Method for manufacturing vehicle interior member and vehicle interior member

Abstract

To provide a method for manufacturing an interior material for a vehicle having stable product characteristics, and the interior material for the vehicle.SOLUTION: The method for manufacturing the interior material for the vehicle includes a crushing step of crushing a waste plastic material made of thermoplastics to obtain small pieces 11, a plate-shaped body forming step of scattering the small pieces 11 on a thermoplastics sheet 13 and hot-pressing them to form a plate-shaped body 18P in which a thermoplastics layer 14 and a small piece layer 12 are laminated, and a hot-press forming step of hot-press forming the plate-shaped body 18P by a pair of forming dies 25.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, a recycled plastic molded product using recycled materials is known, as described in Patent Document 1. Patent Document 1 describes a method of molding recycled materials obtained by crushing waste plastic materials sorted by type, removing foreign matter, washing, and dehydrating them into a recycled plastic molded product. The recycled plastic molded product is a combination of a layer made of recycled material and a layer made of virgin plastic material. Specifically, it has a sandwich structure in which a core layer made of recycled material is sandwiched between skin layers made of virgin plastic material. The recycled material and virgin plastic material are placed separately into an injection molding machine, and the sandwich injection molding machine separately injects them, molding the recycled material sandwiched between the virgin plastic materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-74507 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, to create a sandwich structure by separately injecting recycled and virgin plastic materials, the recycled material for the core layer is injected immediately after the virgin plastic material for the skin layer, allowing the core layer material to flow inside the molten skin layer material. This presents a problem: the leading edge of the core layer material is difficult to fill to the end due to accumulation of skin layer material. Furthermore, in injection molding, the filling condition of the core layer material is easily affected by the melt viscosity of the material, which can easily result in uneven thickness of each layer depending on the filling position. Furthermore, because the purity of recycled materials varies depending on the lot, and the material properties change, there is also the problem of uneven thickness of each layer depending on the lot. This uneven thickness of each layer depending on the filling position or lot results in the problem of inconsistent properties being obtained as the molded product.

[0005] On the other hand, to improve uniformity, recycled materials can be mixed with virgin plastic materials to form pellets. However, if foreign matter remains in the recycled material, there are problems such as reduced strength of the molded product due to stress concentration during molding, and foreign matter precipitates on the surface, reducing design. This limits the areas where it can be used. Furthermore, there are problems such as reduced productivity due to foreign matter clogging the resin flow path and the generation of a distinctive odor from the waste material.

[0006] The technology disclosed in this specification was developed based on the above circumstances, and aims to provide a method for manufacturing a vehicle interior material having stable product characteristics, and a vehicle interior material. [Means for solving the problem]

[0007] The technology disclosed in this specification, which was completed to solve the above-mentioned problems, is a method for manufacturing vehicle interior materials, which sequentially carries out a crushing process in which waste plastic material made of thermoplastic resin is crushed to obtain small pieces, a plate-shaped body forming process in which the small pieces are scattered on a thermoplastic resin sheet and hot-pressed to form a plate-shaped body in which a thermoplastic resin layer and a small piece layer are laminated, and a hot-press molding process in which the plate-shaped body is hot-press molded using a pair of molds.

[0008] According to the above manufacturing method, it is possible to utilize the crushed waste plastic material as it is and provide a vehicle interior material in which each layer has a uniform thickness and has stable product characteristics. Furthermore, since one side of the small piece layer is covered with the thermoplastic resin layer, when the thermoplastic resin layer is placed inside the vehicle cabin, the thermoplastic resin layer can suppress the odor emitted by the small piece layer from being emitted into the vehicle cabin.

[0009] The thermoplastic resin sheet may be translucent. With this configuration, when the thermoplastic resin layer is disposed inside the vehicle cabin, the small piece layer can be seen through the translucent thermoplastic resin layer, and the color and pattern of the small piece layer can be used as a design. In other words, when waste plastic materials are used in the manufacturing process without being separated by color, a wider variety of designs can be realized, which reduces the sorting work and is advantageous in terms of the process.

[0010] Following the hot press molding process, a moving process may be carried out in which the pair of molds are displaced in the mold opening direction to form an injection space between the plate-like body and the mold surface of the mold, and an injection molding process may be carried out in which molten thermoplastic resin is injected from the mold surface side of the mold facing the small piece layer, and a back surface layer made of thermoplastic resin is laminated on the side of the small piece layer opposite the thermoplastic resin layer.

