Mitsubishi Gas Chemical Company, Inc.

Mitsubishi Engineering-plastics Corporation

Nireco Corporation

Miyagawa Kasei Industry Co., Ltd.

Plastron Corporation

Akimasa Kaneishi

Akinori Toyota

Sinji Kiboshi

Hisashi Tahara

Isamu Mio

Hiromi Hayashi

Hiroyuki Imaizumi

Yoshihiro Kayano

Kunio Yamazaki

Shinji Kiboshi

Yoshiharu Ohtuki

Tetsuya Hozumi

Kenzi Kono

Hiroshi Harada

Michiyasu Fukui

Yasuaki Ichinose

An apparatus for introducing a pressurized gas includes a pressurized-gas supply-source, a plurality of measuring tanks, a first pressurized-gas supply-line, pressurized-gas supply valves in the first pressurized-gas supply-line, second pressurized-gas supply-lines and pressurized-gas discharge-control valves disposed in the second pressurized-gas supply-lines. A combination of the measuring tanks is determined on the basis of the amount of a pressurized gas required for forming a hollow portion in a molded article, and the pressurized-gas discharge-control valves disposed in the second pressurized-gas supply-lines are controlled on the basis of the above determination.

Pressurized gas introducing device, and injection molding method for moldings having hollow portion

A light guide plate which is made of a transparent resin and has a first main surface and a second main surface opposite to said first main surface, said first main surface having a surface portion provided with convex portions having a height of 5&#xd7;10m to 6&#xd7;10m each and a pitch of 5&#xd7;10m to 4&#xd7;10m, each convex portion having a tip portion, and the convex portions of at least 80% of the total convex portions having the tip portions having a radius of curvature of 2&#xd7;10m or less.

Light guide plate made of transparent resin, molding method thereof, insert block, mold assembly, and area light apparatus

A light guide plate made of a transparent resin includes a first main surface and a second main surface opposite to the first main surface. The first main surface has a surface portion provided with convex portions having a height in the range of 5&#xd7;10m to 6&#xd7;10m each and a pitch in the range of 5&#xd7;10m to 4&#xd7;10m. The light guide plate having tip portions of at least 80% of the total convex portions with a radius of curvature of 2&#xd7;10m or less, or the surface of the convex portions having a surface roughness of 3&#xd7;10m or less.

Light guide plate with convex portions having low radius of curvature tips, or low surface roughness

A method for the production of a molded article having a hollow portion by utilizing a gas compression apparatus having a gas source, a compressor composed of a piston and a cylinder, and a discharge valve for controlling the flow of pressurized gas discharged from the cylinder, the method comprising introducing the pressurized gas through the discharge valve into a molten resin injected into a cavity of a mold, under the control of the discharge valve while carrying out, in one molding cycle, the intake step of supplying gas from the gas source to the cylinder and the compression step of compressing the gas by movement of the piston in the cylinder, at least twice each on the basis of predetermined compressor operation conditions, and thereby forming the hollow portion in the molded article.

Molding method for producing molded article having a hollow portion

An injection-molding method using an injection molding machine having a mold apparatus comprising

Mold apparatus and injection molding method for producing

A process for the production of a molded article having a hollow structure, using an injection molding machine equipped with a mold apparatus having a mold provided with a cavity, said process comprising the steps of

Mold apparatus for process for injection molding

A gas-feeding nozzle is to be used with a mold attached to an injection molding machine and for introducing a pressurized gas into molten resin injected in a cavity of the mold to produce an injection molded article having a hollow structure. A top forward portion of the gas-feeding nozzle is formed of a gas ejection portion having an inner side wall, along a direction of flow of the pressurized gas, having at least one concavo-convex portion.

