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: A mold gate insert includes a mold gate insert body, which is comprised of a material having a high thermal conductivity, and a thermal insulation element, which is nested in the mold gate insert body. The thermal insulation element is provided to abut a nozzle seal and align the nozzle with a mold gate. The amount of heat transferred from the nozzle to the mold gate insert is reduced by the thermal insulation element.

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: A locking mechanism for locking a valve pin of a nozzle of an injection molding apparatus in an extended position includes a generally oblong detent coupled to a pin. The pin extends through an aperture located at a first end of the detent to secure the detent to an inner wall of a recess, which is located adjacent the piston-receiving cavity of the valve pin. The detent is pivotable about the pin to rotate a second end of the detent into abutment with a return surface of the piston to restrict movement of the valve pin.

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 metering device for an injection molding unit includes a base body having an antechamber in fluid communication with a feed channel for introduction of plastic material, and a metering chamber in fluid communication with a injection channel. The antechamber and the metering chamber are connectable with one another by a closeable passageway. Movably arranged in the base body between the antechamber and the metering chamber is a displacement member in the form of a piston to separate the antechamber and the metering chamber. The piston has a first end face which demarcates the antechamber and a second end face which demarcates the metering chamber, with the first end face defining an effective area which is smaller than an effective area of the second end face.

Abstract: A co-injection nozzle pin (20) having downstream and upstream ends. The nozzle pin has therein a central bore (30) including an upstream end (32) adapted to communicate with a first material and a downstream end (34) exiting at the downstream end of the pin. The nozzle pin also has an outer surface (36) including a first portion (38) having a diameter D1, a second portion (40) having a diameter D2, wherein D2 is less than D1 and the first portion is rearward of the second portion. The pin further includes a channel (46) spiralling around the outer surface and being adapted to communicate with a second material. The channel (46) includes a first segment (52) defined in the first portion (38) of the outer surface and increasing in depth as it travels in a downstream direction and a second segment (54) defined in the second portion (40) of the outer surface and decreasing in depth as it travels in a downstream direction.

Abstract: An injection valve includes an injection channel (17) that opens outwards via an outlet (18) and has a specific inlet for the arrival of the molding material (19A) remote from the outlet (18), in addition to a slider unit (20) that is moveably mounted in the injection channel (17) and controls the outlet thereof (18). The injection channel (17) has a specific outlet (19B) for discharging the molding material. The invention can be used to mold an optical lens made from a polymerizable synthetic material.

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 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: 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: An injection manifold has a main runner provided with a supply inlet intermediate opposite ends of the runner. A number of branches intersect with the runner along its length so as to be disposed at unequal distances from the inlet. In order to achieve more simultaneous delivery, uniform fill rate, and identity of temperature of hot melt across all cavities of a multi-cavity set to achieve more uniform cooling of the preforms, restrictor pin assemblies are provided in association with certain of the branches to adjustably constrict the space available for melt flow from the runner into the branch. In a preferred form each restrictor pin assembly includes a pin aligned axially with the branch and passing transversely through the runner, the pin being adjustable between a fully extended, maximum constriction position in which the tip of the pin is located within the branch and a fully retracted, open position in which the tip is withdrawn out of the branch and is spaced below the opening of the branch.

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: A valve pin actuating mechanism including a valve pin guiding element for connection to a valve pin, a linkage element and an actuator. The valve pin guiding element has a sliding surface for sliding within a channel, and first and second engagement surfaces. The linkage element has first and second arms, which have opposing, inwardly facing arcuate engagement surfaces for engaging the valve pin guiding element. The linkage element is moved by the actuator.

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 mixing heads of reaction molding machines is disclosed which comprises a housing in which a adjustment assembly is provided for slidably moving between two adjustable stops, wherein the adjustment assembly is configured as a control sleeve which includes a pressure chamber with a movable control piston disposed therein and the pressure chamber can be impinged upon by a pressure medium, for example hydraulic fluid and wherein a first stop is provided for the control sleeve and a second stop is provided for the control plunger thereby permitting an adjustment of two operating points that are exactly reproducible, so as to prevent disturbances during operation of the molding process.

