JP6206549B2 - Resin panel and molding method - Google Patents

Description

  The present invention relates to a resin panel such as a package tray, deck board, or floor board installed in a cargo compartment of a vehicle.

  As a technical document filed by the present applicant, there is a document that discloses a technique for blow molding a cylindrical molten resin and molding a panel with a skin (see, for example, Patent Document 1: Japanese Patent Laid-Open No. 10-235720). .

  In the above-mentioned Patent Document 1, an outer rib is thermally welded to the outer surface of one wall portion by blow pressure at the time of blow molding, and an inner rib is formed on the other wall portion so as to protrude until it contacts the inner surface of the one wall portion. The panel with skin is to be molded.

  However, when a cylindrical molten resin is used as in Patent Document 1, the molten resin in the portion where the inner rib is formed is stretched. It is necessary to increase the thickness. As a result, there is a problem that the weight of the finally formed panel with skin becomes heavy. For this reason, as in Patent Document 1, when a cylindrical molten resin is used, there is a problem that it is difficult to reduce the weight and thickness of the finally formed resin panel.

  Usually, the thickness (wall thickness) of the cylindrical molten resin (cylindrical parison) is uniform. Further, when the split mold is clamped, the pressing force for pressing the cylindrical parison against the split mold is uniform over the entire surface of the cylindrical parison. For this reason, the parison pressed against one of the divided molds forming the recess such as the inner rib is stretched due to the blow ratio corresponding to the recess, and a locally thin portion is generated. In addition, since the other split mold does not form a recess, a thin-walled portion does not occur. As a result, the thickness of the cylindrical parison needs to be set in accordance with the thin portion generated on the side of one split mold that forms the recess, thereby causing an extra thickness on the other split mold side. It will be. Therefore, when using a cylindrical parison that is inevitably uniform in thickness, the thickness of the wall portion where the recess is not formed becomes thicker than the thickness of the wall portion where the recess is formed after blow molding. Therefore, there is a problem that it is difficult to reduce the weight and thickness of a resin panel that is molded in a conventional manner.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2010-155583) discloses a luggage board that has excellent strength and rigidity even when the resin panel constituting the luggage board is thinned and lightened. Is disclosed.

  In the above-mentioned Patent Document 2, a plurality of inner ribs integrally welded to the back surface of the front wall are formed on the back wall, and a circular recessed round rib integrally welded to the back surface of the front wall is interposed between the inner ribs of the back wall. It is decided to form a plurality. Thereby, even when the average wall thickness of the resin wall constituting the luggage board is reduced to 1.5 to 2.5 mm to reduce the weight, the required strength and rigidity can be obtained. The average thickness of the resin wall of the luggage board is an average value of the thickness of the front wall and the back wall of the luggage board.

Japanese Patent Laid-Open No. 10-235720 JP 2010-155583 A

  However, since the above-mentioned Patent Document 2 forms an inner rib and a round rib on the back wall side and a thin wall portion is generated, when placing and using the back wall of the luggage board on another member, The abutting surface of the abutting back wall is likely to be easily deformed or cracked. For this reason, in order to make the contact surface difficult to deform and hard to crack, it is necessary to set the thickness of the cylindrical parison to be thick in accordance with the thin portion generated on the back wall side. As a result, the average thickness of the resin wall of the luggage board obtained in Patent Document 2 is 1.5 mm, and if it is thinner than 1.5 mm, the contact surface is likely to be easily deformed or cracked. A new problem will occur.

  The present invention has been made in view of the above circumstances, and while reducing the weight of a resin panel, the resin panel that makes it difficult for the contact surface of the back wall that contacts another member to be deformed and hardly break, and the resin panel An object of the present invention is to provide a molding method.

  In order to achieve this object, the present invention has the following features.

The resin panel according to the present invention is
A resin panel having a back wall having a plurality of abutment surfaces that abut against other members, and a front wall facing the back wall at an interval,
A plurality of ribs welded to the inner surface of the front wall with a part of the back wall recessed toward the front wall;
The thickness of the front wall is substantially the same as the thickness of the back wall or is thin.

The resin panel according to the present invention is
Resin which has a back wall which has a plurality of contact surfaces which contact other members, and a front wall facing the back wall at intervals, and the back wall and the front wall are made of the same resin Panel made of,
A plurality of ribs welded to the inner surface of the front wall with a part of the back wall recessed toward the front wall;
The front wall is lighter than the back wall.

The molding method according to the present invention includes:
A molding method of molding a resin panel having a back wall having a plurality of abutting surfaces that abut against other members and a front wall facing the back wall at an interval using a pair of split molds. There,
The cavity of one split mold is provided with a plurality of projecting portions that protrude toward the other split mold, and the first molten resin that constitutes the back wall on the one split mold side The second molten resin sheet constituting the front wall is located on the other split mold side, and the thickness of the second molten resin sheet is set to the first molten resin sheet. An extruding step of extruding the first molten resin sheet and the second molten resin sheet, with a thickness less than the thickness of
A shaping step of shaping the first molten resin sheet into a shape along the cavity of the one split mold, and extending the first molten resin sheet into a shape along the protruding portion to form a rib. When,
A pair of split molds are clamped to weld peripheral edges of the first molten resin sheet constituting the back wall and the second molten resin sheet constituting the front wall, and And a mold clamping step of welding the tip of the rib formed on the first molten resin sheet to the second molten resin sheet and molding the resin panel.

