JP2021142698A - Manufacturing method for molded product - Google Patents

Abstract

To provide a method for manufacturing a molded product that can reduce costs by reducing processes and material costs, and that does not require adhesives for bonding surface materials or dedicated press machines.SOLUTION: A method for manufacturing a molded product 1 includes a molding process in which an air-impermeable skin material 5 is bonded to the surface of a base material 4 made of a board material 8 containing a plant fiber 2 and a thermoplastic resin 3a that binds the plant fibers to each other, and this method includes: a heating step that heats and softens a board material with a surface skin material bonded to the surface thereof by thermoplastic resin; and a vacuum forming step in which the heat-softened board material is shaped by vacuum forming to form a molded product.SELECTED DRAWING: Figure 3

Description

The present invention relates to a method for producing a molded product, and more specifically, a non-breathable skin material is adhered to the surface of a base material made of a board material containing plant fibers and a thermoplastic resin that binds the plant fibers to each other. The present invention relates to a method for producing a molded product.

As a conventional method for producing a molded product, a method for producing a molded product in which a skin material is adhered to the surface of a base material made of a board material containing plant fibers and a thermoplastic resin that binds the plant fibers to each other is generally known. Has been done. In this method for producing a molded product, for example, as shown in FIG. 4A, a straight fiber 102 and a thermoplastic resin fiber 103 are mixed to form a matte material 107, and then the matte material 107 is heated. It is compressed to form a board material 108 (also referred to as "pre-board"). Next, as shown in FIG. 4B, the board material 108 is heated and softened, and the heat-softened board material 108 is press-molded by a press machine 110 to form a base material 104 having a predetermined shape. Then, as shown in FIG. 4 (c), the adhesive 114 is applied to the surface of the base material 104 and dried, and then the skin material 105 is heated to remove the heated skin material 105 and the adhesive 114. The coated base material 104 is set in the vacuum forming machine 111 and shaped by vacuum forming to obtain a molded body 101.

Japanese Unexamined Patent Publication No. 2003-33902

However, in the above-mentioned conventional method for manufacturing a molded product, there are many steps, and an adhesive 114 is required to bond the skin material 105. Further, a dedicated press 110 is required to shape the base material 104.

The above-mentioned Patent Document 1 describes a technique of laminating a veneer decorative sheet, an adhesive layer, and a thin medium density fiberboard in order, and shaping the laminated body by vacuum forming. There is no description of a technique for efficiently producing a molded product in which a non-breathable skin material is adhered to the surface of a base material made of a board material containing a thermoplastic resin.

The present invention has been made in view of the above situation, and it is possible to reduce the cost by reducing the process and material costs, and to manufacture a molded product that does not require an adhesive for adhering the skin material and a dedicated press machine. The purpose is to provide a method.

In order to solve the above problem, in the invention according to claim 1, a non-breathable skin material is provided on the surface of a base material made of a board material containing a plant fiber and a thermoplastic resin that binds the plant fibers to each other. A method for producing an adhered molded product, which is a heating step of heating and softening the board material having the skin material adhered to the surface by the thermoplastic resin, and vacuum forming the heat-softened board material. The gist is to include a vacuum forming step of shaping and molding the molded body.
The invention according to claim 2 is the invention according to claim 1, wherein the raw cotton of the straight fiber and the raw cotton of the thermoplastic resin fiber are mixed to form a mat material, and the mat material molding step is heated. It is a gist to include a board material molding step of forming the board material by pressing the mat material and the skin material in the thickness direction in a state where the skin material is arranged on the surface side of the mat material.
The gist of the invention according to claim 3 is that the skin material is formed of a synthetic resin sheet in the invention according to claim 1 or 2.
The gist of the invention according to claim 4 is that the molded product is formed in a tray shape in the invention according to any one of claims 1 to 3.

According to the method for producing a molded product of the present invention, a heating step of heating and softening a board material having a skin material adhered to its surface with a thermoplastic resin and a molding of the heat-softened board material by vacuum forming are performed. Includes a vacuum forming step of molding the body. As a result, the molded product can be manufactured at a reduced cost by reducing the process and material costs. Further, since the board material to which the skin material is adhered by the thermoplastic resin is used, the volatile organic compound (VOC) can be reduced without the need for an adhesive for adhering the skin material as in the conventional case. Further, since the molded product can be obtained by shaping the shape of the board material by vacuum forming, a dedicated press machine is not required as in the conventional case.

