Idemitsu Petrochemical Co., Ltd.

Kaoru Wada

Manabu Nomura

Tomokazu Abe

Atsushi Sato

Takayoshi Tanaka

Yasunobu Yamazaki

Toru Shima

Hirohide Mizuno

Kouji Sato

The method of forming a light-weight, fiber-reinforced, particularly glass fiber-reinforced-thermoplastic resin product includes the steps of melting and mixing thermoplastic resin pellets containing parallely oriented fibers 2-100 mm long, injecting the melted resin into a cavity which is closed so that its volume is smaller than that of the final molded product, and, before or after the resin injection is completed, opening the cavity until its volume is equal to that of the final molded product. Unlike the conventional injection-molded products, this product does not require a foaming agent and, if it uses any, requires only a small amount of foaming agent. The product thus formed is light in weight and has fibers uniformly entangled inside, providing an excellent appearance of the surface. Further a skin layer is formed over the surface. These features combined with the reinforcement by the glass fibers offer high strength and high stiffness.

Method of forming a light-weight, fiber-reinforced thermoplastic resin product and a light-weight molded product

The present invention is directed to a method of obtaining a gas-introduced fiber-reinforced resin injection molding and to a molding obtained by the method. According to the present invention, there can be obtained a lightweight gas-introduced fiber-reinforced resin injection molding containing glass fibers or like fibers having excellent rigidity and strength and improved surface properties. The method includes the steps of: injecting into a die a molten resin obtained through the plasticization of a molding material; and introducing gas into the molten resin, the molding material comprising fiber-containing thermoplastic resin pellets which contain reinforcing fibers having a length of 2 mm to 100 mm, the reinforcing fibers accounting for 5% to 70% by weight of the molding material, the die including a movable die capable of advancing into and retracting from the internal cavity of the die, wherein after the injection of the molten resin into the die cavity is started, the movable die is retracted to a position where the die cavity assumes a volume corresponding to the molding, and gas is introduced into the molten resin filling the die cavity.

Method of obtaining a gas-introduced fiber-reinforced resin injection

Disclosed is a method of molding a fiber-reinforced resin laminate which can manufacture a lightweight laminated molding having excellent mechanical characteristics regardless of the shape of a molding, which can readily unite a surface coat material and a molding while the surface coat material is held in good condition, and which can impart excellent appearance to a laminated molding. Also disclosed is a laminated molding manufactured by the method. The method uses a molding material which contains fiber-containing thermoplastic resin pellets which, in turn, contain reinforcing fibers having a length of 2 mm to 100 mm. The reinforcing fibers account for 5% to 70% by weight of the molding material. A molten resin obtained through the plasticization of the molding material is injected into a die, onto which a surface coat material for covering the surface of a molding is previously attached. After injection of the molten resin into the die cavity is started, a movable die is advanced so as to compress the molten resin contained in the die cavity, followed by expansion of the volume of the die cavity to that of an intended molding.

Method of molding a fiber-reinforced resin laminate and a laminated

Method of forming a light-weight, fiber-reinforced thermoplastic resin

Polyolefin resin composition

Disclosed is a glass fiber reinforced polyolefin resin composition comprising 15-80% by weight of polypropylene, 20-60% by weight of polybutene-1 and 5-60% by weight of glass fiber. This resin composition is excellent in the balance of impact strength, stiffness, heat distortion temperature, surface hardness and processability. When this composition is molded, the molded products have no surface roughness and no color shade and have good appearance. The properties are further improved when a modified polyolefin alone or together with a crystal nucleating agent are added.

Glass fiber reinforced polyolefin resin composition

A thermoplastic resin composition which comprises 30 to 99 wt % of a thermoplastic resin and 1 to 70 wt % of granulated fiber formed by granulating inorganic fibers having an average fiber diameter of 0.1 to 1.0 .mu.m, an aspect ratio of 50 to 300, and an oil absorption of 400 ml/100 g and above, said granulated fiber having an average diameter of 0.5 to 5 mm and a bulk density of 0.15 to 0.4. A process for producing a thermoplastic resin composition which comprises mixing in a mixer 30 to 99 wt % of a thermoplastic resin and 1 to 70 wt % of granulated fiber formed by granulating inorganic fibers having an average fiber diameter of 0.1 to 1.0 .mu.m, an aspect ratio of 50 to 300, and an oil absorption of 400 ml/100 g and above, said granulated fiber having an average diameter of 0.5 to 5 mm and a bulk density of 0.15 to 0.4.

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Ichihara, Japan

Kaoru Wada