panel

Abstract

A panel is provided which inhibits peeling of a base material from a surface material. According to the present invention, a panel is provided which includes a base material, and a surface material which is fixed in a recess provided in the base material.

Description

Technical Field

[0001] The present invention relates to a panel used as a luggage panel or the like installed in the luggage compartment of a vehicle. Background Technology

[0002] (Second viewpoint)

[0003] Patent document 2 discloses a panel having multiple ribs that are welded to the inner surface of the surface wall such that a portion of the back wall is recessed toward the surface wall.

[0004] (Points 1 and 3)

[0005] Patent document 1 discloses a panel material formed by mounting a thin steel plate onto a hollow plate.

[0006] (4th viewpoint)

[0007] Patent document 1 discloses a panel formed by mounting a thin sheet-like surface material onto a core material.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2016-7900

[0011] Patent Document 2: WO2013 / 077198 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] (First viewpoint)

[0014] In the structure of Patent Document 1, the interface between the steel plate and the hollow plate is positioned where external force can be easily applied. If an external force is applied to the interface, the steel plate and the hollow plate may peel off.

[0015] The present invention was made in view of the following circumstances, and provides a panel that suppresses the peeling of the substrate and the surface material.

[0016] (Second viewpoint)

[0017] In the panel of Patent Document 2, a rod-shaped reinforcing member is provided inside to improve rigidity. Since the rod-shaped reinforcing member is relatively heavy, its inclusion increases the overall weight of the panel. Furthermore, in the panel of Patent Document 2, the exposed ribs on the back wall result in a poor appearance of the back side.

[0018] The present invention was made in view of the following circumstances, and provides a panel that is lightweight and has an excellent appearance on the back.

[0019] (Third viewpoint)

[0020] In Patent Document 1, strength is increased by mounting a steel plate onto a hollow panel, but even this method sometimes results in insufficient strength. To further increase strength, the thickness of the steel plate can be increased, but this would significantly increase the weight of the panel.

[0021] The present invention was made in view of the following situation, and provides a panel that can suppress a significant increase in weight while improving strength.

[0022] (4th viewpoint)

[0023] For example, the panel in Patent Document 1 has excellent strength. However, after a detailed study of the panel's strength, the inventors found that if a local load is applied to the panel, the panel will bend and easily undergo buckling deformation.

[0024] The present invention was made in view of the following circumstances, and provides a panel that suppresses buckling deformation.

[0025] Problem-solving methods

[0026] (First viewpoint)

[0027] According to the present invention, a panel is provided, comprising a substrate and a surface material, wherein the surface material is fixed in a recess provided in the substrate.

[0028] In the panel of the present invention, a face material is fixed within a recess in the substrate. Therefore, the interface between the substrate and the face material is located within the recess, making it difficult for external forces to be applied to the interface and suppressing peeling between the substrate and the face material.

[0029] Various embodiments of the present invention are illustrated below. The embodiments shown below can be combined with each other.

[0030] Preferably, in the panel described above, the substrate and the surface material are covered by a skin material.

[0031] Preferably, in the panel described above, the width of the peripheral portion between the edge of the recess and the side end of the substrate is 1 to 20 mm.

[0032] Preferably, in the panel described above, if the step difference between the edge of the recess and the edge of the surface material is S, and the thickness of the surface material is T1, then S / T1 is 0.8 or less.

[0033] (Second viewpoint)

[0034] According to the present invention, a panel is provided, comprising a substrate and a face material, wherein the substrate comprises a front wall and a back wall, and has a rib formed by recessing a portion of the back wall toward the front wall and fusing it to the inner surface of the front wall, and the face material is fixed to the back wall in such a way as to cover the opening of the rib.

[0035] Because the panel of the present invention has a face material fixed to the back wall, the panel has high rigidity and does not require reinforcement inside the panel, thus enabling weight reduction. Furthermore, since the face material covers the openings of the ribs on the back of the panel, the ribs are not exposed, resulting in excellent appearance of the back of the panel.

[0036] The following describes various embodiments of the present invention. These embodiments can be combined with each other.

[0037] Preferably, in the panel described above, the back wall is provided with a recess, and the face material is disposed within the recess.

[0038] Preferably, in the panel described above, the parting line formed on the substrate is located at a position adjacent to the edge of the substrate on the back wall side.

[0039] (Third viewpoint)

[0040] According to the present invention, a panel is provided, comprising a core material and a surface material, wherein the core material comprises a substrate and a reinforcing member made of a material having a strength higher than that of the substrate, and the substrate and the reinforcing member are respectively bonded to the surface material.

[0041] In the panel of this invention, the core material is composed of a substrate and a reinforcing material, and the reinforcing material is bonded to the surface material. In this way, strength can be increased by placing the reinforcing material only where strength is required, thus minimizing the amount of reinforcing material used. Therefore, it is possible to increase panel strength while suppressing a significant increase in panel weight.

[0042] Various embodiments of the present invention are illustrated below. The embodiments shown below can be combined with each other.

[0043] Preferably, in the panel described above, the substrate and the reinforcing material are composed of foam, and the foaming ratio of the foam constituting the reinforcing material is lower than the foaming ratio of the foam constituting the substrate.

[0044] Preferably, in the panel described above, the reinforcing member includes a column portion and flange portions disposed at one or both ends of the column portion, the flange portions being bonded to the surface material.

[0045] (4th viewpoint)

[0046] According to the present invention, a panel is provided, comprising a core material, a first and a second surface material, wherein the core material is sandwiched between the first and the second surface material, the thickness of the core material is 15 to 25 mm, and the first and the second surface material are bonded to the core material. If (Young's modulus of the first surface material [GPa]) × (thickness of the first surface material [mm]) 2 The strength index of the first face material is (Young's modulus of the second face material [GPa]) × (thickness of the second face material [mm]).2 The second surface material strength index is the average surface material strength index, and the average of the first and second surface material strength indices is the average surface material strength index. The panel strength index, defined by the average surface material strength index × (10% compressive stress [MPa] of the core material) is 0.7 or higher.