  ADVANTAGE OF THE INVENTION According to this invention, while aiming at weight reduction of a resin-made panel, the resin-made panel which the contact surface of the back wall contact | abutted with another member cannot change easily, and can be obtained easily can be obtained.

It is a figure which shows the structural example of the resin panel 1 of this embodiment, (a) is a whole perspective view of the resin panel 1, (b) is a top view of the resin panel 1 shown in (a) (C) is an AA ′ sectional view shown in (a) and (b), and (d) is a BB ′ sectional view shown in (a) and (b). FIG. 2 is a diagram illustrating a configuration example of a molding apparatus 60 that molds the resin panel 1 of the present embodiment. FIG. 3 is a first view showing an example of a molding process for the resin panel 1. FIG. 4 is a second view showing an example of a molding process for the resin panel 1. FIG. 6 is a third diagram showing an example of a molding process for the resin panel 1. FIG. 10 is a fourth view showing an example of a molding process for the resin panel 1. FIG. 10 is a fifth diagram illustrating an example of a molding process for the resin panel 1. FIG. 10 is a sixth diagram illustrating an example of a molding process for the resin panel 1. FIG. 10 is a seventh diagram illustrating an example of a molding process for the resin panel 1. FIG. 10 is an eighth diagram illustrating an example of a molding process for the resin panel 1. FIG. 5 is a diagram showing another configuration example of the resin panel 1 of the present embodiment.

<Outline of resin panel 1 of this embodiment>
First, an outline of the resin panel 1 of the present embodiment will be described with reference to FIGS. 1, 2, 6, and 9. FIG. 1 shows a configuration example of the resin panel 1 of the present embodiment, FIG. 2 shows a configuration example of a molding apparatus 60 for molding the resin panel 1 shown in FIG. 1, and FIGS. A part of the forming process of the panel 1 is shown.

  As shown in FIG. 1, the resin panel 1 of the present embodiment opposes the back wall 3 having a plurality of contact surfaces 31 that contact other members (not shown), and the back wall 3 at intervals. A resin panel 1 having a front wall 2.

  The resin panel 1 of the present embodiment has a plurality of ribs 3a welded to the inner surface of the front wall 2 with a part of the back wall 3 recessed toward the front wall 2, and the thickness of the front wall 2 Is substantially the same as the thickness of the back wall 3 or is thin. The front wall 2 is lighter than the back wall 3.

  The resin panel 1 of the present embodiment can be molded using, for example, a molding apparatus 60 shown in FIG. In the mold clamping device 14 constituting the molding apparatus 60 shown in FIG. 2, a plurality of projecting portions 33 projecting toward the other split mold 32A are provided in the cavity 116B of one split mold 32B. The protruding portion 33 forms the rib 3a shown in FIG.

  When molding the resin panel 1 of the present embodiment, first, as shown in FIG. 2, the first molten resin sheet P1 constituting the back wall 3 is located on the split mold 32B side, and the split mold is used. On the 32A side, the second molten resin sheet P2 constituting the front wall 2 is located, and the thickness of the second molten resin sheet P2 is made thinner than the thickness of the first molten resin sheet P1, The first molten resin sheet P1 and the second molten resin sheet P2 are extruded from the extrusion device 12. For this reason, when the back wall 3 and the front wall 2 are made of the same resin, the front wall 2 of the resin panel 1 finally formed is lighter than the back wall 3.

  Next, as shown in FIG. 6, the first molten resin sheet P1 is shaped into a shape along the cavity 116B of the split mold 32B, and the first molten resin sheet P1 is shaped along the protruding portion 33. The rib 3a is formed by stretching. Thereby, the rib 3a is formed in the 1st molten resin sheet P1 which comprises the back wall 3. As shown in FIG.

  Next, as shown in FIG. 9, a pair of split molds 32 are clamped to form a first molten resin sheet P1 constituting the back wall 3 and a second molten resin sheet P2 constituting the front wall 2. And the edges of the ribs 3a formed on the first molten resin sheet P1 are welded to the second molten resin sheet P2. Thereby, the resin panel 1 shown in FIG. 1 can be molded.

  In the resin panel 1 of the present embodiment, the thickness of the front wall 2 is substantially the same as or thinner than the thickness of the back wall 3, and since the front wall 2 is lighter than the back wall 3, for example, resin The average thickness of panel 1 (the average value of the average thickness of front wall 2 and the average thickness of back wall 3) can be reduced to less than 1.5 mm to reduce the weight of resin panel 1 and back wall 3 It is possible to make the contact surface 31 difficult to be deformed and hard to crack.

