Abstract: A method and apparatus for proportioning flow and controlling pressure to a gate of an injection mold. The invention decouples the control surface from the gate closure to reduce the required actuation force. Methods for estimating the pressure and flow rate entering the injection mold are included.

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 though. A flow control pin is disposed within the melt stream, either coaxially with the valve pin within the melt channel of the nozzle or within the manifold melt channel. The flow control pin has a head with a complementary geometry with that of the melt channel at a flow control surface. The flow control pin is raised and lowered by an actuation mechanism to constrict or release the flow of the melt stream independent from the movement of the valve pin.

Abstract: A valve pin bushing for a valve gated injection molding apparatus having, a back plate, a valve pin bushing, and a manifold, with axially aligned respective valve pin bores. The valve pin bushing includes a back plate contacting surface and an opposite manifold contacting surface for bearing against the back plate and manifold, respectively. The back plate contacting surface has a surface area larger than a surface area of the manifold contacting surface to draw heat from the valve pin bushing to the cooler back plate. An air gap, which may be sealed by an optional sealing portion, is formed where the flange is spaced away from a central portion of the valve pin bushing near the manifold. The valve pin bushing also includes a tubular member for positioning within the manifold valve pin bore, which defines a portion of the manifold melt passageway.

Abstract: A valve pin adjustment system is provided for use in valve gated injection molding applications which enables adjustments to the positioning of the valve pin without necessitating removal of the clamping plates and valve assembly components, including valve pins. A piston associated with the valve pin includes a cylindrical body having first and second co-axially aligned internally threaded bores of respective first and second diameters. Preferably, the threads formed in the first and second bores are of the opposite hand. First and second externally-threaded cylindrical valve pin positioning members are respectively received in the first and second bores. Each of the positioning members includes a head portion and a tip portion. The tip of the second positioning member is in contact with the head of the first positioning member to lock the first positioning member in place, and the tip of the first positioning member is in contact with a head portion on the valve pin to locate the valve pin.

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: It is provided an apparatus for injection molding articles of plastics material comprising: molds (2a) and countermolds (2b) forming molding units (3), molding cavities (7) being defined inside said molds and countermolds; one injection assembly (8) and one auxiliary assembly (9) adapted to respectively supply melted plastics material and pressurized fluid into the molding cavities; molding units (3) being movable with respect to said injection assembly (8) and auxiliary assembly (9); and removable connecting devices (12, 8a), and check means (20) adapted to avoid counter flows from molding cavities (7), being provided between molding units (3) and injection assembly (8) and auxiliary assembly (9).

Abstract: A nozzle for an injection molding apparatus is provided. The injection molding apparatus includes a manifold and a mold component. The manifold has at least one runner therein that is downstream from a melt source. The mold component defines at least one mold cavity and defining a gate into each mold cavity. The gate defines an axis. The mold component has a mold component alignment surface thereon. The nozzle includes a nozzle body, a tip, a tip surrounding piece and an alignment piece. The nozzle body defines a nozzle body melt passage, which is adapted to be in fluid communication and downstream from the at least one runner. The tip is removably connected to the nozzle body. The tip defines a tip melt passage therethrough. The tip melt passage is downstream from and in fluid communication with the nozzle body melt passage, and is upstream from and in fluid communication with the gate. The tip surrounding piece is removably connected with respect to the nozzle body.

Abstract: The invention relates to an adjustment device for a valve pin on an injection molding machine, and particularly on a multi-cavity machine, having a plurality of valve pins mounted on a common yoke plate which is actuated by a common actuator. The adjustment device includes a pin holder for holding the valve pin, and a locking member. The pin holder has two threaded portions. The first threaded portion is adjustable within a threaded receiving hole in the yoke plate. The second threaded portion is received by the locking member. The locking member has a bottom shoulder which butts against the yoke plate, and retains the pin holder in place.

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: A valve gate assembly for regulating a flow of molten material into a mold. The valve gate assembly includes a movable valve that can move between a fully closed position and a fully open position. The valve gate assembly further includes an actuating system operatively cooperating with the valve to move the valve and infinitely position the valve between the fully closed position and the fully open position.

