Laminated material and method for manufacturing the same

Abstract

To provide a laminated material capable of enhancing strength, and to provide a production method thereof.SOLUTION: A laminated material 10 which is constituted by laminating a plurality of plate materials is such that: the plurality of plate materials include a first plate material 11 produced by compressing and heating a material obtained by mixing at least one of a waste paper-made material and a waste fibrous material with a waste thermoplastic resin material, and wooden second plate materials 12-15; and the first plate material 11 and the second plate materials 12-15 are adhered to each other, are compressed in the lamination direction while being heated, and are bent in the lamination direction of the first plate material 11 and the second plate materials 12-15.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a laminated material constituted by laminating a plurality of plate materials, and a method for producing the same. Background Art

[0002] Conventionally, as a method for producing this type of laminated material, a chair production method described in Patent Document 1 is known. Said production method comprises: arranging a laminated material formed by laminating layers with an adhesive interposed between adjacent wooden veneers between an upper mold and a lower mold, and performing press molding while heating the laminated material. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2012-157484 Summary of the Invention Problems to be Solved by the Invention

[0004] However, since the laminated material used in the above-described conventional production method is formed by laminating a plurality of wooden veneers, there is a problem that the bending strength thereof is lower than that of a synthetic resin plate. By the way, 17 Sustainable Development Goals (SDGs) have been established as specific goals that humanity should achieve by 2030. The 12th goal among them is "Responsible Consumption and Production", in which the goal of "reducing, reusing and recycling waste" is set forth. Accordingly, achieving the above goal by reusing plastic waste, paper waste and textile scraps that are discarded in large quantities every day from enterprises and general households has become an issue to be addressed.

[0005] Therefore, the present invention was created to solve the above-mentioned problems and aims to provide a laminated material and a method for manufacturing the same that can increase strength. Furthermore, the present invention aims to provide a laminated material and a method for manufacturing the same that can achieve the 12th Sustainable Development Goal by recycling plastic waste, paper waste, and textile waste. [Means for solving the problem]

[0012] (No. 1 invention) In order to achieve the aforementioned objectives, the present application 1 The method for manufacturing the laminated material according to the invention is: A method for manufacturing laminated material (10: Figure 4) by stacking multiple plate materials, A first sheet material (11: Figure 4) is manufactured by compressing and heating a raw material which is a mixture of at least one of discarded paper material and discarded fibrous material and discarded thermoplastic resin material, Prepare the second wooden board (12-15: Figure 4), The first board material (11) and the second board material (12-15) Thermosetting adhesive The first step involves bonding and laminating the materials together (steps 2 and 3: Figure 7), The first plate material (11) and the second plate material (12-15), which have been bonded and laminated together in the first process (processes 2 and 3), At a temperature above the curing temperature of the thermosetting adhesive A second step (step 4: Figure 7) involves heating and applying pressure in the stacking direction while bending the first plate material (11) and the second plate material (12-15) in the stacking direction, It is characterized by having the following features.

[0013] (No. 1 (Effects of the invention) This application 1According to the invention, since the first board material constituting the laminated material is manufactured by compressing and heating a raw material which is a mixture of at least one of discarded paper material and discarded fibrous material and discarded thermoplastic resin material, it is possible to increase the bending strength compared to a laminated material constructed by laminating wooden veneers. Furthermore, since the first plate material constituting the laminate is manufactured by compressing and heating a raw material which is a mixture of at least one of discarded paper material and discarded fibrous material and discarded thermoplastic resin material, the discarded paper material and discarded fibrous material and discarded thermoplastic resin material can be reused. Therefore, as a manufacturer of laminated materials, we can achieve the 12th goal of the Sustainable Development Goals. Furthermore, according to the first invention of this application, the thermosetting adhesive used to bond the first and second plates together can be cured by heating the first and second plates at a temperature higher than the temperature at which the thermosetting adhesive cures, thereby increasing the strength of the laminated material.

