JP6003009B2 - 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, in the case of an interior panel used in a bathroom, aesthetic appearance is important, but if not so strong, a cosmetic material is further applied to the front side skin sheet that exhibits the 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.

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. 12, while the attachment member is inserted partway through the through-hole, one skin material sheet is closely bonded to the outer peripheral surface of the insertion portion, and the attachment member is particularly It moved easily with respect to the load in the thickness direction of the sandwich panel, 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 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.

On the other hand, the concave part of the skin material sheet formed by tightly joining one skin material sheet to the outer peripheral surface of the insertion part extends to the other skin material sheet, and the concave part of one skin material sheet is formed in the through hole. If it is joined to the other skin material sheet, the blow ratio of the one skin material sheet becomes too high, resulting in thinning, and the fixing of the mounting member to the one skin material sheet may be insufficient.
From this, in resin sandwich panels that require aesthetics and high rigidity, without providing a through hole extending in the thickness direction in the resin core material, without increasing the blow ratio of one resin skin material sheet too much On the other hand, it is difficult to hold the other resin skin sheet in a flat shape, for example, to adhere a decorative material.
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,
In a form that is in close contact with the part of the outer surface of one resinous skin material sheet that constitutes the recessed part, an insert that is inserted from the outside with respect to the outer surface of one sheet is provided,
On the surface of the resin core material facing the one resin skin sheet, a recess having a size that does not contact the insert is provided at a corresponding position of the insert,
Thereby, the inner surface portion of one resin skin sheet constituting the bottom of the recessed portion is joined to the recessed portion of the resin core material, and the insert has the recessed portion formed of the resin core material. It is set as the structure fixed with respect to the said sandwich panel by joining to.

According to the resin sandwich panel according to the present invention, in particular, when a large load is applied to the resin sandwich panel through the insert fixed to the resin sandwich panel, the through hole, the cutting, While preventing the rigidity reduction of the resin sandwich panel by providing a notch or the like, for example, the concave portion formed in one resin skin sheet extends to the other resin skin sheet over the thickness of the resin core material. By extending the length, the blow ratio of one resin skin sheet is increased too much, and the thickness of the recess is reduced, so that the insert is not sufficiently fixed to the one resin skin sheet. Light weight and high rigidity can be maintained while firmly fixing.
Furthermore, in a resin sandwich panel that requires aesthetics and high rigidity, without providing a through hole extending in the thickness direction in the resin core material, without increasing the blow ratio of one resin skin material sheet, the other The resin skin material sheet is held in a flat shape, and is effective, for example, when a decorative material is bonded.

Further, the concave portion may be provided so as to come out at an edge of the resin core material.
Furthermore, the said recessed part may be provided in the said resin-made core material divided | segmented so that the surface of the adjacent core material may be straddled.
Furthermore, a gap is provided between the divided resin cores adjacent to each other, the recess is provided across the gap, and a metallic reinforcement may be provided in the gap. .
In addition, the insert has an insertion portion that is inserted into the recessed portion, the insertion portion has a tapered shape toward the other resin skin sheet, A joining surface for joining to the resin core material is preferably formed.

Further, the insertion portion may be provided with a protruding flange portion that extends in a lateral direction with respect to the extending direction of the insertion portion.

In order to achieve the above object, a method for molding 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,
An insert fixed to the sandwich panel, a cavity of one mold is provided with a pair of split molds that are provided with a recess for inserting the insert that opens toward the other mold, and an insert on one surface Preparing a resin core with a depression sufficient to pass through;
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 protrusion of the insert while forming a recessed portion that is 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 outer surface to the recess,
Positioning the recess of the pre-molded resin core disposed between two molten thermoplastic resin sheets with respect to the recessed portion, and clamping the pair of split molds And the peripheral surfaces of the two thermoplastic resin sheets are integrated with each other by welding the inner surfaces of the two thermoplastic resin sheets along the pinch-off portions of the pair of molds. And welding the inner surface of the thermoplastic resin sheet and the corresponding surface of the resin core while welding the bottom of the recess to the bottom of the recess of the resin core,
Thus, the 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.
Still 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 split mold so as to be movable in a mold clamping direction toward an outer surface of the corresponding thermoplastic resin sheet. It is preferable that a sealed space is formed by 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.
Further, the one and / or the other thermoplastic resin sheet is preferably preformed in advance and reheated to be in a molten state.
Furthermore, you may have a step which extrudes between said one and said other molten-state thermoplastic resin sheet | seat toward the said pair of division | segmentation metal mold | die in the form which hangs below.
In addition, the thermoplastic resin sheet is formed into two sheets by extruding a molten cylindrical parison and cutting the cylindrical parison along the extrusion direction in at least two places during extrusion. But you can.
Further, the resin core material may be a foamed resin having a predetermined expansion ratio.