Further, in the mat material molding step of molding the mat material by mixing the raw cotton of the straight fiber and the raw cotton of the thermoplastic resin fiber, and in a state where the skin material is arranged on the surface side of the heated mat material. When the board material molding step of forming the board material by pressurizing the mat material and the skin material in the thickness direction is included, the thermoplastic resin fibers are melted and cooled and solidified by heating and compressing the mat material. As a result, a board material in which the plant fibers are bound to each other by the thermoplastic resin and the skin material is adhered to the surface can be obtained.

Further, when the skin material is formed of a synthetic resin sheet, the board material can be easily shaped by vacuum forming.

Further, when the molded product is formed in a tray shape, a molded product having a relatively loose shape can be efficiently manufactured.

The present invention will be further described in the following detailed description with reference to the plurality of references mentioned with reference to non-limiting examples of typical embodiments according to the invention. Similar parts are shown through several figures.
It is explanatory drawing for demonstrating the manufacturing method of the molded article which concerns on Example. It is explanatory drawing for demonstrating the manufacturing method of the molded article which concerns on an Example, (a) shows the heating process of a mat material, (b) shows a pressurizing process of a mat material, (c) is a board material. Is shown. It is explanatory drawing for demonstrating the manufacturing method of the molded body which concerns on Example, (a) shows the heating process of a board material, (b) shows the vacuum forming process of a board material, (c) is a molded body. Is shown. It is explanatory drawing for demonstrating the manufacturing method of the conventional molded body, (a) shows the molding process of a board material, (b) shows the pressing process of a board material, (c) is a base material and a skin material. The vacuum forming process of is shown.

The matters shown here are for exemplifying and exemplifying embodiments of the present invention, and are considered to be the most effective and effortless explanations for understanding the principles and conceptual features of the present invention. It is stated for the purpose of providing what seems to be. In this regard, it is not intended to show structural details of the invention beyond a certain degree necessary for a fundamental understanding of the invention, and some embodiments of the invention are provided by description in conjunction with the drawings. It is intended to clarify to those skilled in the art how it is actually realized.

A method for producing a molded product according to the present embodiment is, for example, as shown in FIG. 3, a board material (8) containing a plant fiber (2) and a thermoplastic resin (3a) for binding the plant fibers to each other. A method for producing a molded product (1) in which a non-breathable skin material (5) is adhered to the surface of a base material (4) made of the same material, wherein the skin material (5) is formed on the surface by a thermoplastic resin (3a). It includes a heating step of heating and softening the bonded board material (8) and a vacuum forming step of shaping the heat-softened board material (8) by vacuum forming to form a molded body (1). ..

In the heating step, as long as the board material (8) is heated and softened, the type and temperature of the heating are not particularly limited. In the heating step, for example, as shown in FIG. 3A, at least the surface side of the board material (8) opposite to the skin material (5) can be heated. Further, the heating step can be carried out using, for example, a far-infrared heater (9), hot air, a hot plate, or the like. Further, the heating temperature in the heating step may be any temperature as long as the thermoplastic resin (3a) can be melted, and is not particularly limited, but is usually 150 to 280 ° C. In particular, when the thermoplastic resin is made of polypropylene resin, it is preferably 170 to 250 ° C., more preferably 180 to 240 ° C., and particularly preferably 190 to 230 ° C.

In the vacuum forming step, the type of vacuum forming is not particularly limited as long as the board material (8) is shaped by vacuum forming to form the molded body (1). In the vacuum forming step, for example, as shown in FIG. 3 (b), the board is vacuum-sucked by pressing the molding die (12) against the surface side of the board material (8) opposite to the skin material (5). The material (8) can be vacuum formed. Further, the molding die (12) may be, for example, a convex mold or a concave mold. Further, as a type of vacuum forming, for example, an air slip method, a plug assist method and the like can be mentioned. Further, it may be pressure-pneumatic molding in which compressed air is applied at the same time as vacuum forming.
The molded product (1) obtained in the vacuum forming step may be used as a product as it is, or may be used as a product after being subjected to post-processes such as trimming and hole processing, if necessary.

