JPS6233258B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a molding material made of a thermoplastic synthetic resin mixed with organic fibers suitable for core materials for automobile interior materials, in which scraps such as felt are recycled as organic fibers. The objective is to efficiently obtain a molding material that is excellent not only in terms of performance but also in terms of economy.

Conventionally, molding materials used for the core material of automobile interior materials have often been based on wood powder made from crushed hardboard waste, mixed with thermoplastic synthetic resin. Powder has short fiber length and large particle size, so when used as a molding material, it has problems such as insufficient strength such as bending and impact resistance.

In the present invention, a fleece is formed after spreading organic fibers such as opened natural fibers, and heated air is passed through the fleece at a temperature at which the thermosetting synthetic resin is molded and solidified to form a bulky felt or a molded board. These bulky felts or molded boards are cut to have a fiber length of about 1 to 5 m/m, and with respect to about 50 to 30% by weight of the cut fibers,
Thermoplastic synthetic resin powder or granules from about 50 to
Mixed with 70% by weight, kneaded to form pellets, and extruded the pellets to form a sheet. Furthermore, when forming the sheet, a nonwoven fabric, cloth, film, etc. is pasted and adhered to one side. These molding materials have strengthened entanglement due to the fiber length of the mixed organic fibers, can be drawn three-dimensionally, have excellent strength such as flexibility and impact resistance, and are heat resistant. By using a large amount of plastic synthetic resin, it is possible to perform cold molding, which results in faster molding speeds than with thermoforming. Furthermore, it should be noted that the organic fibers can be made of bulky felt or scraps of molded boards, which is effective in terms of resource saving.

Embodiments of the present invention will be described below with reference to the drawings.
In Fig. 1, reference numeral 1 refers to a process in which a thermosetting synthetic resin such as a phenolic resin or a melamine resin is applied to spread cotton or other natural fibers as a binder to form a fleece. Bulky felt or molded board formed by permeating heated air at a temperature that allows molding and solidification, as well as scraps thereof, are fed to the cutting machine 2 and cut into fiber lengths of about 1 to 5 m/m. Cut the fiber into 3 pieces. Next, a thermoplastic synthetic resin 4 such as polypropyne or polyethylene is added at a ratio of about 50 to 70% by weight to about 50 to 30% by weight of the cut fibers, and the mixture is put into a kneader 5 as shown in FIG. to form pellets 6. As shown in FIG. 3, this pellet 6 is heated and melted and extruded using an extrusion molding machine 7 to form a sheet-like molding material 8, and then the sheet-like molding material 8 is cut into required dimensions with a cutter 9. Cut them into original fabrics 8a, stack them, etc., and keep them organized.

Next, a process of forming this original fabric 8a into a predetermined shape as a core material for a door will be described. Original fabric 8a
is carried into a heating furnace 11 by a conveyor 10 as shown in FIG. By lowering the upper mold 13b placed on the lower mold 13a of the molding machine 13 and performing cold pressing, the residual heat heated in the heating furnace 11 adapts to the molds of the upper mold 13b and the lower mold 13a. Therefore, a door core material having a predetermined shape can be formed.

Furthermore, in the method of the present invention, when forming the sheet-like molding material 8 shown in FIG. By supplying the molding material, it is possible to obtain a molding material having a skin material that is firmly adhered by being adhered by pressure during the process of passing through the rolls 15.

As described above, the method of the present invention involves kneading felt, etc., formed from natural fibers with a thermosetting synthetic resin as a binder, or cut pieces thereof, and a thermoplastic synthetic resin to form a sheet-like molding material. The thickness and weight of the resulting molding material can be varied freely. Further, since the obtained molding material uses a thermoplastic synthetic resin, it can be formed into a core material of a desired shape by cold molding, so that the molding speed can be increased compared to the thermoforming method. Furthermore, compared to conventional wood flour, the natural fibers have a longer fiber length, are intertwined, and are smaller in thickness, so the fibers are densely distributed within the resin and bend, resulting in excellent strength such as impact resistance. This makes it possible to economically produce materials suitable for core materials for automobile interior materials, as they can be deep-drawn.

[Brief explanation of the drawing]

FIGS. 1 to 3 are schematic diagrams of the manufacturing process of the molding material, and FIGS. 4 and 5 are schematic diagrams of the process of molding the molding material into a core material. 1... Bulky felt or molded board, 3...
Cut fiber, 4... thermoplastic synthetic resin, 6... pellet, 7... extrusion molding machine, 8... sheet-shaped molding material.

Claims (1)

[Scope of Claims] 1. A thermosetting synthetic resin is spread and adhered to opened organic fibers such as natural fibers to form a fleece, and the fleece is heated with heated air at a temperature at which the thermosetting synthetic resin is molded and solidified. The bulky felt or molded board is made to pass through, and the bulky felt or molded board has a fiber length of about 1 to 5 m/m.
The cut fibers are about 50 to 30% by weight.
In contrast, about 50 to 70% by weight of thermoplastic synthetic resin powder or granules are mixed in, kneaded to form pellets, and the pellets are extruded to form a sheet-like molding material. A method for producing a molding material made of a thermoplastic synthetic resin mixed with organic fibers. 2. A patent claim characterized in that when forming a sheet-like molding material by extrusion molding pellets, a sheet-like material such as a nonwoven fabric, cloth, or film is integrally laminated and adhered to one side of the molding material. A method for producing a molding material comprising a thermoplastic synthetic resin mixed with the organic fiber according to item 1.