  For example, since the resin panel which is a luggage board of Patent Document 2 forms an inner rib and a round rib on the back wall side and a thin portion is generated, the back wall side of the luggage board is placed on another member. When used, the abutting surface of the back wall that abuts against other members is easily deformed and easily cracked. For this reason, in order to make the contact surface difficult to deform and hard to crack, it is necessary to set the thickness of the cylindrical parison to be thick in accordance with the thin portion generated on the back wall side. However, if the thickness of the cylindrical parison is set so as to match the thin wall portion that occurs on the back wall side, ribs are not formed on the front wall side, so an extra thickness is generated on the front wall side, and the front wall It will make the side unnecessarily heavy. As a result, the average thickness of the resin wall of the luggage board obtained in Patent Document 2 is limited to 1.5 mm.

  On the other hand, the resin panel 1 of the present embodiment has a wall thickness of the front wall 2 substantially the same as or thinner than the thickness of the back wall 3 in the resin panel 1 shown in FIG. Further, the thickness of the second molten resin sheet P2 constituting the front wall 2 is set so that the front wall 2 is lighter than the back wall 3, and the thickness of the first molten resin constituting the back wall 3 is set. The average thickness of the wall portion of the resin panel 1 can be made less than 1.5 mm by extruding and molding the sheet P1 to be thinner than the thickness of the sheet P1. As a result, the weight of the resin panel 1 can be reduced, and the contact surface 31 of the back wall 3 can be hardly deformed and can be hardly cracked. Therefore, the resin panel 1 is effectively reduced in weight without reducing the strength of the resin panel 1, and the abutting surface 31 of the back wall 3 that abuts against other members is hardly deformed and is not easily cracked. Can be obtained. Hereinafter, the resin panel 1 of the present embodiment will be described in detail with reference to the accompanying drawings.

<Configuration example of resin panel 1>
First, a configuration example of the resin panel 1 of the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing a configuration example of a resin panel 1, FIG. 1 (a) is an overall perspective view of the resin panel 1, and FIG. 1 (b) is a resin shown in FIG. 1 (a). FIG. 1 (c) is a cross-sectional view of the resin panel 1 shown in FIGS. 1 (a) and 1 (b), and FIG. 1 (d) is a cross-sectional view of FIG. It is BB 'sectional drawing of the resin panels 1 shown to (a), (b).

  As shown in FIG. 1 (a), the resin panel 1 of this embodiment includes a front wall 2, a back wall 3, a peripheral wall 4, and a reinforcing material unit 5. As shown in FIGS. 1C and 1D, the resin panel 1 of the present embodiment has a front wall 2 and a back wall 3 facing each other at a predetermined interval. Are connected by a peripheral wall 4. Further, a hollow portion 6 is provided between the front wall 2 and the back wall 3, and the reinforcing material unit 5 is disposed between the front wall 2 and the back wall 3.

  In addition, as shown in FIG. 1 (a), the resin panel 1 of the present embodiment has a decorative member 7 attached to the surface of the front wall 2 for decoration, etc. As shown in d), the back wall 3, the front wall 2, and the decorative member 7 constitute a laminated structure. It is also possible not to attach the decorative member 7.

  Further, the resin panel 1 of the present embodiment has a contact surface 31 on the back wall 3, and the end of the reinforcing material unit 5 is arranged on the contact surface 31 so as to span the contact surface 31. The The contact surface 31 is, for example, a portion that comes into contact with another member when the resin panel 1 is placed on another member in the automobile. The contact surface 31 contacts the other member, and the resin panel 1 Is placed on another member. For this reason, the strength of the resin panel 1 can be improved by arranging the reinforcing material unit 5 so as to span the contact surface 31. Further, the strength of the reinforcing material unit 5 in the direction orthogonal to the longitudinal direction can be improved. The shape and position of the contact surface 31 are not limited to the flat shape and position shown in FIGS. 1A and 1B, and the resin panel 1 when the resin panel 1 is placed on another member. It is possible to change arbitrarily according to the contact relationship between and another member.

  Further, the resin panel 1 of the present embodiment is configured to have a plurality of ribs 3a in which a part of the back wall 3 is recessed toward the front wall 2 and is welded to the inner surface of the front wall 2. 1 to improve the rigidity and strength. The rib 3a of the present embodiment has a bottom, and the bottom of the rib 3a is welded to the inner surface of the front wall 2. The shape of the rib 3a is not particularly limited, and can be configured in an arbitrary shape according to the specifications of the resin panel 1. As the shape of the rib 3a, for example, an arbitrary shape such as an elliptical shape, a rectangular shape, or a polygonal shape can be used. In FIG. 1, slit ribs are provided as the ribs 3a, but inner ribs can also be provided. Further, the number of ribs 3a is not particularly limited, and an arbitrary number of ribs 3a can be provided according to the shape of the resin panel 1. In addition, the resin panel 1 shown in FIG. 1 is provided with rectangular ribs 3 a that are not parallel to the longitudinal direction of the reinforcing material unit 5. As a result, the strength of the reinforcing material unit 5 in the direction parallel to the longitudinal direction can be improved.

