JP2871510B2 - Method for producing fiber molded product - Google Patents

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 molded product suitable for, for example, interior materials of 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 formed into a predetermined shape by cold pressing. A method for manufacturing an automobile interior material has been provided (Japanese Patent Application Laid-Open No. 3-61028).

[0003]

However, in the above method, when the mat is heated to soften and expand the expandable thermoplastic resin fibers, the mat loses its shape. In addition, there is a problem that the amount of trimming after cold pressing is large and a large amount of cuts is generated.

[0004]

Means for Solving the Problems According to the present invention, as a means for solving the above-mentioned conventional problems, a mat containing foamable fibers is set in a molding die, and the mat is formed in the molding die. By injecting hot air and / or steam into the
And the fiber molded article by softening foam the foamable textiles Ma Tsu bets, there is provided a method for producing a fiber molded article to cool the fiber molded product in a forming die.

[0005] The mat comprising a foamable fibers used in the present invention [expandable fiber mat containing] effervescent fibrous web or needle punched nonwoven fabric or a mixed fiber of foamable fibers and other fibrous web or needle, It is a punched nonwoven fabric. The foamable fiber is a fiber of a thermoplastic resin mixed with a foaming agent or a composite fiber coated on the surface of a non-foamable fiber with a thermoplastic resin mixed with a foaming agent, and the thermoplastic resin is, for example, polyethylene, Polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyester, polyamide, polyurethane, acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-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-NN.N ' -Dinitrosoterephthalamide, dinitrosopentadi Down,
Examples include diazoaminobenzene, 1.1′-azobisformamide, p-toluenesulfonic acid amide, azodicarbonamide, benzenesulfonylhydrazide, toluenesulfonylhydrazide, p-toluenesulfonylsemicarbazide, trihydrazinotriazine and the like. The non-foamable fibers are, for example, synthetic fibers such as polyester fiber, polyethylene fiber, polypropylene fiber, polyamide fiber, acrylic fiber, urethane fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, and acetate fiber, or pulp, cotton, wool. , Natural fiber such as palm fiber, hemp fiber, bamboo fiber or glass fiber, ceramic fiber, carbon fiber,
It is an inorganic fiber such as a metal fiber. Further, as the other fibers to be mixed with the expandable fibers, the same as the non-expandable fibers are used, and among the non-expandable fibers, particularly preferable are glass fibers, ceramic fibers, carbon fibers,
There are rigid fibers such as metal fibers, bamboo fibers, coconut fibers, and hemp fibers. The thickness of the foamable fiber and other fibers is 0.02 to
1.0 mm and a length of 5 to 200 mm are desirable. When the foamable fiber is mixed with another fiber, the mixing weight ratio of the foamable fiber and the other fiber is 2: 8 to 8: 2. It is desirable to be about. The foamable fibers and other fibers may be used in combination of two or more. Further, the basis weight of the foamable fiber mat is preferably about 300 to 1500 g / m ² .

[0006]

The mat containing the expandable fiber is cut into a size of a substantially desired fiber molded product and set in a molding die. In the molding die, the mat containing the expandable fiber is heated with hot air and / or steam. It is injected, and included in the mat
Re that it is uniformly heated to softening foaming temperature or higher of the thermoplastic resin foaming agent mixed with the foamable fibers. In this way, the thermoplastic resin mixed with the foaming agent of the expandable fiber constituting the mat including the expandable fiber is softened and foamed to bind the expandable fibers to each other or the expandable fiber and other fibers, The mat including the expandable fiber is formed into a predetermined shape. After molding, the molded product is cooled by sending cooling water through the molding die or by blowing cold air or cold water onto the mat, and then taking out the molded product from the molding die. As described above, since the mat containing the expandable fiber is softened and foamed while the size is regulated by the size of the target fiber molded product in the molding die, trimming of the molded product is not necessary in principle, and trimming is not necessary. Even if it occurs, the generation of cut ends is extremely small.

[0007]

Embodiment An embodiment of the present invention is shown in FIGS. The mat (1) containing expandable fibers shown in FIG. 1 is cut to the size of a substantially desired fiber molded product, and mounting holes (2, 3, 4, 5) for lamps and the like are opened by punching. . The scraps generated at this time can be recycled to the mat (1) containing the expandable fiber to produce a cheaper product. The mat (1) is set in a mold (6) shown in FIG. The molding die (6) is composed of an upper die (7) and a lower die (8). 9,10) are provided respectively,
Further, cooling water channels (11, 11) are provided inside the mold surfaces of the upper mold (7) and the lower mold (8).
12) is provided. When the mat (1) is set in the mold (6), hot air or steam from the introduction path (9, 10),
Alternatively, hot air and steam are both injected. The steam may be further heated. The thermoplastic resin mixed with the foaming agent of the foamable fiber constituting the mat (1) softens and foams by the injection of the hot air and / or steam,
When the expandable fibers are used together or when other fibers are used in combination, the expandable fibers and other fibers are bound to form the mat (1) into a predetermined shape. At this time, the mat (1) expands due to softening and foaming of the thermoplastic resin mixed with the foaming agent,
The expansion is regulated in the molding die (6), and a molded product having a size substantially equal to the intended molded product is obtained. After molding, the molded product is cooled by introducing cooling water into the cooling channels (11, 12) of the molding die (6), or
Alternatively, cool air may be blown from the introduction paths (9, 10) or cooling water may be injected. After cooling, the molded product is removed from the mold (6). In this way, a ceiling material (1A) for an automobile as shown in FIG. 3 is obtained.

[0008] In the following, foamable fibers used in the present embodiment are included.
The composition example of a non-mat. Composition Example 1 Needle-punched nonwoven fabric of a 6: 4 weight ratio mixed fiber of polypropylene fiber and glass fiber mixed with 5% by weight of azodicarbonamide (basis weight 700 g / m ² ) Composition Example 2 p-toluenesulfonic acid amide on glass fiber surface Punched non-woven fabric of a polyvinyl chloride fiber mixed with 5% by weight of dinitrosopentadiene (based weight: 600 g / m ² )
m ² )

[0009]

Therefore, in the present invention, a lightweight and rigid fiber molded product can be manufactured with the occurrence of cut off being minimized. The method of the present invention is particularly useful when applied to interior materials such as ceiling materials, door trims, trunk room trims and rear parcels of automobiles.

[Brief description of the drawings]

 1 to 3 show one embodiment of the present invention.

FIG. 1 is a perspective view of a foamable fiber mat.

FIG. 2 is an explanatory view at the time of molding.

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

[Explanation of symbols]

1 Mat containing foamable fiber 1A Ceiling material 6 Mold 7 Upper die 8 Lower die 9,10 Introductory channel 11,12 Cooling water channel

Claims (4)

(57) [Claims] 1. A set in a mold a mat comprising a foamable fibers, foaming textiles of the Ma Tsu bets by injecting hot air and / or steam 該Ma Tsu preparative within forming die
And the fiber molded article by softening foaming method for producing a fiber molded article which is characterized by cooling the fiber molded product in a forming die 2. A mat containing the expandable fiber comprises an expandable fiber .
2. A web or needle-punched non-woven fabric comprising:
Method for producing fiber molded product according to 3. The method according to claim 1, wherein the mat containing the expandable fiber is a web of mixed fibers of the expandable fiber and another fiber or a needle-punched nonwoven fabric. 4. Other fibers are glass fiber, ceramic fiber,
The method for producing a fiber molded product according to claim 3, wherein the fiber is one or more rigid fibers selected from carbon fibers, metal fibers, bamboo fibers, palm fibers, and hemp fibers.