Interior material and method for manufacturing the same

Abstract

To provide an interior material having a configuration capable of forming a light transmission part in a shorter period of time.SOLUTION: An interior material includes: a first tabular member 20 which has a tabular shape including a natural fiber and a thermoplastic resin and has through holes 21 of a predetermined pattern that penetrate in a sheet thickness direction; and a second tabular member 40 having light permeability which has a tabular shape including a natural fiber and a thermoplastic resin and which is joined in such a shape as to cover the through holes 21 with respect to one surface 20A in the first tabular member 20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to an interior material and a method for manufacturing an interior material. [Background technology]

[0002] Conventionally, as interior materials, plate-shaped members formed by binding natural fibers such as kenaf with thermoplastic resins have been used. Natural fibers absorb carbon dioxide by photosynthesis, and are therefore effective in protecting the global environment. In order to enhance the design of such plate-shaped members, a method has been considered in which a thin-walled portion is formed by thinning the plate-shaped member to a degree that allows light to partially pass through, and when light is irradiated onto the plate-shaped member, the light passes through the thin-walled portion, which is the light-transmitting portion, and the thin-walled portion emerges as a pattern. When the plate-shaped member contains natural fibers, it is difficult to manufacture a plate-shaped member having a thin-walled portion by injection molding. For this reason, it is considered to form the thin-walled portion by processing the plate-shaped member. As a processing method for forming a thin-walled portion in a plate-shaped member, the one described in the following Patent Document 1 is known. Patent Document 1 describes a method for forming a thin-walled portion by forming a recess in a plate-shaped member by cutting. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-30160 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned cutting process, if the recess is formed in one process, there is a concern that the plate-shaped member may crack, or that large shavings generated by cutting may get into the recess and hinder the process. For this reason, it is necessary to repeatedly form shallow recesses to form a recess of a predetermined depth, which poses the problem of a long processing time.

[0005] The technology disclosed in this specification was completed based on the above circumstances, and aims to provide an interior material configured to enable the formation of a light-transmitting portion in a shorter time, and a method for manufacturing the interior material. [Means for solving the problem]

[0006] As a means for solving the above problems, the interior material disclosed in this specification is characterized by comprising a first plate-like member which is in the form of a plate containing natural fibers and thermoplastic resin and has a predetermined pattern of through holes penetrating in the plate thickness direction, and a second plate-like member which is in the form of a plate containing natural fibers and thermoplastic resin and is joined to one side of the first plate-like member in a manner covering the through holes, and which is optically transparent.

[0007] With this configuration, light can be transmitted through the interior material at the locations corresponding to the through holes, and a predetermined pattern corresponding to the shape of the through holes can be displayed by irradiating the interior material with light. Since the through holes are covered by the second plate-like member, the back side of the interior material is prevented from being seen through the through holes. Furthermore, compared to a method of forming a thin portion by cutting a plate-like member to form a light-transmitting portion, the through holes can be formed in a single operation, and therefore the light-transmitting portion can be formed in a shorter time.

[0008] Next, as a means for solving the above-mentioned problems, the manufacturing method for interior materials disclosed in this specification is characterized by comprising a through hole forming process for forming a predetermined pattern of through holes penetrating in the thickness direction of a first plate-shaped member containing natural fibers and thermoplastic resin, and a joining process, which is performed after the through hole forming process, for joining a second plate-shaped member containing natural fibers and thermoplastic resin and having optical transparency to one side of the first plate-shaped member in a manner covering the through holes.

[0009] With this configuration, light can be transmitted through the interior material at the locations corresponding to the through holes, and a predetermined pattern corresponding to the shape of the through holes can be displayed by irradiating the interior material with light. Since the through holes are covered by the second plate-like member, the back side of the interior material is prevented from being seen through the through holes. Furthermore, compared to a method of forming a thin portion by cutting a plate-like member to form a light-transmitting portion, the through holes can be formed in a single operation, and therefore the light-transmitting portion can be formed in a shorter time.