[0014] (No. 2 invention) In order to achieve the aforementioned objectives, the present application 2 The method for manufacturing the laminated material according to the invention is as described above. 1 In the method for manufacturing laminated material according to the invention, In the second step (Step 4: Figure 7), The first plate material (11) is characterized by heating the first plate material (11) to a temperature above the softening point of the thermoplastic resin material contained in the first plate material (11).

[0015] (No. 2 (Effects of the invention) This application 2 According to the invention, since the first sheet material is heated to a temperature above the softening point of the thermoplastic resin material contained in the first sheet material, the thermoplastic resin material contained in the first sheet material can be softened to at least some extent, so that the first sheet material is less likely to crack when bent in the lamination direction of the first and second sheet materials.

[0018] (No. 3 invention) To achieve the aforementioned object, the first 3 invention's method for producing a laminated material is, in the above-described first 1 invention's or the second invention method for producing a laminated material according to the first step (Step 2, Step 3: Fig. 7), characterized in that after polishing the adhesive surface of a first plate member (11), the first plate member (11) and a second plate member (12 to 15) are bonded to each other.

[0019] (Effect of the 3 Invention) According to the first 3 invention of the present application, since the first plate member and the second plate member are bonded to each other after polishing the adhesive surface of the first plate member, the permeability of an adhesive on the adhesive surface of the first plate member can be improved, whereby the adhesive strength between the first plate member and the second plate member can be increased. Accordingly, the bending strength of the laminated material can be increased. (Fourth Invention) To achieve the aforementioned objective, the method for manufacturing a laminated material according to the fourth invention of this application is, in the method for manufacturing a laminated material according to the first or second invention described above, In the laminated material (10) obtained by the second step (step 4), the surface of the first plate material (11) is characterized in that a pattern formed from at least one of the discarded paper material and the discarded fibrous material and the discarded thermoplastic resin material is exposed. (Effects of the fourth invention) According to the fourth invention of this application, since the surface of the first plate material constituting the laminated material has a pattern exposed that is formed from at least one of discarded paper material and discarded fibrous material and discarded thermoplastic resin material, a different design can be applied to it than when the pattern of a wooden veneer is exposed on the surface. Furthermore, since at least one of the paper material and fibrous material forming the first sheet material and the thermoplastic resin material are arranged irregularly, and a different pattern is exposed for each first sheet material, it is possible to manufacture products with a unique design by using this laminated material. [Advantageous Effects of Invention]

[0020] According to the laminated material and the method for producing the same according to the invention of the present application, it is possible to provide a laminated material that can have increased strength and a method for producing the same. Furthermore, according to the laminated material and the method for producing the same according to the invention of the present application, by reusing at least one of discarded paper materials and discarded fibrous materials, and discarded thermoplastic resin materials, it is possible to provide a laminated material that can contribute to achieving the 12th Sustainable Development Goal and a method for producing the same. [Brief Description of Drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of a chair using a laminated material according to an embodiment of the invention of the present application. [Figure 2] This is an enlarged explanatory diagram of the part indicated by the symbol E2 in Figure 1. [Figure 3] This is an enlarged explanatory diagram of the part indicated by the symbol E1 in Figure 1. [Figure 4] This is an explanatory diagram showing the laminated structure of a laminated material. [Figure 5] This is a front view diagram of a laminated material manufacturing apparatus. [Figure 6] Figure 5 is a front view illustrating how the laminated material is bent by the manufacturing apparatus shown. [Figure 7] This is a process diagram showing the manufacturing process of laminated materials. [Modes for carrying out the invention]

[0022] A laminated material according to an embodiment of the present invention and a method for manufacturing the same will be described with reference to the drawings. (Chair structure) Figure 1 is a perspective view of a chair using laminated material according to this embodiment. The chair 1 comprises a seat 2, a backrest 3, four legs 4, crossbars 5 and 6, and two armrests 7. The seat 2 and backrest 3 are integrally molded and are formed from laminated material 10 bent at approximately 90 degrees. Fixing members (not shown) for fixing the seat 2 to the crossbars 5 and 6 are attached to the underside of the seat 2. The rear left and right legs 4, 4 are connected by a rear crossbar 5. The front left and right legs 4 (the left leg 4 is not shown in the figure) are connected by a front crossbar 6. The right armrest 7 is attached to the upper end of the right leg 4, 4, and the left armrest 7 is attached to the upper end of the left leg 4.