[0047] The inventors conducted thorough research and discovered that when a local load is applied to a panel, the panel deforms locally, causing buckling deformation. Furthermore, based on this discovery, by setting the panel strength index, which is related to the local strength of the panel, to 0.7 or higher, buckling deformation can be effectively suppressed, thus completing this invention.

[0048] Various embodiments of the present invention are illustrated below. The embodiments shown below can be combined with each other.

[0049] Preferably, in the above-mentioned panels, the panel strength index is 5.0 or less.

[0050] Preferably, in the above-described panel, the weight per unit area of ​​the panel is 3000 g / m². 2 the following. Attached Figure Description

[0051] Figure 1 (First Viewpoint) Figure 1A This is a cross-sectional view of panel 1 according to an embodiment of the present invention. Figure 1B yes Figure 1A A magnified view of region B in the image. Figure 1C From Figure 1B The illustration excludes the outer skin material 4 and the adhesive layer 7.

[0052] Figure 2 yes Figure 1B Exploded view (adhesive layers 6 and 7 are not shown).

[0053] Figure 3 (Second viewpoint) Figure 3A This is a cross-sectional view of panel 1 according to an embodiment of the present invention. Figure 3B yes Figure 3A A magnified view of region B in the image. Figure 3C yes Figure 3B A magnified view of region C in the image.

[0054] Figure 4, Figure 4A yes Figure 3B The exploded diagram, Figure 4B yes Figure 4A A magnified view of region B in the image.

[0055] Figure 5 This is a cross-sectional view used to illustrate the manufacturing process of the substrate 2 with the skin material 4 welded on.

[0056] Figure 6 (Third viewpoint) Figure 6A This is a perspective view of panel 1 according to an embodiment of the present invention. Figure 6B This is a 3D view of core material 12.

[0057] Figure 7 yes Figure 6A An enlarged view of the end face of region A in the image.

[0058] Figure 8 This is a perspective view showing the state in which the two ends of the long side of panel 1 are supported by support member 17.

[0059] Figure 9, Figures 9A to 9D These respectively represent the second to fifth embodiments, and... Figure 7 The corresponding diagram.

[0060] Figure 10 (4th viewpoint) Figure 10A This is a perspective view of panel 1 according to an embodiment of the present invention. Figure 10B yes Figure 10A An enlarged view of the end face of region B in the image. Figure 10C From Figure 10B Illustration showing only the core material 12 being pulled out. Detailed Implementation

[0061] The following describes embodiments of the present invention. The various features shown in the embodiments described below can be combined with each other. Furthermore, each feature independently enables the invention to succeed. The features described in the embodiments of the first to fourth views can be combined with each other.

[0062] (First viewpoint)

[0063] 1. Structure of Panel 1

[0064] like Figures 1A-2 As shown, in one embodiment of the present invention, the panel 1 includes a substrate 2, a surface material 3, and a skin material 4. The panel 1 is preferably approximately cuboid in shape. The panel 1 can be used as a luggage rack or similar fixture installed in a vehicle's luggage compartment.

[0065] The substrate 2 is preferably a plate-shaped component. The substrate 2 can be a foamed material or a non-foamed material. Furthermore, the substrate 2 can be a hollow material or a solid material. The substrate 2 is preferably formed by molding using a mold. In this case, since the substrate 2 can be pre-shaped into the desired form before manufacturing the panel 1, the operability is excellent. Furthermore, since the substrate 2 can be shaped to match the desired panel shape, a product with optimized shape can be obtained.

[0066] Examples of substrate 2 include bead-foamed molded bodies obtained by bead foaming, foamed or non-foamed sheet molded bodies obtained by imparting an uneven shape to a foamed or non-foamed resin sheet, and foamed or non-foamed hollow molded bodies obtained by molding a foamed or non-foamed, cylindrical preform or two resin sheets.

[0067] The bead-molded body may be composed of expanded polystyrene, expanded acrylonitrile styrene, expanded polypropylene, etc., with a foaming ratio of, for example, 20 to 50 times, specifically, 20, 25, 30, 35, 40, 45, 50 times, or within any two values ​​exemplified here.

[0068] The foamed preform or foamed resin sheet may be made of polyolefins such as polyethylene or polypropylene, and the foaming ratio of the molded body using it is, for example, 1.1 to 8 times, specifically, for example, 1.1, 1.5, 2, 3, 4, 5, 6, 7, 8, or within any two values ​​exemplified herein.

[0069] The thickness of the substrate 2 is, for example, 5 to 25 mm, preferably 8 to 20 mm. Specifically, this thickness can be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, or 25 mm, or within any two values ​​exemplified herein. The thickness of the substrate 2 refers to the distance at the point where the distance between the surface 2f and the back surface 2r of the substrate 2 is greatest.

[0070] The substrate 2 has recesses 5. One recess 5 is provided on both the surface 2f and the back surface 2r of the substrate 2. A face material 3 is fixed within each recess 5. The planar shape of the recess 5 (from...) Figure 1A The shape of the substrate 2 when viewed from above is preferably a roughly rectangular shape.

[0071] The face material 3 is a plate-shaped component. By fixing the face material 3 within the recess 5, the rigidity of the panel 1 can be improved. Therefore, the thickness of the substrate 2 can be reduced, thereby making the panel 1 lighter. The face material 3 can be made of a material with higher rigidity per unit thickness than the substrate 2, such as metal (aluminum, iron, etc.) or fiber-reinforced resin. The thickness of the face material 3 is, for example, 0.1 to 3 mm, preferably 0.3 to 1.5 mm. Specifically, this thickness is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0 mm, or within any two values ​​exemplified herein. It should be noted that, unless otherwise specified, the values ​​of thickness, depth, etc., in this specification refer to average values.

[0072] The method for fixing the face material 3 into the recess 5 is not particularly limited; it can be fused to the substrate 2 or bonded to the substrate 2 by the adhesive layer 6. Examples of adhesives constituting the adhesive layer 6 include polyurethane-based adhesives and olefin-based adhesives. The thickness of the adhesive layer 6 is, for example, 0.01 to 0.5 mm, specifically, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 mm, or within any two values ​​exemplified herein.

