A method for injection molding of plastic material by means of at least one injector whose pin valve can be displaced between a fully closed position and a maximum open position in a controlled fashion according to a position and speed of the pin valve. During displacement of the pin valve from the fully closed position to the maximum open position, and/or vice versa, the pin valve is stopped in intermediate positions and the displacement speed thereof is uniform and constant. An initial opening step at maximum speed and one or more steps of inversion of the motion of the pin valve can be provided for.

A light-emitting device includes a light-emitting element on a molded part. The molded part is formed by molding and curing a thermosetting epoxy resin composition comprising (A) the reaction product of a triazine derived epoxy resin with an acid anhydride, (B) an internal parting agent having m.p. 50-90° C., (C) a reflective agent, (D) an inorganic filler, and (E) a curing catalyst.

A hot runner injection molding apparatus includes a hot runner nozzle and a first heater coupled to the nozzle body of the nozzle. A separate mold gate insert surrounds a nozzle tip area of the nozzle. The mold gate insert is heated by a second heater that is separate and independent from the nozzle body heater. The temperature generated by the first and second heaters is measured by a first thermocouple and a second thermocouple, respectively. A controller is used to adjust at any time the temperature of the first and second heaters independently. The second heater is used to either i) melt, and thus enable a faster removal of, a colder molten material accumulated around the nozzle tip during a color change procedure or ii) to reduce or increase the temperature of the nozzle tip differently from one nozzle to the next.

A hot runner injection molding apparatus includes a hot runner nozzle and a first heater coupled to the nozzle body of the nozzle. A separate mold gate insert surrounds a nozzle tip area of the nozzle. The mold gate insert is heated by a second heater that is separate and independent from the nozzle body heater. The temperature generated by the first and second heaters is measured by a first thermocouple and a second thermocouple, respectively. A controller is used to adjust at any time the temperature of the first and second heaters independently. The second heater is used to either i) melt, and thus enable a faster removal of, a colder molten material accumulated around the nozzle tip during a color change procedure or ii) to reduce or increase the temperature of the nozzle tip differently from one nozzle to the next.

An injection molding apparatus and hot runner system are disclosed. The injection molding apparatus includes a plurality of mold plates in which the hot runner system is received. A manifold receives molding material and has a manifold channel that extends between an inlet and an outlet. A nozzle delivers moldable material to a mold cavity. The nozzle has a nozzle channel in fluid communication between the manifold channel and the mold cavity. A valve pin seal is located at the upstream end of the nozzle, and a valve pin that is connected to an actuator extends through the manifold and nozzle is slidably received in the valve pin seal. The hot runner system further includes a thermal bridge that is in conductive thermal communication with the valve pin seal and a cooled one of the plurality of mold plates.

A valve gate assembly having an actuator assembly configured to simultaneously control a plurality of valve pins to regulate flow of a liquid resin to a mold cavity of an injection molding apparatus is configured to allow fast and easy removal of the actuator assembly from the pins simultaneously by providing a valve plate having a plurality of slots or pockets for receiving and releasably holding a corresponding one of the pins.

An injection molding system (1000) comprising: an actuator (5) having a housing (20) comprised of radial (20r, 20ri, 20ro, 20roa, 20rob, 20roc, 20rod) and axial walls (20a, 20ai, 20aue, 20ade) that form an enclosed chamber (45) containing a heat conductive chamber fluid (CF), a rotor and driver driven by electrical energy and supported within the chamber by the radial and axial walls, wherein one or more of the radial and axial walls comprise a heat conductive material that has an inner surface disposed in heat conductive contact with the heat conductive fluid (CF) contained within the enclosed chamber, an actuator tube or channel (25) disposed within the one or more of the radial and axial walls, a source (260) of heat absorptive fluid (25f) sealably interconnected to the actuator tube or channel (25).

A polymer injection molding system in one embodiment includes a manifold comprising internal flow conduits configured for conveying polymer in a fluidic state. The manifold may be part of a hot or cold runner type molding unit. An injection nozzle fluidly coupled to the flow conduits interfaces with a mold cavity and is configured to inject polymer therein to form a molded article. The nozzle has a tubular valve body defining a central axial passage which receives a movable elongated valve pin. The valve pin is linearly movable to change the nozzle between open and closed positions for discharging or stopping polymer flow therefrom. The valve pin is further rotatable about its axis to induce shear on the polymer. This maintains the polymer in its flowable fluidic state between molding cycles to prevent polymer cold slug formation within the nozzle which can disrupt the flow resulting in incompletely formed articles.

A method for manufacturing a molded part by an injection molding machine while changing between multiple molds, the method including transporting a stack mold including an intermediate mold to a molding operation position inside the injection molding machine, wherein the intermediate mold includes a first unit for closing a first opening portion for delivering a resin to a cavity and a second unit for closing a second opening portion for receiving the resin from a next to the intermediate mold, the next mold including a third unit for closing a third opening portion for receiving the resin, injecting the resin into the mold, closing the opening portions by the first unit, second unit, and third unit, and unloading the mold from the molding operation position after the resin is injected into the mold, where the first, second, and third opening portions are closed in this order.

A method for manufacturing a molded part by an injection molding machine while changing between multiple molds, the method including transporting a stack mold including an intermediate mold to a molding operation position inside the injection molding machine, wherein the intermediate mold includes a first unit for closing a first opening portion for delivering a resin to a cavity and a second unit for closing a second opening portion for receiving the resin from a next to the intermediate mold, the next mold including a third unit for closing a third opening portion for receiving the resin, injecting the resin into the mold, closing the opening portions by the first unit, second unit, and third unit, and unloading the mold from the molding operation position after the resin is injected into the mold, where the first, second, and third opening portions are closed in this order.