The molded body (1) is not limited in shape, size, use, etc., but is preferably formed in a tray shape having a relatively loose shape because the board material is formed by vacuum forming.
Examples of the molded body include interior materials and exterior materials of automobiles, railroad vehicles, ships, airplanes, and the like. Of these, as interior and exterior materials for automobiles, specifically, seat backboards, package trays, door base materials, pillar garnishes, switch bases, quarter panels, side panels, armrests, automobile door trims, seat structural materials, and ceilings. Materials, console boxes, automotive dashboards, various instrument panels, deck trims, bumpers, spoilers, cowlings, etc.
Since the molded body (1) is lightweight and has high rigidity, it is particularly useful as an interior material for automobiles. In particular, since the seat backboard is a plate-like material having a relatively gentle shape, it is particularly suitable as a molded body by vacuum forming. Further, since the package tray is a plate-like product having a large size of, for example, 1,500 × 1,300 mm or 1,300 × 700 mm and a relatively gentle shape, it is particularly suitable as a molded product by vacuum forming.

In addition to the above-mentioned molded products, examples thereof include interior materials and exterior materials for buildings, furniture, and the like. That is, door covering materials, door structural materials, desks, chairs, shelves, covering materials for various furniture such as chests of drawers, and the like can be mentioned. In addition, a packaging body, an accommodating body such as a tray, a protective member, a partition member, and the like can be mentioned.

The plant fiber (2) constituting the board material (8) is a fiber extracted from a plant body (stem, stem, branch, leaf, root, etc.), and is a leaf vein plant fiber, a bast plant fiber, and a woody substance. Includes plant fibers and the like.
The plant body that is the source of plant fiber is not limited, for example, kenaf, hemp, jute hemp, ramie, flax, Manila hemp, sisal hemp, ganpi, sansho, 楮, banana, pineapple, coconut, corn, sugar cane, etc. Examples include bagasse, palm, papyrus, reeds, esparto, survivorgrass, wheat, rice, bamboo, various coniferous trees (sugi and hinoki, etc.), broadleaf trees and cotton. As these plants, only one kind may be used, or two or more kinds may be used in combination.
Among the above-mentioned plants, kenaf, hemp, jute hemp, ramie, and flax (flux) are preferable as the plant body which is the source of the plant fiber, and kenaf is particularly preferable, and further, kenaf is preferable. Kenaf fibers collected from the kenaf bast are particularly preferred.

The specific shape of the plant fiber (2) is not limited, but for example, the average fiber length can be 10 to 200 mm (further 20 to 170 mm, particularly 25 to 150 mm, especially 30 to 90 mm). This average fiber length is based on JIS L1015, and single fibers are randomly taken out one by one by the direct method, straightened without stretching, and the fiber length is measured on a scale, for a total of 200 fibers. It is the average value of the measured values.
The fiber diameter of the plant fiber is also not limited, but for example, the average fiber diameter can be 1 to 2500 μm (further, 10 to 2000 μm, particularly 100 to 1750 μm, particularly 200 to 1500 μm). This average fiber diameter is an average value of values measured using an optical microscope at the center of each of the 200 single fibers used for measuring the average fiber length in the length direction.

The thermoplastic resin (3a) constituting the board material (8) functions as, for example, a binder resin for binding the plant fibers (2) to each other, and the skin material (5) is formed on the surface of the board material (8). Functions as a binder resin to be bonded.
The type of thermoplastic resin is not limited, and well-known ones can be used.
As the thermoplastic resin, a crystalline resin having a large molding shrinkage rate is mainly targeted. The crystalline resin has a crystalline portion in which molecules are regularly arranged when the temperature of the molten resin drops to the crystallization temperature and solidifies.
Specific examples of the crystalline resin include thermoplastic resins such as polyolefin resins, polyester resins, polyamide resins, fluororesins, polyacetal resins, polyphenylene sulfide resins, and polyether ether ketone resins. Only one of these may be used, or two or more thereof may be used in combination.
However, the thermoplastic resin is not limited to the crystalline resin, but also includes an amorphous resin having a small molding shrinkage rate. Specific examples of the amorphous resin include polyvinyl chloride, polystyrene, polymethylmethacrylate, ABS (acrylonitrile-butadiene-styrene), and polycarbonate.