[0010] The method may further include a resin filling step, which is performed after the joining step, of filling the through holes with a resin having optical transparency. By filling the through holes with a resin, the rigidity can be increased.

[0011] In addition, in the resin filling step, in a state in which the first plate-like member and the second plate-like member are press-molded by a molding die, a molten resin having optical transparency is injected onto a surface of the first plate-like member opposite to the second plate-like member, thereby filling the through-hole with the molten resin. The through-hole can be filled with resin while molding the first plate-like member and the second plate-like member. Furthermore, by filling the through-hole with the molten resin, the resin can be welded to the inner surface of the through-hole, and the work related to joining the resin can be omitted. Effect of the Invention

[0012] According to the present invention, it is possible to provide an interior material having a configuration that enables a light transmitting portion to be formed in a shorter time, and a method for manufacturing the interior material. [Brief description of the drawings]

[0013] [Figure 1] Cross-sectional view of interior material [Diagram 2] A diagram of the first plate-shaped member viewed from outside the vehicle compartment [Diagram 3] FIG. 3 is a cross-sectional view of the first plate-shaped member before the through holes are formed. [Figure 4] Cross-sectional view showing a through-hole forming step [Diagram 5] Cross-sectional view showing the joining process [Figure 6] 1 is a cross-sectional view of a first plate-shaped member having a recess formed therein according to a comparative example; [Figure 7] FIG. 11 is a cross-sectional view of a first plate-shaped member and a second plate-shaped member according to a second embodiment, the first plate-shaped member and the second plate-shaped member being disposed between a pair of molds. [Figure 8] Cross-sectional view showing the resin filling process DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <Embodiment 1> A first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 6. In this embodiment, an interior material 10 used as a door trim for a vehicle is illustrated. As shown in Fig. 1, the interior material 10 includes a first plate-shaped member 20 having a plate shape containing natural fibers and a thermoplastic resin, and a second plate-shaped member 40 having a plate shape containing natural fibers and a thermoplastic resin.

[0015] Kenaf fibers, for example, are used as the natural fibers contained in the first plate-shaped member 20 and the second plate-shaped member 40. The type of natural fibers contained in the first plate-shaped member 20 and the second plate-shaped member 40 is not limited to this, and vegetable fibers extracted from cotton, hemp, sisal, jute, etc., inorganic fibers such as glass fibers and carbon fibers, synthetic resin fibers, etc. can be used. Among these, linear fibers (kenaf fibers) derived from kenaf, a plant of the Malvaceae family that has a woody stem, is an annual plant that grows extremely quickly, has excellent carbon dioxide absorption properties, and contributes to reducing the amount of carbon dioxide in the atmosphere and effectively utilizing forest resources, etc., are particularly preferred.

[0016] In the first plate-shaped member 20 and the second plate-shaped member 40, the natural fibers are bound by a thermoplastic resin as a binder. For example, polypropylene is used as the thermoplastic resin contained in the first plate-shaped member 20 and the second plate-shaped member 40. The type of thermoplastic resin contained in the first plate-shaped member 20 and the second plate-shaped member 40 is not limited to this, and polyethylene or the like may be used. The natural fibers contained in the first plate-shaped member 20 and the second plate-shaped member 40 may be different, and the thermoplastic resins contained in the first plate-shaped member 20 and the second plate-shaped member 40 may also be different.

[0017] 1 and 2, the first plate-like member 20 has a predetermined pattern of through holes 21 penetrating in the plate thickness direction. In this embodiment, an arrangement of a plurality of longitudinal through holes 21 is illustrated, but the shape of the through holes is not limited thereto. The second plate-like member 40 is joined to one surface 20A (the surface on the design surface side) of the first plate-like member 20 in a manner covering the plurality of through holes 21.

[0018] The thickness of the second plate-like member 40 is smaller than that of the first plate-like member 20, and is set to a thickness that is light-transmitting. The thickness of the first plate-like member 20 is, for example, about 2.5 mm, and the thickness of the second plate-like member 40 is set within a range of, for example, 0.2 mm to 0.4 mm. The basis weight of the second plate-like member 40 is, for example, 50 to 600 g / m 2 The fiber content in the second plate-shaped member 40 is set within the range of, for example, 10% by weight to 75% by weight, and the thermoplastic resin content in the second plate-shaped member 40 is set within the range of, for example, 25% by weight to 90% by weight.