[0073] If the area of ​​the bottom surface 5c of the recess 5 is S1, and the area of ​​the surface of the face material 3 opposite to the bottom surface 5c of the recess 5 is S2, then S2 / S1 is, for example, 0.8 to 1, preferably 0.9 to 1. In this case, almost the entire recess 5 is filled by the face material 3, which increases the rigidity of the panel 1. Specifically, S2 / S1 is, for example, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, or any two values ​​exemplified here.

[0074] The depth of the recess 5 is preferably set such that the step difference between the edge 5a of the recess 5 and the edge 3c of the face material 3 is small, and more preferably, there is no step difference. With a step difference, either edge 5a or edge 3c can be made higher. If the step difference is S and the thickness of the face material 3 is T1, then S / T1 is preferably 0.8 or less. In this case, the step difference is smaller compared to the case where the face material 3 is disposed on the substrate 2 without the recess 5. This value is, for example, 0 to 0.8, specifically, for example, 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or within any two values ​​exemplified here. The depth of the recess 5 is preferably the same as the total thickness of the face material 3 and the adhesive layer 6. In this case, the step difference between the edge 5a of the recess 5 and the edge 3c of the face material 3 can be eliminated.

[0075] The depth of the recess 5 is, for example, 0.1 to 3 mm, preferably 0.3 to 1.5 mm. Specifically, this depth is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0 mm, or within any two values ​​exemplified herein.

[0076] If the thickness of the substrate 2 is T and the depth of the recess 5 is D, then D / T is, for example, 0.01 to 0.3, preferably 0.02 to 0.2. Specifically, this value is, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.2, 0.3, or within any range of two values ​​exemplified herein.

[0077] The width W of the peripheral portion 2b between the edge 5a of the recess 5 and the side end 2a of the substrate 2 is preferably 1 to 20 mm. If the width W is too small, the strength of the peripheral portion 2b will be too low, making it susceptible to damage by external forces. If the width W is too large, the area where the face material 3 is absent will become too large, potentially resulting in insufficient rigidity of the panel 1. Specifically, the width W is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 mm, or may be within any two values ​​exemplified here. The width W of the peripheral portion 2b is preferably constant over the entire circumference of the substrate 2. When the width W is not constant over the entire circumference, it is preferable that its average value is within the above-mentioned range, and more preferably that both its minimum and maximum values ​​are within the above-mentioned range.

[0078] The skin material 4 is configured to cover the substrate 2 and the face material 3. Preferably, the skin material 4 covers the face material 3 disposed in the recess 5 of the surface 2f of the substrate 2, the peripheral portion 2b of the surface 2f of the substrate 2, and the side surface 2s of the substrate 2. This improves the appearance when the surface 1f and side surface 1s of the panel 1 are easily distinguishable by the user (e.g., luggage panel). Furthermore, since the interface between the substrate 2 and the face material 3 is covered by the skin material 4, peeling of the face material 3 from the substrate 2 is prevented. Preferably, the skin material 4 covers part or all of the face material 3 disposed in the recess 5 of the back surface 2r of the substrate 2, and the peripheral portion 2b of the back surface 2r of the substrate 2. This, since the interface between the substrate 2 and the face material 3 on the back surface 2r side is covered by the skin material 4, peeling of the face material 3 on the back surface 2r side from the substrate 2 is prevented.

[0079] In one example, the outer skin material 4 is a non-woven fabric, which can be bonded to the face material 3 and the substrate 2 through the adhesive layer 7.

[0080] 2. Manufacturing method of panel 1

[0081] Panel 1 can be manufactured by the following method.

[0082] (1) Substrate preparation process

[0083] In the substrate preparation process, a substrate 2 with a recess 5 is prepared.

[0084] (2) Surface material fixing process

[0085] In the face material fixing process, the face material 3 is fixed within the recess 5 of the substrate 2. The face material 3 can be fixed, for example, by welding or bonding. In bonding, an adhesive layer is placed between the substrate 2 and the face material 3, and then the face material 3 is pressed against the bottom surface 5c of the recess 5, thereby fixing the face material 3 to the bottom surface 5c of the recess 5. The adhesive layer is applied (e.g., by spraying or roller coating) to the bottom surface 5c of the recess 5 or the face material 3.

[0086] (3) Skin material fixing process

[0087] In the skin material fixing process, an adhesive is applied to the parts (face material 3 and substrate 2) where the skin material 4 is fixed, and then the skin material 4 is fixed to the face material 3 and substrate 2 by pressing the skin material 4 onto the parts where the adhesive is applied.

[0088] 3. Other manufacturing methods for panel 1

[0089] In "2. Method for Manufacturing Panel 1", after preparing a substrate 2 with recesses 5, a face material 3 is fixed within the recesses 5. However, a substrate 2 without recesses 5 can also be prepared, and the face material 3 can be pressed onto the substrate 2 while it is placed on the substrate 2, so that the face material 3 is embedded in the substrate 2, forming recesses 5 on the substrate 2. This method also allows the face material 3 to be fixed within the recesses 5. In this case, the substrate 2 is preferably made of a material that is easily indented by pressing (e.g., foam, especially bead-molded foam).

[0090] The process of pressing the face material 3 onto the substrate 2 can be performed either with an adhesive layer between the substrate 2 and the face material 3, or without an adhesive layer. In the latter case, the face material 3 is fixed to the substrate 2 by pressing the face material 3 onto the substrate 2 to form a recess 5, and then pressing the face material 3 onto the substrate 2 with an adhesive layer between them. The former process involves fewer steps and is therefore preferred. This pressing can be performed using, for example, a pressing roller or a press machine.

[0091] In this manufacturing method, the skin material fixing process can be performed in the same way as in "2. Manufacturing method of panel 1".

[0092] 4. Other implementation methods

[0093] • The outer skin material 4 can be omitted when it is not needed.

