Injection molding system with flow control
AssigneeMold-Masters Limited
InventorDenis Babin
Life of this patent
Estimating the term…
Abstract
An injection molding system includes a manifold and a valve gated hot runner nozzle. The gating mechanism includes an actuated valve pin, where the mold gate orifice is open when the valve pin is in a first position to allow melt to flow there through. The mold gate orifice is closed when the valve pin is in a second position to prevent melt from flowing there through. A first flow control surface is disposed on said valve pin within the melt channel of the nozzle. The first flow control surface has a complementary geometry with that of the melt channel at a second flow control surface. The valve pin is raised and lowered to a lesser degree than that required to seat and unseat the valve pin head to constrict or release the flow of a melt stream in the melt channel.
Claims26
An injection molding system comprising:
- a manifold having a plurality of manifold melt channels for conveying a melt stream;
- a plurality of nozzles, wherein each nozzle has a nozzle melt channel fluidly connected at a first end to a respective manifold melt channel and at a second end to a mold gate of a separate mold cavity, the nozzle further including an actuated valve pin slidably positionable within the nozzle melt channel having a head portion for opening and closing the mold gate, wherein the valve pin has a flow control surface upstream of the head portion thereof that is slidably positionable for controlling the flow rate of the melt stream through the nozzle melt channel towards the mold gate.
An injection molding system comprising:
- a plurality of nozzles, wherein each nozzle has a melt channel for conveying a melt stream into a separate mold cavity through a mold gate;
- and
- an actuated valve pin slidably positionable within the nozzle melt channel having a tip portion for closing the mold gate to stop the flow of the melt stream into said mold cavity and a first flow control surface on an upstream portion of the valve pin for controlling a flow rate of the melt stream within the melt channel, wherein the first flow control surface has a corresponding second flow control surface as a portion of the melt channel such that the flow rate of the melt stream is reduced when the first flow control surface of the valve pin is slidably positioned at or near the second flow control surface of the nozzle melt channel.
A method of injection molding comprising:
- providing a plurality of mold cavities of substantially equal volume, such that each mold cavity is fed by a single mold gate;
- injecting a molten material via an injection molding manifold into a plurality of hot runner nozzles, wherein each nozzle is in fluid communication with a respective mold cavity via a respective mold gate, and each nozzle having a nozzle melt channel with a valve pin therein;
- and
- independently actuating each valve pin in its respective nozzle melt channel into an injection open position that is defined as a distance D between a flow control surface of the valve pin and the mold gate, wherein a distance D varies from one nozzle to another such that each mold cavity is filled with substantially the same amount of molten material during an injection cycle.
A method of injection molding comprising:
- providing a plurality of mold cavities, such that each mold cavity is fed by a single mold gate;
- injecting a molten material via an injection molding manifold into a plurality of hot runner nozzles, wherein each nozzle is in fluid communication with a respective mold cavity via a respective mold gate, and each nozzle having a nozzle melt channel with a movable valve pin therein, wherein the valve pin has a tip portion to close the mold gate and a flow control surface located in the nozzle melt channel upstream from said tip portion;
- and
- reducing the amount of molten material injected through each nozzle into each mold cavity by individually and independently moving the valve pin flow control surface in the nozzle melt channel toward its respective mold cavity before closing each mold gate with the tip portion of the valve pin.
Dependencies are inferred from the claim text.