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, such a sandwich panel 10 includes a front surface skin sheet 12A, a back surface skin sheet 12B, and a foaming foam core interposed between both skin sheets 12A and 12B. The sandwich panel 10 includes a decorative material sheet 14, a front surface skin material sheet 12A, foamed material 13 and a decorative material sheet 14 bonded to the outer surface of the front surface skin material sheet 12A. It is a laminated structure of the core material 13 and the back surface skin sheet 12B.

The insert 40 will be described. The insert 40 is a jig attached to the sandwich panel 10 from the outside. For example, the insert 40 is used to fix a separate member to the sandwich panel 10. 10 needs to be firmly fixed.
As shown in FIG. 2, the insert 40 is made of metal and protrudes from the outer surface 41 of the back side skin material sheet 12B to which the insert 40 is attached, and the outer surface 41 of the back side skin material sheet 12B. And an insertion portion 46 to be inserted into a recessed portion 44 (described later). For example, the main body portion 42 is provided with a recess 48 for mounting a separate member to fix the separate member using the insert 40, and the insertion portion 46 faces the front surface skin sheet 12A. It has a tapered shape. When the sandwich panel 10 is formed, the taper taper degree is such that the molten thermoplastic resin sheet P1 that forms the back surface skin sheet 12B that covers the outer peripheral surface of the insert 40 is the foam core 13 as will be described later. It may be determined from the viewpoint of preventing the molten thermoplastic resin sheet P <b> 1 from being torn and causing poor molding by contacting the recess 50.
The insertion portion 46 is provided with an overhanging flange portion 52 that expands in the lateral direction with respect to the extending direction of the insertion portion 46. As a result, the molten thermoplastic resin sheet P constituting the back surface skin sheet 12B wraps around the outer peripheral surface of the overhang flange portion 52, particularly the constricted portion 54 between the overhang flange portion 52 and the main body portion 42. Thus, the metal insert 40 that is difficult to be directly welded to the thermoplastic resin sheet P1 can be firmly fixed to the thermoplastic resin sheet P1. In this respect, when the insert 40 is not made of metal but is made of resin, in particular, the same material as the thermoplastic resin sheet P1, the insert 40 is easily welded to the thermoplastic resin sheet P. Such an overhanging flange portion 52 may be omitted.
What is necessary is just to set the depth of the insertion part 46 so that the recessed part 44 of the back surface skin material sheet 12B formed by the formation of the sandwich panel 10 can be abutted and welded to the recessed part 50 of the foamed core material 13. In this sense, a welding surface 45 is formed at the tapered tip end of the insertion portion 46, and the width thereof is such that the recessed portion 44 of the back side skin sheet 12B sufficiently abuts the recessed portion 50 of the foam core material 13. What is necessary is to determine from the viewpoint that the insert 40 is firmly fixed to the sandwich panel 10 by welding.
As described above, the insert 40 is inserted from the outside with respect to the outer surface 41 of 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. .

In the corresponding position of the insert 40 of the resin foam core material 13, there is provided a recess 50 that is a space large enough not to contact the insert 40, so that the bottom of the recess 44 is interposed via the recess 50. The portion of the inner surface 47 of the back side skin material sheet 12B to be configured is joined to the concave portion 50 of the foam core material 13, and the insert 40 is joined by joining the foam core material 13 to both skin material sheets 12A and B. The sandwich panel 10 is firmly fixed.