[0094] The recess 5 may also be provided only on one of the surface 2f and the back surface 2r of the substrate 2. In this case, the face material 3 is only provided on the surface with the recess 5.

[0095] (Second viewpoint)

[0096] 1. Structure of Panel 1

[0097] like Figures 3A to 4B As shown, in one embodiment of the present invention, the panel 1 includes a substrate 2, a surface material 3, and a skin material 4. The panel 1 is preferably approximately cuboid in shape. The panel 1 can be used as a luggage rack or similar fixture installed in a vehicle's luggage compartment.

[0098] The substrate 2 has a front wall 21 and a back wall 22, and has a rib 23 formed by recessing a portion of the back wall 22 toward the 21 and fusing it to the inner surface of the front wall 21.

[0099] The outer wall 21 and the back wall 22 may be composed of a resin composition. The resin composition includes a resin and may also include additives such as fillers. Examples of resins include olefin-based resins such as polyethylene and polypropylene. Examples of fillers include fibrous fillers such as glass fiber and carbon fiber, or particulate fillers such as talc and mica. Adding fillers can improve rigidity and reduce the rate of linear expansion. If the total amount of resin and filler is 100% by mass, the filler content is, for example, 20 to 50% by mass, preferably 30 to 40% by mass. This content can be, for example, 20, 25, 30, 35, 40, 45, or 50% by mass, or within any two values ​​exemplified herein.

[0100] The filler content of the back wall 22 is preferably lower than that of the surface wall 21. At this time, the rigidity of the back wall 22 side of the panel 1 decreases, but the rigidity of the back wall 22 side of the panel 1 can be improved by providing the surface material 3. Therefore, by making the filler content of the back wall 22 lower than that of the surface wall 21, and by using the surface material 3 to strengthen the back wall 22, a particularly lightweight and highly rigid panel 1 can be obtained.

[0101] The wall thickness of the surface wall 21 and the back wall 22, excluding the rib 23, is, for example, 0.5 to 2.0 mm, preferably 0.8 to 1.5 mm. This thickness can be, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 mm, or within any range of two values ​​exemplified herein. It should be noted that, unless otherwise specified, wall thickness, depth, etc., in this specification refer to average values.

[0102] The thickness of the back wall 22 is preferably less than the thickness of the surface wall 21. This improves the rigidity of the surface wall 21 side of the panel 1 and makes the panel 1 lighter. Furthermore, the rigidity of the back wall 22 side of the panel 1 is improved by providing the surface material 3. Therefore, by making the thickness of the back wall 22 less than the thickness of the surface wall 21 and by reinforcing the back wall 22 with the surface material 3, a particularly lightweight and highly rigid panel 1 can be obtained. If the thickness of the back wall 22 is Tr and the thickness of the surface wall 21 is Tf, then Tr / Tf is, for example, 0.1 to 0.9, preferably 0.3 to 0.7, for example 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or any two values ​​exemplified here.

[0103] The front wall 21 and the back wall 22 can be foamed or non-foamed, but the foaming ratio of the back wall 22 is preferably higher than that of the front wall 21. In this case, the rigidity of the back wall 22 side of the panel 1 will decrease, but the rigidity of the back wall 22 side of the panel 1 can be improved by providing the face material 3. Therefore, by making the foaming ratio of the back wall 22 higher than that of the front wall 21, and by using the face material 3 to reinforce the back wall 22, a particularly lightweight and highly rigid panel 1 can be obtained.

[0104] The shape of the opening of rib 23 is not particularly limited, and can be circular, elliptical, rectangular, polygonal, etc. The bottom of rib 23 is the welded portion 8 where the surface wall 21 and the back wall 22 are fused. In the welded portion 8, the surface wall 21 and the back wall 22 are compressed, and the wall thickness of the welded portion 8 is preferably less than the sum of the wall thickness of the surface wall 21 and the wall thickness of the back wall 22. If the wall thickness of the welded portion 8 is Tw, then Tw / (Tf+Tr) is, for example, 0.5 to 0.95, for example, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, or within any two values ​​exemplified here. Furthermore, Tw / Tf can be, for example, 0.8 to 1.2, such as 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, or 1.20, or any two values ​​exemplified here.

[0105] The substrate 2 is preferably provided with a plurality of ribs 23. The plurality of ribs 23 are preferably distributed in a regular manner. In this case, the rigidity of the panel 1 is particularly high.

[0106] The thickness T of the thickest part of the substrate 2 is, for example, 5 to 25 mm, preferably 8 to 20 mm. Specifically, this thickness is, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25 mm, or it can be within any two values ​​exemplified here.

[0107] like Figure 5As shown, in one example, the substrate 2 can be formed by molding a pair of resin sheets 31, 32 using a pair of molds 41, 42. A parting line PL is formed on the substrate 2 at a position corresponding to the parting surface of the molds 41, 42. A front wall 21 and a back wall 22 are fused together at the parting line PL. The parting line PL formed on the substrate 2 is preferably located at a position adjacent to the edge 2c on the side of the back wall 22 in the thickness direction of the substrate 2. If the parting line PL is located at this position, it has the advantages of being inconspicuous and aesthetically pleasing, and users will not feel hurt by touching the parting line PL. Furthermore, when the skin material 4 is integrally molded, the skin material 4 disposed on the side of the front wall 21 covers the area where the parting line PL is located, but by setting the parting line PL at a position adjacent to the edge 2c, almost the entire side 2s of the substrate 2 is covered by the skin material 4, thus having an aesthetic advantage.

[0108] Furthermore, the edge 2c is preferably provided as a protrusion 2d that protrudes from the side 2s of the substrate 2. By providing the protrusion 2d, the width of the weld between the surface wall 21 and the back wall 22 is increased, thereby improving the strength of the parting line PL.