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: A stack injection molding apparatus includes a melt homogenizing element provided between a first transfer nozzle, which is coupled to a melt source, and a second transfer nozzle, which is coupled to a manifold. The melt homogenizing element is used for redistributing a melt stream in order to provide a homogenized melt stream having a generally uniform temperature and viscosity profile or sectional distribution.

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 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: An extrustion molding system includes a die having a first opening with a unvariable shape and a second opening with a variable shape, an extruder which feeds resin to the die, and a gear pump arranged between the die and the extruder. An ECU conducts a first sequence control to change the shape of the second opening and a second sequence control to change the rotation speed of the first gear pump in synchronism with a change in the shape of the second opening.

Abstract: A runner-less molding device for thermosetting resins and rubbers, characterized by a movable runner bush (15), through which an uncured or unvulcanized fluid material kept at a low temperature supplied from a pouring nozzle (31) can flow, is slidably arranged in a temperature controlling bush (13) communicating with a gate (4) of a cavity (1); an insulation space (A) is formed by moving the movable runner bush (15) apart from the gate (4) during heating; a valve pin (18) is movably inserted into said movable runner bush (15); and the valve pin (18) is arranged so as to open and close the gate (4) in accordance with a pouring operation of the fluid material.

Abstract: Injection molding apparati, systems and methods are provided for limiting forward valve pin movement during flow control. According to one embodiment, an injection molding apparatus is provided that includes an actuator, and a valve pin coupled to the actuator. The valve pin is adapted to open and close a gate to a mold, and to control a rate of material flow through the gate during an injection cycle. The actuator is further adapted to control the valve pin in a first range of movement in which the valve pin is adapted to control the rate of material flow and cannot close the gate, and to control the valve pin in a second range of movement which includes the valve pin closing the gate.

Abstract: An injection molding apparatus has at least a nozzle having a nozzle body and a nozzle tip. A securing device is used to secure the nozzle tip to the nozzle body via non-metallic threads or threads having a non-metallic coating that mate with complementary threads on the nozzle body. In this example, through use of the non-metallic threads or threads having a non-metallic coating, the securing device has a longer life than conventional securing devices that were made from steel or titanium by eliminating or substantially reducing thread galling.

Abstract: A two-piece transfer seal for coupling a nozzle tip to a nozzle of an injection molding apparatus includes a retaining member removably connected to a downstream end of the nozzle and a removably connected nozzle sealing member. The retaining member is comprised of a first material and at least the sealing face of the sealing member is comprised of a second material. In certain applications, the nozzle sealing member is a mold gate insert. In certain applications, the two-piece transfer seal does not retain the nozzle tip, which is metallurgically bonded to the nozzle.

Abstract: An injection molding head designed to attach to a prior art extruder designed for extruding relatively large slabs of epoxy based adhesive materials, including materials that may be filled with glass beads or fibers. The injection molding apparatus constructed according to the preferred embodiment of the present invention as described utilizes cooler temperatures and lesser internal pressure during the extruding process than does conventional plastic injection molding machines. The preferred embodiment generally includes an outlet end portion having an outlet end opening, an inlet end portion having an inlet end opening, a center member having an inlet passage with an inlet opening and an outlet passage with an outlet opening, and first and second transfer units. The first and second transfer units are disposed opposite the other with the center member therebetween.

Abstract: According to the present invention, a cross over nozzle is provided of two parts which, when joined, define a housing having a passage extending therethrough, a tapered valve seat extending about the passage and a valve member having a tapered valve head disposed in the passage for engaging the valve seat. The two parts are axially separable at an interface extending through the valve seat/valve head. In order to open the valve, both valve parts are first joined and then moved together as one member in the same direction relative to the housing axially away from the valve seat. Similarly, the valve members are jointly moved into engagement with the valve seat before the cross over nozzle is separated. Accordingly, unlike the valve gate design, the valve interface between the two parts of the valve head isn't exposed to molten resin and therefore molten resin isn't trapped therebetween to cause a string upon opening.

