Abstract: An improved injection molding nozzle shows a high hardness and is chemically stable so that the inner surface thereof is not corroded nor the gas or the fluid forced to penetrate into the gap between the injection molding nozzle and the valve pin seize the valve pin regardless of the temperature and the pressure of the material to be injected. Additionally, the valve pin is not pliable and does not give rise to a collapse on the part of the valve pin. The injection molding nozzle to be used for resin and molten metal is characterized in that it is made of a ceramic material and at least part of the outer periphery is covered with metal.

Abstract: Improved method and apparatus for injection molding particularly useful with multiple hot runner valve gates to fill a single large mold cavity. A hot runner injection nozzle is provided having a gate through which melt is injected into a mold cavity, and a valve stem is movable on the injection nozzle between an open position permitting flow of melt through the gate and a closed position blocking the flow of melt through the gate. The valve stem is movable to at least one position between the open and closed positions restricting the flow of melt through the valve gate.

Abstract: An injection molding machine, and stack assembly, employing a novel mold gate insert that can decrease the cycle time of the machine, and crystallinity and other defects in the mold gate area of plastic articles. A mold gate insert is described that is formed in two pieces. A first portion of the insert can forms a gate land for valve gated machines, and can thermally shield the nozzle tip. This first portion is made of a wear resistant material having a relatively low thermal conductivity, such as H13 tool steel. A second portion of the insert forms a section of the mold cavity and is made of a relatively highly thermally conductive material, such as beryllium copper. During the cooling phase of the injection cycle, the second portion provides rapid dissipation of heat to cool the section of the mold cavity, while the first portion creates a thermal barrier to shield the nozzle tip from the cooling of the second portion.

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.

Abstract: The hot-runner coinjection distributor block arrangement comprises several block parts (6, 7) which with the help of heating elements (8) may be brought to differing temperatures. These block parts (6, 7) are spaced from one another with an intermediate piece (9) and are supported via a support element (10) on the head plate (2). In this support element (10) spring elements, preferably a disc spring (11) is incorporated, which spaces the support element (10) from the head plate (2) and press the two block parts (6, 7) onto one another also in the cold mode. In the hot mode these disc springs (11) permit an axial expansion of the block parts (6, 7) and reduce the tension force exerted onto the support element (10). Peg-like formations of the intermediate piece (9) and of the support element (10) ensure that the bores for the guiding of the closure needle or of the feed channel (13) by the thermal expansion of the block parts (6, 7) are retained, i.e. are not laterally displaced.

Abstract: A seepage system for an injection molding apparatus includes a manifold plate with a first portion and a second portion abutting the first portion, and a seepage passage positioned between the first and second portions. The second portion may have at least a portion of a melt passage, and the seepage passage may have an outlet. The seepage system also has one or more seepage channels, with each seepage channel being connected to and in communication with the seepage passage. Moreover, the seepage system includes one or more seepage bores for receiving the flow of excess material, with each seepage bore being connected to and in communication with one of the seepage channels. Gravity is used to assist the flow of excess material from the one or more seepage bores through the seepage channels and the seepage passage.

Abstract: A method for controlling a screw injecting apparatus having a heating cylinder and a screw slidably and rotatably received in the heating cylinder and designed to carry out a plasticizing-metering phase in which a predetermined amount of a molten material is accumulated forwardly of the screw by plasticizing and kneading a raw molding material via the screw and the heating cylinder, a waiting phase in which the screw is held inactive for a period between completion of the metering and subsequent injection of the molten material, and an injecting phase in which the molten material is injected. The method comprises the step of causing the apparatus to vibrate the molten material at a predetermined low frequency axially of the screw during the plasticizing-metering phase. By vibrating the molten material at a low frequency during the relatively long plasticizing-metering phase, the viscosity of the molten material can be reduced.

Abstract: An injection molding machine valve gate nozzle having a rack driven valve pin actuator for moving the valve pin between open and closed positions during each holding cycle of operation. The valve pin actuator is sealed from the fluid flow stream and the nozzle body has a valve pin guide which substantially separates the melt stream from the valve pin during passage through the nozzle for enhanced long-term operation. The actuator has a modular construction which lends itself to economical manufacture and efficient use in multiple drop or single drop molding machines without modification.