[0011] According to the above-mentioned configuration, a sandwich structure is formed in which the small piece layer is sandwiched between the thermoplastic resin layer and the back surface layer, and the strength of the vehicle interior material can be increased.

[0012] In the injection molding process, a protrusion protruding from the back surface layer toward the opposite side of the small piece layer may be integrally formed. With this configuration, fastening portions, reinforcing ribs, etc. can be integrally formed on the back surface layer by injection molding.

[0013] Another technology disclosed in this specification, which was completed to solve the above-mentioned problems, is a vehicle interior material in which a thermoplastic resin layer made of a translucent thermoplastic resin and constituting the interior design surface of the vehicle is laminated on the back surface with a small piece layer in which small pieces made of thermoplastic resin are dispersed and compressed.

[0014] According to the above-mentioned configuration, the small pieces (small piece layer) compressed in a dispersed state can be seen through the translucent design surface layer, so the color and pattern of the small piece layer can be used as a design. Furthermore, since the interior side of the small piece layer is covered with the thermoplastic resin layer, when the small piece layer is made of waste plastic, the thermoplastic resin layer can suppress the odor emitted by the small piece layer from emitting into the interior of the vehicle.

[0015] A back surface layer made of a thermoplastic resin may be provided on the back surface of the small piece layer, and a protrusion protruding toward the outside of the vehicle cabin may be integrally formed on the back surface layer. According to the above configuration, a sandwich structure is formed in which the small piece layer is sandwiched between the thermoplastic resin layer and the back surface layer, thereby increasing the strength of the vehicle interior material. In addition, fastening portions, reinforcing ribs, etc. can be integrally provided on the back surface layer. [Effects of the Invention]

[0016] According to the technology disclosed in this specification, it is possible to provide a method for manufacturing a vehicle interior material having stable product properties, and the vehicle interior material. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view of an ornament board according to an embodiment; [Figure 2] A photograph of part of the ornament board viewed from the first resin layer side [Figure 3] An explanatory diagram showing the pulverization process and the plate-shaped body forming process [Figure 4] FIG. 10 is an explanatory diagram showing a state in which a plate-shaped body is placed between a pair of forming dies. [Figure 5] An explanatory diagram showing the hot press molding process [Figure 6] An explanatory diagram showing the movement process [Figure 7] An explanatory diagram showing the injection molding process DETAILED DESCRIPTION OF THE INVENTION

[0018] One embodiment will be described with reference to Figures 1 to 7. In this embodiment, an ornament board (an example of a vehicle interior material) 10 that forms part of a door trim attached to an automobile (vehicle) door and a method for manufacturing the ornament board 10 will be described.

[0019] The ornament board 10 of this embodiment is formed using crushed material (an example of small pieces, hereinafter sometimes referred to as recycled material) 11 obtained from discarded plastic material, and makes use of the color and pattern of the crushed material 11. Fig. 1 is a cross-sectional view of the ornament board 10, and this ornament board 10 has a three-layer structure in which a crushed material layer (an example of a small piece layer) 12 made of crushed material 11 is sandwiched between resin layers 14 and 15 made of virgin material (non-recycled material) on the front and back sides. In the following description, the upper surface shown in Fig. 1 will be referred to as a design surface 10A arranged inside the vehicle cabin, and the lower surface will be referred to as a back surface 10B.

[0020] Of the front and back resin layers 14, 15, the layer constituting the design surface 10A (hereinafter referred to as the first resin layer 14) is a layer formed from a colorless and transparent thermoplastic resin sheet 13. The thermoplastic resin constituting the first resin layer (an example of a thermoplastic resin layer) 14 can be, for example, polypropylene, but is not limited thereto. The layer constituting the back surface 10B (hereinafter referred to as the second resin layer 15) is a layer formed by injection molding. The second resin layer (an example of a back surface layer) 15 is integrally provided with an attachment boss (an example of a protrusion) 16 for fastening the ornament board 10 to a board member disposed around it. The attachment boss 16 is formed to protrude from the back surface of the second resin layer 15 (the back surface 10B of the ornament board). The resin used for the second resin layer 15 and the attachment boss 16 can be, for example, polypropylene, a thermoplastic resin, but is not limited thereto.