Abstract: An improved injection molding apparatus having a valve-gated injection nozzle for regulating a flow of molten material through a connecting passageway to a mold cavity. An end portion of the valve stem is configured to cooperate with a complementary sealing portion of the connecting passageway, when the valve stem is configured in a closed position. The mold cavity further includes a vestige forming portion that is located adjacent the sealing portion that is partially defined by a bottom portion of the valve stem when it is configured in the closed position. The apparatus is characterized in that the vestige forming portion extends radially outwardly from the sealing portion such that a first cross-sectional area of the sealing portion is smaller than a second cross-sectional area of the vestige forming portion. Accordingly, tearing along the vestige of the part is substantially avoided.

Abstract: A process and apparatus for plastics injection moulding comprises injecting a quantity of molten plastics material into a mould cavity (30) and injecting pressurised gas (52) or pressurised liquid into the plastics material in the mould cavity. After holding the pressure of the gas or liquid on the plastics material in the mould cavity for a period of time in order to apply a packing pressure to the plastics material, a portion of the molten plastics material is expelled into one or more secondary cavities (32) or expelled back into the barrel (22) of the injection moulding machine. The step of injecting the plastics material may be effected with or without packing of the plastics material prior to the injection of the pressurised gas or liquid.

Abstract: An anti-drool mechanism suitable for use in an injection molding system is provided herein. An injection molding machine includes a retractable machine nozzle for injecting a melt stream into a manifold. Between the machine nozzle and the manifold is an anti-drool mechanism, which includes a melt passage and a fixed pin disposed within the melt passage. The fixed pin is sized so that the melt stream will flow around the pin. The fixed pin has a head portion configured to engage with the machine nozzle and includes a first sealing surface. An actuated shut-off collar is also disposed within the melt passage, surrounding the pin, and includes a second sealing surface configured to cut off the flow of the melt stream when in contact with the first sealing surface.

Abstract: The present invention is an injection molding apparatus having a cast manifold. The manifold is made from a cast block and includes at least one pipe and a junction component fixed therein. The junction component has an axial bore having a first end and a second end, and at least one radial bore fluidly connected to the axial bore and having an opening to an outer surface of the junction component. A melt is introduced into the manifold and travels through the radial and axial bores of the junction component and through at least one pipe connected thereto to an injection molding nozzle for injection into a mold cavity. A manifold of the present invention may have a plurality of pipes and junction components to form a branched multi-level cast manifold.

Abstract: An injection molding apparatus for delivering a melt stream of moldable material to a mold cavity. A valve pin extends through a melt channel of the apparatus that is axially movable to control the melt stream within the melt channel and/or to selectively open a gate to allow communication with the mold cavity. A processing sensor is coupled to the valve pin and is axially movable therewith. By example, the processing sensor may be a pressure sensor and/or a temperature sensor for sensing processing condition(s) of the melt stream and providing sensed information to a controller.

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: 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: The invention relates to an injection molding apparatus including a mold block, a nozzle, a gating system and a slug heater. The mold block defines a mold cavity having a mold cavity inlet. The nozzle has a nozzle inlet. The nozzle inlet is fluidically connectable downstream from a melt source. The nozzle inlet is upstream from the mold cavity inlet. A melt flow passage extends from the nozzle inlet to the mold cavity inlet. The gating system includes a valve pin and an actuator. The valve pin is movable between an open position wherein melt flow is permitted into the mold cavity, and a closed position wherein the valve pin blocks the melt flow passage to prevent melt flow into the mold cavity. The actuator is operatively connected to the valve pin to move the valve pin between the open and closed positions.