[0109] The face material 3 is a plate-shaped component, fixed to the back wall 22 in such a way that it covers the openings 23a of the ribs 23. This improves the rigidity of the panel 1. Therefore, it eliminates the need for rod-shaped reinforcing members within the panel 1, allowing for a lighter panel 1. Furthermore, by covering the openings 23a of the ribs 23 with the face material 3, the appearance of the back surface 1r of the panel 1 is improved. The face material 3 covers the openings 23a of at least one rib 23 provided on the back wall 22, preferably covering the openings 23a of multiple ribs 23, and most preferably covering the openings 23a of all ribs 23. The material, thickness, etc., of the face material 3 are described in the same way as in the first viewpoint.

[0110] The method of fixing the face material 3 to the back wall 22 is the same as the method of fixing the face material 3 to the recess 5 in the first viewpoint.

[0111] Preferably, a recess 5 is provided in the back wall 22, and a face material 3 is provided within the recess 5. Therefore, since the interface between the back wall 22 and the face material 3 is located within the recess 5, external forces are difficult to apply to the interface, thus suppressing peeling between the back wall 22 and the face material 3. The recess 5 is preferably provided within a region containing multiple ribs 23. The planar shape of the outer periphery of the recess 5 (from...) Figure 4A The shape of the substrate 2 when viewed from below is preferably approximately rectangular.

[0112] If the area of ​​the region surrounded by the outer periphery of the recess 5 is S1, and the area of ​​the surface of the material 3 opposite to the recess 5 is S2, then the explanation of S2 / S1 is the same as the explanation of S2 / S1 in the first viewpoint.

[0113] The description of the depth of recess 5 is the same as that of recess 5 in the first viewpoint.

[0114] If the thickness of the thickest part of the substrate 2 is T, then the explanation of D / T when the depth of the recess 5 is D is the same as the first viewpoint.

[0115] The description of the width W of the peripheral portion 2b between the edge 5a of the recess 5 and the edge 2c of the back wall 22 side of the substrate 2 is the same as that in the first viewpoint.

[0116] The skin material 4 is preferably configured to cover the surface 2f and side 2s of the substrate 2. This improves the appearance of the surface 2f and side 2s. The skin material 4 can also cover the substrate 2 and the face material 3 on the back 2r of the substrate 2. In one example, the skin material 4 is a non-woven fabric. The skin material 4 can be omitted if not needed.

[0117] 2. Manufacturing method of panel 1

[0118] Panel 1 can be manufactured by the following method.

[0119] (1) Substrate preparation process

[0120] In the substrate preparation process, in one example, such as Figure 5 As shown, a pair of resin sheets 31 and 32 in a molten state can be formed by molding them using a pair of openable and closable molds 41 and 42. The resin sheets 31 and 32 form the front wall 21 and the back wall 22. Furthermore, by placing a skin material 4 between the mold 41 and the resin sheet 31, the skin material 4 can be fused to the front wall 21 during the manufacture of the substrate 2 (i.e., integral molding). The resin sheets 31 and 32 can be formed by extruding the resin composition from a T-die.

[0121] In one example, by using molds 41 and 42 to depressurize and attract resin sheets 31 and 32 respectively, and shaping the resin sheets 31 and 32 into the shapes of the molding surfaces 41a and 42a of molds 41 and 42, the molds 41 and 42 are closed, thereby obtaining a substrate 2 with the skin material 4 welded on.

[0122] It should be noted that the skin material 4 may not be placed between the mold 41 and the resin sheet 31, and the skin material 4 may be fused or bonded to the substrate after the substrate 2 is manufactured.

[0123] (2) Surface material fixing process

[0124] In the face material fixing process, the face material 3 is fixed to the back wall 22. The face material 3 can be fixed, for example, by welding or bonding. When bonding, adhesive is applied (e.g., by spraying or balling) to the back wall 22, and then the face material 3 is pressed against the back wall 22, thereby fixing the face material 3 to the back wall 22.

[0125] (Third viewpoint)

[0126] 1. First Implementation Method

[0127] 1-1. Structure of Panel 1

[0128] like Figures 6A-7 As shown, in one embodiment of the present invention, the panel 1 includes a core material 12 and a surface material 3. The panel 1 is preferably in a generally rectangular parallelepiped shape. The panel 1 can be used as a luggage rack or similar device installed in the luggage compartment of a vehicle.

[0129] The core material 12 is preferably a plate-shaped component. The thickness of the core material 12 is, for example, 5 to 25 mm, preferably 8 to 20 mm. Specifically, this thickness is, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, or 25 mm, or within any two values ​​exemplified herein. The thickness of the core material 12 refers to the distance between the maximum distance between the opposing first and second main surfaces 12a and 12b of the core material 12. The core material 12 preferably has a recess in which the face material 3 is fixed. This prevents the face material 3 from peeling off the core material 12. The core material 12 includes a base material 14 and a reinforcing material 15.

[0130] The description of substrate 14 is the same as that of substrate 2 in the first viewpoint.

[0131] The reinforcing member 15 is made of a material with a strength higher than that of the base material 14. Examples of reinforcing members 15 include metals, wood, and resins. Plastics can be foamed or non-foamed. In this specification, "strength" refers to Young's modulus at 25°C. The value of {strength of reinforcing member 15 / strength of base material 14} is, for example, 1.1 or more, preferably 1.5 or more, and more preferably 2 or more. This value is, for example, from 1.1 to 1000, specifically, for example, 1.1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, 100, 1000, or may be within the range of any two values ​​exemplified herein or greater than any value.

[0132] In this embodiment, the substrate 14 and the reinforcing material 15 are formed of foam, and the expansion ratio of the reinforcing material 15 is lower than that of the substrate 14. Since the strength of a foam increases with a lower expansion ratio, by making the expansion ratio of the reinforcing material 15 lower than that of the substrate 14, the strength of the reinforcing material 15 can be made higher than that of the substrate 14. Furthermore, the substrate 14 and the reinforcing material 15 are preferably made of the same resin. At this time, since the substrate 14 and the reinforcing material 15 are easy to weld, the substrate 14 and the reinforcing material 15 can be easily integrated, for example, by insert molding. If the expansion ratio of the reinforcing material 15 is M1 and the expansion ratio of the substrate 14 is M2, then M1 / M2 is, for example, 0.1 to 0.9, specifically, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or within any two values ​​exemplified here.

