Abstract: An injection molding apparatus is disclosed having a single level manifold that utilizes a melt splitter. The manifold defines an inlet and a plurality of outlets with at least one upstream melt channel and a plurality of downstream melt channels that are situated between the inlet and the plurality of outlets. The upstream melt channel branches into the plurality of downstream melt channels with the upstream melt channel and each of the downstream melt channels longitudinally extending in the same plane. The melt splitter is at least partially positioned within the upstream melt channel where the upstream melt channel intersects with the plurality of downstream melt channels. The melt splitter divides a melt flow received from the upstream melt channel into substantially equal volumes and then directs each of the substantially equal volumes into a respective one of the plurality of downstream melt channels.

Abstract: An injection molding apparatus is disclosed having a single level manifold that utilizes a melt splitter. The manifold defines an inlet and a plurality of outlets with at least one upstream melt channel and a plurality of downstream melt channels that are situated between the inlet and the plurality of outlets. The upstream melt channel branches into the plurality of downstream melt channels with the upstream melt channel and each of the downstream melt channels longitudinally extending in the same plane. The melt splitter is at least partially positioned within the upstream melt channel where the upstream melt channel intersects with the plurality of downstream melt channels. The melt splitter divides a melt flow received from the upstream melt channel into substantially equal volumes and then directs each of the substantially equal volumes into a respective one of the plurality of downstream melt channels.

Abstract: An injection molding system is disclosed having a self-regulating valve for balancing melt flow. The self-regulating valve includes a control rod configured to balance the melt flow rate through a hot runner system. The self-regulating valve reacts to an injection or melt pressure within the hot runner system and a pre-set force provided by an external force device. The self-regulating valve is an open-loop system as it requires neither a measurement of pressure by a sensor nor feedback from a processor in order to regulate the melt flow. The self-regulating valve mechanically reacts to changes in melt pressure on control surfaces thereof by “bobbing” upwards/downwards to decrease/increase the melt flow accordingly. The self-regulating valve compensates for conditions that affect melt pressure, such as an increase/decrease in melt viscosity, changes in melt temperature, and/or mold cavity size without the use of a processing device.

Abstract: An injection molding system is disclosed having a self-regulating valve for balancing melt flow. The self-regulating valve includes a control rod configured to balance the melt flow rate through a hot runner system. The self-regulating valve reacts to an injection or melt pressure within the hot runner system and a pre-set force provided by an external force device. The self-regulating valve is an open-loop system as it requires neither a measurement of pressure by a sensor nor feedback from a processor in order to regulate the melt flow. The self-regulating valve mechanically reacts to changes in melt pressure on control surfaces thereof by “bobbing” upwards/downwards to decrease/increase the melt flow accordingly. The self-regulating valve compensates for conditions that affect melt pressure, such as an increase/decrease in melt viscosity, changes in melt temperature, and/or mold cavity size without the use of a processing device.

Abstract: An injection molding system is disclosed having a self-regulating valve for balancing melt flow. The self-regulating valve includes a control rod configured to balance the melt flow rate through a hot runner system. The self-regulating valve reacts to an injection or melt pressure within the hot runner system and a pre-set force provided by an external force device. The self-regulating valve is an open-loop system as it requires neither a measurement of pressure by a sensor nor feedback from a processor in order to regulate the melt flow. The self-regulating valve mechanically reacts to changes in melt pressure on control surfaces thereof by “bobbing” upwards/downwards to decrease/increase the melt flow accordingly. The self-regulating valve compensates for conditions that affect melt pressure, such as an increase/decrease in melt viscosity, changes in melt temperature, and/or mold cavity size without the use of a processing device.

Abstract: An edge gated injection molding apparatus includes a manifold having a manifold channel for receiving a melt stream of moldable material under pressure. A nozzle is coupled to the manifold and a nozzle melt channel of the nozzle receives the melt stream from the manifold channel. A mold cavity communicates with the nozzle melt channel of the nozzle and receives melt through a mold gate. The mold gate is located at an edge of the mold cavity. A chamber receives melt from the nozzle channel and communicates with the mold cavity through the mold gate. A portion of the chamber is located forward of the mold gate. A valve pin is slidable through the nozzle channel from a first position in which the mold gate is open to a second position in which an outer side surface of the valve pin blocks the mold gate.