Abstract: An injection molding method, an injection mold and a valve gate device, in which a movable pin moves easily, without excess force being exerted thereto, to properly open and close a gate. Closing a gate 10B by a cylindrical movable pin 27 allows excess resin to easily return back to a resin conveying path side through an outer edge portion at the end of the movable pin 27, so that even a large-diameter gate 10B can be reliably closed by the movable pin 27 which can be easily moved due to reduced resin resistance on the movable pin 27.

Abstract: A mold bushing for injecting plastic material into a mold cavity. The bushing member has a one-piece body member with a central passageway for a shut-off gate pin member and a separate and distinct passageway for the molten plastic material. A tip member is positioned on the end of the body member and has a material discharge chamber. A gate or orifice opened and closed by the pin member is positioned either in the tip member or the mold. A wear bushing member is positioned in the discharge chamber or the end of the body member and acts to support the end of the pin member and prevent the flow of plastic material into the central passageway. The body member is heated by an annular cast heater member or the like. The wear bushing member can be indexed for proper positioning relative to the body member and the plastic flow passageway. The wear bushing member preferably has a body portion which partially fills the discharge chamber in the tip member.

Abstract: Valve gated injection molding apparatus having several valve pins (62) extending through each heated nozzle (12) driven by a common actuating mechanism (70). A valve bushing (100) is seated in the front end (96) of each heated nozzle (12). A central melt bore (50) in each heated nozzle (12) splits in the valve bushing (100) near the front end of the heated nozzle (12) from where the melt flows around each of the valve pins (62) to the gates (66).

Abstract: A hot runner valve gated injection molding device which directs melt from a melt channel to a melt cavity, including a guide sleeve positioned at the gate end of the nozzle body and surrounding the valve stem to guide the valve stem inside the guide sleeve and to provide a sealing device at the gate end of the nozzle body.

Abstract: Multi-layer injection molding apparatus having integral multi-layer melt dividing bushings seated in the melt distribution manifold for dividing a first melt passage extending to annular melt channels in heated nozzles. Matching melt channels machined in the front face of the first layer and the rear face of the second layer of each melt dividing bushing form a melt conduit which branches from an inlet to two spaced holes extending through the second layer. A pair of matching melt channels machined in the front face of the second layer and the rear face of the third layer of each melt dividing bushing form two melt conduits, each of which branch from one of the holes through the second layer to two of four spaced holes through the third layer. The four holes through the third layer align with four melt bores leading to the annular melt channel in one of the heated nozzles. A second melt passage may extend through a central bore in each melt dividing bushing to a central melt channel in the heated nozzle.

Abstract: A novel valve gated injection molding system and valve gate reduces the formation of gate vestiges on parts molded therewith and enhances cooling of the tip of the valve stem during the cooling portion of an injection molding cycle. Channels are provided and extend from an area adjacent the contact area of the sealing portions of the stem tip and gate to the melt channel of the injection nozzle. These channels allow material, which would otherwise form a thin film layer in the contact area of the sealing portions of the stem tip and gate, to be expressed through the channels and back to the injection nozzle. As the formation of thin films is inhibited, an increased contact area, in addition to the contact area of the tip and gate sealing portions, can be provided to improve the transfer of heat energy from the tip to the gate when the gate is cooled.

Abstract: In a valve gate device and an injection mold provided with the valve gate device, a movable pin moves easily in order to properly open and close the gate, thereby preventing damage to the valve gate device and the mold. A movable pin 17 is made more durable by using a harder material for the movable pin 17 than for a valve body 11, and a slight distance can be maintained between the movable pin 17 and the valve body 11 by making the thermal expansion coefficient of the movable pin 17 smaller than that of the valve body 11, so that the problem of initial improper movement of the movable pin 17 can be eliminated.

