inserted from the outside in a substantially orthogonal direction is provided,
In the corresponding position of the insert of the resin core material, a space extending in the thickness direction of the resin core material is provided,
The insert has an insertion portion to be inserted into the recessed portion on the plate surface, and the insertion portion is embedded in the recessed portion, and corresponds to the one resin skin material sheet constituting the recessed portion. The recess closes the recess,
A resin sandwich panel comprising at least one of the following configurations (1) to (2).
(1) The inner surface portion of one resin skin sheet constituting the bottom of the recessed portion is joined to the inner surface of the other resin skin sheet, and the insert has the recessed portion on the other sheet. To the sandwich panel.
(2) the insert part has an opening, opposing portions between the one of the resin skin material sheets constituting the recessed portion is joined through the opening. The resin-made sandwich panel according to claim 1, comprising the configuration (1). The resin sandwich panel according to claim 1 or 2, comprising the configuration (2). The resin according to any one of claims 1 to 3, wherein the width of the space is set to be greater than the sum of the plate thickness of the plate surface and twice the thickness of one resin skin sheet. Sandwich panel. The said space is a resin sandwich panel as described in any one of Claims 1-4 comprised by the through-hole provided in the said resin core material. The said space is a resin-made sandwich panel as described in any one of Claims 1-4 comprised by the notch provided in the said resin-made core material. The said space is in the said resin-made core materials divided | segmented, Comprising: The resin-made sandwich panel as described in any one of Claims 1-4 comprised by the clearance gap between adjacent core materials. Said insert further has a protrusion coupled to the insertion portion, the front Symbol protrusion is provided so as to protrude from the resin sandwich panel, according to any one of claims 1 to 7 Resin sandwich panel. On the outer surface of the corresponding position of the recessed portion of the other resin skin sheet, a recess extending toward the one resin skin sheet is provided, and the recessed portion and the recess are butt-joined. The resin sandwich panel according to any one of claims 1 to 8. The resin sandwich panel according to claim 7, wherein a metallic reinforcement is provided in a gap between the divided resin cores. A method for forming a sandwich panel having a resin core material interposed between two resin skin sheets, using two molten thermoplastic resin sheets,
An insert fixed to a sandwich panel and having a plate surface, and a recess in one mold cavity that opens toward the other mold and inserts the insert in a direction in which the plate surface is substantially orthogonal to the cavity A pair of split molds and a resin core having a space extending in the thickness direction are formed, and the peripheral edges of the cavities of each of the pair of split molds are prepared. Placing the two molten thermoplastic resin sheets between the pair of split molds in a form that protrudes around the annular pinch-off portion;
A sealed space is formed between the at least one mold and the corresponding thermoplastic resin sheet, and air is decompressed from the sealed space, so that the thermoplastic resin sheet is sucked and applied along the cavity. The insert, while forming a recess recessed toward the other split mold in accordance with the insert that is previously inserted into the recess and protrudes from the cavity with respect to the thermoplastic resin sheet Welding the projecting outer surface to the recess,
Positioning the space of the preformed resin core disposed between the two molten thermoplastic resin sheets with respect to the recessed portion, and passing the recessed portion through the space, The pair of split molds are moved to the mold clamping position, and the inner surfaces of the two thermoplastic resin sheets are welded along the pinch-off portions of the pair of molds, thereby making two strips of thermoplastic resin. And integrating the peripheral portions of the sheet, and welding the inner surface of the thermoplastic resin sheet and the corresponding surface of the resin core,
The insert has an insertion portion to be inserted into the recessed portion on the plate surface, and the insertion portion is embedded in the recessed portion, and corresponds to the one resin skin material sheet constituting the recessed portion. A method for producing a resin sandwich panel, wherein the recessed portion is closed by a portion and includes at least one of the following configurations (1) to (2).
(1) When welding the inner surface of the thermoplastic resin sheet and the corresponding surface of the resin core material, the bottom of the recessed portion is connected to the inner surface of the other thermoplastic resin sheet via the space. Weld.
(2) The insertion portion has an opening, and is pressed against the protruding outer surface of the insert and forms a concave portion when the thermoplastic resin sheet is sucked and shaped along the cavity. The portions of the thermoplastic resin sheet facing each other are welded to each other through the opening. The method for producing a resin sandwich panel according to claim 11, comprising the configuration (1). The method for producing a resin sandwich panel according to claim 11 or 12, comprising the configuration (2).   The width of the space perpendicular to the plate surface is set to be equal to or greater than the sum of the plate thickness of the plate surface and twice the thickness of one molten thermoplastic resin sheet. 14. A method for producing a resin sandwich panel according to any one of 13 above. 15. The resin core material according to claim 11, wherein the resin core material is pressed against and welded to the thermoplastic resin sheet formed by the suction before the pair of split molds are clamped. The manufacturing method of the sandwich panel made of resin as described in 1.   The depressurization step includes a step of moving an outer frame that is externally fitted to a peripheral edge of the at least one split mold so as to be movable in a mold clamping direction toward an outer surface of a corresponding thermoplastic resin sheet, The sealed space is configured by any one of the outer surface of the corresponding thermoplastic resin sheet, the inner peripheral surface of the outer frame, and the respective cavities of the pair of split molds. The manufacturing method of the resin-made sandwich panel of description.   The resin sandwich panel according to any one of claims 11 to 15, wherein the one and / or the other thermoplastic resin sheet is preformed in advance and reheated to be in a molten state. Production method. 16. The method according to any one of claims 11 to 15, further comprising a step of extruding the one and the other molten thermoplastic resin sheets downwardly between the pair of split molds. A method for producing a resin sandwich panel as described in 1. 19. The thermoplastic resin sheet is formed into two sheets by extruding a molten cylindrical parison and cutting the cylindrical parison in at least two locations along the extrusion direction during extrusion. A method for producing a resin sandwich panel as described in 1. The resin core member is a foamable resin of a predetermined expansion ratio, a manufacturing method of the resin sandwich panel according to any one of claims 11 to claim 19.