Abstract: An injection molding system is disclosed having a self-regulating valve for balancing melt flow. The self-regulating valve includes a control rod configured to balance the melt flow rate through a hot runner system. The self-regulating valve reacts to an injection or melt pressure within the hot runner system and a pre-set force provided by an external force device. The self-regulating valve is an open-loop system as it requires neither a measurement of pressure by a sensor nor feedback from a processor in order to regulate the melt flow. The self-regulating valve mechanically reacts to changes in melt pressure on control surfaces thereof by “bobbing” upwards/downwards to decrease/increase the melt flow accordingly. The self-regulating valve compensates for conditions that affect melt pressure, such as an increase/decrease in melt viscosity, changes in melt temperature, and/or mold cavity size without the use of a processing device.

Abstract: An injection molding apparatus that includes a nozzle having a nozzle channel, a mold cavity in communication with the nozzle channel of the nozzle for receiving a melt stream of moldable material from the nozzle channel through a mold gate; and a valve pin that is axially movable through the nozzle channel of the nozzle between a first retracted position in which the valve pin closes the mold gate to block melt flow between the nozzle channel and the mold cavity, an extended position in which an end portion of the valve pin extends through the mold gate and into the mold cavity, and a third retracted position in which the end portion of the nozzle pin is withdrawn from the mold cavity into the nozzle and spaced apart from the mold gate thereby opening the mold gate.

Abstract: An injection molding apparatus comprises a manifold having a manifold channel for receiving a melt stream of moldable material under pressure and delivering the melt stream to a nozzle channel of a nozzle. A mold cavity is in communication with the nozzle channel of the nozzle and receives melt through a mold gate. A valve pin is axially movable through the nozzle channel of the nozzle to selectively open the mold gate. The mold gate is open when the valve pin is in an extended position and a portion of the valve pin is received in the mold cavity. At least one groove is provided in an outer surface of the valve pin and at least a portion of the outer surface of the valve pin is in continuous engagement with the mold gate to align the valve pin relative to the mold gate. When the valve pin is in the extended position, the groove is aligned with the mold gate to allow melt to flow between the nozzle channel and the mold cavity.

Abstract: A sprue bushing includes a melt channel for receiving a melt stream of moldable material from a source. The melt channel includes a first portion, a second portion and a decompression cavity located between the first portion and the second portion. A manifold having a manifold channel receives the melt stream from the melt channel of the sprue bushing and delivers the melt stream through the nozzle channels of several hot runner nozzles towards at least one mold cavity. A decompression device, which includes a rod having an enlarged head, is movable by an actuator to reciprocate within the decompression cavity between a retracted position and an extended position. Movement of the enlarged head from the extended position to the retracted position causes the suck back of the molten material in the hot runner nozzle and causes a portion of the molten material to be drawn toward the decompression cavity.

Abstract: An improved melt distribution system and method is provided for a multi-level stack mold having three or more moving platens. The injection machine communicates with a bifurcated sprue bar for providing pressurized melt through the first moving platen to a central distribution manifold in the second moving platen. From the central distribution manifold, the flow of pressurized melt is distributed to the first and third platens for transfer to a plurality of mold cavities.

Abstract: An edge gated injection molding apparatus includes a manifold having a manifold channel for receiving a melt stream of moldable material under pressure. A nozzle is coupled to the manifold and a nozzle melt channel of the nozzle receives the melt stream from the manifold channel. A mold cavity communicates with the nozzle melt channel of the nozzle and receives melt through a mold gate. The mold gate is located at an edge of the mold cavity. A chamber receives melt from the nozzle channel and communicates with the mold cavity through the mold gate. A portion of the chamber is located forward of the mold gate. A valve pin is slidable through the nozzle channel from a first position in which the mold gate is open to a second position in which an outer side surface of the valve pin blocks the mold gate.

Abstract: A stack or tandem injection molding apparatus includes a first melt transfer nozzle coupled to a stationary platen and a second melt transfer nozzle coupled to a movable platen. A melt transfer device includes a first valve pin extending through a first melt transfer channel of the first melt transfer nozzle and a second valve pin extending through a second melt transfer channel of the second melt transfer nozzle. At least one groove is provided in the outer surface of the first valve pin. The first valve pin is movable relative to the first and second melt transfer nozzles to selectively locate the groove across a portion of the first melt transfer channel and a portion of the second melt transfer channel to allow melt to flow therebetween in the mold closed position and to prevent drooling in the mold open position.