Abstract: A closing element, which has an open position and a closed position and is actuated by an actuating element, is arranged in the nozzle channel of a nozzle body. In the closing position, the closing element separates a region that is at least temporarily in open communication with the injection mold, the region being able to be influenced by a second actuating element associated with the nozzle body. Due to the fact that the pressure element is arranged in the nozzle body and can be actuated independently from the nozzle body and the plastifying cylinder, a nozzle body is created and a method is provided that enable the dosing process and dwell pressure process to be separated with a compact structure.

Abstract: A nozzle is provided for an injection molding apparatus. The injection molding apparatus includes a mold block. The mold block defines at least one mold cavity that has a gate. The nozzle includes a nozzle body, a valve pin, an actuator, a first heating element and a second heating element. The nozzle body defines a nozzle body melt channel that is in fluid communication with and downstream from a melt source and that is in fluid communication with and upstream from the gate. The valve pin includes an upstream portion that defines a valve pin melt channel, wherein the valve pin melt channel has an inlet and at least one outlet. The inlet and the at least one outlet are in fluid communication with the nozzle body melt channel. The valve pin further includes a tip piece connected to the upstream portion. The valve pin is movable in the nozzle body melt channel for controlling the melt flow through the gate.

Abstract: An injection molding apparatus includes a nozzle body, a valve pin, a nozzle tip, a seal piece, and a mold gate insert. The nozzle body has a melt channel. The valve pin is at least partially positioned in the melt channel. The valve pin has a first guidance and alignment structure thereon. The nozzle tip is connected to the nozzle body. The seal piece is connected to the nozzle body. The mold gate insert defines a gate and is in contact with the seal piece. The nozzle tip has a higher thermal conductivity than the nozzle body. The seal piece has a lower thermal conductivity than the nozzle body. The mold gate insert has a higher thermal conductivity than the seal piece. The mold gate insert includes a second guidance and alignment structure thereon that contacts the first guidance and alignment structure before the valve pin contacts the gate.

Abstract: The present invention relates to an injector device for injecting thermoplastic material. The device comprises a dispenser (8) feeding a transit passage (12) of an injector nozzle (7) with thermoplastic material, said passage opening out into the mold cavity (2) and being capable of being closed by a sliding needle (21). The needle (21) presents an extender (24) which passes through the dispenser (8) into ambient air via guide means (38) in order to co-operate with controlled means (30) for moving the needle (21). Sealing is provided between the extender (24) and the guide means (38) by the thermoplastic material itself, which material leaks between them from the dispenser (8) and accumulates in an annular groove (43) in one of them. The invention is applicable to injection molding devices.

Abstract: In-line valve-gated nozzles for a single or multiple cavity applications wherein a valve-gated hot runner nozzle has a melt channel uniformly heated along the entire path. The valve pin is driven by an actuation device that is located adjacent to the nozzle to regulate the flow of melt. The actuation device has a linear motion and applies a uniform axial pressure on to the valve pin. This valve-gated nozzle can be linked directly to a machine nozzle, to an injection manifold or to a stack mold.

Abstract: A valve gate is provided for an injection molding manifold having at least one drop defining at least one channel for transporting a flow of plasticized melt therethrough. The valve gate has a pin mounted in the manifold to extend across the channel in a sliding relation. The pin has a transversely extending aperture that aligns with the channel opening the flow. Reciprocating movement of the pin in a direction transverse to the flow of the plasticized melt opens and closes flow thereof.

Abstract: A valve bushing assembly for use in an injection molding apparatus is provided. The injection molding apparatus includes a manifold block, a valve pin, and an actuator block. The manifold block has at least one melt channel therein. The manifold block has an exterior surface that faces the actuator block, and has a manifold pass-through extending from the exterior surface to the at least one melt channel. The manifold pass-through has a manifold sealing surface therein. The manifold pass-through permits the valve pin to pass therethrough. The actuator block has an actuator attached thereto, that is operatively connected to the valve pin. The valve bushing assembly includes a bushing and a spacer. The bushing is adapted to be received in the manifold pass-through. The bushing has a bushing pass-through that is adapted to align with the manifold pass-through and is adapted to slidably receive the valve pin.