More specifically, the shape of the recessed portion 50 is a columnar shape, and the axis of the column is provided so as to be orthogonal to the back surface skin sheet 12B. The shape of the recessed portion 50 depends on the shape of the insert 40. What is necessary is just to determine, and similarly to the taper degree of the insertion portion 46 of the insert 40 described above, the thermoplastic resin sheet P1 in the molten state constituting the back surface skin sheet 12B covering the outer peripheral surface of the insert 40 is the foam core 13. It may be determined from the viewpoint of preventing the molten thermoplastic resin sheet P <b> 1 from being torn and causing poor molding by contacting the recess 50.
In this sense, the diameter of the recess 50 is greater than a value obtained by adding twice the thickness of the back surface skin sheet 12B covering the periphery of the overhang flange portion 52 to the width of the overhang flange portion 52. There is a need to.
In particular, when a plurality of inserts 40 are provided for the sandwich panel 10 and a plurality of recesses 50 are provided for the foam core material 13 for that purpose, the size of each recess 50 is ensured from the viewpoint of ensuring high rigidity of the sandwich panel 10. The size is preferably as small as possible, and the size of the recess 50 may be determined so that the insert 40 can be easily inserted in a non-contact manner and does not cause a decrease in rigidity in consideration of the taper degree of the insertion portion 46 of the insert 40 described above.
The position where the recess 50 is provided may be determined according to the position where the insert 40 is provided on the sandwich panel 10. As a modification, as shown in FIGS. 3 to 5, the recess 50 is formed at the edge of the resin core 12. It may be provided so as to be detached, or may be provided so as to straddle the surface of the adjacent core material 12 in the divided resin core material 13, and in that case, the adjacent divided resin core material 13. A gap is provided between them, and a recess 50 is provided across the gap, and a metallic reinforcement (not shown) is provided in the gap, thereby ensuring the rigidity of the sandwich panel 10. It is.
FIG. 6 is a modification of the insert 40 and constitutes an insert nut. For example, a screw portion provided on a member is screwed into the nut to fix the member to the sandwich. Unlike the case of FIG. 1, the upper surface of the insert 40 is flush with the outer surface 41 of the back-side skin material sheet 12 </ b> B, there is no main body portion protruding from the outer surface 41, and the insert portion 46 is embedded in the recess 50. ing.

The foam core 13 is formed of a resin to which a foaming agent is added. As the resin for forming the foamed core material 13, polyolefin (eg, polypropylene, high density polyethylene), polyamide, polystyrene, which is a homopolymer or copolymer of olefins such as ethylene, propylene, butene, isoprene pentene, and methyl pentene. , 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 formed, the 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 sheet 12B. This is because the melted thermoplastic resin sheet P <b> 1 that forms the shape is vacuum-sucked toward the one cavity 74 </ b> A to form the recessed portion 44 having a shape along the outer peripheral surface of the insertion portion 46 of the insert 40.

As described above, by providing the protruding flange portion 52 in the insertion portion 46, the molten thermoplastic resin sheet P1 wraps around the constricted portion 54 between the main body portion 42 and the protruding flange portion 52. The insert 40 is more closely attached to the back surface skin sheet 12B and is firmly fixed.

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. 7, 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 communicating with the inside of the cylinder 66, and a plunger 72 provided in the accumulator 70, and resin pellets introduced from the hopper 65 are screwed by the hydraulic motor 68 in the cylinder 66. 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. A pair of sheet-like thermoplastic resin sheet P extruded and spaced apart While being pinched by the roller 79, it is sent out downward and is suspended between the divided 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. However, two divided molds 73 and a sheet-like heat in which the mold 73 is melted are used. 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.

  The cavity 74A of one mold 73A of the split mold 73 for shaping the molten sheet-like thermoplastic resin sheet P1 is formed with a cavity recess 75 for fitting the main body 42 of the insert 40. The cavity recess 75 is formed so that the sheet-like thermoplastic resin sheet P1 is formed from the cavity 74A when the molten sheet-like thermoplastic resin sheet P1 forming the back surface sheet 12B is suction-molded toward the cavity 74A. The body portion 42 of the insert 40 is pressed against the outer peripheral surface of the insertion portion 46 of the protruding insert 40 so as to form the recess 44 and not flow into the gap between the cavity recess 75 and the body portion 42. Is fitted without gaps.

