Nissei Plastic Industrial Co., Ltd.

Teijin Limited

Yasuhiko Takeuchi

Toshiyasu Koda

Mamoru Miyagawa

Yuji Hayashi

Kazutoshi Takayama

Masaaki Minamimura

Minoru Yamazaki

Ikuo Uwadaira

Hidemi Aoki

Yoshitoshi Yamagiwa

Kazuo Anzai

Taku Kawano

Hiromitsu Miyajima

Kouichi Shimizu

Kiyoto Takizawa

Hodaka Yokomizo

Takayoshi Shioiri

Haruo Okada

Takahiro Kobayashi

Yoshiharu Yanagimachi

Michihiro Tatsuno

Jitsuo Oda

Kunio Yuhara

When a plurality of striped molded products are molded at a time, the molded products having a striped pattern and an outstanding design property are obtained by preventing part of molten resins from being unevenly distributed in an inappropriate manner when being fed into a cavity of a metal mold. A hot runner nozzle is provided with a first resin flow path and a plurality of second resin flow paths. The first flow path has a funnel section which continues with a nozzle gate at a centripetal position and which allows a first molten resin to be gathered at the centripetal position of the funnel section so as to feed the resin into the nozzle gate. The second resin flow paths have a plurality of corresponding discharge ports facing and communicating with the funnel section of the first resin flow path, each of the discharge ports being disposed around the centripetal position, so that the second molten resin different from the first molten resin is fed into the funnel section.

Hot runner nozzle, metal mold equipped with hot runner nozzle, and molding method and molded product provided by metal mold

A thin multilayer container having favorable gas barrier properties is provided using a technique applicable to the molding of the thin multilayer container, by means of ensuring the gas barrier properties at a joint of ends of a film, when the container is molded with disposing the film having the gas barrier properties in a portion to be a container trunk portion. When molding the container with disposing in advance the film having the gas barrier properties in the portion to be the container trunk portion, while a container surface resin is fed from an injection molding nozzle into a container trunk forming portion of a mold, a gas barrier resin is fed into a position corresponding the joint of the label film as an intermediate layer between a portion of the container surface resin being spread along a core mold and a portion of the container surface resin being spread along a cavity mold.

Method for manufacturing cup-shaped container

At a filling termination stage when performing multi-layer molding by means of a hot runner nozzle, an intermediate layer in a multi-layer molded article is prevented from being formed in a shape causing the intermediate layer to enter into a sprue in a portion of a mold cavity in a mold corresponding to the sprue. The multi-layer molded article with no intermediate layer being exposed in a sprue cut portion can be therefore obtained. In this manner, a diameter of a discharge port opening and closing mechanism part for opening and closing the resin discharge ports in the shut pin is made different from a diameter of a nozzle gate opening and closing mechanism part configured of the projection for pushing out the molten resin in the nozzle gate.

Hot runner nozzle and mold for forming multi-layer molded article using the same

A control method for supplying an inert gas from an inert gas source to a storage container for a molten metal through a gas feed path provided with a flow sensor for monitoring the gas flow rate and a solenoid valve for opening and closing the gas feed path for use with metal molding. The control method includes steps of turning off the solenoid valve if a temperature of the storage container is lower than a preset temperature, and turning off the flow sensor; otherwise turning on the solenoid valve and turning on the flow sensor; and stopping the output of the heater of the storage container when the gas flow rate is lower than the preset amount; these steps are controlled in accordance with a command signal from a controller.

Control method for supplying inert gas during metal molding

A device for melting, storing, and feeding a metal material is provided which can store a large amount of molten metal material corresponding to molding cycles with a compact configuration, using barrels to melt bar-shaped metal materials and a tank-and-barrel storage unit to store the molten metal material. The storage unit for the molten metal material is composed of an upper storage tank and a lower material temperature control barrel having a smaller diameter, the barrel being perpendicularly arranged under and in communication with the bottom center of the tank. The melting barrels for bar-shaped metal materials are made of barrel bodies having an inside diameter and a length appropriate to accommodate the bar-shaped metal materials. A more than one melting barrel is vertically arranged in parallel on a lid member of the storage tank, with their bottom openings facing the inside of the storage tank.

Device for melting, storing, and feeding metal material from bar-shaped metal material intended for injection apparatus for molding metal product

Leakage of molten metal material from between a cylinder body having a tight-fitting liner and a nozzle member of an injection apparatus is prevented through the interaction of the nozzle member and a coupling ring with the liner.

Injection cylinder in injection apparatus for molding metal material

There is provided a method for melting a material rod in a material melting and holding apparatus of a metal molding apparatus where the material melting and holding apparatus provided for the metal molding apparatus includes a furnace body of a melting and holding furnace, and a melting cylinder for a material rod and a material supply cylinder for directly supplying the material rod into the furnace body provided in parallel with each other on the furnace body, upon startup of molding, the material rod is melted using the melting cylinder prior to supplying the molten material from the melting cylinder into the melting and holding furnace, and the material rod subsequently supplied from the material supply cylinder to a bottom portion of the furnace body is submerged and melted by the molten material, thereby maintaining the submersion melting in the melting and holding furnace after the startup of molding.

Material melting and holding apparatus of metal molding apparatus and rod material melting method

A method of preventing leaking of molten metal from a nozzle in an injection apparatus comprising, metering the molten metal by travel of a plunger head backward from a most forward position to a most backward position at the rear of a supply opening while maintaining nozzle contact after completion of an injection step and supplying molten metal from a furnace into a cylinder body through the supply opening, after completion of the metering, closing the supply opening by travel of the plunger head forward at a low speed from the backward position to a stand-by position ahead of the supply opening for cutting off the communication between the molten metal in the cylinder body and the molten metal in the furnace.