[0023] (Laminated wood structure) Next, the structure of the laminated material 10 used in chair 1 will be explained with reference to the diagram. As shown in Figure 4, the laminated material 10 is constructed by sequentially laminating second plates 12-15 on top of a first plate 11. In Figure 4, the thickness of each plate is drawn thicker than its actual thickness to make the laminated structure of each plate easier to understand, and the total length of the laminated material 10 (the length from left to right in the drawing) is drawn shorter than its actual length. Furthermore, in the following, when explaining matters common to the first plate 11 and the second plates 12-15, they may simply be referred to as "plates."

[0024] The first plate material 11 is formed by compressing and heating crushed waste thermoplastic resin material (hereinafter referred to as resin raw material) and shredded waste paper material (hereinafter referred to as paper raw material). Discarded thermoplastic resin materials include, for example, thermoplastic resin containers, products, parts, and waste generated during the manufacturing process of products discarded by businesses and households, and the resin raw material is obtained by crushing at least one of these materials. Examples of thermoplastic resins include polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). Discarded paper materials include, for example, paper containers, packaging paper, and printing paper discarded by businesses and households, and the paper raw material is obtained by shredding at least one of these materials. As shown in Figure 2, patterns formed by the mixed resin raw material R and paper raw material P are exposed on the front and back surfaces of the first plate material 11.

[0025] Incidentally, regarding the mixing ratio of the resin raw material R and the paper raw material P in the first plate material 11, if the mixing ratio of the resin raw material R is small, problems may occur such as cracks or splits occurring in the bent parts or insufficient strength when the laminated material 10 is bent during the manufacturing process. Conversely, if the mixing ratio of the resin raw material R is large, problems occur such as the laminated material 10 becoming heavier and the heating time until the resin raw material R reaches its softening point becoming longer. Therefore, in this embodiment, the mixing ratio of the resin raw material R and the paper raw material P in the first plate material 11 is set to 55-60% for the resin raw material R and 35-40% for the paper raw material P, and ingenuity has been taken to prevent the above-mentioned problems from occurring.

[0026] The first sheet material 11 is formed by filling a mold of a compression molding machine with a mixture of resin raw material R and paper raw material P, and then compressing it while heating it. The pressure applied to pressurize the raw materials is, for example, 15 kg / cm2. The temperature at which the raw materials are heated during pressurization is the molding temperature required when molding a resin molded product using a thermoplastic resin, which is the resin raw material. For example, if the resin raw material R is polypropylene, the temperature is 200-300°C. If resins with different molding temperatures are mixed, the molding temperature is set to the temperature of the resin with the highest molding temperature, and the process is controlled so that each resin melts and is molded.

[0027] The second boards 12-15 are wooden veneers, which can be made from hardwoods such as beech or birch. The second boards 12-15 are laminated so that the grains of adjacent boards intersect (e.g., perpendicularly). The first board 11 and the second boards 12-15 are bonded to each other with an adhesive. For example, a melamine-urea co-condensation resin adhesive can be used as the adhesive. Also, as shown in Figure 1, the laminated material 10 is bent at the boundary between the seat board 2 and the back board 3. More specifically, as shown in Figure 3, the laminated material 10 is bent at a bending angle θ in the lamination direction of the first board 11 and the second boards 12-15. In the illustrated example, the bending angle θ is approximately 90 degrees.