  In the resin panel 1 of the present embodiment, a plurality of ribs 3a are formed on the back wall 3 having the contact surface 31 while reducing the weight of the resin panel 1. For this reason, in order to make the contact surface 31 of the back wall 3 difficult to deform and crack, the average thickness of the back wall 3 is configured in the range of 1.1 mm to 1.7 mm. Further, unlike the back wall 3, the front wall 2 does not form the ribs 3a, and thus the average thickness of the front wall 2 is configured in the range of 0.7 mm to 1.2 mm. Thereby, the resin panel 1 can be reduced in weight, and the resin panel 1 which is difficult to be deformed and is difficult to break can be obtained.

  For example, if the average thickness of the back wall 3 is less than 1.1 mm, the portion where the rib 3a is formed becomes thinner, so that pinholes are likely to occur and the contact surface 31 is likely to be deformed. It becomes easier to crack. For this reason, the average thickness of the back wall 3 is configured to be 1.1 mm or more. Further, if the average thickness of the back wall 3 is greater than 1.7 mm, it becomes uselessly thick and it becomes difficult to reduce the weight of the resin panel 1. In addition, the thickness difference between the back wall 3 and the front wall 2 is increased, the distance between the back wall 3 and the front wall 2 is changed, and the contact surface 31 is easily deformed. For this reason, the average thickness of the back wall 3 is configured in the range of 1.1 mm to 1.7 mm. In addition, the front wall 2 has an average wall thickness of 0.7 mm or more and 1.2 mm or less for the same reason as the back wall 3. Thereby, the resin panel 1 can be reduced in weight, and the resin panel 1 which is difficult to be deformed and is difficult to break can be obtained. The resin panel 1 of the present embodiment is configured with an average thickness of the back wall 3 in a range of 1.1 mm to 1.7 mm, and an average thickness of the front wall 2 in a range of 0.7 mm to 1.2 mm. As a result, the weight of the molded product without the decorative member 7 is set to 2.5 to 4.2 kg / m2, and the resin panel 1 can be reduced in weight and the contact surface 31 of the back wall 3 can be deformed. It is possible to make it difficult to crack. However, the weight of the molded product is lighter on the front wall 2 than on the back wall 3.

  In the present embodiment, the average wall thickness of the front wall 2 and the back wall 3 is at least 10 locations (provided that the rib 3a is provided) at substantially equal intervals along the longitudinal direction of the front wall 2 and the back wall 3. It means the average value of the thickness measured at 10 points a1 to a10 shown in FIG. For example, in the case of the configuration example of the resin panel 1 shown in FIG. 1, as shown in FIG. 1 (b), the measurement was performed at 10 portions a 1 to a 10 where the rib 3 a is not provided on the front wall 2. It is the average thickness. The back wall 3 is an average value of the wall thickness measured at each part at a position opposed to each part a1 to a10 measured at the front wall 2.

  The front wall 2 and the back wall 3 are configured using resin sheets P1 and P2 described later. The materials of the resin sheets P1 and P2 constituting the front wall 2 and the back wall 3 are not particularly limited, and known materials can be applied. For example, engineering, such as polyethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer, vinyl chloride resin, ABS resin (acrylonitrile-styrene-butadiene resin), polyamide resin, polystyrene resin, polyester resin, polycarbonate resin, modified polyphenylene ether, etc. Plastics and mixed resins obtained by blending them are suitable, and fillers such as glass fibers, carbon fibers, calcium carbonate, talc, mica can be appropriately added. In addition, the front wall 2 and the back wall 3 are preferably made of a resin material having a high melt tension from the viewpoint of preventing thickness variation due to drawdown, neck-in, etc. In order to improve transferability and followability, it is preferable to use a resin with high fluidity.

  Further, the material constituting the decorative member 7 is not particularly limited, and a known material can be applied. For example, knitted fabrics, woven fabrics, non-woven fabrics, or polyvinyl chloride (PVC), thermoplastic polyurethane elastomer (TPU) or fibers obtained by processing natural fibers, recycled fibers, semi-synthetic fibers, synthetic fibers and blends thereof. A thermoplastic elastomer (TPE) such as a thermoplastic polyolefin elastomer (TPO), a resin sheet made of a thermoplastic resin such as a polyethylene polyolefin resin, and a laminate sheet thereof can be appropriately selected.

  Further, the material constituting the reinforcing material unit 5 is not particularly limited, and a known material can be applied. For example, metal (aluminum or the like) or hard plastic is applicable. Further, the shape of the reinforcing material unit 5 is not limited to the shape shown in FIG. 1 and can be configured in an arbitrary shape. For example, it may be configured in a cylindrical shape, a C shape, a U shape, or the like. However, since the resin panel 1 of the present embodiment forms the rib 3a on the back wall 3, it is necessary to dispose the reinforcing material unit 5 at a location where the rib 3a is not formed.

<Example of molding method for resin panel 1>
Next, an example of a method for forming the resin panel 1 of the present embodiment will be described with reference to FIGS. FIG. 2 shows a configuration example of a molding apparatus 60 for molding the resin panel 1, and FIGS. 3 to 10 are diagrams showing an example of a process for molding the resin panel 1. The extrusion apparatus 12 shown in FIG. A state in which the resin sheet P and the split mold 32 are viewed from the T die 28 side is shown.