Abstract: Valve gated multi-cavity injection molding apparatus. A number of valve pins extend forwardly from a valve pin plate, each in alignment with a gate leading to a cavity in the mold. A pair of cam bars extend beside a pair of actuator bars attached to the valve pin plate. Rectangular slide blocks attached to each actuator bar fit in diagonal grooves in the adjacent cam bar, whereby longitudinal movement of the cam bars moves the valve pin plate and the valve pins forwardly and rearwardly. The cam bars are driven longitudinally by electromechanical or hydraulic actuating mechanism to simultaneously and accurately stop the valve pins in at least three different precise positions during each injection cycle.

Abstract: In an injection molding machine for thermoplastic resin, a mold clamping hydraulic circuit is constituted as a hydraulic circuit which can be optionally set to a pressure-free or substantially pressure-free state upon completion of closure of a mold mounted to a clamping unit. A movable mold of the clamping unit can be retracted with a low injection pressure by injecting the molten resin via an injection unit. A nozzle port opening to a space of a mold cavity is closed simultaneously with completion of the charge of predetermined amount of resin, and a mold clamping force at a high pressure is generated on the forward side of the mold clamping unit, thereby producing mold clamping at a predetermined position. Since the mold is in a pressure-free or substantially pressure-free state, the injection pressure may also be low.

Abstract: A pressure-activated valve for conducting pressurized gas into a mold cavity of an injection molding apparatus is preferably constructed as an easily replaceable unit. The preferred valve includes a pin having a flared head section. The head section has a planar face transverse to an axis of the pin so as to approximately conform to a neighboring contour of the mold cavity. The valve also includes a body in which a passageway intersects a second end of the body to define a port and a flaring seat communicates through a first end of the body between the passageway and the mold cavity. A restrainer which abuts against the second end of the body includes a guideway aligned with the passageway through the body as well as at least one cross-channel which admits pressurized gas to that passageway through the port. The pin extends through both the passageway and the guideway so that its head portion is positioned near the seat.

Abstract: A valve for controlling the flow of fluent plastic material from an injection molding machine to a mold cavity. The valve includes an axially slidable valve pin that interacts with a material outlet to control flow through the valve selectively. The valve pin is actuated by an eccentric cam arrangement that positively drives the valve pin between positions where it is engaged with or disengaged from the material outlet. The cam acts on the valve pin only in an axial direction to avoid wear occasioned by side loads imposed on a valve pin.

Abstract: A valve device for an injection nozzle in an injection molding machine which includes a piston defined therein with a vertical cylindrical space having a lower portion partially receiving the injection nozzle adapted to inject molten resin into the cavity of a mold, and an upper portion partially receiving a connector adapted to connect the injection nozzle to a cylinder serving to supply molten resin. The piston also has a valve pin carrying portion configured to vertically support a valve pin in such a fashion that the valve pin moves vertically. The valve pin carrying portion extends diametrically across the cylindrical space of the piston. The valve pin carrying portion of the piston is provided at a central portion thereof with a hole for carrying a head of the valve pin in such a manner that the valve pin extends downwardly in a vertical direction. In this valve device, it is possible to not only obtain an optimum stroke of the piston, but also to minimize the size of the valve device.

Abstract: A multilayer injection molding machine manufactures a molded product formed of a plurality of layers of resins or colors by press fitting resins from a core layer injection unit and a skin layer injection unit to a cavity part formed by pressing and clamping a moving metal mold to a fixed metal mold fixed to a support member. The multilayer injection molding machine is formed by integrating a connecting device body interposed between the fixed metal mold and the support member so as to support the fixed metal mold to the support member and an injection unit connecting device provided on the connecting device body and having a plurality of resin passages allowing the cavity part to communicate with each injection unit.

Abstract: Valve gated multi-cavity injection molding apparatus for five layer molding having actuating mechanisms for reciprocating elongated valve members between four different positions. Each actuating mechanism has a front and a rear aligned cylinders, a first piston connected to the head of one of the valve members in the front cylinder and second and third pistons in the rear cylinder. The third piston has a stem portion which extends forwardly through the second piston into the front cylinder. Hydraulic pressure from four hydraulic lines connected to each actuating mechanism reciprocates each elongated valve member between the different positions. In the first closed position, the front end of the valve member is seated in the gate. In the second position, the front end of the valve member is retracted sufficiently to allow an initial amount of PET to flow from an outer annular melt channel through the gate.