Abstract: An injection nozzle for plastic injection moulding equipment having a nozzle tip (4) with an internal hollow element (5) made of a material with high thermal conductivity, and an external hollow element (6) made of a material with a lower thermal conductivity. The internal hollow element (5) is connected to the body (1) of the injector nozzle independently with respect to the external hollow element (6), and a space of mutual separation (19) is defined between the internal and external hollow elements (5, 6).

Abstract: A valve pin assembly for an injection molding apparatus comprising a valve pin capable of movement up and down in a nozzle to open and close a ring gate. An annular passage is created through the nozzle and is unobstructed and without restriction at all points up to and through the ring gate, permitting melt to flow freely to the gate and, depending on the position of the valve pin, into the mold cavity. The valve pin has a head with a diameter larger than the valve pin shaft for selectively closing the gate. The ring gate channel diameter is larger than the melt channel diameter to permit parts with large apertures therein to be formed.

Abstract: A stack injection molding apparatus has first and second arrays of valve gate injection nozzles and separate mechanisms for independently actuating the nozzles of each array. A separate reciprocating yoke plate engages the valve pins of each nozzle array, and is actuated by either one centrally located actuator or a pair of symmetrically located actuators.

Abstract: The present invention provides an injection molding die having a simplified valve gate and simplified attachment structures for the valve gate. The die includes: a first die 4 with a gate 7; a second die 20 forming, together with the first die 4, a molding cavity 23 that communicates with the gate 7; a manifold 10 containing a molding material supply path 12 communicating with the gate 7; a thermal insulation space 16 disposed between the first die 4 and the manifold 10; and a valve gate 24 disposed between the first die 4 and the manifold 10 opening and closing the gate. The valve gate 24 includes: a valve pin 25 passing through the first die 4 and the manifold 10 and opening and closing the gate 7; a sealing member 27 mounted on the manifold 10 where the valve pin 25 passes through and providing a seal between the manifold 10 and the first die 4; and a heater 29 heating the manifold 10.

Abstract: A stack injection molding apparatus has first and second arrays of valve gate injection nozzles and separate mechanisms for independently actuating the nozzles of each array. A separate reciprocating yoke plate engages the valve pins of each nozzle array, and is actuated by either one centrally located actuator or a pair of symmetrically located actuators.

Abstract: The actuating unit comprises a piston element (21) slidable in a cylinder element (20) and connectable to a closure rod (16) slidable in an injection duct (14) between an extended position in which it blocks an injection hole (15) and an injection position in which it is retracted into the injection duct. The piston element (21) has an engaged seat (46, 47) which can house a head end portion (16a) of the rod (16). The engagement seat is shaped so as to allow the piston element (21) to be translated transversely relative to the axial direction of movement of the rod (16) in order to release the piston element (21) from the rod.

Abstract: An optical disk and a method of producing it, particularly a stamper for molding a semiconductor disk base capable of forming an optical disk sufficiently compatible with commercially available CD (Compact Disk) players, a method of producing a stamper, a method of producing an optical disk base, a method of producing an optical disk, and an optical disk base and optical disk are disclosed. The present invention improves both of transferability and tact of an optical disk base molding cycle, allows a fine pattern to be formed in a transfer surface, and makes it needless to change existing molding equipment. In addition, when guide grooves formed in the optical disk are filled with a pigment by spin coating, the guide grooves have a substantially uniform configuration in the radial direction of the disk. The optical disk is sufficiently compatible with various CD players available on the market.

Abstract: A valve pin for use in a melt channel in an injection molding machine. The valve pin has a valve pin body and at least one thermocouple substantially completely inside the valve pin body.

Abstract: The invention relates to an injection molding device (1) having an elongated nozzle (3) and a valve pin (11) coaxially in a channel of the nozzle. The valve pin can be displaced by means of an actuating cylinder (15) and is guided through a bush (13) at the upper end (12) of the nozzle. Cooling means (14, 18) are associated with said bush (13).

