Aronkasei Co., Ltd.

Kabushiki Kaisha Meiki Seisakusho

Shiraishi Central Laboratories Co., Ltd.

Tadashi Hasegawa

Shigemi Kushida

Yoshimitsu Tabata

Shinichi Nakamura

Ryozo Morita

Takashi Korenaga

Kazuyuki Izumo

Nobuyoshi Sugie

Katsuyuki Enomoto

The object of the present invention is to provide a plastic molded material having uniform foamed structure at a low price. To attain said object, a method comprising; mixing particle containing 30 to 70% by weight of water in thermoplastic resin, heating and melting said thermoplastic resin in which said particles containing water are mixed under a high pressure, releasing said high pressure to form foamed structure and cooling to solidify said foamed thermoplastic resin.

Method for production of foamed plastics

A screw-in-plunger injection apparatus is provided which is advantageously used for molding either a large-size or a small-size product. The injection apparatus is capable of selectively carrying out a plunger-type injection operation and an inline-screw-type injection operation. In the plunger-type injection operation, an injection plunger 12 and a screw 10 are advanced in an injection cylinder 14, so that a melted resin fed to a storage space provided on the side of one axial end of the injection plunger 12 is injected. In the inline-screw-type injection operation, a surface of the axial end of the injection plunger 12 is held in abutment with the injection cylinder 14, so that the storage space is reduced to provide a reduced storage space to and from which the melted resin is fed by the rotation of the screw and is injected by the movement of the screw in an axial direction thereof.

Screw-in-plunger injection apparatus

An injection molding machine for thermoplastic resin consisting of an accumulator in which a plunger is slidably provided and an injection mold, the sprue of which connects with the nozzle of said accumulator, wherein said plunger consists of a cylinder and a screw rotatably arranged in said cylinder, the tip of said screw protrudes from the front end of said cylinder and the maximum diameter of said tip is larger than the diameter of said screw, and the ratio of the effective volume of said plunger to the effective volume of said accumulator is in the range between 1:4 to 1:10 is provided in the present invention. By using said injection molding machine a large size product can be molded at a low injection pressure.

Injection molding machine

A two-layer structure molded by using thermoplastic resin is provided in the instant invention. Said two-layer structure comprises one layer (a) of thermoplastic resin in which no electroconductive filler is mixed, and the other layer (b) of thermoplastic resin in which electroconductive filler is mixed wherein one or more projections which penetrate said layer (b) are formed on said layer (a).

Two-layer structure molded by using thermoplastic resin

Growing community of inventors

Nagoya, Japan

Tadashi Hasegawa