[0028] (Laminated material manufacturing equipment) Next, the manufacturing apparatus for the laminated material 10 according to this embodiment will be described with reference to the figures. As shown in Figures 5 and 6, the manufacturing apparatus 60 comprises a bed 40, a lower mold 20 positioned on the bed 40, an electrode 21 provided on the upper surface of the lower mold 20, an upper mold 30 positioned opposite the lower mold 20, an electrode 31 provided on the lower surface of the upper mold 30, a slide 41 supporting the upper mold 30, a piston 50 for raising and lowering the slide 41, and a pair of slide guides 42, 42 that support the slide 41 so that it can move up and down.

[0029] The lower mold 20 and the upper mold 30 are shaped to form a bent shape from a flat laminated material 10. In this embodiment, the lower mold 20 is formed in a concave shape, and the upper mold 30 is formed in a convex shape. The bending angle θ of the lower mold 20 and the upper mold 30 is approximately 90 degrees. The bottom portion 21a of the lower mold 20 and the convex portion 31a of the upper mold 30 are formed as curved surfaces, and are designed so that when the laminated material 10 is bent at the bending angle θ, the bent portion exhibits a curved surface. The piston 50 is inserted into a hydraulic cylinder (not shown) and moves back and forth by hydraulic drive. The electrodes 21 and 31 are electrically connected to a high-frequency generator (not shown), and the laminated material 10 sandwiched between the electrodes 21 and 31 is heated by high frequency.

[0030] (Method of manufacturing laminated material) Next, the manufacturing method of the laminated material 10 will be explained with reference to Figure 7. First, the first plate material 11 and the second plate materials 12-15 are prepared (Step 1). Next, thermosetting adhesive is applied to the bonding surfaces of the first plate material 11 and the second plate materials 12-15 (Step 2). At this time, the bonding surface of the first plate material 11 to which the adhesive is applied is roughened so that the thermosetting adhesive can easily penetrate from the bonding surface (adhere easily to the bonding surface). Next, the second plate materials 12-15 are laminated in order on top of the first plate material 11, and each plate material is bonded to each other to create a laminated material 10 (Step 3).

[0031] Next, as shown in Figures 5 and 6, the laminate 10 is set in the lower mold 20 of the manufacturing apparatus 60, the electrodes 21 and 31 are energized, the upper mold 30 is lowered, and the laminate 10 is heated, pressurized, and bent (step 4). At this time, when the laminate 10 begins to bend, care is taken to reduce the lowering speed of the upper mold 30 so that stress is not suddenly applied to the bent portion of the first plate material 11. The time for heating and pressurizing the laminate 10 is determined by experiments conducted in advance. Specifically, it is determined by the time required for the thermosetting adhesive applied between each plate material to harden, and the time required for the temperature of the resin raw material R forming the first plate material 11 to rise above its softening point. Note that until the thermosetting adhesive applied between each plate material hardens, the thermoplastic adhesive between each plate material is in a gel-like state, so the friction between each plate material is small. Therefore, when the laminate 10 bends, each plate material shifts slightly in a direction different from the lamination direction, which allows the stress on each plate material to be relieved. This prevents stress from being concentrated at the bending point due to pressure, thus preventing cracks or breakage at the bending point during bending.

[0032] Next, the upper mold 30 is raised to remove the laminated material 10 from the lower mold, and the removed laminated material 10 is cured (step 5). Specifically, the laminated material 10 is allowed to air dry for a predetermined time. At this time, stress is generated between each plate material due to the heating and pressurizing of the laminated material 10, and there is a risk that the laminated material 10 will deform in a direction different from the lamination direction and the bending direction. For this reason, predetermined locations on the periphery of the laminated material 10 are clamped with predetermined clamping members (clampers) to control the deformation of the laminated material 10. Next, the laminated material 10 is processed (step 6). For example, the laminated material 10 is processed into a predetermined shape using an NC machine tool. Also, as shown in Figure 1, if the laminated material 10 is used as the seat plate 2 and back plate 3 of the chair 1, the corners of the laminated material 10 are cut to create a rounded edge. In addition, holes for handles may be processed in the part that will become the back plate 3. Furthermore, the left and right sides of the back plate 3 may be cut inward into an arc shape. Furthermore, the front, back, and end surfaces of the laminated material 10 are ground (roughened) using a sander, and urethane coating or the like is applied to each ground surface. Next, the product using the laminated material 10 is assembled (step 7). For example, a chair 1 using the laminated material 10 is assembled as shown in Figure 1. Steps 2 and 3 are examples of the first steps of the present invention, and step 4 is an example of the second steps of the present invention.