Abstract: A control and regulating device for a needle element (24) of a hot or cold channel (20) of a plastic molding tool, wherein a rotary movement of a drive device is converted by a converting device (26) into an axial movement of the needle element (24). In order to achieve optimum plastic production, that is to say to permit optimum movement of the needle element (24) both during the idle stroke movement and also during the process regulation phase and during deceleration, the converting device has at least one slide path (30) and a follower element (50) which is guided in the slide path (30), wherein the at least one slide path (30) which is angled, that is to say which has path pitches which are different from each other, is formed on a slide path surface which is concentric with respect to the center line (42) of the needle element.

Abstract: An injection molding device (1) having a valve pin (11) and an actuating cyclinder (15) connected to the valve pin (11). The valve pin head (37) is releasably attached to the piston (33) of the cylinder such that the cylinder can be removed while leaving the valve pin (11) from the nozzle such that a low headspace can be achieved above the nozzle.

Abstract: The invention relates to compression injection plastic molding using a repository space, for the temporary storage of the molding material melt to prevent structural faults and reduce workpiece costs. The molten molding material is first fed into the repository space, whose volume corresponds to the volume of the mold cavity. When the injection process starts, the bottom of the piston aligns with the edge of the repository space and with the wall of the mold cavity so that a small amount of molding material melt reaches the mold cavity directly. The piston then slides into the cylinder. The repository space, which continuously becomes larger, is filled with a melted material at almost no pressure. The melt is conveyed into the plastic core until tho supply of the melted molding material is ended. The piston is then retracted, and the mold cavity is thus completely filled with molding material.

Abstract: A flow deflector apparatus and method in an injection molding system which transitions a flowing medium around an obstruction, said flowing medium exhibiting reduced stagnation points and substantially uniform flow characteristics downstream of the obstruction.

Abstract: The present invention relates to an in-mold gate opening and closing mechanism in which it is easy to adjust the gate balance, more specially, in an in-mold gate opening and closing mechanism, in which a gate pin disposed in a gate in a mold is moved in line with resin pressure in the gate, the gate is opened by the gate pin escaping from the gate when the resin pressure exceeds an appointed pressure level when filling resin, and the gate is closed by the gate pin moving the gate direction when the resin pressure is lowered from the appointed pressure level when a filling of the resin is completed, wherein the gate is opened by a gate pin escaping from the gate when the resin pressure exceeds a pressing force of a spring adjusted by a mechanism for adjusting the spring pressure when filling resin.

Abstract: An injection molding apparatus and method for multi-layer molding of preforms and closures has a central melt channel, an annular melt channel radially spaced from the central melt channel, and an annular ring channel surrounding the central melt channel. The central melt channel has a first portion for flow of a first material, a second portion for flow of the first material and a second material, and a flow extension connecting the first portion and the second portion. The flow extension has a flow opening in communication with the annular ring channel for flow of the second material. The apparatus and method also include a cavity for receiving flow of the first material and the second material from the central melt channel, and for receiving flow of the first material from the annular melt channel. In addition, the apparatus and method include a melt passage having a first melt portion in communication with the central melt channel, and a second melt portion in communication with the annular melt channel.

Abstract: An injection molding apparatus and method for multi-layer molding of preforms and closures has a central melt channel, an annular melt channel radially spaced from the central melt channel, and an annular ring channel surrounding the central melt channel. The central melt channel has a first portion for flow of a first material, a second portion for flow of the first material and a second material, and a flow extension connecting the first portion and the second portion. The flow extension has a flow opening in communication with the annular ring channel for flow of the second material. The apparatus and method also include a cavity for receiving flow of the first material and the second material from the central melt channel, and for receiving flow of a third material from the annular melt channel.

Abstract: Injector (1) for injection molding of plastic materials, comprising a body (2, 6) and a passage for running hot plastic material into the mold, an axially mobile pin (7) in the body (2, 6) for controlling said passage and a linear actuator (8) for controlling the movement of the pin (7) between an advanced closed position of said passage and a retracted open position of said passage. The injector (1) is equipped with a pressure sensor (13) detecting the pressure inside the mold, which is operative associated to said pin (7).