  The resin panel 1 of this embodiment can be molded using a molding apparatus 60 shown in FIG. A molding device 60 shown in FIG. 2 has an extrusion device 12 and a mold clamping device 14, and sends the molten resin sheets P1 and P2 extruded from the extrusion device 12 to the mold clamping device 14. The resin sheets P1 and P2 are blow-molded 14 to form the resin panel 1 shown in FIG. The resin sheet P1 constitutes the back wall 3, and the resin sheet P2 constitutes the front wall 2.

  In the resin panel 1 of the present embodiment, since the rib 3a is formed on the back wall 3, as shown in FIGS. 2 to 10, the protruding portion 33 for forming the rib 3a forms the back wall 3 side. A plurality of cavities 116B of one split mold 32B are provided. The projecting portion 33 is formed in a shape corresponding to the rib 3a formed on the back wall 3, and is provided in the cavity 116B so as to project toward the other split mold 32A configuring the front wall 2 side. The protrusion 33 shown in FIG. 2 forms the rib 3a in the longitudinal direction of the resin panel 1 shown in FIG. 1, and the protrusion 33 shown in FIGS. 3 to 10 is the resin panel 1 shown in FIG. The rib 3a in the short direction is formed.

  Further, since the resin panel 1 of the present embodiment is configured by making the thickness of the back wall 3 relatively thicker than the front wall 2, the back wall 3 is configured rather than the resin sheet P2 constituting the front wall 2. The thickness of the resin sheet P1 to be increased is increased. Hereinafter, an example of a method for forming the resin panel 1 of the present embodiment will be described in detail.

  As shown in FIG. 1, when the decorative member 7 is provided on the surface of the front wall 2, as shown in FIG. 3, the sheet-like decorative member 7 is provided with a temporary fixing pin (not shown) provided in the split mold 32A. ) Is temporarily fixed so as to cover the cavity 116A of the split mold 32A.

  Next, as shown in FIG. 2, the resin sheets P1 and P2 are extruded from the T-die 28 of the extrusion device 12, and the extruded resin sheets P1 and P2 are passed through a pair of rollers 30 so that the thickness of the resin sheets P1 and P2 is increased. The thickness is adjusted and suspended between the pair of split molds 32.

  The extrusion capability of the extrusion device 12 is appropriately selected from the viewpoint of the size of the resin panel 1 to be molded, the draw-down of the resin sheets P1 and P2, and the prevention of neck-in occurrence. More specifically, from a practical viewpoint, the amount of extrusion per shot in intermittent extrusion is preferably 1 to 10 kg, and the extrusion speed of the resin sheets P1 and P2 from the extrusion slit is several hundred kg / hour or more, More preferably, it is 700 kg / hour or more. From the viewpoint of preventing the resin sheet P1, P2 from being drawn down or neck-in occurrence, the resin sheet P1, P2 extrusion process is preferably as short as possible, depending on the type of resin, MFR value, MT value, In addition, the extrusion process should be completed within 40 seconds, more preferably within 10 to 20 seconds. For this reason, the extrusion amount of the resin sheets P1 and P2 per unit area and unit time from the extrusion slit is 50 kg / hour cm 2 or more, more preferably 150 kg / hour cm 2 or more.

  The extrusion device 12 of the present embodiment is such that the thickness of the front wall 2 is substantially the same as the thickness of the back wall 3 or thin, and the front wall 2 is lighter than the back wall 3. The thickness of the second molten resin sheet P2 constituting the front wall 2 is made thinner than the thickness of the first molten resin sheet P1 constituting the back wall 3 and extruded. For example, the thickness of the resin sheet P2 constituting the front wall 2 is adjusted so that the average thickness of the front wall 2 of the resin panel 1 of the final molded product is in the range of 0.7 mm to 1.2 mm. Further, the resin sheet P1 constituting the back wall 3 is adjusted so that the average thickness of the back wall 3 of the resin panel 1 of the final molded product is in the range of 1.1 mm to 1.7 mm. The thickness of the resin sheets P1 and P2 can be changed by adjusting the interval between the extrusion slits, the interval between the rollers 30, and the rotation speed of the rollers 30.

  However, the resin sheets P1 and P2 are preferably made of a resin material having a high melt tension from the viewpoint of preventing thickness variation due to drawdown, neck-in, etc. It is preferable to use a resin material with high fluidity in order to improve the property and followability. For example, the resin sheets P1 and P2 are polyolefins (for example, polypropylene and high-density polyethylene) that are homopolymers or copolymers of olefins such as ethylene, propylene, butene, isoprenepentene, and methylpentene, and are 230 ° C. MFR (measured according to JIS K-7210 at a test temperature of 230 ° C. and a test load of 2.16 kg) of 3.0 g / 10 min or less, more preferably from 0.3 to 1.5 g / 10 min, or Amorphous resin such as acrylonitrile / butadiene / styrene copolymer, polystyrene, high impact polystyrene (HIPS resin), acrylonitrile / styrene copolymer (AS resin), MFR at 200 ° C. (according to JIS K-7210) According to a test temperature of 200 ° C. and a test load of 2.16 kg) of 3.0 to 60 g / 10 min, more preferably 30 to 50 g / 10 min and a melt tension at 230 ° C. (manufactured by Toyo Seiki Co., Ltd.) A strand tension tester was used to extrude a strand from an orifice with a diameter of 2.095 mm and a length of 8 mm at a preheating temperature of 230 ° C. and an extrusion speed of 5.7 mm / min. The tension when wound) is 50 mN or more, preferably 120 mN or more.