Examples of the above-mentioned polyester resin include polylactic acid, aliphatic polyester resin, aromatic polyester resin and the like. Examples of the aliphatic polyester resin include polycaprolactone and polybutylene succinate. Examples of the aromatic polyester resin include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.
Examples of the above-mentioned fluororesin include polytetrafluoroethylene and ethylene / tetrafluoroethylene copolymers.

Among the above-mentioned, as the thermoplastic resin, a polyolefin resin is preferable.
Examples of the olefin monomer constituting the polyolefin resin include ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene and 1-. Examples include hexene and 1-octene. Only one of these may be used, or two or more thereof may be used in combination.
That is, examples of the polyolefin resin include polyethylene resins such as an ethylene homopolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, and an ethylene / 4-methyl-1-pentene copolymer. ..
These polyethylene resins are resin in which 50% or more of the total number of constituent units is derived from ethylene. Further, polypropylene resins such as a propylene homopolymer, a propylene / ethylene copolymer (propylene / ethylene random copolymer, etc.), and a propylene / 1-butene copolymer can be mentioned. These polypropylene resins are resin in which 50% or more of the total number of constituent units is derived from propylene.

The board material (8) can be made of only the plant fiber (2) and the thermoplastic resin (3a), but if necessary, a plasticizer (plasticizer for the binder resin), an antioxidant, and a difficulty It can contain other components such as flame retardants, lubricants, fungicides, antibacterial agents, fillers and colorants.
When the board material contains other components, the content of the other components is usually 0.1 to 10 parts by mass when the total mass of the plant fiber and the thermoplastic resin is 100 parts by mass.

The ratio of the total amount of the plant fiber (2) contained in the board material (8) to the total amount of the thermoplastic resin (3a) is not limited, but the total amount of the total amount of the plant fiber and the total amount of the thermoplastic resin is 100 mass. In the case of%, the ratio of the total amount of plant fibers can be 10 to 90% by mass, preferably 15 to 85% by mass, more preferably 20 to 80% by mass, still more preferably 25 to 75% by mass. Preferably, 30 to 70% by mass is particularly preferable, 35 to 65% by mass is more preferable, and 40 to 60% by mass is particularly preferable.

The thickness of the board material (8) is not particularly limited and may be an appropriate thickness depending on the intended use of the molded product, but is usually 0.5 to 200 mm, particularly 0.5 to 80 mm. can. When the thickness of the base material is 0.5 to 200 mm, it can be used as a lightweight member having sufficient strength in many applications.

The basis weight of the board material (8) is not particularly limited, and may be, for example, 200 to 3000 g / m ² . The basis weight is more preferably a 400~2500g / ^{m 2,} further preferably a 600~2000g / ^{m 2,} it is preferable that further 800~1800g / ^{m 2.}

The skin material (5) is a sheet-like member that is adhered to one surface of the board material (8) with a thermoplastic resin (3a). The skin material (5) is non-breathable for vacuum forming the breathable board material (8) containing the plant fiber (2). Further, as the skin material, for example, a synthetic resin sheet such as vinyl chloride resin or TPO (thermoplastic olefin) resin, leather such as synthetic leather or genuine leather can be used. As the skin material, for example, a single sheet material of a synthetic resin sheet or a laminated sheet material in which a cushion layer such as polypropylene foam, polyethylene foam, or polyurethane foam is lined on the back surface of the single sheet material can be used.

As a method for producing a molded product according to the present embodiment, for example, as shown in FIGS. 1 and 2, the raw cotton of the spot fiber (2) and the raw cotton of the thermoplastic resin fiber (3) are mixed and matted. The mat material molding process for molding the material (7) and the mat material and the skin material are pressed (compressed) in the thickness direction with the skin material (5) placed on the surface side of the heated mat material (7). Then, a form including a board material forming step of forming the board material (8) can be mentioned.

In the mat material molding step, for example, as shown in FIG. 1, the raw cotton of the plant fiber (2) and the raw cotton of the thermoplastic resin fiber (3) are mixed, and then the plant fiber and the thermoplastic resin fiber are entangled. The matte material (7) can be formed. As the cotton mixing method, for example, there are a dry method and a wet method, but since plant fibers have hygroscopicity, when the cotton is mixed by a wet method such as a papermaking method, an advanced drying step is required. , A dry method that can more easily mix cotton is preferable. Further, examples of the dry method include an air ray method and a card method, but an air ray method that can efficiently mix cotton with a simpler device is preferable. In the air ray method, each fiber is suspended by an air flow and then deposited on a conveyor belt or the like, and plant fibers and resin fibers are mixed and deposited to form a web.

