JPH08199462A - Production of fiber molding - Google Patents

Abstract

PURPOSE: To provide a lightweight fiber molding having a high rigidity by setting an expandable fiber mat in a prescribed forming mold, then jetting hot air and/or steam, expanding and forming the mat and further cooling the formed mat. CONSTITUTION: An expandable fiber mat 1 is formed of a web or a needle punched nonwoven fabric comprising expandable fibers such as polypropylene fibers containing 5wt.% azodicarbonamide or a mixture of the expandable fibers with one or two or more rigid, fibers selected from glass fibers, ceramic fibers, carbon fibers, metallic fibers, bamboo fibers, coconut fibers, hemp fibers, etc. The resultant expandable fiber mat is then set in a prescribed forming mold 6 comprising a top force 7 and a bottom force 8 and hot air or steam or both are then jetted through introduction passages 9 and 10 to soften and expand the mat 1. Thereby, a molding is formed and cooling water is introduced into cooling water passages 11 and 12 to cool the molding. The cooled molding is subsequently taken out of the forming mold 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber molding suitable for interior materials for automobiles.

[0002]

2. Description of the Related Art Conventionally, a mat of mixed fibers obtained by mixing an expandable thermoplastic resin fiber with an inorganic fiber is heated to soften and expand the expandable thermoplastic resin fiber, and then molded into a predetermined shape by cold pressing. A method for manufacturing an automobile interior material is provided (Japanese Patent Laid-Open No. 3-61028).

[0003]

However, in the above method, when the mat is heated to soften and expand the expandable thermoplastic resin fiber, the mat loses its shape, and therefore a non-woven fabric is lined to prevent it. In addition, there is a problem in that the trimming amount after cold pressing is large and a large amount of edge cutting occurs.

[0004]

As a means for solving the above-mentioned conventional problems, the present invention sets an expandable fiber mat in a mold, and heats the expandable fiber mat in the mold with hot air and / or Alternatively, the present invention provides a method for producing a fiber molded product, which comprises spraying water vapor to soften and foam the expandable fiber mat to form a fiber molded product, and cooling the fiber molded product in the mold.

[Expandable Fiber Mat] The expandable fiber mat used in the present invention is a web of expandable fibers or a needle-punched nonwoven fabric, or a web of mixed fibers of expandable fibers and other fibers or a needle-punched nonwoven fabric. . The expandable fiber is a fiber of a thermoplastic resin mixed with a foaming agent or a composite fiber in which a thermoplastic resin mixed with a foaming agent is coated on the surface of a non-expandable fiber, and the thermoplastic resin is, for example, polyethylene, Polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyester, polyamide, polyurethane, acrylonitrile-butadiene-styrene copolymer, methylmethacrylate-butadiene-styrene copolymer, etc., and a foaming agent mixed with the thermoplastic resin. For example, 2,
2'-azobisisobutyronitrile, p, p'-oxybis (benzenesulfonylhydrazide), p, p'-oxybis (benzenesulfonylsemicarbazide), N.
N′-dimethyl-N · N′-dinitrosoterephthalamide, dinitrosopentadiene, diazoaminobenzene,
Examples include 1.1'-azobisformamide, p-toluenesulfonic acid amide, azodicarbonamide, benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, and trihydrazinotriazine. Further, the non-foaming fibers are, for example, polyester fibers, polyethylene fibers, polypropylene fibers, polyamide fibers, acrylic fibers, urethane fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, synthetic fibers such as acetate fibers, or pulp, cotton, wool. Natural fibers such as palm fibers, hemp fibers, and bamboo fibers, or inorganic fibers such as glass fibers, ceramic fibers, carbon fibers, and metal fibers. Further, as the other fibers mixed with the expandable fibers, the same fibers as the non-expandable fibers are used, and particularly preferable ones among the non-expandable fibers are glass fibers, ceramic fibers, carbon fibers and metal fibers. There are rigid fibers such as, bamboo fiber, coconut fiber and hemp fiber. The foamable fiber and other fibers have a thickness of 0.02 to 1.0 mm and a length of 5 to
200 mm is preferable, and when mixing the expandable fiber and the other fiber, it is preferable that the mixing weight ratio of the expandable fiber and the other fiber is about 2: 8 to 8: 2.
Further, the expandable fiber and the other fiber may be used in combination of two or more kinds. Furthermore, the basis weight of the expandable fiber mat is 300 to 1
About 500 g / m ² is desirable.

