JPH05293842A - Production of composite molded object - Google Patents

Abstract

PURPOSE:To produce simply a composite molded object capable as a ski board, a snow board or a tennis racket. CONSTITUTION:A core material composed of a thermoplastic foamed resin and having a circular or polygonal cross-sectional shape and surface materials each composed of a fiber reinforced thermoplastic resin sheet are softened under heating and placed in a mold in a softened state in the order of the lower surface material, the core material and the upper surface material to be subjected to compression molding.

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 composite molded body suitable for various molded products such as skis, snowboards and tennis rackets.

[0002]

2. Description of the Related Art Conventionally, a ski having a fiber-reinforced resin sheet laminated on both upper and lower surfaces of a foam synthetic resin core constituting a ski body has been disclosed in Japanese Patent Laid-Open No. 3-244482.

[0003]

However, in the ski plate described in the above publication, a fiber-reinforced resin sheet previously cut in the same pattern as the upper and lower surfaces of the ski is laminated on the upper and lower sides of a core body previously formed in the form of a ski. Since it is manufactured by heating and pressurizing in a pressure vessel, there are problems that the process is complicated, mechanization is difficult, and the manufacturing cost becomes expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide a method for producing a composite molded body capable of easily molding various molded products such as skis, snowboards and tennis rackets.

[0005]

In order to solve the above-mentioned problems, the present invention provides a surface comprising a core material made of a thermoplastic foam resin having a circular or polygonal cross section and a fiber-reinforced thermoplastic resin sheet. A composite molding, characterized in that the lower surface material, the core material, and the upper surface material are placed in the mold in this order and softened by heating and softening the material and the core material and the surface material in a softened state. The main point is the body manufacturing method.

Since both the core material and the matrix of the surface material used in the present invention are made of a thermoplastic resin, they are softened by heating, for example, in an oven, and while they are in a softened state, they are placed in a mold at room temperature. A desired molded product can be easily obtained by simply placing the lower surface material, the core material, and the upper surface material in this order and compression-molding them into a predetermined shape, and this molding process can be mechanized.

As the resin for the core material used in the present invention, polymethylmethacrylate, polyvinyl chloride, polycarbonate, etc. are preferably used, and as the reinforcing fibers constituting the surface material, carbon fiber, glass fiber, and Aramid fiber or the like is preferably used, and polymethylmethacrylate, polyamide or the like is preferably used as the matrix resin of the surface material.

[0008]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

(Example 1) As a surface material, a prepreg sheet obtained by impregnating glass fiber cloth with polymethylmethacrylate resin (Basis weight: 1.000 g / m ² , resin content: 3)
0 wt%, thickness 0.5 mm), rod-shaped vinyl chloride foam (40 mm x 40 mm x 1800 m) as a core material
m, density 0.7 g / cc), both the core material and the surface material were placed in an oven at 160 ° C. to be softened, and then immediately placed in a mold at room temperature, the lower surface material, the core material, and the upper surface material in this order. Place and compression mold, and after about 5 minutes, remove from the mold and have a width of 75 mm and a thickness of 5 mm in the cross section of the tip, a width of 65 mm and a thickness of 15 mm in the cross section of the center, A 1800 mm Alpine ski plate having a width of 77 mm and a thickness of 3 mm and a rectangular cross section in the longitudinal direction was obtained.

The obtained plate was lightweight, had high rigidity, had no warp or sink due to thermal stress, and had high dimensional accuracy.
In addition, the ski itself has excellent vibration damping and is comfortable to ride in.

(Example 2) As a surface material, a fabric prepreg sheet obtained by impregnating a woven fabric of carbon fiber into a plain weave structure with a polymethylmethacrylate resin
0 g / m ² , resin content 35 wt%, thickness 0.50 m
m) and a rod-shaped vinyl chloride foam (20) as a core material
mm × 20 mm × 1200 mm, density 0.5 g / cc)
Both the core material and the surface material are placed in an oven at 160 ° C for softening, and immediately the lower surface material tape, the core material, and the upper surface material tape are placed in this order on a mold at room temperature and compression molded. After about 5 minutes, it was removed from the mold and a tube for a tennis racket was obtained. The grip portion of this raw pipe has a cross-sectional dimension of about 20 mm in width and 30 mm in height by arranging two of the above composite structures, and the string portion has a minor axis of about 10 mm and a major axis of about 3 mm.
It has an oval shape of 0 mm. To this, a pre-injection-molded part as a throat was fitted and adhered to a groove previously provided in the string portion of the main body to obtain a desired tennis racket.

The obtained racket is lightweight and has high rigidity,
There was no warp or sink due to thermal stress, and the dimensional accuracy was high. Further, since the racket itself has a high vibration damping property, the racket has excellent characteristics with less load on the human body.

[0016]

According to the present invention configured as described above,
It has excellent effects such that skis, snowboards, and tennis rackets can be manufactured extremely easily and can be easily mechanized.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area B29K 105: 04 105: 06 B29L 31:52 4F

Claims (1)

[Claims] 1. A core material made of a thermoplastic foamed resin having a circular or polygonal cross section and a surface material made of a fiber reinforced thermoplastic resin sheet are softened by heating to soften the core material and the surface material. A method for producing a composite molded body, characterized by placing a lower surface material, a core material, and an upper surface material in the mold in that order and performing compression molding.