[0021] In this ornament board 10, the first resin layer 14 constituting the design surface 10A is a colorless and transparent layer, so that the crushed material layer (an example of a small piece layer) 12 made of crushed material 11 can be seen through the first resin layer 14. In other words, the colors and patterns of the crushed material 11 constituting the crushed material layer 12 are utilized. Figure 2 shows an example of the ornament board 10 of this embodiment formed by the manufacturing method described below, in which the surface of the crushed material 11, which is a mixture of various colors, is crushed, and a beautiful mottled pattern can be seen through the first resin layer 14.

[0022] Next, a manufacturing method for manufacturing the ornament board 10 will be described. The ornament board 10 of this embodiment is manufactured by sequentially performing a crushing step of obtaining crushed material 11 from waste plastic material, a plate-shaped body forming step, a hot press molding step, a moving step, and an injection molding step. Each step will be specifically described below.

[0023] <Crushing process> The pulverization step is a step in which waste plastic material made of thermoplastic resin is pulverized to obtain pulverized material 11. As the waste plastic material, for example, one or more of the following can be used: non-standard substrates, substrate scraps, and vehicle interior materials recovered through recycling. The color of the waste plastic material is not particularly limited, and a mixture of various colors is acceptable. In addition, the method for pulverizing the waste plastic material is not particularly limited, and methods such as cutting, tearing, and smashing can be used.

[0024] The obtained pulverized material 11 is subjected to removal of foreign matter, washing, and dehydration to produce recycled material. The ornament board 10 and door trim manufactured by this technology can also be reused as waste plastic material. In this embodiment, pulverized material 11 with a size of 8 mm to 15 mm is used, which is sorted by specific gravity.

[0025] <Plate-shaped body forming process> In the plate-shaped body forming process, as shown in Fig. 3, a colorless and transparent thermoplastic resin sheet 13 is placed on a conveyor (not shown) and transported downstream (to the right in Fig. 3), and the pulverized material 11 obtained in the pulverization process is scattered on this resin sheet 13 to form a layer of pulverized material 11. At this time, the scattered pulverized material 11 is heated by a heater 21 to a soft, semi-molten state, and the layer of pulverized material 11 is compressed onto the resin sheet 13 by, for example, a pair of rollers 22, thereby forming a two-layer flat plate-shaped body 18P in which the pulverized material 11 is solidified on the resin sheet 13. The obtained plate-shaped body 18P is then cut to appropriate dimensions by a cutter 23 to form a plate-shaped body 18P of a predetermined size.

[0026] <Hot press molding process> In the heat press molding process, the plate 18P obtained in the plate forming process is heated and then press-molded using a mold 25 to form a plate 18M shaped into a predetermined shape. Specifically, as shown in FIGS. 4 and 5, the heated plate 18P is sandwiched between an upper mold 26 and a lower mold 27 and press-molded. At this time, the plate 18P is oriented so that the layer of colorless and transparent resin sheet 13 (hereinafter referred to as first resin layer 14) is disposed on the upper surface and the layer of pulverized material 11 (hereinafter referred to as pulverized material layer 12) is disposed on the lower surface. The plate 18P is pressed against a mold surface 26A of the upper mold 26 and a mold surface 27A of the lower mold 27 to be shaped into a predetermined shape (see FIG. 5). The thickness of the plate-like body 18M at this time (the dimension of the gap between the mold surface 26A of the upper mold 26 and the mold surface 27A of the lower mold 27) is set to be smaller than the thickness (2.3 mm to 3.0 mm) of the completed ornament board 10. Specifically, it is set to be approximately 1.3 mm to 2.0 mm.

[0027] <Moving process> Next, upper mold 26 and lower mold 27 are moved slightly apart so that the dimension of the gap between mold surface 26A of upper mold 26 and mold surface 27A of lower mold 27 becomes equal to the thickness of ornament board 10 in its completed form. That is, as shown in Fig. 6, upper mold 26 and lower mold 27 are displaced in the mold opening direction to form injection space S1 inside molding die 25. In this embodiment, the thickness dimension of the formed injection space S1 (mold opening dimension of molding die 25) is approximately 1.0 mm.

[0028] <Injection molding process> Next, while the molding die 25 is kept closed, molten resin (polypropylene resin) is injected into the injection space S1 from an injection device (not shown) provided in the lower die 27 (see FIG. 7). The molten resin flows through the injection space S1 between the plate-like body 18M and the mold surface 27A of the lower die 27, filling every corner of the injection space S1.