Abstract: An arrangement and method for mounting a core pin for an injection molding a part, includes mounting a core pin in a cavity plate to extend upwardly through the cavity and into an opening in one end of a valve sleeve operated to control melt injection through a gate in a heated injection nozzle. The core pin moves away from the injection nozzle when the cavity plate is separated to remove the part.

Abstract: An injection nozzle with a cushion ring is disclosed. In the injection nozzle used for injecting pressurized and melted resin into the cavity of a mold during an injection molding process, an axial hole is formed at the lower end of a nozzle body with an annular step being formed at the upper end of the axial hole. A nozzle tip is axially received in the axial hole and is stepped at its external surface, thus forming a stop shoulder at the external surface. The nozzle tip is brought into contact with the core of the cavity at its lower end during an injection molding process. A cushion ring, made of a stainless steel and having an O-ring shape, is interposed between the annular step of the axial hole and the top end of the nozzle tip. The stop shoulder of the nozzle tip is stopped by a stop ring, thus retaining the nozzle tip in the axial hole of the nozzle body.

Abstract: An apparatus and a method for the melt extrusion of a molten thermoplastic polymer, e.g., as fibers and nonwoven webs, which apparatus and method utilize ultrasonic energy to assist in the melt-extrusion process. The apparatus includes a die housing which defines a chamber adapted to receive the molten thermoplastic polymer and a means for applying ultrasonic energy to a portion of the molten thermoplastic polymer. The die housing includes a chamber adapted to receive the molten thermoplastic polymer, an inlet orifice adapted to supply the chamber with the molten thermoplastic polymer, and an extrusion orifice adapted to receive the molten thermoplastic polymer from the chamber and extrude the polymer. The means for applying ultrasonic energy is located within the chamber. The method involves supplying a molten thermoplastic polymer and extruding the molten thermoplastic polymer through an extrusion orifice in the foregoing apparatus to form a threadline.

Abstract: A valve-gated injection moulding device in which an actuating device of the valve pin comprises a sliding member having its walls in sliding engagement with an axial guide track. The sliding member comprises a radial opening defined by an upper and a lower contact surface. A free end of an actuating lever having two curved actuating surfaces extends radially into the opening of the sliding member. Thanks to this construction, a compact and accurate actuating device is provided which reduces radial forces on the valve pin, such that it can be operated without friction or wear. Residual radial forces are taken up by the sliding member. The stroke of the actuating device can be adjusted after mounting in a cavity plate of an injection moulding device.

Abstract: A shut-off valve is mounted between an injection nozzle and a mold. The valve has a piston within the valve body, A material passage is formed through the piston having an exit aperture and a terminal end. When material is injected through the material passage, the piston is forced to a downstream position which allows the material to flow into the mold. A pneumatic pressure applied to the piston forces the piston to a closed position after injection.

Abstract: Multi-cavity injection molding apparatus having a number of heated nozzles extending from a melt distribution manifold. Each nozzle is aligned with a tapered insert seated in an opening extending through the manifold. Each insert has a melt duct with a smoothly curved bend to connect the melt passage in the melt distribution manifold with the melt bore through the nozzle. Each insert has a flat disc portion abutting against the rear surface of the manifold. Screws extend through this disc portion and the manifold into an outer collar portion of the nozzle to secure the insert and the aligned nozzle directly to the manifold, while allowing the nozzle to be mounted with its electrical terminal having a selected orientation.

Abstract: A valve gated injection molding system to facilitate improved melt flow to the gate of the nozzle. The system includes an annular flow insert through which the valve pin passes. The annular flow insert includes an annular groove on its outer surface. The edge of the annular groove is spaced from the wall of the melt channel so that some of the melt can flow longitudinally between the edge of the groove and the wall, while the remainder of the melt flows in the groove. The flow direction initiated by the annular flow insert eliminates flow separation and dead spots about the valve pin. The system also includes an actuator assembly including a sled attached to the valve pin.