Method for preventing leaking of molten metal in injection molding of metal material

A preform for a multi-layered hollow vessel has excellent moldability and productivity and is free from the deterioration of the characteristic properties of the vessel even when a recycled material is filled in large quantities. A molded product is produced by filling a first material and a second material into the cavity of an injection mold in a single molding step including (i) the substep of injecting the first material, (ii) the substep of injecting the first material and the second material at the same time and (iii) the substep of injecting the first material which are carried out continuously in this order.

Multi-layer preliminary formed body and method of manufacturing the formed body

An injection molding apparatus of a metal material places a heating cylinder in an inclined position. The heating cylinder includes a nozzle at a tip thereof and a screw disposed inside. In this way, the metal material in a liquid phase state can be transferred and metered accurately in a reliable manner at all times by flowing due to the inclination and a transfer force produced by rotation of the screw. A clamping apparatus is provided to oppose the injection apparatus and includes a mold having a sprue bush inside. The injection apparatus and the clamping apparatus are placed on an apparatus platform in an inclined position at the same angle with the mold in a lower end, so that the metal material in the liquid phase state in the heating cylinder flows down toward the head due to self-weight. The nozzle and sprue bush are positioned on the same straight line, thereby maintaining nozzle touch without bending the nozzle.

Method and apparatus for injection molding metal material

A method of metering a metal material in a liquid phase in molding injection provides accurate and reliable transfer of the metal material. A heating cylinder housing a rotatable and axially movable screw, is inclined with its head pointing downward, so that the metal material in the liquid phase state flows down into a front chamber due to self-weight. At the forward position after injection, the screw is forced to retract to a set position, whereby a predetermined quantity of a liquid phase material primarily stored on the periphery of the head portion of the screw is accumulated by suction due to a negative pressure in the front chamber of the heating cylinder. Further, a constant quantity of the liquid phase material can be metered each time in the front chamber by stopping and then rotating the screw at a retraction position.

Metering method of metal material in injection molding

There is provided an injection apparatus comprised of a heating cylinder which is closed by a front end member having a nozzle. The apparatus is further comprised of a plasticating screw in the heating cylinder in a freely rotating and reciprocating manner, and a plunger connected to the front end of the screw. The plunger has a conical front end in which flow channels are formed. The front end member has a measuring chamber formed therein at an internal central location thereof. The measuring chamber has a predetermined length and an internal diameter which is reduced by 8 to 15% with respect to an internal diameter of the heating cylinder. The diameter of the injection plunger is set almost equal to the diameter of the measuring chamber, whereby the injection plunger is inserted into the measuring chamber in a freely reciprocating manner. A gap is formed on the external peripheral surface of the plunger due to the difference between the heating cylinder internal diameter and the plunger diameter, and the gap functions as a plastication-accelerating block. The block is formed so as to have a distance longer than an injection stroke, whereby uniform plastication is achieved and uneven temperature in the material is eliminated. Further, the plunger advance blocks the gap, which leads to uniform density and precise measurement of the material.

Injection apparatus

An injection screw comprise a rear end to a front end of an effective length of the screw compartmented in the order of a feed zone, a compression zone and a metering zone, wherein the metering zone is constituted by the first metering zone, the second metering zone and the relaxation zone. A root diameter of the second metering zone is formed in a smaller diameter than a root diameter of the first metering zone and a screw channel depth is set deeper than a screw channel depth of the first metering zone. Variations in a resin temperature at injecting is solved and melting and kneading through a entire screw further are improved by only partial changing of the configuration of the metering zone.

Injection screw

An improved method of manufacturing a multilayer molding having a core and a surface layer by means of a double nozzle structure can eliminate a damaging phenomenon of producing a mixture of a resin material for forming the core remaining in and out of the aperture of the inner nozzle of the double nozzle structure and a resin material for forming the surface layer in the initial stages of molding operation by effectively driving back the remaining resin into the inner nozzle. A double nozzle structure that can suitably be used with such a method includes a shut-off pin arranged in the inner nozzle disposed at the center of the outer nozzle. The resin material for forming the core is driven out simultaneously with the resin material for forming the surface layer coming from the outer nozzle. The operation of resin injection from the inner nozzle is terminated at an arbitrarily selected moment during the operation of injecting the resin material for the surface layer of the outer nozzle. Then, the inside of the inner nozzle is brought into a no-load condition while the shut-off pin is held to its open position. Thereafter, the remaining resin material for the core found in and out of the aperture of the inner nozzle is driven back into the inner nozzle by the pressure of the resin injected from the outer nozzle. Finally, the inner nozzle is closed by the shut-off pin and the injecting operation of the outer nozzle is terminated.

Method of manufacturing a multilayer molding

A method of injection molding whereby a polyethylene terephthalate (PET) without being predried or with having an irregular-shape is fed by a feed screw from a material feeder to an injection cylinder and plasticated by an injection screw. The rotational torque of the injection screw is detected in correspondence with the revolution speed of the feed screw during material feed, and a flection point of the rotational torque is determined. The feed screw is operated at a revolution speed within a range around the flection point of the rotational torque to provide a stable feed rate of the PET and to avoid difficulty in rotating the injection screw.

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Nagano-ken, Japan

Yasuhiko Takeuchi