[0006]

The expandable fiber mat is cut into the size of the fiber molded product of interest and set in the mold, and the expandable fiber mat is sprayed with hot air and / or steam in the mold. The thermoplastic resin mixed with the foaming agent of the expandable fiber constituting the mat is uniformly heated to a temperature equal to or higher than the softening foaming temperature. Thus, the thermoplastic resin mixed with the foaming agent of the expandable fiber constituting the expandable fiber mat softens and expands to bind the expandable fibers to each other or to the expandable fiber and another fiber, The fiber mat is molded into a predetermined shape. After the molding, cooling water is passed through the molding die, or cold air or cold water is sprayed on the mat to cool the molding, and then the molding is taken out of the molding die. In this way, since the expandable fiber mat is softened and foam-molded by controlling the dimensions to the size of the target fiber molded product in the molding die, it is not necessary to trim the molded product in principle, and The occurrence of scraps is extremely small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is shown in FIGS. FIG.
The expandable fiber mat (1) shown in (1) is cut to the size of the target fiber molding, and the holes for mounting lamps (2, 3, 4, 5) and the like are opened by punching. The scraps generated at this time can be recycled to the expandable fiber mat (1) to manufacture a cheaper product. The mat (1) is set in the mold (6) shown in FIG. The mold (6) comprises an upper mold (7) and a lower mold (8), and the upper mold (7)
In the lower mold (8), there are provided hot air or steam introduction paths (9, 10) opening at various points on the mold surface, and the upper mold (7)
And cooling water channels (11, 12) are provided inside the mold surface of the lower mold (8). When the mat (1) is set in the molding die (6), hot air or steam, or hot air and steam are both injected from the introduction passages (9, 10). The steam may be heated further. When the thermoplastic resin mixed with the foaming agent of the expandable fibers constituting the mat (1) is softened and foamed by the above hot air and / or steam injection, and the expandable fibers are used together or other fibers are used in combination. The mat (1) is molded into a predetermined shape by binding the expandable fiber and another fiber. At this time, the mat (1) expands due to softening and foaming of a thermoplastic resin mixed with a foaming agent, but the expansion is restricted in the molding die (6), and a molded product having a size of a substantially intended molded product is obtained. . After molding, cooling water is introduced into the cooling water channels (11, 12) of the molding die (6) to cool the molded article, or
Cold air may be blown from (9, 10) or cooling water may be sprayed. After cooling, the molded product is taken out from the molding die (6). In this way, an automobile ceiling material (1A) as shown in FIG. 3 is obtained.

The composition examples of the expandable fiber mat used in this example are shown below. Composition Example 1 Needle punched non-woven fabric of a mixed fiber of polypropylene fiber and glass fiber mixed with 5% by weight of azodicarbonamide in a ratio of 6: 4 (weight per unit area: 700 g / m ² ) Composition Example 2 p-toluenesulfonic acid amide on the surface of glass fiber Polyethylene-coated foamable fiber web mixed with 7% by weight of the composition (Basis weight: 500 g / m ² ) Composition example 3 Polyvinyl chloride fiber needle punched non-woven fabric (Basis weight: 600 g / m ^{2 of} unit weight: 500 g / m ² )
m ² )

[0009]

According to the present invention, therefore, a lightweight and highly rigid fiber molded product can be manufactured while minimizing the occurrence of edge breakage. The method of the present invention is particularly useful when applied to interior materials such as automobile ceiling materials, door trims, luggage compartment trims, and rear parcels.

[Brief description of drawings]

 1 to 3 show an embodiment of the present invention.

FIG. 1 is a perspective view of an expandable fiber mat.

[Fig. 2] An explanatory view during molding

FIG. 3 is a perspective view of a molded ceiling material.

[Explanation of symbols]

 1 Expandable fiber mat 1A Ceiling material 6 Mold 7 Upper mold 8 Lower mold 9,10 Inlet channel 11,12 Cooling channel

Claims (4)

[Claims] 1. A foamable fiber mat is set in a molding die,
Hot air and / or the expandable fiber mat in the mold
Alternatively, a method for producing a fiber molded article is characterized in that the expandable fiber mat is softened and foamed by spraying steam to obtain a fiber molded article, and the fiber molded article is cooled in the mold. 2. The method for producing a fiber molded product according to claim 1, wherein the expandable fiber mat is a web of expandable fibers or a needle punched nonwoven fabric. 3. The method for producing a fiber molded article according to claim 1, wherein the expandable fiber mat is a web of mixed fibers of expandable fibers and other fibers or a needle punched nonwoven fabric. 4. The other fiber is glass fiber, ceramic fiber,
The method for producing a fiber molded article according to claim 3, which is one or more rigid fibers selected from carbon fiber, metal fiber, bamboo fiber, coconut fiber, and hemp fiber.