In the air ray method, the form of the web is not particularly limited, and the web may consist of only one layer of web formed by being mixed and deposited, or two or more layers of web may be laminated. The thickness of the mat material can be adjusted by the number of layers of the web, and the basis weight of the board material produced thereby can also be adjusted. Further, in the web, the plant fiber and the thermoplastic resin fiber are more sufficiently entangled and entangled so as to be mixed to form a mat material. The entanglement method is not particularly limited, and examples thereof include a needle punch method, a stitch bond method, and a water punch method.

The basis weight and thickness of the mat material (7) and the density determined by the basis weight and the thickness are not particularly limited, but the basis weight is usually 400 to 3000 g / m ² , preferably 600 to 2000 g / m ² . The thickness is preferably 5 mm or more (usually 50 mm or less), and more preferably 8 to 40 mm, particularly 10 to 30 mm. Furthermore, the density is 0.3 g / cm ³ or less (typically, 0.05 g / cm ³ or higher). This density can be measured according to JIS K7112 (a method for measuring the density and specific gravity of plastic-non-foamed plastic).

The plant fiber (2) constituting the mat material (7) has the same composition as the plant fiber (2) constituting the board material (8). Further, as the material of the thermoplastic resin fiber (3) constituting the mat material (7), for example, the material exemplified by the thermoplastic resin (3a) constituting the board material (8) can be applied.
The average fiber length of the thermoplastic resin fiber is not particularly limited, but is preferably 10 mm or more. When the average fiber length is 10 mm or more, it is easy to mix cotton with plant fibers (in particular, entanglement between fibers is likely to be formed), and it is easy to improve the bending strength of the board material. The average fiber length is more preferably 10 to 150 mm, more preferably 20 to 100 mm, and particularly preferably 30 to 70 mm. Further, the thermoplastic resin fiber preferably has a shorter fiber length than the plant fiber. The method for measuring the average fiber length is the same as that for plant fibers.

The fineness of the thermoplastic resin fiber (3) is also not particularly limited, but the fineness is preferably 1 to 100 dtex. With a fineness in this range, it is easy to mix cotton with plant fibers, and each fiber can be dispersed more uniformly. The fineness is more preferably 1 to 50 dtex, more preferably 1 to 20 dtex, particularly 3 to 10 dtex. The fiber diameter of the resin fiber having a fineness of 3 to 10 dtex depends on the resin used, but is, for example, about 3.8 to 37.5 μm when a polypropylene resin and / or an ethylene-propylene block copolymer resin is used. .. The method for measuring the fiber diameter is the same as that for plant fibers.

The mass ratio of the plant fiber (2) and the thermoplastic resin fiber (3) is also not particularly limited, but when the total of the plant fiber and the thermoplastic resin fiber is 100 mass%, the plant fiber is 30 to 95 mass%. Is preferable. Within this range, a board material having excellent bending strength and shapeability can be used. The content of this plant fiber is more preferably 40 to 85% by mass, more preferably 45 to 75% by mass. Within such a range, physical properties such as bending strength and shapeability are further improved. The mass of the plant fiber shall be a measured value at an equilibrium moisture content of 10%.

In the board material forming step, for example, as shown in FIG. 2A, at least the surface side of the mat material (7) on which the skin material (5) is arranged is heated, and the heated mat material (7) is heated. The board material (8) can be formed by pressurizing the mat material and the skin material in the thickness direction with the skin material (5) arranged on the surface.
In the board material molding step, the heating temperature of the mat material (7) may be any temperature as long as it can melt the thermoplastic resin fiber (3), and is not particularly limited, but is usually 150 to 280 ° C. In particular, when the thermoplastic resin fiber is made of polypropylene resin, the temperature is preferably 170 to 250 ° C, more preferably 180 to 240 ° C, and particularly preferably 190 to 230 ° C. Further, the mat material (7) can be heated by using, for example, a hot plate (20), a far-infrared heater, hot air, or the like. The pressing force of the mat material (7) is also not particularly limited, but is preferably 0.5 to 8 MPa, more preferably 0.7 to 5 MPa, and particularly preferably 1 to 4 MPa. By compressing by this pressurization, the plant fibers can be bound to each other more firmly.
It should be noted that heating and pressurization may be performed at the same time, or may be continuously pressurized after heating, and after this heating and pressurization, the board material is usually at an environmental temperature, for example, 20 to 30 ° C. It is cooled to a degree.