  In order to prevent the resin sheets P1 and P2 from cracking due to impact, it is preferable that hydrogenated styrene thermoplastic elastomer is added in an amount of less than 30 wt%, preferably less than 15 wt%. Specifically, styrene-ethylene / butylene-styrene block copolymer, styrene-ethylene / propylene-styrene block copolymer, hydrogenated styrene-butadiene rubber and mixtures thereof are suitable as hydrogenated styrene-based thermoplastic elastomers, 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 min. It is preferably 5.0 g / 10 min or less and 1.0 g / 10 min or more.

  Further, the resin sheets P1 and P2 may contain an additive. Examples of the additive include inorganic fillers such as silica, mica, talc, calcium carbonate, glass fiber, and carbon fiber, plasticizer, and stabilizer. , Colorants, antistatic agents, flame retardants, foaming agents and the like. Specifically, silica, mica, glass fiber or the like is added in an amount of 50 wt% or less, preferably 30 to 40 wt% with respect to the molding resin.

  The molding apparatus 60 of the present embodiment can stretch and thin the resin sheets P1 and P2 by sending the resin sheets P1 and P2 sandwiched between the pair of rollers 30 downward by the rotation of the pair of rollers 30. By adjusting the relative speed difference between the extrusion speed of the resin sheets P1 and P2 and the delivery speed at which the resin sheets P1 and P2 are sent downward by the pair of rollers 30 by the rotational speed of the pair of rollers 30 It is possible to prevent the occurrence of drawdown or neck-in. For this reason, the restriction | limiting with respect to the kind of resin, especially the MFR value and MT value, or the extrusion amount per unit time can be made small.

  In the molding apparatus 60 of the present embodiment, the resin sheets P1 and P2 are arranged between the divided molds 32, and the frame member 128 is moved toward the corresponding resin sheets P1 and P2 by a frame member driving device (not shown). As shown in FIG. 4, the frame member 128 is brought into contact with the resin sheets P1 and P2, and the resin sheets P1 and P2 are held by the frame member 128. The frame member 128 has an opening 130, and the frame member 128 holds the resin sheets P1 and P2.

  Next, the frame member 128 is moved toward the split mold 32, and as shown in FIG. 5, the resin sheets P1 and P2 are brought into contact with the pinch-off portion 118 of the split mold 32, and the resin sheets P1, P2 and the pinch-off portion are contacted. 118 and the cavity 116 form a sealed space 117. Further, the reinforcing material unit 5 (see FIG. 1) held by the suction plate 119 of the manipulator (not shown) is inserted between the divided molds 32 as shown in FIG. The reinforcing material unit 5 shown in FIG. 5 is the reinforcing material unit 5 shown in FIG. The position where the reinforcing material unit 5 is held by the suction disk 119 is not particularly limited, and can be held at an arbitrary position.

  Next, the inside of the sealed space 117B is sucked through the divided mold 32B, the resin sheet P1 constituting the back wall 3 is pressed against the cavity 116B, and the resin sheet P1 constituting the back wall 3 as shown in FIG. Is shaped into a shape along the uneven surface of the cavity 116B. A vacuum suction chamber (not shown) is provided inside the split mold 32B of the present embodiment. The vacuum suction chamber communicates with the cavity 116B through the suction hole, and the suction hole is formed from the vacuum suction chamber. Thus, the resin sheet P1 is adsorbed toward the cavity 116B, and the resin sheet P1 is shaped into a shape along the outer surface of the cavity 116B. In addition, ribs 3a are formed on the outer surface of the resin sheet P1 by the protrusions 33 provided on the outer surface of the cavity 116B. Thereby, a plurality of ribs 3a are formed on the resin sheet P1.

  Further, the manipulator is moved toward the divided mold 32B, and as shown in FIG. 7, the reinforcing material unit 5 is pressed against the resin sheet P1 adsorbed by the cavity 116B of the divided mold 32B, and the reinforcing material unit 5 is moved to the resin sheet. Paste to P1. At this time, the reinforcing material unit 5 is attached to the resin sheet P1 so that both ends of the reinforcing material unit 5 are positioned on the contact surface 31 (see FIG. 1) of the back wall 3.

  The resin sheets P1 and P2 of the present embodiment include a filler. Examples of the filler include an inorganic or organic filler. From the viewpoint of obtaining a reinforcing effect, the fibrous filler includes glass fiber, potassium titanate whisker. Carbon fiber and the like, talc, mica, montmorillonite and the like as the plate-like filler, and calcium carbonate and the like as the granular filler. Examples of the needle-like filler include magnesium. Calcium carbonate can obtain reinforcing effects such as bending elastic modulus, bending strength, heat distortion temperature, and dimensional stability. In addition, talc and montmorillonite can obtain reinforcing effects such as bending elastic modulus, bending strength, heat distortion temperature, and dimensional stability. Mica can obtain reinforcing effects such as flexural modulus, flexural strength, thermal deformation temperature, dimensional stability, and compressive strength. Glass fiber, potassium titanate whisker, and carbon fiber can obtain reinforcing effects such as bending elastic modulus, bending strength, tensile elastic modulus, thermal deformation temperature, dimensional stability, and compressive strength. For this reason, it is preferable to use a fibrous filler from the viewpoint of obtaining a reinforcing effect.