Abstract: A valve pin guide is provided for guiding a valve pin from a nozzle into a gate of a mold cavity in an injection molding apparatus. The valve pin guide defines a guide aperture therethrough. The guide aperture is adapted to receive and guide the valve pin into alignment with the gate. The valve pin guide is positioned downstream from said nozzle and upstream from said gate.

Abstract: An injection molding nozzle is provided having a first sealing member to substantially eliminate the leakage of molten material from around the injection nozzle. A second sealing member is configured to substantially reduce the leakage of a pressurized fluid, such as air, which may be used to open and close a valve stem associated with the injection nozzle.

Abstract: A valve bushing assembly for use in an injection molding apparatus is provided. The injection molding apparatus includes a manifold block, a valve pin, and an actuator block. The manifold block has at least one melt channel therein. The manifold block has an exterior surface that faces the actuator block, and has a manifold pass-through extending from the exterior surface to the at least one melt channel. The manifold pass-through has a manifold sealing surface therein. The manifold pass-through permits the valve pin to pass therethrough. The actuator block has an actuator attached thereto, that is operatively connected to the valve pin. The valve bushing assembly includes a bushing and a spacer. The bushing is adapted to be received in the manifold pass-through. The bushing has a bushing pass-through that is adapted to align with the manifold pass-through and is adapted to slidably receive the valve pin.

Abstract: In an injection molding machine, an apparatus for automatically controlling the movement of two or more valve pins wherein each valve pin is driven by a separately controlled fluid driven cylinder each cylinder being mounted on a heated manifold and being interconnected to a separate valve pin for effecting reciprocal movement of the valve pin wherein the reciprocal movement of the valve pin controls the flow of molten plastic being delivered through a nozzle which delivers molten plastic to a gate of a mold.

Abstract: The present invention provides an injection molding die having a simplified valve gate and simplified attachment structures for the valve gate. The die includes: a first die 4 with a gate 7; a second die 20 forming, together with the first die 4, a molding cavity 23 that communicates with the gate 7; a manifold 10 containing a molding material supply path 12 communicating with the gate 7; a thermal insulation space 16 disposed between the first die 4 and the manifold 10; and a valve gate 24 disposed between the first die 4 and the manifold 10 opening and closing the gate. The valve gate 24 includes: a valve pin 25 passing through the first die 4 and the manifold 10 and opening and closing the gate 7; a sealing member 27 mounted on the manifold 10 where the valve pin 25 passes through and providing a seal between the manifold 10 and the first die 4; and a heater 29 heating the manifold 10.

Abstract: A movable mold is disposed so as to face the stationary mold and to be advanceable and retractable. The movable mold forms a cavity in cooperation with the stationary mold when mold clamping is performed. A sprue is disposed to face the cavity and has a concave portion formed at a front end thereof. A cut punch is reciprocatively disposed to face the cavity at a position corresponding to the concave portion. The cut punch enters the concave portion when advanced. A drive section is provided to advance and retract the cut punch when driven. A controller drives the drive section such that during the mold clamping, the cut punch is advanced at a predetermined extension force in order to perform gate cutting and such that the extension force is made no greater than a preset value before the mold is opened.

Abstract: A system for injection moulding of large plastics components in a single shot comprises an extruder and an accumulator fed from the extruder The accumulator leads into the mould (14) via a mould valve (12) opive, when closed, to close the mould cavity substantially at the mould surface and also to close an outlet (20a) from the accumulator. The valve passage of the mould valve is of relatively large cross-section, typically several centimetres or more which facilitates injection at relatively low pressures and also facilitates passage of stones and other particulate matter which may be present if the extrudate is composed of post-consumer recycled plastics.