[0133] The specific gravity of the reinforcing material 15 is generally greater than that of the base material 14. The value of {specific gravity of reinforcing material 15 / specific gravity of base material 14} is, for example, 1.1 or higher. This value is, for example, 1.1 to 1000, specifically 1.1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, 100, 1000, or within any two values ​​exemplified here, or is greater than any value.

[0134] The reinforcing member 15 is preferably an elongated component. If the length along the long side is L, and the diameter of the circumscribed circle at the largest part of the cross-section perpendicular to the long side is D, then L / D is preferably 5 or more, more preferably 10 or more, and even more preferably 20 or more. L / D is, for example, 5 to 1000, specifically, for example, 5, 10, 15, 20, 50, 100, 1000, or it can be within any two values ​​exemplified herein or any value or more. The cross-sectional shape of the reinforcing member 15 is preferably constant along the long side.

[0135] The reinforcing member 15 can be placed at any position and in any size within the core material 12. However, the specific gravity of the reinforcing member 15 is generally higher than that of the base material 14. Therefore, in order to suppress weight gain, the amount of reinforcing member 15 used is preferably the minimum required. If the volume of the core material 12 is V1 and the volume of the reinforcing member 15 is V2, then V2 / V1 is preferably 0.5 or less, more preferably 0.3 or less. V2 / V1 is, for example, 0.001 to 0.5, specifically, for example, 0.001, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, or within the range of any two values ​​exemplified herein or less. If the mass of the core material 12 is W1 and the mass of the reinforcing member 15 is W2, then W2 / W1 is preferably 0.8 or less, more preferably 0.5 or less, and more preferably 0.3 or less. W2 / W1 can be, for example, 0.001 to 0.8, specifically 0.001, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or within the range of any two values ​​listed here, or below any value.

[0136] In one example, the reinforcing member 15 is arranged such that its long side direction is along the long side direction or short side direction of the core material 12. If the length of the core material 12 along the long side direction of the reinforcing member 15 is LC, and the length of the reinforcing member 15 along its long side direction is L, then L / LC is preferably 0.5 or more, and more preferably 0.8 or more. This allows for a wide range of improvements in the strength of the panel 1. L / LC is, for example, 0.5 to 1.0, specifically, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or any two values ​​exemplified herein.

[0137] The thickness of the reinforcing material 15 relative to the thickness of the core material 12 is, for example, 0.1 to 1.0, specifically, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or within any two values ​​exemplified here.

[0138] The length of the core material in the short side direction (the length in the direction perpendicular to both the long side direction and the thickness direction) is, for example, 10 to 100 mm, preferably 20 to 40 mm. Specifically, this length is, for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 mm, or within any two values ​​exemplified herein.

[0139] In one example, if the length of the long side of the core material 12 is LL, and the distance from the center of the long side of the core material 12 to the reinforcing member 15 is D, then it is preferable to arrange the reinforcing member 15 so that its long side is along the short side of the core material 12 at a position where D / LL is 0.20 to 0.45. Figure 8 As shown, with the two ends of the panel 1 supported by the support members 17 along its long side, if a large piece of luggage 18 is placed near the middle of the long side of the panel 1, the panel 1 tends to buckle easily at a D / LL ratio of 0.20 to 0.45. Therefore, by providing a reinforcing member 15 at such a position, the buckling of the panel 1 can be suppressed. Specifically, the D / LL ratio is, for example, 0.20, 0.25, 0.30, 0.35, 0.40, or 0.45, or any two values ​​shown here.

[0140] The reinforcing member 15 can be disposed throughout the entire thickness of the core material 12, or it can be disposed only in a portion of the thickness direction. The reinforcing member 15 can be exposed on only one side of the core material 12, or it can be exposed on both sides of the core material 12.

[0141] On the exposed surface of the reinforcing member 15, the substrate 14 and the reinforcing member 15 are preferably on the same surface. This makes it easy to bond the substrate 14 and the reinforcing member 15 to the surface material 3.

[0142] The face material 3 is a plate-shaped component, fixed to the core material 12 by bonding it to the substrate 14 and the reinforcing member 15. By bonding the face material 3 not only to the substrate 14 but also to the reinforcing member 15, the face material 3 and the reinforcing member 15 are integrated, significantly enhancing the reinforcing effect of the reinforcing member 15 while suppressing noise generated by interference between the reinforcing member 15 and other components during vibration. The face material 3 can be made of a material with a strength per unit thickness higher than that of the substrate 14. The description of the material, thickness, etc., of the face material 3 is the same as in the first viewpoint.

[0143] The method of bonding the face material 3 to the substrate 14 and the reinforcing material 15 by means of the adhesive layer 6 is the same as the method of fixing the face material 3 in the recess 5 in the first view.

[0144] The face material 3 may be provided on only one of the first and second main surfaces 12a and 12b of the core material 12, or it may be provided on both the first and second main surfaces 12a and 12b.

[0145] 1-2. Manufacturing method of panel 1

[0146] Panel 1 can be manufactured by the following method.

[0147] (1) Core material preparation process

[0148] In the core material preparation process, the core material 12 is prepared. The core material 12 can be formed by embedding the reinforcing material 15 during the molding of the substrate 14, or by joining (inserting, bonding, welding, etc.) the substrate 14 and the reinforcing material 15 after they are prepared separately.

[0149] (2) Surface material fixing process

[0150] In the face material fixing process, the substrate 14 and the reinforcing material 15 are respectively bonded to the face material 3. This bonding can be performed by applying adhesive to the substrate 14 and the reinforcing material 15 (e.g., spraying, ball-brush application), and then pressing the face material 3 onto the substrate 14 and the reinforcing material 15.

[0151] 2. Second Implementation Method

[0152] use Figure 9A The second embodiment of the present invention will be described below. This embodiment is similar to the first embodiment, with the main difference being the structure of the reinforcing member 15. The following description will focus on these differences.