  As the fibrous filler, for example, short fibers having a fiber length of 0.2 to 0.5 mm and long fibers having a fiber length of 3 to 12 mm can be used. In the case where a fibrous filler is used, the fibrous filler is oriented in the extrusion direction of the resin sheets P1 and P2, but the fibrous filler is oriented in the same direction as the reinforcing material unit 5. It is preferable to extrude the resin sheets P1 and P2. Thereby, the reinforcing material unit 5 in the same direction as the orientation of the fibrous filler can be reduced in weight.

  Next, the suction platen 119 is detached from the reinforcing material unit 5, the manipulator is pulled out from between the two divided molds 32, and the resin sheet P2 constituting the front wall 2 is pressed against the cavity 116A, as shown in FIG. As shown, the resin sheet P2 is shaped into a shape along the cavity 116A. Note that a vacuum suction chamber (not shown) is also provided inside the split mold 32A of the present embodiment, and the vacuum suction chamber communicates with the cavity 116A via a suction hole and is sucked from the vacuum suction chamber. By sucking through the hole, the resin sheet P2 is adsorbed toward the cavity 116A, and the resin sheet P2 is shaped into a shape along the outer surface of the cavity 116A.

  Next, the two divided molds 32 are clamped by the mold driving device, and the reinforcing material unit 5 and the rib 3a are pressed against the resin sheet P2 adsorbed in the cavity 116A of the divided mold 32A as shown in FIG. Then, the reinforcing material unit 5 and the rib 3a are attached to the resin sheet P2. Further, the periphery of the two resin sheets P1 and P2 is welded to form a parting line PL.

  In this embodiment, when the resin panel 1 in which the reinforcing material unit 5 and the resin sheets P1, P2 are integrated is clamped with the split mold 32, the reinforcing material unit 5 is used with the split mold 32. It is preferable to compress the resin sheets P1 and P2. Thereby, the adhesive strength between the reinforcing material unit 5 and the resin sheets P1 and P2 can be further improved.

  Through the above steps, the resin panel 1 formed by sandwiching the reinforcing material unit 5 between the molten resin sheets P1 and P2 is completed.

  Next, as shown in FIG. 10, the two split molds 32 are opened, the cavity 116 is separated from the completed resin panel 1, and burrs formed around the parting line PL are removed. This completes the molding of the resin panel 1 shown in FIG.

<Operation / Effect of Resin Panel 1 of the Present Embodiment>
Thus, when the resin panel 1 of this embodiment is molded, first, as shown in FIG. 2, in the resin panel 1 shown in FIG. The thickness of the second molten resin sheet P2 constituting the front wall 2 is substantially the same as or thinner than the thickness of the back wall 3, and the front wall 2 is lighter than the back wall 3. The thickness is made thinner than the thickness of the first molten resin sheet P1 constituting the back wall 3 and extruded from the extrusion device 12.

  Next, as shown in FIG. 6, the first resin sheet P1 is shaped into a shape along the cavity 116B of the split mold 32B, and the first resin sheet P1 is stretched into a shape along the protruding portion 33. Ribs 3a are formed. Thereby, the rib 3a is formed in the 1st resin sheet P1 which comprises the back wall 3. FIG.

  Next, as shown in FIG. 7, the reinforcing material unit 5 is attached to the first resin sheet P1 on which the ribs 3a are formed.

  Next, as shown in FIG. 9, a pair of split molds 32 are clamped to form a first resin sheet P1 constituting the back wall 3, a second resin sheet P2 constituting the front wall 2, The edges of the ribs 3a formed on the first resin sheet P1 are welded to the second resin sheet P2. Further, the reinforcing material unit 5 is attached to the second resin sheet P2. Thereby, the resin panel 1 shown in FIG. 1 can be molded.

  In the resin panel 1 of the present embodiment, the thickness of the front wall 2 is substantially the same as the thickness of the back wall 3 or is thin, and the front wall 2 is lighter than the back wall 3, for example, The average thickness of the resin panel 1 (average value of the average thickness of the front wall 2 and the average thickness of the back wall 3) can be made less than 1.5 mm to reduce the weight of the resin panel 1 and The contact surface 31 of the wall 3 can be made difficult to be deformed and hard to crack.