[0019] The thicknesses of the first plate-like member 20 and the second plate-like member 40, the basis weight of the second plate-like member 40, and the contents of fibers and thermoplastic resin in the second plate-like member 40 are not limited to the above values ​​and can be changed as appropriate. The second plate-like member 40 may be optically transparent by appropriately setting the material, thickness, basis weight, contents of natural fibers and thermoplastic resin, etc.

[0020] Furthermore, in the interior material 10, a lighting device 50 is disposed on the opposite side (the outside of the vehicle compartment) of the first plate-like member 20 to the second plate-like member 40, and is capable of emitting light to each through-hole 21. An example of the lighting device 50 is one in which a plurality of light sources (LEDs, etc.) are arranged along the surface direction of the first plate-like member 20. Furthermore, the lighting device may include a light source and a light-guiding member that guides light from the light source and emits it toward the through-hole.

[0021] When the lighting device 50 is not in operation, the through holes 21 covered by the second plate-like member 40 are not visible to passengers in the vehicle cabin. In contrast, when the lighting device 50 is operated, the emitted light from the lighting device 50 is emitted into the vehicle cabin through each through hole 21 and the second plate-like member 40. This allows the multiple through holes 21 to be displayed as a pattern to the passengers.

[0022] Next, a manufacturing method of the interior material 10 of this embodiment will be described. The manufacturing method of the interior material 10 of this embodiment includes a through hole forming step of forming a through hole 21 in the first plate-like member 20, and a joining step, which is performed after the through hole forming step, of joining the second plate-like member 40 to one surface 20A of the first plate-like member 20 in a manner covering the through hole 21. The first plate-like member 20 and the second plate-like member 40 can be manufactured by laminating a mixed fiber in which natural fibers and thermoplastic resin fibers are mixed to form a fiber web, entangling the fibers constituting the fiber web with each other using an entangling device to form a nonwoven fiber mat, and then hot pressing the fiber mat using a pressing device to reduce its thickness and mold it into a plate shape with higher rigidity than the fiber mat.

[0023] (Through hole formation process) In the through hole forming step, a plurality of cutting blades 23 are pressed against the first plate-shaped member 20 to form a plurality of through holes 21, as shown in FIGS.

[0024] (Joining process) In the joining process, the first plate-shaped member 20 and the second plate-shaped member 40 are heated separately while being spaced apart from each other, and are then heated to a temperature at which the thermoplastic resin contained in the first plate-shaped member 20 and the second plate-shaped member 40 melts. As shown in Fig. 5, the first plate-shaped member 20 and the second plate-shaped member 40 are then pressed using a press device 51. Thereafter, the first plate-shaped member 20 and the second plate-shaped member 40 are cooled, whereby the molten thermoplastic resin cools and solidifies and performs the function of a binder, so that the second plate-shaped member 40 is joined (welded) to one surface 20A of the first plate-shaped member 20, and the first plate-shaped member 20 and the second plate-shaped member 40 are integrated together.

[0025] The first plate-shaped member 20 and the second plate-shaped member 40 may be integrated by pressing them while heating them. However, if the first plate-shaped member 20 and the second plate-shaped member 40 are heated while they are in contact with each other, the second plate-shaped member 40 may expand due to heat, and the expanded portion may enter the through-hole 21, causing a concern that the portion of the second plate-shaped member 40 corresponding to the through-hole 21 may become thin. As a result, the thickness of the portion covering the through-hole 21 in the second plate-shaped member 40 may differ for each through-hole 21, causing a concern that unevenness may occur in the light that passes through the second plate-shaped member 40 and is emitted into the vehicle interior. For this reason, it is more preferable to heat the first plate-shaped member 20 and the second plate-shaped member 40 separately while they are spaced apart from each other, as in the above method.