[0153] In this embodiment, the reinforcing member 15 is H-shaped and includes a column portion 15a and flange portions 15b and 15c provided at both ends of the column portion 15a. The flange portions 15b and 15c are both bonded to the surface material 3.

[0154] The H-shaped reinforcing member 15 has a high strength improvement effect per unit volume, thus significantly improving the strength of the panel 1. Furthermore, in this embodiment, the flange portions 15b and 15c are respectively bonded to the surface material 3, further enhancing the strength improvement effect.

[0155] The thickness of flange portions 15b and 15c is, for example, 0.5 to 5 mm, preferably 1 to 3 mm. Specifically, this thickness is, for example, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 mm, or may be within any two values ​​exemplified herein.

[0156] 3. Third Implementation Method

[0157] use Figure 9B The third embodiment of the present invention will be described. This embodiment is similar to the second embodiment, with the main difference being the method of bonding the reinforcing member 15 to the surface material 3. The following description will focus on these differences.

[0158] In this embodiment, the structure of the reinforcing member 15 is the same as in the second embodiment, except that only the flange portion 15b is bonded to the face material 3, while the flange portion 15c is not bonded to the face material 3. Even in this way, it is possible to achieve the effects of improving strength and noise suppression.

[0159] 4. Fourth Implementation Method

[0160] use Figure 9C The fourth embodiment of the present invention will be described. This embodiment is similar to the third embodiment, with the main difference being the structure of the reinforcing member 15. The following description will focus on these differences.

[0161] In this embodiment, the reinforcing member 15 has a flange 15b at one end of the column portion 15a, but no flange at the other end of the column portion 15a. The flange 15b is bonded to the face material 3. The other end of the column portion 15a may or may not be bonded to the face material. Even in this manner, the effects of improved strength and noise suppression can be achieved.

[0162] 5. Fifth Implementation Method

[0163] use Figure 9D The fifth embodiment of the present invention will be described. This embodiment is similar to the fourth embodiment, with the main difference being the structure of the reinforcing member 15. The following description will focus on these differences.

[0164] In this embodiment, the reinforcing member 15 has a flange 15b at one end of the column portion 15a, but no flange at the other end of the column portion 15a. The flange 15b is bonded to the face material 3. The other end of the column portion 15a does not reach the face material 3 but extends to the middle of the core material 12. Even in this manner, it is possible to achieve the effects of improved strength and noise suppression.

[0165] 6. Other implementation methods

[0166] If necessary, a skin material can be provided to cover both the core material 12 and the face material 3. This improves the aesthetics while preventing the face material 3 from peeling off from the core material 12. In one example, the skin material is a non-woven fabric, which can be bonded to both the face material 3 and the core material 12 via an adhesive layer.

[0167] (4th viewpoint)

[0168] 1. First Implementation Method

[0169] 1-1. Structure of Panel 1

[0170] like Figures 10A to 10C As shown, in one embodiment of the present invention, the panel 1 includes a core material 12 and first and second surface materials 3a and 3b. The core material 12 is sandwiched between the surface materials 3a and 3b. The panel 1 is preferably in a generally cuboid shape. The panel 1 can be used as a luggage panel or the like installed in the luggage compartment of a vehicle.

[0171] Let the length of panel 1 in the first direction be L1, and the length of the second direction perpendicular to the first direction be L2, where L1 ≥ L2. L1 is, for example, 600–1200 mm, specifically 600, 700, 800, 900, 1000, 1100, or 1200 mm, or any value between any two values ​​listed here. L2 is, for example, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, or 1200 mm, or any value between any two values ​​listed here. The value of L2 / L1 is, for example, 0.3–1, specifically 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0, or any value between any two values ​​listed here.

[0172] From the viewpoint of lightweighting panel 1, the weight per unit area (mass per unit area) is preferably 3000 g / m². 2 The following is an example of the weight per unit area: 1500–3000 g / m². 2 Specifically, for example, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000 / m 2 It can also be within the range of any two values ​​listed here, or below any value.

[0173] The core material 12 is preferably a plate-shaped component. The thickness of the core material 12 is 15 to 25 mm, preferably 18 to 22 mm. If the core material 12 is too thin, the overall deflection of the panel 1 will be too large. On the other hand, if the core material 12 is too thick, the weight of the panel 1 will be too large. Specifically, this thickness is, for example, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 mm, or any two values ​​exemplified here. The thickness of the core material 12 refers to the distance between the maximum distance between the opposing first and second main surfaces 12a and 12b of the core material 12. Preferably, the core material 12 is provided with a recess, in which the surface materials 3a and 3b are fixed. This prevents the surface materials 3a and 3b from peeling off from the core material 12.

[0174] Except for the matters described in this viewpoint, the description of the core material 12 is the same as that of the substrate 2 in the first viewpoint.

[0175] The 10% compressive stress of the core material 12 is, for example, 0.1 to 1.0 MPa. If this value is too small, it is easy to cause buckling deformation, while if this value is too large, it will make the weight of the panel 1 too large. Specifically, this value is, for example, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00 MPa, or within any range of two values ​​exemplified here. The 10% compressive stress of the core material 12 can be measured according to JIS K 7220.

[0176] The unit area weight of core material 12 is, for example, 400-1000 g / m². 2 Specifically, for example, 400, 500, 600, 700, 800, 900, 1000 g / m³ 2 It can also be within the range of any two values ​​exemplified here.

[0177] The face materials 3a and 3b are plate-shaped components, bonded to the main surfaces 12a and 12b of the core material 12. The face materials 3a and 3b can be made of a material with a higher rigidity per unit thickness than the core material 12, such as metal (aluminum, iron, etc.) or fiber-reinforced resin. The thickness of the face materials 3a and 3b is, for example, 0.05 to 1 mm, preferably 0.08 to 0.5 mm. Specifically, it is, for example, 0.05, 0.08, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.60, 0.70, 0.80, 0.90, or 1.00 mm, or within any range of two values ​​exemplified herein. It should be noted that, unless otherwise specified, thickness, depth, etc., in this specification refer to average values.