[0033] (Effects of the embodiment) (1) According to the laminated material 10 and its manufacturing method according to the above embodiment, the first plate material 11 constituting the laminated material 10 is manufactured by compressing and heating a raw material which is a mixture of discarded thermoplastic resin material and discarded paper material, so that it can be made stronger than a laminated material which is made by laminating wooden veneers. Furthermore, since the first plate material 11 constituting the laminated material 10 is manufactured by compressing and heating a raw material which is a mixture of discarded thermoplastic resin material and discarded paper material, the discarded thermoplastic resin material and discarded paper material can also be reused.

[0034] (2) Furthermore, according to the laminated material 10 of the embodiment described above, the first plate material 11 constituting the laminated material 10 can be reused as a raw material for the first plate material by crushing it, so that the reuse of discarded thermoplastic resin materials and discarded paper materials can be continued, and the manufacturer of the laminated material 10 can achieve the 12th goal of the Sustainable Development Goals.

[0035] (3) Furthermore, according to the laminated material 10 of the embodiment described above, since the surface of the first plate material 11 constituting the laminated material 10 has a pattern formed from a thermoplastic resin material and a paper material exposed, it is possible to apply a different design from that of a wooden veneer with a pattern exposed on the surface. Furthermore, the thermoplastic resin material and paper material forming the first plate material 11 are arranged irregularly, and a different pattern is exposed for each first plate material 11. Therefore, by manufacturing products using this laminated material 10, it is possible to manufacture products with a unique design.

[0036] (4) Furthermore, according to the manufacturing method of the laminated material 10 according to the embodiment described above, the first plate material 11 is heated to a temperature above the softening point of the thermoplastic resin material contained in the first plate material 11, so that the thermoplastic resin material contained in the first plate material 11 can be softened to some extent, and the first plate material 11 is less likely to crack when the first plate material 11 and the second plate materials 12 to 15 are bent in the lamination direction.

[0037] (5) Furthermore, according to the manufacturing method of the laminated material 10 according to the embodiment described above, the thermosetting adhesive used to bond the first plate material 11 and the second plate materials 12 to 15 together can be cured by heating the first plate material 11 and the second plate materials 12 to 15 at a temperature higher than the temperature at which the thermosetting adhesive hardens, thereby increasing the strength of the laminated material 10.

[0038] (6) Furthermore, according to the manufacturing method of the laminated material 10 according to the embodiment described above, since the adhesive surface of the first plate material 11 is roughened before bonding the first plate material 11 and the second plate material 12 to each other, the penetration of the adhesive on the adhesive surface of the first plate material 11 (ease of adhesion of the adhesive) can be increased, and thus the adhesive strength of the first plate material 11 and the second plate material 12 can be increased. Therefore, the strength of the laminated material 10 can be increased.

[0039] (7) As described above, the laminated material 10 and its manufacturing method according to the above-described embodiment can provide a laminated material and its manufacturing method that can increase strength. Furthermore, the laminated material 10 and its manufacturing method according to the above-described embodiment can provide a laminated material and its manufacturing method that can achieve the 12th Sustainable Development Goal by reusing discarded thermoplastic resin and discarded paper.

[0040] (Other embodiments) (1) In the laminated material 10 of the embodiment described above, the first plate material 11 is placed on only one side, but the first plate material 11 can also be placed on both sides. In addition, the first plate material can be placed inside the second plate material. (2) In the embodiment described above, only the central part of the laminated material 10 was bent, but the shapes of the lower mold 20 and the upper mold 30 can be changed to bend at multiple points, including the central part. For example, the front end of the seat board 2 (Figure 1) can be curved downwards. Using a chair 1 configured in this way, the back of the thighs of the person sitting in the chair 1 will not come into contact with the front end of the seat board 2, thus improving seating comfort. The upper end of the backrest 3 can also be curved backwards.