Abstract: The valve includes:

Abstract: A nozzle system is provided for an injection molding machine. The nozzle system includes a nozzle tip that is removably connected to a nozzle body with a sealing and mounting sleeve element. The nozzle body includes a first connector for releasably connecting with a second connector defined on the sleeve. The sleeve element further includes an alignment bearing for engaging a bearing surface defined on the nozzle body for precisely locating the nozzle tip within the nozzle body along on a predetermined axis. Further embodiments of the invention provide a valve pin disposed in the nozzle body and nozzle tip. The valve pin includes a bearing surface for engaging a guiding surface defined on the second melt channel for aligning the end of the valve pin with a mold gate. Further embodiments also provide an integrally connected nozzle tip and sleeve element.

Abstract: A nozzle (10) and gate (18) for a plastic injection mold (12) wherein the gate (18) has a primary sealing surface (50) located adjacent to the vestige (22) and a secondary sealing surface (54) located behind or inwardly of the primary sealing surface (50). The nozzle (10) has an insert retainer (42) threadably mounted therein to hold a tip or torpedo type insert (64). The insert retainer (42) has an outer annular primary seal (46) which engages the gate primary sealing surface (50), and an intermediate annular secondary seal (56) which engages the gate secondary sealing surface (54). The primary seal (46) prevents hot plastic from passing behind the nozzle and the secondary seal (56) ensures that even if some plastic gets behind the primary seal, it will not pass behind secondary seal (56) and contact heating coil (33). The main body portion may be shaped to form a third seal (80) for engagement with the secondary sealing surface (54) behind the position of the secondary seal (56).

Abstract: An extrusion die for injecting plasticizable elastomers into a cavity of an injection-molding die, wherein the extrusion die is mounted on a cold-channel block which, for distribution of the material plasticized in a plasticization aggregate, is arranged between the aggregate and the injection-molding die. The extrusion die opening can be closed off with a needle that forms the extrusion-die-opening end of an insert that can be displaced in the extrusion die body and has a material transport channel. An external drive is provided for the displacement movement.

Abstract: An injection manifold has a main runner provided with a supply inlet intermediate opposite ends of the runner. A number of branches intersect with the runner along its length so as to be disposed at unequal distances from the inlet. In order to achieve more simultaneous delivery, uniform fill rate, and identity of temperature of hot melt across all cavities of a multi-cavity set to achieve more uniform cooling of the preforms, restrictor pin assemblies are provided in association with certain of the branches to adjustably constrict the space available for melt flow from the runner into the branch. In a preferred form each restrictor pin assembly includes a pin aligned axially with the branch and passing transversely through the runner, the pin being adjustable between a fully extended, maximum constriction position in which the tip of the pin is located within the branch and a fully retracted, open position in which the tip is withdrawn out of the branch and is spaced below the opening of the branch.

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: 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: 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: 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: The present invention relates to an injection molding appartus having a linear actuator for a control valve with a position sensor and a cooling assembly, wherein the position sensor is integrated into or positioned proximal to the cooling assembly.

Abstract: A valve pin actuating mechanism for an injection molding apparatus is provided. The injection molding apparatus includes at least one melt channel and a valve pin that is movable in the melt channel. The valve pin actuating mechanism includes an actuator, a linkage element and a stop. The linkage element has a mechanically upstream connector and a mechanically downstream connector. The linkage element is connected at least indirectly to the actuator at the mechanically upstream connector and is connected at least indirectly to the valve pin at the mechanically downstream connector. The linkage element is rotatable by actuation of the actuator. The stop is configured to engage a limit surface to limit the angle of rotation of the linkage element. The stop and the limit surface are configured to engage mechanically upstream from the downstream connector of the linkage element.

Abstract: This invention teaches a hot runner injection molding apparatus for co-injecting at least two different materials into a mold cavity. A pin valve gated hot runner nozzle includes separate melt channels for each material and a melt chamber for accurately metering one of the materials. The melt chamber is in communication with an injection piston. The controlled movement of the valve pin and of the injection piston insures that the desired amount of a first and at least a second material is injected into the mold cavity. Depending of the composition and the processing window of the materials, the co-injection hot runner nozzle is in communication with either a single or multiple manifolds.

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.