  In addition, since the reinforcing material unit 5 is attached to the inner surfaces of the front wall 2 and the back wall 3 to form the resin panel 1, it is possible to prevent the reinforcing material unit 5 from being displaced.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  For example, in the resin panel 1 of the above-described embodiment, as shown in FIG. 1, only one linear reinforcing material unit 5 is arranged. However, as shown in FIG. 11, it is also possible to arrange a plurality of reinforcing material units 5. The resin panel 1 shown in FIG. 11 is configured by arranging two reinforcing material units 5. Further, six rectangular ribs 3a are formed between the reinforcing material units 5 in a non-parallel manner. Even in the configuration of the resin panel 1 shown in FIG. 11, the average wall thickness of the front wall 2 is 1.2 mm or less, and the average wall thickness of the back wall 3 is 1.7 mm or less. The average thickness of panel 1 (average value of average thickness of front wall 2 and average thickness of back wall 3) can be made less than 1.5 mm to reduce the weight of resin panel 1 and make contact It is possible to make the surface 31 difficult to deform and hard to crack.

  In the above-described embodiment, one resin panel 1 has been described as an example. However, for example, it is possible to configure a resin panel in which a first resin panel and a second resin panel are connected via a hinge portion.

  In the above-described embodiment, the reinforcing material unit 5 is disposed inside the resin panel 1 by attaching the reinforcing material unit 5 to the molten resin sheets P1 and P2 and clamping the mold. However, after the resin panel 1 is molded, the reinforcing material unit 5 can be inserted into the resin panel 1 by inserting the reinforcing material unit 5 from the side surface of the resin panel 1. However, in the case of the rectangular reinforcing material unit 5 as shown in FIGS. 1 and 11, it is possible to insert from the side surface of the molded resin panel 1, but a plurality of reinforcing materials facing different directions from each other. In the case of the shape of the ladder-shaped reinforcing material unit or the like configured by the step, the ladder-shaped reinforcing material unit can be attached to the molten resin sheets P1 and P2 and molded as in the above-described molding method. preferable.

DESCRIPTION OF SYMBOLS 1 Resin panel 2 Front wall 3 Back wall 3a Rib 31 Contact surface 4 Peripheral wall 5 Reinforcement unit 6 Hollow part 7 Cosmetic member

Claims (11)

A resin panel having a back wall having a plurality of abutment surfaces that abut against other members, and a front wall facing the back wall at an interval,
A plurality of rectangular ribs that are recessed to the front wall and welded to the inner surface of the front wall, with a portion of the back wall recessed.
The rib has a flat weld surface with the front wall,
The reinforcing member disposed so as to be stretched to the abutment surface is provided between the said table wall back wall, the rectangular rib, the longitudinal direction of the ribs and the reinforcing material A resin panel formed non-parallel. The reinforcing member is provided so as to pass between the two rectangular ribs,
The two rectangular ribs, Ru arranged in the longitudinal direction of each rib, the resin panel of claim 1.   3. The resin panel according to claim 1, wherein the rectangular rib is provided between a pair of reinforcing members extending in one direction so as to extend non-parallel to the one direction. The thickness of the table walls, the thickness of the back wall and the same, or a thin-walled, plastic panel according to any one of claims 1 to 3. The back wall and the front wall are made of the same resin,
The resin panel according to any one of claims 1 to 4, wherein the front wall is lighter than the back wall. The average wall thickness of the front wall is 1.2 mm or less,
The average wall thickness of the said back wall is 1.7 mm or less, The resin-made panels as described in any one of Claims 1-5 characterized by the above-mentioned. A molding method of molding a resin panel having a back wall having a plurality of abutting surfaces that abut against other members and a front wall facing the back wall at an interval using a pair of split molds. There,
The cavity of one split mold is provided with a plurality of rectangular protrusions that protrude toward the other split mold, and a first wall that constitutes the back wall on the one split mold side. The molten resin sheet is located, the second molten resin sheet constituting the front wall is located on the other split mold side, and the first molten resin sheet and the second molten resin sheet An extrusion process for extruding
The first molten resin sheet is shaped into a shape along the cavity of the one split mold, and the first molten resin sheet is stretched into a shape along the protruding portion to form a rectangular rib. The shaping process;
Arrangement step of disposing a reinforcing material on the first molten resin sheet on which the rectangular ribs are formed so as to be bridged over the portion to be the contact surface and non-parallel to the longitudinal direction of the ribs Have
A pair of split molds are clamped to weld peripheral edges of the first molten resin sheet constituting the back wall and the second molten resin sheet constituting the front wall, and A mold clamping step of welding the tip of the rib formed on the first molten resin sheet to the second molten resin sheet so that the welding surface is flat, and molding the resin panel. A molding method characterized by the above. The reinforcing member is disposed so as to pass between the two rectangular ribs,
The two rectangular ribs, Ru arranged in the longitudinal direction of each of the ribs, forming method according to claim 7.   The molding method according to claim 7 or 8, wherein the reinforcing member is disposed between a pair of reinforcing members extending in one direction so that the rectangular rib extends non-parallel to the one direction.   In the extrusion step, the first and second molten resin sheets are extruded such that the thickness of the second molten resin sheet is thinner than the thickness of the first molten resin sheet. The molding method according to any one of claims 7 to 9. The extrusion process includes
In the resin panel molded in the mold clamping step, the first melting is performed so that the average thickness of the front wall is 1.2 mm or less and the average thickness of the back wall is 1.7 mm or less. molding method according to extrude the resin sheet to the second molten resin sheet, any one of claims 7 to claim 10, characterized in that.