  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. 9, a vacuum suction chamber 85 is provided inside the split mold 73 </ b> A, and the vacuum suction chamber 85 communicates with the cavity 74 </ b> A through the suction hole 87 and extends from the vacuum suction chamber 85 to the suction hole 87. 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 13 having the recess 50 formed therein is prepared in advance, and the insert 40 is fitted into the cavity recess 75 of the cavity 74A, and the insertion portion 64 of the insert 40 protrudes from the cavity 74A toward the other mold 73B. Arrange so that. Further, the decorative material 14 is placed in the cavity 74B.
Next, as shown in FIG. 7, 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. 8, the mold 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. 9, 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, a recess 44 that is recessed toward the other split mold 73B is formed on the thermoplastic resin sheet P1 in accordance with the insert 40 that is fitted in the cavity recess 75 in advance and protrudes from the cavity 74A. However, the protruding outer surface of the insertion portion 46 of the insert 40 is welded to the recessed portion 44. In particular, the thermoplastic resin sheet P1 wraps around the constricted portion 54, whereby the metal insert 40 is 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 the position of the recess 50 of the foam core material 13 is determined using, for example, a known manipulator. Is adjusted with respect to the position of the formed recessed portion 44 so that the recessed portion 44 that is the molten thermoplastic resin sheet P <b> 1 does not contact the recessed portion 50. While positioning, the surface of the foam core 13 is pressed against the inner surface of the thermoplastic resin sheet P1 to be welded and fixed. 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 recessed portion 50 can be easily set.

Next, as shown in FIG. 10, 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 welding the decorative material 14 to the thermoplastic resin sheet P2, the welding surface 45 at the bottom of the recess 44 is welded to the recess 50 of the resin foam core material 13. Thus, the insert 40 tightly fixed to the thermoplastic resin sheet P1 is firmly attached to the resin sandwich panel 10 by the resin foam core 13 being welded to both the thermoplastic resin sheets P1 and P2. Fixed It is.
The extruded thermoplastic resin sheet P may be formed into a sheet by crushing the molten cylindrical parison, or at least two locations during extrusion by extruding the molten cylindrical parison. The cylindrical parison may be cut along the extrusion direction to form two sheets.

Next, as shown in FIG. 11, the two divided molds 73 are opened, the completed resin sandwich panel 10 is separated from the cavity 74, and the 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 having the above configuration, particularly when a large load is applied to the resin sandwich panel 10 through the insert 40 fixed to the resin sandwich panel 10, For example, by providing the recess 50, the notch 56, etc., the rigidity of the resin sandwich panel 10 is prevented from being lowered. For example, the recess 44 formed in one resin skin sheet 12B is formed on the other resin skin sheet 12A. By extending over the thickness of the resin core material 13 to the extent that the blow ratio of one resin skin sheet 12B is excessively increased and the recess 44 is thinned, one resin skin of the insert 40 Without being insufficiently fixed to the material sheet 12B, it is possible to maintain lightness and high rigidity while firmly fixing the insert 40. .
Furthermore, in the resin sandwich panel 40 that requires aesthetics and high rigidity, the resin core material 13 is not provided with a through-hole extending in the thickness direction, and the blow ratio of one resin skin material sheet 12B is not excessively increased. In addition, the other resin skin sheet 12A is effective in the case where the decorative material 14 is bonded, for example, by holding it flat.

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.
Further, in the present embodiment, the case where the single insert 40 is provided has been described. However, the present invention is not limited to this. For example, the plurality of inserts 40 are arranged in a straight line at intervals in the longitudinal direction of the sandwich. In that case, the size of the recess 50 provided in the foam core 13 is preferably as small as possible from the viewpoint of preventing a decrease in rigidity as long as interference during insertion of the insert 40 can be avoided. .

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, the recessed portion 44 of the thermoplastic resin sheet P1 needs to be positioned and clamped so as not to contact the recessed portion 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 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 molded, the insert 40 is placed in the mold cavity, and the foam core 13 is inserted between the two molten thermoplastic resin sheets P. Regarding the timing of each placement, the former was described as before the two molten thermoplastic resin sheets P were placed in the split mold, and the latter was after suction molding of the thermoplastic resin sheets P. Without being limited thereto, the insert 40 may be installed by suction molding the molten thermoplastic resin sheet P on the side where the insert 40 is provided. May be arranged before the mold is clamped, and may be before the suction molding of the thermoplastic resin sheet P.