[0041] (3) In the embodiments described above, the mixing ratio of the resin raw material R and the paper raw material P in the first plate material 11 was exemplified as 55-60% for the resin raw material R and 35-40% for the paper raw material P. However, the mixing ratio is not limited to this and can be changed depending on the type of resin raw material R and paper raw material P and the particle size of the raw materials. (4) Discarded fibrous material can also be used as the raw material for the first board material 11. Alternatively, both discarded paper material and discarded fibrous material can be used as the raw material for the first board material. By using this first board material 11, it is possible to provide a laminate and a method for manufacturing the same that can achieve the 12th Sustainable Development Goal by reusing at least one of the discarded paper material and the discarded fibrous material and discarded thermoplastic resin. Discarded fibrous material refers to, for example, textile waste discarded from businesses and households, or shredded or fibroused used clothing, used cloth and fabric scraps, and does not matter whether it is natural fiber or synthetic fiber. (5) The pressurizing time, pressure, heating temperature, and heating time required to heat and pressurize the first plate material 11 and the second plate materials 12 to 15 to obtain the laminated material 10 can be changed according to the mixing ratio of the raw materials constituting the first plate material 11, the type of thermoplastic resin, the particle size of each raw material, the thickness of each plate material, the type of the second plate materials 12 to 15, and the thickness of the laminated material 10 to be obtained.

[0042] (6) The raw materials for the first plate material 11 may also include glass, porcelain, etc. Furthermore, thermosetting resins may also be included. (7) In the embodiments described above, a melamine-urea cocondensation resin adhesive was used as the adhesive, but solvent-type adhesives such as melamine resin adhesives, urea resin adhesives, phenol resin adhesives, resorcinol resin adhesives, and water-based adhesives (so-called white bond) in which vinyl acetate resin is dispersed (emulsified) in water can also be used. When using a solvent-type adhesive, in step 4 (Figure 7), the first plate material 11 and the second plate materials 12-15 are heated to a temperature above the temperature at which the solvent contained in the solvent-type adhesive evaporates and hardens. (8) The laminated material according to the present invention can also be applied to products other than chairs, such as desks, tables, shelves, flower pots, display cases, wall materials, works of art, sports equipment such as skateboards, and even structural parts of vehicles such as automobiles. [Explanation of Symbols]

[0043] 1 chair 2 Seat board 3 back plate 10 Laminated material 11. First board 12-15 Second board 20 Lower mold 21 electrodes 30 Upper mold 31 electrode 50 pistons

Claims

1. A method for manufacturing laminated materials by stacking multiple plate materials together, A first sheet material manufactured by compressing and heating a raw material mixture comprising at least one of discarded paper material and discarded fibrous material and discarded thermoplastic resin material, Prepare a second wooden board, A first step of bonding and laminating the first and second plates together with a thermosetting adhesive, The first and second plates, which have been bonded and laminated together in the first step, are subjected to pressure in the lamination direction while being heated at a temperature above the curing temperature of the thermosetting adhesive, and are bent in the lamination direction of the first and second plates. A method for manufacturing laminated material, characterized by having the following features.

2. In the second step described above, The method for manufacturing a laminated material according to claim 1, characterized in that the first plate material is heated to a temperature above the softening point of the thermoplastic resin material contained in the first plate material.

3. In the first step described above, A method for manufacturing a laminated material according to claim 1 or 2, characterized in that the adhesive surface of the first plate material is polished, and then the first plate material and the second plate material are bonded to each other and laminated.

4. The method for manufacturing a laminated material according to claim 1 or 2, characterized in that, in the laminated material obtained by the second step, a pattern formed by at least one of the discarded paper material and the discarded fibrous material and the discarded thermoplastic resin material is exposed on the surface of the first plate material.

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