Abstract: An apparatus for controlling plastic melt flow in an injection molding machine comprising: a thermally conductive housing having a fluid flow channel sealably disposed in the housing, the channel having an input end sealably connected to a source of flow of a plastic melt material and an output end for controllably delivering the flow of plastic material to an input aperture of a mold cavity; an elongated pin disposed within at least a portion of the channel for controlling output of the flow of plastic melt through the output end of the channel, the pin having a head end and a pin end and a length extending between the head end and the pin end; the pin being slidably mounted along its length through an aperture in the housing such that the pin is slidably movable through the aperture between at least one unrestricted flow position and at least one restricted flow position; the head end of the pin extending outside the housing and being readily connectable to and disconnectable from a pin reciprocating mechan

Abstract: Valve gated injection molding apparatus having three position valve member actuating mechanism for multilayer molding. A first melt passage extends to the gate through an annular channel in a heated nozzle, while a second melt passage extends around an elongated valve member in a central melt channel. A rack member engaging the rear end of the valve member is driven by a pinion member connected to a front piston in a front cylinder. A rear piston in a shorter rear cylinder aligned with the front cylinder has a stem extending forwardly into the front cylinder. First, air pressure applied behind the rear piston retracts the valve member from a first closed position to a second partially open position wherein melt flows only through the annular channel. Then, air pressure applied behind the front piston retracts the valve member to a third fully open position wherein melt flows simultaneously through both melt channels to provide the three layers.

Abstract: The flow forming member for a polymer melt comprises an inlet point as well as an outlet point, a tubular channel connecting these points and a rod-like body arranged along the channel axis. At least one static mixing element is arranged in the channel, preferably at least two static mixing elements are arranged one after the other. The mixing elements have apertures for the accommodation of the rod-like body. A firm connection exists between the body and the mixing elements. A minimum gap is provided between the mixing elements and the channel wall which permits a displacement of the body in the channel or an insertion into the channel.

Abstract: A method of injection-molding three-layer moldings, especially bottle blanks, having inner and outer layers of a "material A" and of a "material B". Material B can be a material that acts as a barrier against the gases O.sub.2, CO.sub.2, and SO.sub.2, and against water vapor (H.sub.2 O). The method employs a device that comprises at least one mold and at least one flat hot runner. The mold has several cavities and the hot runner has the same number of dies. Material A is supplied to the cavities (1.1) through an annular gap between the inner (2.1) and the outer (2.2) component of each die. Material B is forced into the cavities through a hollow needle (3) that extends through the center of the inner die component by a piston (4) that is integrated into the die and cannot rotate. The needle has a port (6) that opens into it at a right angle and remains open as long as the needle remains advanced, in a closing position, and that is blocked when the needle is retracted. A reservoir (3.

Abstract: Multi-cavity injection molding apparatus for three layer molding having elongated pins for fixed pin gating or valve gating. Each elongated pin has a central melt bore extending rearwardly from its front end to a number of laterally extending bores. A low viscosity barrier material such as EVOH or nylon flows through these bores to the gate leading to the cavity. This allows coinjection with fixed pins and sprue gating in one embodiment and by valve gating in another embodiment.

Abstract: A valve gated injection molding system to facilitate improved melt flow to the gate of the nozzle. The system includes an annular flow insert through which the valve pin passes. The annular flow insert includes an annular groove on its outer surface. The edge of the annular groove is spaced from the wall of the melt channel so that some of the melt can flow longitudinally between the edge of the groove and the wall, while the remainder of the melt flows in the groove. The flow direction initiated by the annular flow insert eliminates flow separation and dead spots about the valve pin. The system also includes an actuator assembly including a sled attached to the valve pin.