[0178] The unit area weight of surface materials 3a and 3b is, for example, 400-1000 g / m². 2 Specifically, for example, 400, 500, 600, 700, 800, 900, 1000 g / m³ 2 It can also be within the range of any two values ​​exemplified here.

[0179] The face materials 3a and 3b are respectively bonded to the core material 12 via adhesive layers 6a and 6b. The adhesives constituting the adhesive layers 6a and 6b can be polyurethane-based or olefin-based adhesives, preferably one-component reactive polyurethane adhesives. The thicknesses of the adhesive layers 6a and 6b are, for example, 0.01 to 0.5 mm, specifically, for example, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 mm, or within any two values ​​exemplified herein. The weight per unit area of ​​the adhesive layers 6a and 6b is, for example, 10 to 100 g / m². 2 Specifically, for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 g / m³ 2 It can also be within the range of any two values ​​exemplified here.

[0180] If (Young's modulus of the first face material 3a [GPa]) × (thickness of the first face material 3a [mm]) 2 The strength index of the first face material is (Young's modulus of the second face material 3b [GPa]) × (thickness of the second face material 3b [mm]). 2 The second surface material strength index is the average surface material strength index, which is the average surface material strength index. The panel strength index, defined by the average surface material strength index × (10% compressive stress of the core material [MPa]), is 0.7 or higher.

[0181] The surface material strength index is an indicator representing the strength of surface materials 3a and 3b. The strength indices of the first and second surface materials, as well as the average surface material strength index, are preferably 1.5 or higher and preferably 10 or lower. If this value is too small, it can easily cause buckling deformation; if this value is too large, it can easily make the panel 1 too heavy. Specifically, this value can be, for example, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, or 10.0, or within any range of two values ​​exemplified here.

[0182] The panel strength index is an indicator of the strength related to the local strength of panel 1. The panel strength index is 0.7 or higher, preferably 5.0 or lower. If the value is too small, it is easy to cause buckling deformation; if the value is too large, it is easy to make the weight of panel 1 too large. Specifically, this value can be, for example, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0, or it can be within the range of any two values ​​listed here.

[0183] With the support panel 1 held at both ends in the first direction, the buckling load (the minimum load caused by buckling deformation) when applying a pressure with a contact surface diameter of 50 mm to the center of the panel 1 in the first direction is preferably 40 kg or more, and preferably 300 kg or less. If this value is too small, buckling deformation is likely to occur; if this value is too large, the weight of the panel 1 will be too large. Specifically, this value is, for example, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, or 300 kg, or it can be within any two values ​​exemplified here.

[0184] 1-2. Manufacturing method of panel 1

[0185] Panel 1 can be manufactured by applying an adhesive (e.g., spraying or ball-bearing) to core material 12 and then pressing face materials 3a and 3b onto core material 12.

[0186] 2. Other implementation methods

[0187] When necessary, a skin material can be provided to cover the core material 12 and the face materials 3a and 3b. This improves the aesthetics while preventing the face materials 3a and 3b from peeling off from the core material 12. In one example, the skin material is a non-woven fabric, which can be bonded to the face materials 3a and 3b and the core material 12 via an adhesive layer.

[0188]

Example

[0189] (4th viewpoint)

[0190] A panel 1 with a planar shape of 1000mm × 450mm was manufactured using the core material 12 and surface materials 3a and 3b shown in Table 1. A one-component reactive polyurethane adhesive was used as the adhesive for bonding the core material 12 to the surface materials 3a and 3b, to achieve a viscosity of 60g / m³. 2The coating was applied in the same manner. In the examples and comparative examples in Table 1, the materials and thicknesses of the face materials 3a and 3b were the same. Al5052 was used as Al, and SUS304 was used as SUS. The core material 12 was manufactured using HEATPOR GR (JSP Co., Ltd.).

[0191] With the support panel 1 supported at both ends along its long side, a load is applied to the middle of the long side of panel 1 using a pressing method with a contact surface diameter of 50 mm. The load is increased by 10 kg each time, and the load at which buckling deformation occurs is defined as the buckling load. The results are shown in Table 1.

[0192] Table 1

[0193]

[0194] As shown in Table 1, in all embodiments where the panel strength index is 0.7 or higher, buckling deformation is not easily caused.

[0195] Explanation of symbols

[0196] 1: Panel, 1f: Surface, 1r: Back side, 1s: Side, 2: Substrate, 2a: Side end, 2b: Peripheral part, 2c: Edge, 2d: Protrusion, 2f: Surface, 2r: Back side, 2s: Side, 3: Face material, 3a: First face material, 3b: Second face material, 3c: Edge, 4: Skin material, 5: Recess, 5a: Edge, 5c: Bottom surface, 6: Adhesive layer, 6a: Adhesive layer, 6b: Adhesive layer, 7: Adhesive layer, 8: Welded part, 12: Core material, 12 a: First main surface, 12b: Second main surface, 14: Substrate, 15: Reinforcing material, 15a: Column, 15b: Flange, 15c: Flange, 17: Support component, 18: Luggage, 21: Front wall, 22: Back wall, 23: Rib, 23a: Opening, 31: Resin sheet, 32: Resin sheet, 41: Mold, 41a: Molding surface, 42: Mold, 42a: Molding surface, A: Area, B: Area, C: Area, PL: Parting line, T: Thickness.

Claims

1. A panel comprising a core material, a first surface material, and a second surface material. The aforementioned core material is sandwiched between the first and second face materials. The thickness of the aforementioned core material is 15~25mm. The first and second face materials are bonded to the core material. If we make (Young's modulus of the first face material [GPa]) × (thickness of the first face material [mm]) 2 The first surface material strength index, (Young's modulus of the second face material [GPa]) × (Thickness of the second face material [mm]) 2 The second surface material strength index, The average of the first and second surface material strength indices is the average surface material strength index. The panel strength index, defined by the average surface material strength index × (10% compressive stress of the core material [MPa]), is 0.7 or higher and 5.0 or lower.

2. The panel according to claim 1, characterized in that, The weight per unit area of ​​the above panel is 3000g / m². 2 the following.

Images