[0026] Also, the first plate-shaped member 20 and the second plate-shaped member 40 may be integrated in the form of a fiber mat. By performing the joining process in the form of a fiber mat, the first plate-shaped member 20 and the second plate-shaped member 40 can be easily joined to each other and can be joined more firmly. However, if the second plate-shaped member 40 is in the form of a relatively soft fiber mat, there is a concern that when the first plate-shaped member 20 and the second plate-shaped member 40 are pressed, the fibers constituting the second plate-shaped member 40 may enter the through-holes 21, causing the portions of the second plate-shaped member 40 corresponding to the through-holes 21 to become thin-walled. In order to prevent such a situation, it is preferable to previously heat-press the first plate-shaped member 20 and the second plate-shaped member 40 to reduce their thickness and make them more rigid than the fiber mat.

[0027] Next, the effects of this embodiment will be described. According to this embodiment, light can be transmitted through the parts of the interior material 10 that correspond to the through holes 21, and a predetermined pattern that corresponds to the shape of the through holes 21 can be displayed by irradiating the interior material 10 with light. Furthermore, because the through holes 21 are covered by the second plate-like member 40, it is possible to prevent the back side of the interior material 10 from being seen through the through holes 21.

[0028] 6, when a thin-walled portion is formed by cutting the first plate-like member 20 to form the light-transmitting portion 24, it is necessary to repeatedly form shallow recesses with a cutting blade to form the recesses 25 of a predetermined depth, which increases the processing time. Also, it is necessary to engrave the shape of the light-transmitting portion 24 by moving the cutting blade along the plane of the first plate-like member 20, which increases the processing time.

[0029] Compared to a method of forming a light-transmitting portion by such cutting processing, in this embodiment, the through hole 21 can be formed in a single operation (the operation of pressing multiple cutting blades against the first plate-like member 20), and therefore the light-transmitting portion (the through hole 21 and the portion of the second plate-like member 40 covering the through hole 21) can be formed in a shorter time.

[0030] <Embodiment 2> Next, a second embodiment of the present invention will be described with reference to Figs. 7 and 8. The same parts as those in the above embodiment are given the same reference numerals and the overlapping description will be omitted. As shown in Fig. 8, the interior material 110 of this embodiment includes a first plate-shaped member 20, a second plate-shaped member 40, a resin plate 131, and a plurality of resin parts 132. In this embodiment, the first plate-shaped member 20 and the second plate-shaped member 40 in an integrated state are molded into a predetermined product shape by a molding device 160, and the through-holes 21 of the first plate-shaped member 20 are filled with resin. As shown in Fig. 7, the molding device 160 includes a pair of molding dies 161, 162 arranged opposite each other, and an injection device 163. Of the pair of molding dies 161, 162, the upper die 161 includes a driving device (e.g., an electric motor, an air cylinder, a hydraulic cylinder, etc.) not shown, and is a movable die that can move up and down relative to the lower die 162. Upper die 161 has a molding surface 161A that is recessed upward. Lower die 162 has a molding surface 162A that bulges upward.

[0031] The injection device 163 is, for example, a screw type, and is capable of injecting a molten resin having optical transparency (for example, acrylic or polycarbonate) toward a resin supply path 164 formed through the lower mold 162. The lower mold 162 has a recess 165 recessed into the molding surface 162A. The recess 165 is provided at a position corresponding to the plurality of through holes 21, and is configured to communicate with each of the through holes 21 when the pair of molding dies 161, 162 are in a closed state (see FIG. 8). The resin supply path 164 extends from the injection device 163 toward the recess 165.

[0032] In addition to the through hole forming step and joining step described in the above embodiments, the manufacturing method for interior material 110 of this embodiment includes a resin filling step that is performed after the joining step and fills through holes 21 with a light-transmitting resin. In the resin filling step, in a state in which the first plate-like member 20 and the second plate-like member 40 are press-molded by a pair of molding dies 161, 162, a light-transmitting molten resin is injected onto a surface 20B of the first plate-like member 20 opposite to the second plate-like member 40, thereby filling the through holes 21 with the molten resin.

