Abstract: 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.

Abstract: A gas-introduced injection molding is disclosed, which is obtained by charging molten resin into a die and introducing gas into the charged molten resin. The molding thus obtained has a sufficient thickness portion extending linearly as a framework and a sheet-like small thickness portion integral with the sufficient thickness portion and having a uniform thickness, a space being formed inside the sufficient thickness portion. Thus, even by reducing the overall thickness of the molding it is possible to ensure sufficient rigidity with the hollow portion, and the molding is thus best suited as a sheet-like product requiring a predetermined rigidity, such as an automobile bumper, a household electric product casing, etc.

Abstract: A gas-introduced injection molding is disclosed, which is obtained by charging molten resin into a die and introducing gas into the charged molten resin. The molding thus obtained has a sufficient thickness portion extending linearly as a framework and a sheet-like small thickness portion integral with the sufficient thickness portion and having a uniform thickness, a space being formed inside the sufficient thickness portion. Thus, even by reducing the overall thickness of the molding it is possible to ensure sufficient rigidity with the hollow portion, and the molding is thus best suited as a sheet-like product requiring a predetermined rigidity, such as an automobile bumper, a household electric product casing, etc.

Abstract: An improved tape automated bonding is disclosed. A heater head employs a heat conducting member and a bonding tip member. The heat conducting member formed of a material, such as molybdenum or tungsten, has a U-shaped contour which comprises a pair of halves and an interconnection for generating bonding heat by undergoing high frequency electric current. The bonding tip member is bonded to the interconnection of the conducting member. The tip member is formed of material, such as diamond or cubic boron nitride, which is higher in resistivity and thermal conductivity than the conducting member.

Abstract: A method for producing a block copolyamide, which comprises polycondensing a prepolymer prepared from a dimerized fatty acid and a diamine and having a number average molecular weight of from 1,000 to 50,000, with a polyamide material other than said prepolymer component or a prepolymer thereof.

Abstract: A copolyamide resin containing a dimerized fatty acid as a copolymer component, which has (1) at least 25 equivalent %, based on the total number of terminal groups, of hydrocarbon groups having from 6 to 22 carbon atoms at its terminals, (2) a content of a dimerized fatty acid of from 0.1 to 40% by weight based on the total amount of the resin, and (3) a melt viscosity as measured at 240.degree. C. of from 2,000 to 15,000 poise.

Abstract: A polypropylene composition comprising a crystalline polypropylene and a precipitated calcium carbonate which is subjected to a surface-treatment with a suitable dispersant, and has an average particle diameter of from 0.1 to 0.4.mu..