It is a fragmentary sectional view around insert 40 of resin sandwich panel 10 concerning a 2nd embodiment of the present invention. It is a perspective view of insert 40 inserted in resin sandwich panel 10 concerning a 1st embodiment of the present invention. It is a top view which shows the relationship between the foaming core material 13 and the insert 40 of the resin-made sandwich panels 10 concerning 1st Embodiment of this invention. It is a top view which shows the relationship between the foaming core material 13 and the insert 40 of the resin sandwich panel 10 which concerns on the modification of this invention. It is a top view which shows the relationship between the foaming core material 13 and the insert 40 of the resin-made sandwich panels 10 which concern on the further modification of this invention. It is a figure similar to FIG. 7 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 insert 40 of conventional resin sandwich panel 10.

P Thermoplastic resin sheet PL Parting line 10 Resin sandwich panel 12A Front side skin sheet 12B Back side skin sheet 13 Foam core 14 Cosmetic material 40 Insert 41 Outer surface 42 Main body 43 Inner surface 44 Recessed Part 45 Welding surface 46 Insertion part 47 Outer surface 48 Recess 50 Through hole 52 Overhang flange part 54 Neck part 56 Notch 58 Cavity 75 Cavity recess 60 Resin sandwich panel molding device 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 (13)

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,
In a form that is in close contact with the part of the outer surface of one resin skin material sheet that constitutes the recessed portion, an insert that is inserted from the outside with respect to the outer surface of one resin skin material sheet is provided,
On the surface of the resin core material facing the one resin skin sheet, a recess having a size that does not contact the insert is provided at a corresponding position of the insert,
Thereby, the inner surface portion of one resin skin sheet constituting the bottom of the recessed portion is joined to the recessed portion of the resin core material, and the insert has the recessed portion formed of the resin core material. A resin sandwich panel, which is fixed to the sandwich panel by bonding to the sandwich panel.         The resin-made sandwich panel according to claim 1, wherein the concave portion is provided so as to come out to an edge of the resin-made core material.         2. The resin sandwich panel according to claim 1, wherein the recess is provided in the divided resin core material so as to straddle the surface of the adjacent core material. The gap is provided between the divided resin cores adjacent to each other, the concave portion is provided across the gap, and a metallic reinforcement is provided in the gap. Resin sandwich panel.         The insert has an insertion portion that is inserted into the recessed portion, the insertion portion has a tapered shape toward the other resin skin sheet, and the tapered tip portion is made of the resin. The resin sandwich panel according to claim 1, wherein a bonding surface for bonding to the core material is formed. The resin sandwich panel according to claim 5, wherein the insertion portion is provided with a protruding flange portion that extends in a lateral direction with respect to a direction in which the insertion portion extends. A method for forming a sandwich panel having a resin core material interposed between two resin skin sheets,
An insert fixed to the sandwich panel, a cavity of one mold is provided with a pair of split molds that are provided with a recess for inserting the insert that opens toward the other mold, and an insert on one surface Preparing a resin core with a depression sufficient to pass through;
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 protrusion of the insert while forming a recessed portion that is 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 outer surface to the recess,
Positioning the recess of the pre-molded resin core disposed between two molten thermoplastic resin sheets with respect to the recessed portion, and clamping the pair of split molds And the peripheral surfaces of the two thermoplastic resin sheets are integrated with each other by welding the inner surfaces of the two thermoplastic resin sheets along the pinch-off portions of the pair of molds. And welding the inner surface of the thermoplastic resin sheet and the corresponding surface of the resin core while welding the bottom of the recess to the bottom of the recess of the resin core,
Thereby, the insert is firmly fixed to the resin sandwich panel, and the method for producing a resin sandwich panel is provided. The resin sandwich panel according to claim 7, wherein the resin core material is pressed against and welded to the thermoplastic resin sheet formed by the suction before clamping the pair of split molds. Production method.   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 resin sandwich according to claim 7 or 8, wherein a sealed space is formed by 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. Panel manufacturing method.   The method for producing a resin sandwich panel according to claim 7 or 8, wherein the one and / or the other thermoplastic resin sheet is preformed in advance and reheated to be in a molten state. The resin-made product according to claim 7 or 8, further comprising a step of extruding the one and the other molten thermoplastic resin-made sheets downwardly between the pair of split molds. A method for manufacturing a sandwich panel. 12. The thermoplastic resin sheet is formed into two sheets by extruding a molten cylindrical parison and cutting the cylindrical parison along at least two places along the extrusion direction during extrusion. A method for producing a resin sandwich panel as described in 1. The method for producing a resin sandwich panel according to claim 7 or 8, wherein the resin core material is a foam resin having a predetermined expansion ratio.

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