Abstract: An improved melt distribution system and method is provided for a multi-level stack mold having three or more moving platens. The injection machine communicates with a bifurcated sprue bar for providing pressurized melt through the first moving platen to a central distribution manifold in the second moving platen. From the central distribution manifold, the flow of pressurized melt is distributed to the first and third platens for transfer to a plurality of mold cavities.

Abstract: An injection molding apparatus that includes a nozzle having a nozzle channel, a mold cavity in communication with the nozzle channel of the nozzle for receiving a melt stream of moldable material from the nozzle channel through a mold gate; and a valve pin that is axially movable through the nozzle channel of the nozzle between a first retracted position in which the valve pin closes the mold gate to block melt flow between the nozzle channel and the mold cavity, an extended position in which an end portion of the valve pin extends through the mold gate and into the mold cavity, and a third retracted position in which the end portion of the nozzle pin is withdrawn from the mold cavity into the nozzle and spaced apart from the mold gate thereby opening the mold gate.

Abstract: An injection molding apparatus comprises a manifold having a manifold channel for receiving a melt stream of moldable material under pressure and delivering the melt stream to a nozzle channel of a nozzle. A mold cavity is in communication with the nozzle channel of the nozzle and receives melt through a mold gate. A valve pin is axially movable through the nozzle channel of the nozzle to selectively open the mold gate. The mold gate is open when the valve pin is in an extended position and a portion of the valve pin is received in the mold cavity. At least one groove is provided in an outer surface of the valve pin and at least a portion of the outer surface of the valve pin is in continuous engagement with the mold gate to align the valve pin relative to the mold gate. When the valve pin is in the extended position, the groove is aligned with the mold gate to allow melt to flow between the nozzle channel and the mold cavity.

Abstract: A sprue bushing includes a melt channel for receiving a melt stream of moldable material from a source. The melt channel includes a first portion, a second portion and a decompression cavity located between the first portion and the second portion. A manifold having a manifold channel receives the melt stream from the melt channel of the sprue bushing and delivers the melt stream through the nozzle channels of several hot runner nozzles towards at least one mold cavity. A decompression device, which includes a rod having an enlarged head, is movable by an actuator to reciprocate within the decompression cavity between a retracted position and an extended position. Movement of the enlarged head from the extended position to the retracted position causes the suck back of the molten material in the hot runner nozzle and causes a portion of the molten material to be drawn toward the decompression cavity.

Abstract: An improved melt distribution system and method is provided for a multi-level stack mold having three or more moving platens. The injection machine communicates with a bifurcated sprue bar for providing pressurized melt through the first moving platen to a central distribution manifold in the second moving platen. From the central distribution manifold, the flow of pressurized melt is distributed to the first and third platens for transfer to a plurality of mold cavities.

Abstract: A guide for a manifold plug of an injection molding apparatus comprises a guide body projecting from an inner wall of the manifold plug diametrically opposing an inlet of a manifold plug channel formed in the manifold plug. The inlet is aligned with a manifold channel of a manifold. The outlet of the manifold plug channel is aligned with a nozzle channel of a nozzle. The inlet is at an angle to the outlet. A guide surface is provided on the guide body for abutting a downstream portion of a valve pin extending into the manifold plug channel. The guide also facilitates flow of a melt stream of moldable material through the manifold plug channel.

Abstract: A stack or tandem injection molding apparatus includes a first melt transfer nozzle coupled to a stationary platen and a second melt transfer nozzle coupled to a movable platen. A melt transfer device includes a first valve pin extending through a first melt transfer channel of the first melt transfer nozzle and a second valve pin extending through a second melt transfer channel of the second melt transfer nozzle. At least one groove is provided in the outer surface of the first valve pin. The first valve pin is movable relative to the first and second melt transfer nozzles to selectively locate the groove across a portion of the first melt transfer channel and a portion of the second melt transfer channel to allow melt to flow therebetween in the mold closed position and to prevent drooling in the mold open position.