In an injection process, molten resin is successively injected from a first flow channel and a second flow channel connected with each other in order into a cavity of a metal mold. High-temperature resin existing in the first flow channel is injected in advance into the cavity as a part of a single shot of molten resin to later form a skin layer of a molded article. Other low temperature resin near a flowable limit existing in the second flow channel is subsequently injected into the cavity as another part of the single shot of molten resin to later form a core layer of the molded article. A low temperature resin remaining in the first flow channel when injection is completed is warmed to be a high-temperature resin before the next cycle, thereby allowing successive molding of molded articles.

An injection molding machine includes an edge gate nozzle with a nozzle body having a primary melt channel and a nozzle head having first and second secondary melt channels that feed melt to first and second nozzle tips. First and second heaters are disposed in the nozzle head to provide heat to the secondary melt channels. In some embodiments, the heaters are positioned adjacent to the secondary melt channels, with first heater is closer to the first secondary melt channel than to the second secondary melt channel. In some embodiments, the heaters are positioned adjacent to the nozzle tips, with the first heater closer to the first nozzle tip than to the second nozzle tip. In some embodiments, each heater is adjacent to both the respective nozzle tip and secondary melt channel. In some embodiments, each heater is individually controllable.

Hot-runner manifolds that contain one or more types of non-melt channels in addition to melt channels, and injection-molding systems containing such hot-runner manifolds. The differing types of non-melt channels include: coolant channels for carrying a coolant for cooling the tips of hot-tip nozzles, for example, during hot latching operations; heating-fluid channels for carrying a heating fluid for heating melt within melt channels within the hot-runner manifolds; and actuation-fluid channels for carrying actuation fluid to valves of valve-actuated nozzles. In each case, nozzles can be formed unitarily monolithically with the hot-runner manifolds and one or more of the various types of non-melt channels can be continuously routed within such unitary monolithic nozzles. Freeform fabrication processes can be used to form hot-runner manifolds of the present disclosure, which often contain complex/intricate internal passageways that form the various types of melt and non-melt channels.

In an injection process, molten resin is successively injected from a first flow channel and a second flow channel connected with each other in order into a cavity of a metal mold. High-temperature resin existing in the first flow channel is injected in advance into the cavity as a part of a single shot of molten resin to later form a skin layer of a molded article. other low temperature resin near a flowable limit existing in the second flow channel is subsequently injected into the cavity as another part of the single shot of molten resin to later form a core layer of the molded article. A low temperature resin remaining in the first flow channel when injection is completed is warmed to be a high-temperature resin before the next cycle, thereby allowing successive molding of molded articles.

In an injection process, molten resin is successively injected from a first flow channel and a second flow channel connected with each other in order into a cavity of a metal mold. High-temperature resin existing in the first flow channel is injected in advance into the cavity as a part of a single shot of molten resin to later form a skin layer of a molded article. Other low temperature resin near a flowable limit existing in the second flow channel is subsequently injected into the cavity as another part of the single shot of molten resin to later form a core layer of the molded article. A low temperature resin remaining in the first flow channel when injection is completed is warmed to be a high-temperature resin before the next cycle, thereby allowing successive molding of molded articles.

An injection molding machine includes an edge gate nozzle with a nozzle body having a primary melt channel and a nozzle head having first and second secondary melt channels that feed melt to first and second nozzle tips. First and second heaters are disposed in the nozzle head to provide heat to the secondary melt channels. In some embodiments, the heaters are positioned adjacent to the secondary melt channels, with first heater is closer to the first secondary melt channel than to the second secondary melt channel. In some embodiments, the heaters are positioned adjacent to the nozzle tips, with the first heater closer to the first nozzle tip than to the second nozzle tip. In some embodiments, each heater is adjacent to both the respective nozzle tip and secondary melt channel. In some embodiments, each heater is individually controllable.

A hot runner injection molding apparatus comprising an injection molding manifold having an inlet melt channel and a plurality of outlet melt channels and a plurality of hot runner nozzles coupled to the outlet melt channels. Each hot runner nozzle includes a nozzle body defining a first nozzle body melt channel having a first axis. A nozzle tip housing is coupled to the nozzle body which includes at least two auxiliary melt channel portions each auxiliary melt channel portion has a second axis which is angled with respect to the first axis. At least two nozzle tips are arranged at the nozzle tip housing and in the area of each nozzle tip a nozzle tip heater is arranged, which is oriented substantially along the first melt channel.

An injection molding system is disclosed. The injection molding system includes: a mold; a hot runner including: a manifold; one or more injection nozzles coupled to the manifold; a plurality of heaters in thermal contact with the manifold and the one or more injection nozzles, the heaters being arranged into one or more defined heating zones within the hot runner; and at least one temperature sensor associated with each heating zone, and a system controller coupled to the plurality of heaters, the system controller being configured to: for each heating zone: determine a setpoint temperature associated with the heating zone; obtain, via a temperature sensor, measurement of a current local temperature of the heating zone; determine a control gain value associated with the heating zone; and compute a predicted heating time for the heating zone based on the setpoint temperature, the current local temperature, and the control gain value, determine a heating schedule for the hot runner based on the predicted heating times for the heating zones; and operate the plurality of heaters in accordance with the heating schedule.