[0033] More specifically, in the resin filling step, the first plate-like member 20 and the second plate-like member 40 are heated by a heating means (such as a heater that generates heat by passing electricity) not shown in the figure, and both plate-like members 20, 40 are softened. Thereafter, both plate-like members 20, 40 are disposed between a pair of molding dies 161, 162, and the pair of molding dies 161, 162 are closed. As a result, both plate-like members 20, 40 are sandwiched between the molding surface 161A and the molding surface 162A, and are press-molded into a shape that follows the shapes of the molding surfaces 161A, 162A.

[0034] Next, while maintaining the state in which both plate-like members 20, 40 are sandwiched between both molding surfaces 161A, 162A, molten resin is injected from injection device 163 into resin supply path 164. The resin injected into resin supply path 164 is supplied to recess 165 and then filled into each of through holes 21 communicating with recess 165. Thereafter, the injected molten resin cools and solidifies, so that the resin filled in recess 165 becomes plate-shaped resin plate 131, and the resin filled in through hole 21 becomes resin part 132 joined to the inner surface of through hole 21. This completes the manufacture of interior material 110.

[0035] Next, the effects of this embodiment will be described. In this embodiment, the rigidity can be increased by filling the through holes 21 with resin. Furthermore, the rigidity can be increased by molding the resin plate 131.

[0036] In the resin filling step, the through holes 21 can be filled with resin while the first plate-like member 20 and the second plate-like member 40 are being molded. Furthermore, by filling the through holes 21 with molten resin, the resin parts 132 can be welded to the inner surfaces of the through holes 21, and the work of joining the resin can be omitted.

[0037] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, and for example, the following embodiments are also included within the technical scope. (1) The interior materials 10, 110 illustrated in the above embodiment are not limited to those for vehicles. For example, the interior materials 10, 110 can be applied to vehicles such as trains and recreational vehicles as ground vehicles, airplanes and helicopters as flying vehicles, and ships and submarines as marine and underwater vehicles, and the interior materials 10, 110 may be used for purposes other than vehicles. (2) In the above embodiment, the through holes 21 are formed in the first plate-shaped member 20 using the cutting blade 23, but the method of forming the through holes 21 is not limited to this. For example, the through holes 21 may be formed by laser processing. (3) The shape of the through-hole is not limited to the shape (elongated) exemplified in the above embodiment, and may be modified as appropriate. (4) In the above embodiment, a configuration was illustrated in which the second plate-shaped member 40 is arranged on the interior side of the vehicle cabin relative to the first plate-shaped member 20, but this is not limited to this. For example, the first plate-shaped member 20 may be arranged on the interior side of the vehicle cabin relative to the second plate-shaped member 40 to form a design surface. [Explanation of symbols]

[0038] Reference Signs List 10, 110... interior material, 20... first plate-shaped member, 20A... one surface of first plate-shaped member, 21... through hole, 40... second plate-shaped member, 161, 162... molding die

Claims

1. A first plate-like member containing natural fibers and a thermoplastic resin and having a predetermined pattern of through holes penetrating in a plate thickness direction; an optically transparent second plate-like member that contains natural fibers and a thermoplastic resin, is joined to one surface of the first plate-like member in a manner that covers the through hole, and

2. a through hole forming step of forming a predetermined pattern of through holes penetrating a first plate-like member containing natural fibers and a thermoplastic resin in a plate thickness direction; a joining step, which is performed after the through hole forming step, of joining a second plate-like member having a plate shape including natural fibers and a thermoplastic resin and having optical transparency to one surface of the first plate-like member in a manner covering the through hole.

3. The method for manufacturing an interior material according to claim 2, further comprising a resin filling step, which is carried out after the joining step, of filling the through-holes with a resin having optical transparency.

4. 4. The method for manufacturing an interior material according to claim 3, wherein in the resin filling step, while the first plate-like member and the second plate-like member are press-molded by a molding die, a molten resin having optical transparency is injected onto a surface of the first plate-like member opposite the second plate-like member to fill the through hole with the molten resin.

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