Abstract: A valve-gated injection moulding device, wherein the actuating device of the valve pin comprises a first arm and a second arm. The first arm is hingingly connected in a first end tot he rearward end of the valve pin. The second end of the first arm is hingingly connect to a displacement device, which can be moved along a radial displacement trajectory. The second arm is with its first end hingingly connected to the midpoint of the first arm. The second end of the second arm is connected in a fixed hinge point to a support of the injection moulding device. In this way, using a radial actuating device, only an axial force is exerted on the valve pin. The stroke of the valve pin can easily be adjusted from outside the mould by increasing or decreasing the stroke of the piston. The actuating device is relatively small, and does not require a large re-routing of the melt passage as it is positioned radially outwardly from the longitudinal center line of the valve pin. it can be operated from outside the mould.

Abstract: A valve gate injection nozzle includes a valve stem for guiding molten resin to a molding area. The valve stem includes an input area for receiving the molten resin, a central area following the input area for processing the molten resin and an output area following the central area for connection of the nozzle with the molding area. The central area includes a first zone for splitting the molten resin into a plurality of streams, a second zone for mixing and homogenizing the molten resin, and a third zone for combing the plurality of streams and forming recombined molten resin for subsequent direction in a homogenized state to the output area. The nozzle further includes a nozzle body portion for enclosing the valve stem, wherein the nozzle body portion preferably includes means for heating the resin. An injection molding system incorporating this nozzle as well as a method for homogenizing molten resin are also disclosed.

Abstract: A mold bushing for injecting plastic material into a mold cavity. The bushing member has a one-piece body member with a central passageway for a shut-off gate pin member and a separate and distinct passageway for the molten plastic material. A tip member is positioned on the end of the body member and has a material discharge chamber. A gate or orifice opened and closed by the pin member is positioned either in the tip member or the mold. A wear bushing member is positioned in the discharge chamber or the end of the body member and acts to support the end of the pin member and prevent the flow of plastic material into the central passageway. The body member is heated by an annular cast heater member or the like. The wear bushing member can be indexed for proper positioning relative to the body member and the plastic flow passageway. The wear bushing member preferably has a body portion which partially fills the discharge chamber in the tip member.

Abstract: A device for injection molding articles of plastics material having hollow spaces. The device includes a molding tool with a mold cavity. Plastics material melt is fed to the mold cavity through a nozzle. Another pressurized medium is supplied to the mold cavity through a hollow needle at a location different from the location of the nozzle. A needle core is mounted in the hollow needle. The needle core is axially displaceable within certain limits. The opening of the hollow needle to the mold cavity can be opened and closed or its cross-sectional area can be varied by moving the needle core.

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: Injection molding apparatus including a first mold cavity having an inlet, a second mold cavity having an inlet, a source of a first material to be injected, a source of a second material to be injected, and a co-injection manifold including a nozzle housing including a first outlet adapted to communicate with the first mold cavity inlet, a second outlet adapted to communicate with the second mold cavity inlet, first and second spaced apart inlets respectively adapted to communicate with the first and second sources of material to be injected, a first passageway communicating between the first inlet and the first and second outlets, and a second passageway communicating between the second inlet and the first and second outlets.

Abstract: Apparatus for fluid-assisted injection molding systems or co-injection molding systems. A pair of concentric movable pin members are positioned in a mold bushing and selectively controlled to facilitate or prevent the passage of molten plastic material and a fluid into the mold cavity. An inner pin member is positioned within a hollow pin member and both pin members are controlled by piston members which are selectively moved in a block member by selective pressurization from a hydraulic or pneumatic source. Movements of the piston members selectively controls the operation of the pin members and thus the operation of the fluid-assisted injection molding system.

Abstract: An injection molding nozzle is provided that includes a heater disposed about an insert seated in the nozzle body. The heater provides extra heat about the insert where heat loss to the mold can cause a reduction in melt temperature. The heater remains on from one injection cycle to the next injection cycle. In one embodiment, a thermocouple is used to measure the temperature about the insert so that the intensity of the heater can be adjusted accordingly. The heater can also be used with nozzles used in multiple nozzle applications to balance the flow of the nozzles.