[0029] The lower mold 27 is provided with a boss molding space S2 for molding the mounting boss, and the molten resin is filled up to the boss molding space S2. In the above-described movement step, when the upper mold 26 and the lower mold 27 are displaced in the mold opening direction, the plate-like body 18M may be attached to the lower mold 27 rather than the upper mold 26. Even in such a case, however, the molten resin is injected from the lower mold 27 side in the injection molding step, so that the plate-like body 18M moves so as to be pressed against the upper mold 26, and the molten resin fills the space between the plate-like body 18M and the lower mold 27.

[0030] After the molten resin has cooled and solidified, the upper mold 26 and the lower mold 27 are separated to open the molding die 25, thereby obtaining the ornament board 10 shown in Figure 1, in which the decorative surface 10A side is covered with a transparent first resin layer 14 and the back surface 10B side has a second resin layer 15 with an integrally formed mounting boss 16.

[0031] Next, the effects of this embodiment will be described. The method for manufacturing ornament board 10 of this embodiment includes a crushing step of crushing waste plastic material made of thermoplastic resin to obtain crushed material 11, a plate-like body forming step of scattering crushed material 11 on a thermoplastic resin sheet 13 and hot-pressing it to form plate-like body 18P in which first resin layer 14 and crushed material layer 12 are laminated, and a hot-press molding step of hot-press molding plate-like body 18P using a pair of molding dies 25.

[0032] The above manufacturing method utilizes crushed waste plastic material as it is, making it possible to provide an ornamental board 10 with uniform layer thickness and stable product characteristics. Furthermore, because one side of the crushed material layer 12 is covered with the first resin layer 14, when the first resin layer 14 is placed inside the vehicle cabin, the first resin layer 14 can prevent odors emitted by the crushed material layer 12 from escaping into the vehicle cabin.

[0033] Furthermore, the thermoplastic resin sheet 13 is translucent. With this configuration, when the first resin layer 14 is disposed on the interior side of the vehicle, the pulverized material layer 12 can be seen through the translucent first resin layer 14, and the color and pattern of the pulverized material layer 12 can be used as a design. In other words, when waste plastic materials are used in the manufacturing process without being separated by color, a wider variety of designs can be realized, which reduces the sorting work and is advantageous in terms of the process.

[0034] In addition, following the hot press molding process, the method includes a moving process in which a pair of molding dies 25 are displaced in the mold opening direction to form an injection space S1 between the plate-like body 18M and the mold surface of the molding dies 25, and an injection molding process in which molten thermoplastic resin is injected from the mold surface 27A side of the lower die 27 of the molding dies 25 that faces the pulverized material layer 12, to laminate a second resin layer 15 made of thermoplastic resin on the opposite side of the pulverized material layer 12 to the first resin layer 14.

[0035] According to the above-described configuration, the crushed material layer 12 is sandwiched between the first resin layer 14 and the second resin layer 15, and the strength of the ornament board 10 can be increased.

[0036] Furthermore, in the injection molding process, a mounting boss 16 is integrally formed from the second resin layer 15, protruding toward the opposite side of the crushed material layer 12. In this way, fastening portions, reinforcing ribs, etc. can be integrally formed on the second resin layer 15 by injection molding.

[0037] In addition, the ornament board 10 of this embodiment is made of a translucent thermoplastic resin and is formed by laminating a crushed material layer 12 on the back surface of a first resin layer 14 that constitutes the interior design surface 10A of the vehicle, in which crushed material 11 made of thermoplastic resin is dispersed and compressed.

[0038] According to the above configuration, the pulverized material 11 (pulverized material layer 12) compressed in a dispersed state can be seen through the translucent first resin layer 14, so that the pulverized material layer 12 can be used as a design element. Furthermore, since the interior side of the pulverized material layer 12 is covered with the first resin layer 14, when the pulverized material layer 12 is made of waste plastic, the first resin layer 14 can prevent odors from being emitted into the interior of the vehicle.

[0039] In addition, a second resin layer 15 made of a thermoplastic resin is provided on the back surface of the pulverized material layer 12, and a mounting boss 16 protruding toward the outside of the vehicle cabin is integrally formed on the second resin layer 15. With the above configuration, a sandwich structure is formed in which the pulverized material layer 12 is sandwiched between the first resin layer 14 and the second resin layer 15, thereby increasing the strength of the ornament board 10. In addition, fastening portions, reinforcing ribs, etc. can be integrally provided on the second resin layer 15.