Gas-feeding nozzle and apparatus and method employing such nozzle

Gas-feeding device for injection molding

A gas-feeding nozzle 10 for use in a mold 42 attached to an injection molding machine and for introducing a pressurized gas into a molten resin 60 injected into the cavity 48 of the mold, for producing a molded article having a hollow structure, the gas-feeding nozzle 10 comprising a non-return valve 12 provided at an outlet end of the gas-feeding nozzle 10 and a mechanism 14 for preventing the inflow of molten resin, the mechanism is provided upstream to the non-return valve 12 in the flow direction of the pressurized gas.

Gas-feeding nozzle

A drive apparatus for driving a movable member of a plastic molding die apparatus is provided which drives and controls a movable shaft for holding a gas injection nozzle by using a plurality of cylinders so that the gas injection nozzle of the die apparatus for use in a gas injection molding method can easily be changed. Resin is supplied from a position through a second die into a cavity formed between a first die and the second die, the drive apparatus disposed adjacent to the first die is used to drive the movable shaft for holding the nozzle of a gas supply means to supply gas into the resin in the cavity so that a hollow product is molded. The nozzle of the gas supply means is disposed at the leading portion of the hollow movable shaft. The drive apparatus includes a plurality of cylinders which are disposed at fixed positions adjacent to the first die with respect to the movable shaft and which are substantially the same, a connection plate for establishing the connections among rods of the plurality of fluid cylinders and the movable shaft, and a fluid control source for simultaneously driving the plurality of cylinders. The rod of each fluid cylinder and the connection plate are connected to each other while having plays in the axial direction and the radial direction.

Drive apparatus for driving movable member in plastic molding die

An injection-molded article of a thermoplastic resin having a base body defining an outer shape of the injection-molded article, a thick-wall portion rising from the base body, and a foot portion formed on the base body and at a foot of the thick-wall portion, the foot portion rising from the base portion, having a thickness which gradually increases toward the thick-wall portion, and having a (maximum thickness of the foot portion)/(width extending from the thick-wall portion to an end of the foot portion) ratio of 1/40 to 1/2, at least the thick-wall portion having a hollow portion.

Injection-molded article having high-quality appearance

A method for producing a handle-shaped molded article (1) having a thick grip portion (2) and at least one thick fitting portion (3) by injection molding using an injection molding apparatus (10) equipped with a mold having a cavity (60), a resin gate (46) provided in a portion (62) where the fitting portion is to be formed and a gas inlet (48) provided in a portion (64) where the grip portion is to be formed. A hollow structure (4) is formed in the grip portion (2) and a solid structure is formed in the fitting portion (3) by injecting a molten resin into the cavity (60) through the resin gate (46), thereby filling molten resin in a fitting portion-forming cavity zone formed of that portion (62) of the mold where the resin gate is provided and the fitting portion is to be formed and further filling molten resin in part of the rest of the cavity. A pressurized gas is introduced into the cavity (60) through the gas inlet (48) while maintaining an injection pressure, P, at a predetermined value, the injection pressure, P, being defined by

Method of injection molding with air assist for making a handle-shaped

A gas injection technique of injecting an inert gas (e.g., nitrogen gas) into a molten resin in a cavity, involves utilizing the strokes of reciprocation of a piston in the compression cylinder are used in a series mode, to perform a two-stage compression within the same cylinder, thereby providing a high-pressure gas. The method can also include establishing a relationship or pattern of the amount of movement of the piston with the speed of movement of the piston established to provide optimum control of the relationship between the pressure generated and piston stroke, and quantity of gas injected. The injecting gas pressure can be detected, to control a hold pressure, or the relationship between a piston stroke and generated pressure, so as to obtain optimal injecting pressure during the injection molding operation. A gas injection apparatus comprises a compression cylinder with a piston wherein the volumes of the two chambers on both sides of the piston are of such a compression ratio to provide the first compression. The apparatus also includes pipe lines communicating the two chambers with each other through a check valve, a gas supplying conduit pipe connected upstream of the check valve, and a conduit pipe connecting the chamber located downstream of the check valve to the cavity, wherein the piston is reciprocated to perform two-stage compression to provide a high pressure gas as required.

Growing community of inventors

Hiratsuka, Japan

Akimasa Kaneishi