Abstract: Injection mold for manufacturing disc-shaped plastic objects with a central hole, which mold comprises: a first mold part; a second mold part displaceable relative to this first mold part; which two mold parts are displaceable between a closed first position, in which they together partially bound a mold cavity corresponding to the shape of an object for manufacture, and an open second position in which a formed object can be removed; a third mold part which in an active position extends through the mold cavity and in the region of this mold cavity has a shape corresponding to the shape of the central hole, which third mold part is axially displaceable relative to the first and second mold parts between said active position and a retracted rest position; which third mold part bounds with the guide sleeve a channel which is connectable to the injection nozzle of an injection molding device, which channel can be opened and closed by means of a valve consisting of a valve seat which is formed by a part of the in

Abstract: A valve pin actuator is disclosed that includes a cylinder mounted to the clamping plate, a piston slidably mounted in the cylinder, and a valve pin assembly carried by the piston. A hydraulic or pneumatic circuit is provided for controlling the movement of the piston, and in turn translation of the valve pin between the seated and unseated positions. The valve pin assembly includes a first part removably secured to the piston so as to translate therewith, and a second part for receiving the valve pin and secured to said manifold. The actuator assembly enables removal of the clamping plate without removal of the valve pin assembly, and also adjusting of the valve pin without removal of the clamping plate. The assembly further provides a clearance between the piston and valve pin assembly, to accommodate expansion and movement of the manifold that would otherwise cause a side load to be exerted on the valve pin.

Abstract: In an injection molding machine having first and second nozzles for delivering melt material to first and second mold cavities of first and second molds respectively, apparatus for controlling delivery of the melt material from the nozzles to the mold cavities, each nozzle having an exit aperture communicating with a gate of a cavity of a respective mold and being associated with an actuator interconnected to a melt flow controller, the apparatus comprising a sensor for sensing a selected condition of the melt material through at least one of the nozzles; an actuator controller interconnected to each actuator, the actuator controller interconnected to the actuator associated with the at least one nozzle comprising a computer interconnected to the sensor, the computer receiving a signal representative of the selected condition sensed by the sensor, the computer including an algorithm utilizing a value corresponding to a signal received from the sensor as a variable for controlling operation of the actuator for

Abstract: An injection molding device (1) including an actuating cylinder (15) with a piston (33). A valve pin (11) is actuated by the cylinder (15), the piston including a fluid passage (55) via which pressure medium can pass when the piston is in a position between its upper and its lower end position, and which is at least partly closed off when the piston is in its lower and/or its upper end position. Hereby relatively simple position indicator of the valve pin (11) is formed.

Abstract: A leak preventing device for fluid shooting nozzle of an injection molding machine includes a material stop valve pivotally screwed with a front side of a vertical flow passageway of a hot-material passageway plate, a shaft position base provided at a rear side of the vertical flow passageway, a shaft inserting through the stop valve, the vertical flow passageway and the shaft position base, and a material stop end at front end of the shaft supported by a support plate in the material stop valve. The rear end of the shaft protrudes out of the shaft position base and connected to a piston fixed with a mold fix plate for mutual movement to let the stop end of the shaft rod fitting in a shooting nozzle in the stop valve to prevent raw material inside from leaking out. Besides, after a screw conveying tube shoots out raw material, the remaining pressure in a flow passageway will push the leak-preventing portion to prevent leaking.

Abstract: The invention relates to an injection molding device (1) having an elongated nozzle (3) and a valve pin (11) coaxially in a channel of the nozzle. The valve pin can be displaced by means of an actuating cylinder (15) and is guided through a bush (13) at the upper end (12) of the nozzle. Cooling means (14, 18) are associated with said bush (13).

Abstract: An injection molding device (1) having a valve pin (11) and an actuating cyclinder (15) connected to the valve pin (11). The valve pin head (37) is releasably attached to the piston (33) of the cylinder such that the cylinder can be removed while leaving the valve pin (11) from the nozzle such that a low headspace can be achieved above the nozzle.

Abstract: A valve gating apparatus for injection molding including at least one shutter disposed between the gate and the cavity melt channel into a mold cavity. The shutter is removably fastened to a rail member. When the rail member is moved laterally, the shutter moves between a closed position wherein flow of melt from the nozzle into the cavity is inhibited, and an open position wherein flow of melt into the cavity is unimpeded by the shutter.

Abstract: A valve stem is mounted in a nozzle body, with the valve stem moving from an open position retracted from the injection orifice permitting the flow of resin to the mold cavity, to a closed position blocking the injection orifice and preventing the flow of resin to the mold cavity, and to an advanced position within the gate nub area to assist in the ejection of a molded part and clear the gate nub area.