Abstract: A valve pin actuator for a valve-gated injection molding system. The actuator has an annular piston mounted in and movable back and forth along an annular bore along a pin axis. The piston extends radially outwardly of any melt passages fluidly communicating with an injection molding nozzle. A tie bar extends substantially diametrically across the piston for securing an upper end of a valve pin extending into the injection molding nozzle to cause the valve pin to move axially with the piston thereby moving the valve pin between open and shut positions.

Abstract: A needle valve nozzle (1) with injection mold (2) has a channel (11) for injection molding of flat workpieces form its narrow side. The channel (11) lies in the interior of the valve needle (10) belonging to the nozzle and extends over a partial longitudinal region of this valve needle (10). The channel (11) has an inlet (12) in the interior of the housing (6) of the needle valve nozzle (1) and at least one lateral exit (13) at an outlet before the free end (10a) of the valve needle (10) facing the injection mold (2), so that the open position of the needle valve nozzle provided for injection molding is reached by pushing the valve needle (10) with this exit (13) so far out of the housing (6) that the lateral exit (13) comes to lie at the level of the mold or cavity to be filled, while for the closed position, the valve needle (10) with this exit (13) can be retracted into the housing (6).

Abstract: Valve gated injection molding apparatus having a valve member with a cylindrical front end portion. A one-piece insert mounted at the front end of a nozzle has both a gate and locating blades extending inwardly from an outer body into a central opening leading to the gate. The inner surfaces of the blades fit around the front end portion of the reciprocating valve pin to guide and very accurately locate it in alignment with the gate. Very accurately maintaining the front end portion of the reciprocating valve pin in alignment with the gate allows it to be cylindrical rather than tapered which produces a much cleaner gate mark.

Abstract: An injection molding apparatus comprising an injection unit having a plurality of injection nozzles of which respective distal end portions move back and forth between a first position and a second position, a mold clamp unit comprising a first mold clamp unit having a first frame body and an upper mold, a second mold clamp unit having a second frame body and a lower mold. A plurality of nozzle reception portions to which the distal end portions of the injection nozzles fit respectively are formed in one of the first and second frame bodies, and a resin introduction passage for introducing the molten resin from central portions of the plurality of nozzle reception portions to a plurality of cavities formed between the upper mold and lower mold as they are clamped is formed. The plurality of injection nozzles are mounted to the injection unit so as to permit the respective distal end portions to move loosely in any direction in response to an external force applied thereto.

Abstract: A valve gate assembly including a movable valve stem for guiding molten resin to a molding area, a nozzle body portion enclosing the valve stem and a mold cavity for receiving molten plastic to form a molded part formed between cooperating first and second mold halves. An injection orifice is provided downstream of the valve stem communicating with the mold cavity for transfer of the molten plastic to the mold cavity, and a movable core pin is provided contacting the valve stem and movable between a forward position opening the injection orifice and a rearward position closing the injection orifice.

Abstract: Disclosed is a valve gate apparatus for an injection mold comprising: a valve gate 6 in communication with a mold cavity; a valve pin 3 adapted to be actuated to open and close the valve gate 6, received therein for reciprocal movement in the axial direction of a probe assembly 1 equipped with a body heater 2; and a resin melt passage 7 formed within the probe assembly 1 at the position where the valve pin 3 is opened; the resin melt passage 7 having a gradually curved region 8 formed adjacent the opening end of the passage.

Abstract: A needle seal nozzle assembly for a plastics injection machine, injection mold or hot-runner system, includes a housing defining a passageway for feeding a melt from an inlet to an outlet, with housing being formed by a first housing portion having one end facing the inlet, and by a second housing portion facing the other end of the first housing portion and having an interior forming part of the passageway. The first housing portion includes a substantially cylindrical tubular body which defines a fluid channel that forms another part of the passageway and is fluidly connected to the interior of the second housing portion. Received in fluidtight manner between the first and second housing portions is a slide for displacement between a first position in which a fluid flow through the outlet is cut and a second position in which the flow of melt is open through the outlet.