The reference numerals in parentheses of each configuration described in the above-described embodiment indicate the correspondence with the specific configurations described in the examples described later.

Hereinafter, the present invention will be specifically described with reference to the drawings.

As shown in FIG. 3C, the method for producing a molded product according to the present embodiment is a molded product in which a non-breathable skin material 5 is adhered to one surface of a base material 4 made of a plate-shaped board material 8. It is a method of manufacturing 1. The molded body 1 (that is, the base material 4) is formed in a tray shape. Further, as shown in FIG. 2C, the board material 8 contains a plant fiber 2 (kenaf fiber or the like) and a thermoplastic resin 3 (polypropylene resin fiber or the like) that binds the spot fibers 2 to each other. There is. Further, the skin material 5 is formed of a non-breathable synthetic resin sheet.

The method for producing a molded product includes a mat material molding step, a board material molding step, a heating step, and a vacuum forming step described below.

As shown in FIG. 1, the mat material forming step is a step of forming the mat material 7 by mixing the raw cotton of the straight fiber 2 and the raw cotton of the thermoplastic resin fiber 3. In this mat material forming step, the raw cottons of the fibers 2 and 3 are mixed to form a web and laminated, and then the fibers 2 and 3 are entangled with each other by a needle punch or the like to form the mat material 7.

In the board material forming step, as shown in FIG. 2, the mat material 7 and the skin material 5 are pressurized (compressed) in the thickness direction with the skin material 5 arranged on one surface of the heated mat material 7. This is a step of forming the board material 8 (also referred to as “pre-board”). In this board material forming step, one surface side of the mat material 7 is heated by a hot plate or the like, and then the mat material 7 and the skin material 5 are cold-pressed with the skin material 5 arranged on one surface side of the mat material 7. The board material 8 is obtained by pressurizing by molding.
According to the board molding process, the thermoplastic resin fibers 3 are melted and cooled and solidified by heating and compressing the mat material 7, so that the plant fibers 2 are bound to each other by the thermoplastic resin 3a and the skin material 5 is adhered to the surface. The finished board material 8 is obtained.

As shown in FIG. 3A, the heating step is a step of heating and softening the board material 8 to which the skin material 5 is adhered to one surface by the thermoplastic resin 3a. In this heating step, both surface sides of the board material 8 are heated by a far-infrared heater 9 or the like.

As shown in FIG. 3B, the vacuum forming step is a step of shaping the heat-softened board material 8 by vacuum forming to form the molded body 1. In this vacuum forming step, the board material 8 is set in the vacuum forming machine 11, the molding die 12 is pressed against the surface side of the board material 8 opposite to the skin material 5, and the molding die 12 is opened from the hole 12a opened in the molding surface of the molding die 12. The board material 8 is shaped by vacuum suction, and a molded product 1 in which the skin material 5 is adhered to one surface of the base material 4 having a predetermined shape is obtained.

In the molded product 1 obtained in the vacuum forming step, as shown in FIG. 3C, the plant fibers 2 are bonded to each other by the thermoplastic resin 3a, and the skin material 5 is attached to the surface of the base material 4. Is glued. Further, the molded body 1 obtained in the vacuum forming step is used as a product by subjecting post-processes such as trimming and hole processing as necessary.

Next, the action and effect of the method for producing the molded product of this example will be described.
According to the method for producing a molded product of this embodiment, a heating step of heating and softening a board material 8 having a skin material 5 adhered to a surface by a thermoplastic resin 3a and a vacuum forming of the heat-softened board material 8 are performed. It includes a vacuum forming step of shaping and molding the molded body 1. As a result, the molded product 1 can be manufactured at a reduced cost by reducing the process and material costs. Further, since the board material 8 to which the skin material 5 is adhered by the thermoplastic resin 3a is used, an adhesive for adhering the skin material is not required as in the conventional case, and the volatile organic compounds (VOC) are reduced. can. Further, since the molded body 1 is obtained by shaping the shape of the board material 8 by vacuum forming, a dedicated press machine is not required as in the conventional case.