[0040] As described above, according to this embodiment, it is possible to provide an ornament board 10 with stable product characteristics and a method for manufacturing the ornament board 10.

[0041] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included in the technical scope.

[0042] (1) In the above embodiment, the first resin layer 14 is formed from a colorless and transparent thermoplastic resin sheet 13. However, the first resin layer may be formed from a translucent colored sheet or a non-translucent colored sheet depending on the desired design.

[0043] (2) In the above embodiment, an ornament board 10 having a three-layer structure in which the front and back of the pulverized material layer 12 made of pulverized material 11 are sandwiched between resin layers (first resin layer 14 and second resin layer 15) made of virgin material is exemplified. However, the vehicle interior material may also have a two-layer structure in which a thermoplastic resin layer made of a thermoplastic resin sheet is laminated on one side of the small piece layer made of small pieces.

[0044] (3) In the above embodiment, the mounting boss 16 is provided as a protrusion on the rear surface 10B of the ornament board 10. However, the protrusion is not limited to a mounting boss, and a rib, a mounting seat, etc. may also be provided. In addition, a configuration in which no protrusion is provided is also included in the technical scope.

[0045] (4) In the above embodiment, in the plate-shaped body forming process, the semi-molten pulverized material 11 scattered on a colorless and transparent thermoplastic resin sheet 13 is compressed by a pair of rollers 22 to form the plate-shaped body 18P. However, the plate-shaped body may also be formed using, for example, a thick hot plate press device or a hot belt press device equipped with a heat generating means such as a heater that generates heat when electricity is applied.

[0046] (5) In the above embodiment, the hot press molding process is performed using a pair of molds 25 having an upper mold 26 and a lower mold 27, but it is also possible to use a mold having a vertical mold surface that presses horizontally.

[0047] (6) The vehicle interior material is not limited to the ornament board 10 of the vehicle door trim, but can also be used for other vehicle interior materials such as a vehicle ceiling material or instrument panel. Also, the material is not limited to a vehicle, and can be used for other vehicle interior materials. [Explanation of symbols]

[0048] 10: Ornament board (vehicle interior material) 10A: Design surface 10B: Back surface 11: Crushed material (small pieces) 12: Crushed material layer (small piece layer) 13: Thermoplastic resin sheet 14: First resin layer (thermoplastic resin layer) 15: Second resin layer (back surface layer) 16: Mounting boss (protrusion) 18M, 18P: Plate-shaped body 25: Mold 26: Upper mold 26A: Mold surface 27: Lower mold 27A: Mold surface S1: Injection space S2: Boss molding space

Claims

1. a crushing step of crushing waste plastic material made of thermoplastic resin to obtain small pieces; a plate-shaped body forming step of scattering the small pieces on a thermoplastic resin sheet and hot-pressing the sheet to form a plate-shaped body in which a thermoplastic resin layer and a small piece layer are laminated; and a hot press molding step of hot press molding the plate-like body using a pair of molds.

2. 2. The method for manufacturing a vehicle interior material according to claim 1, wherein the thermoplastic resin sheet has light-transmitting properties.

3. a moving step following the hot press molding step of displacing the pair of molds in a mold opening direction to form an injection space between the plate-like body and mold surfaces of the molds; 3. The method for manufacturing a vehicle interior material according to claim 1, wherein an injection molding process is carried out in sequence, in which a molten thermoplastic resin is injected from a mold surface side of the mold facing the small piece layer, and a back surface layer made of a thermoplastic resin is laminated on the opposite side of the small piece layer to the thermoplastic resin layer.

4. 4. The method for manufacturing a vehicle interior material according to claim 3, wherein a protrusion protruding from the back surface layer toward the opposite side of the small piece layer is integrally formed in the injection molding step.

5. This vehicle interior material is made by laminating a small piece layer, in which small pieces made of thermoplastic resin are dispersed and compressed, on the back surface of a thermoplastic resin layer that is made of a translucent thermoplastic resin and that constitutes the interior design surface of the vehicle.

6. 6. The vehicle interior material according to claim 5, wherein a back surface layer made of a thermoplastic resin is provided on the back surface of the small piece layer, and a protrusion protruding toward the outside of the vehicle cabin is integrally formed on the back surface layer.

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