Further, in this embodiment, a mat material molding step of mixing the raw cotton of the straight fiber 2 and the raw cotton of the thermoplastic resin fiber 3 to form the mat material 7, and a skin material on the surface side of the heated mat material 7. The board material forming step of forming the board material 8 by pressurizing the mat material 7 and the skin material 5 in the thickness direction in the state where the 5 is arranged is included. As a result, the thermoplastic resin fibers 3 are melted and cooled and solidified by the heat compression of the mat material 7, so that the plant fibers 2 are bound to each other by the thermoplastic resin 3a and the skin material 5 is adhered to the surface of the board. Material 8 is obtained.

In particular, in this embodiment, the skin material 5 is simultaneously bonded at the time of molding the board material 8 and the shape is formed by vacuum forming, so that the conventional bonding process and the bonding layer (that is, the adhesive and the primer) can be obtained. It becomes unnecessary, and it is possible to minimize the process and space, reduce the material, and reduce the cost by using general-purpose equipment (that is, a vacuum forming machine).

Further, in this embodiment, the skin material 5 is formed of a synthetic resin sheet. Thereby, the board material 8 can be easily formed by vacuum forming.

Further, in this embodiment, the molded body 1 is formed in a tray shape. As a result, the molded product 1 having a relatively loose shape (for example, a seat backboard, a package tray, etc.) can be efficiently manufactured.

It should be noted that the present invention is not limited to the above-mentioned examples, and various modifications can be made within the scope of the present invention according to the purpose and application. That is, in the above embodiment, a method for producing a molded product including a mat material molding step, a board material molding step, a heating step and a vacuum molding step has been exemplified, but the present invention is not limited to this, and for example, one surface is made of a thermoplastic resin 3a. By preparing the board material 8 to which the skin material 5 is adhered in advance, a method for producing a molded product that does not include the mat material molding step and the board material molding step but includes the heating step and the vacuum molding step may be used.

Further, in the above embodiment, the embodiment in which the mat material 7 is pressed with the skin material 5 arranged on the surface of the mat material 7 after heating is illustrated, but the present invention is not limited to this, and for example, the surface of the mat material 7 is covered. The mat material 7 may be heated and compressed with the skin material 5 arranged.

Further, in the vacuum forming step of the above-described embodiment, the vacuum forming may be performed while applying compressed air into the pneumatic box 13 (see FIG. 3B).

The above examples are for illustration purposes only and are not to be construed as limiting the invention. Although the present invention has been described with reference to typical embodiments, the language used in the description and illustration of the invention is understood to be descriptive and exemplary rather than restrictive. As described in detail here, modifications can be made within the scope of the appended claims without departing from the scope or spirit of the invention in that form. Although specific structures, materials and examples have been referred to herein in detail of the invention, it is not intended to limit the invention to the disclosures herein, but rather the invention is claimed in the accompanying claims. It shall cover all functionally equivalent structures, methods and uses within the scope.

The present invention is not limited to the embodiments detailed above, and various modifications or modifications can be made within the scope of the claims of the present invention.

The present invention is widely used as a technique for producing a molded product in which a non-breathable skin material is adhered to the surface of a base material molded from a board material containing plant fibers and a thermoplastic resin that binds the plant fibers to each other. It will be used.

1; molded body, 2; plant fiber, 3; thermoplastic resin fiber, 3a; thermoplastic resin, 4; base material, 5; skin material, 7; mat material, 8; board material.

Claims (4)

A method for producing a molded product in which a non-breathable skin material is adhered to the surface of a base material made of a board material containing plant fibers and a thermoplastic resin that binds the plant fibers to each other.
A heating step of heating and softening the board material having the skin material adhered to the surface by the thermoplastic resin, and a heating step.
A method for producing a molded product, which comprises a vacuum forming step of shaping the heat-softened board material by vacuum forming to form the molded product. A mat material molding step of mixing the raw cotton of the spot fiber and the raw cotton of the thermoplastic resin fiber to form a mat material, and
1 The method for producing a molded product according to. The method for producing a molded product according to claim 1 or 2, wherein the skin material is formed of a synthetic resin sheet. The method for producing a molded product according to any one of claims 1 to 3, wherein the molded product is formed in a tray shape.

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