Abstract: A distribution system 18 of an injection moulding system 10 comprises an inlet 19 for receiving pressurized liquid plastic material, at least a first nozzle 24a and a second nozzle 24b for injecting liquid plastic material into a mould cavity 34, a distributor 20 for distributing the liquid plastic material from the inlet 19 over a first flow path 40a to the first nozzle 24a and over a second flow path 40b to the second nozzle 24b. The distribution system 18 is adapted for sequentially injecting liquid plastic material into the mould cavity 34 via the first flow path 40a and the second flow path 40b. The distribution system 18 is adapted for reducing pressure energy of liquid plastic material in the distributor 20, when liquid plastic material is injected into the mould cavity 34 via the first flow path 40a.

Abstract: A system and process for injection molding polymer articles is described. The system and process are designed to reduce gate blush. In one embodiment, an injection molding device injects a molten polymer composition into a runner that extends from an injection point to a gate. The gate is positioned adjacent to an opening leading into a mold cavity. In accordance with the present disclosure, the system includes one or more overflow passages that divert flow of the polymer composition so as to temporarily reduce the flow rate and pressure of the polymer composition entering the mold.

Abstract: A method for producing a molded product consisting of a resin polymerized by a melt polycondensation reaction, comprising continuous feeding of a prepolymer in molten state from a prepolymer feeding port to a polymerization reactor, discharging from holes of a porous plate, followed by polymerization while dropping along a supporting substrate under reduced pressure, and molding by transferring to at least one molding machine in molten state without solidification, wherein transfer pressure to said molding machine is controlled so as to maintain at an arbitrary pressure from 0.1 to 100 MPa (absolute pressure).

Abstract: A molding device including a mold having a stationary portion arranged on a stationary platen of a press, and a movable portion arranged on a movable platen of the press, at least one injection channel for injecting material into the movable portion of the mold, and a feeder device for feeding the mold with plastics material, the feeder device including a stationary installation including a first metering device for metering a first quantity of material. The feeder device includes at least one second metering device arranged on the movable platen, the second metering device being connected to the first metering device in such a manner as to be fed with plastics material by said first metering device, and being connected to the injection channel for injecting material into the movable portion of the mold in such a manner as to be capable of feeding it with plastics material.

Abstract: In a method of operating an injection molding machine of a type having an injection plunger for pushing melt from an injection space anteriorly of an injection plunger into an injection mold, a plasticizing screw of an extruder is continuously operated to continuously feed melt through a melt channel into the injection space. A passage through the melt channel is closed to allow backup of melt backwards into the extruder, and the injection plunger is moved forward to inject a shot amount from the injection space into the injection mold.

Abstract: A hot runner system including a shoot pot system for transferring melt from a single shooting pot to multiple nozzles. Melt is fed from a source of melt into the cavity through the multiple nozzles, and a valve isolates melt in the cavity from melt in the source. A plunger within the cavity is driven forward to inject melt in the cavity into a mold cavity at high pressure without significantly increasing the pressure of melt in the source. The plunger optionally functions as both the plunger and the valve by opening and closing communication between the cavity and the manifold as it is rotated.

Abstract: Apparatus and method whereby coinjection molding shooting pot actuation structure is configured to be installed in a coinjection hot runner with a coinjection nozzle, the coinjection nozzle having at least two melt channels ending at the same gate. The shooting pot is preferably disposed in one of a mold cavity half and a mold core half. A shooting pot piston is configured to discharge a melt from the shooting pot. A transmission structure is configured to (i) extend through one of the mold cavity half and the mold core half, and (ii) to transmit a force to the shooting pot piston. Actuation structure is disposed on the opposite side of the mold cavity half from the coinjection hot runner, and is configured to provide the force to the transmission structure. This configuration conserves space in the mold.

Abstract: In an injection device 10 having a plunger 11 reciprocably inserted into a heating cylinder 16, in which a molten material M is injected by the plunger 11 via a nozzle 21, a sealing portion 13 set so that the molten material M is prevented from easily entering a gap A between the plunger 11 and an inner wall 32 of the heating cylinder 16 is provided on the portion of the plunger 11, on the side of the nozzle 21, and the portion of the sealing portion 13, on the side of the nozzle 21 is a core keeping portion 14 provided so that an annular portion 20 which is formed on a front portion of the plunger 11 and is connected to a storage portion 19 of the molten material M is formed between the core keeping portion 14 and the inner wall 32 of the heating cylinder 16.

Abstract: An injection molding apparatus for injecting resin into a mold comprises an injection cylinder in fluid communication with the mold, wherein movement of a piston relative to the cylinder injects a selected quantity of resin into the mold. A plasticizing unit includes a flighted screw rotating in a heated containment barrel for plasticizing resin. The plasticizing unit is in fluid communication with the injection cylinder for supplying the injection cylinder with plasticized resin. A valve is provided for selectively placing the injection cylinder in fluid communication with the mold and placing the plasticizing unit in fluid communication with the injection cylinder, wherein the valve exerts pressure on resin in the mold independently of the injection cylinder or plasticizing unit. The valve is actuated by relative movement between the mold and one of the injection cylinder and the plasticizing unit.

Abstract: An injection molding machine includes a plasticating unit for plasticating a thermoplastic resin, and an injecting unit connected to the plasticating unit through a connecting passage to inject the plasticated resin into a mold. In the connecting passage, provided is a buffering unit for reserving the resin in an amount at least equal to the quantity of the resin injected per one shot. The plasticated resin is temporarily reserved in the buffering unit, and then, the reserved resin is fed to the injecting unit when the measuring is carried out, whereby the plasticating unit can be driven continuously simultaneously with the operation of the injecting unit and the mold. The molding cycle can shortened with the plastication efficiency being enhanced.

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 rubber extruder includes a barrel, a screw rod extending into the barrel, a threaded member threadedly engaging the screw rod and rotatable relative to the screw rod, a limiting member for limiting rotation of the screw rod upon rotation of the threaded member so as to permit axial movement of the screw rod, and a driving unit for rotating the threaded member.

Abstract: An injection molding machine includes a plasticating unit for plasticating a thermoplastic resin, and an injecting unit connected to the plasticating unit through a connecting passage to inject the plasticated resin into a mold. In the connecting passage, provided is a buffering unit for reserving the resin in an amount at least equal to the quantity of the resin injected per one shot. The plasticated resin is temporarily reserved in the buffering unit, and then, the reserved resin is fed to the injecting unit when the measuring is carried out, whereby the plasticating unit can be driven continuously simultaneously with the operation of the injecting unit and the mold. The molding cycle can shortened with the plastication efficiency being enhanced.

Abstract: An injection molding apparatus for injecting resin into a mold comprises an injection cylinder in fluid communication with the mold, wherein movement of a piston relative to the cylinder injects a selected quantity of resin into the mold. A plasticizing unit includes a flighted screw rotating in a heated containment barrel for plasticizing resin. The plasticizing unit is in fluid communication with the injection cylinder for supplying the injection cylinder with plasticized resin. A valve is provided for selectively placing the injection cylinder in fluid communication with the mold and placing the plasticizing unit in fluid communication with the injection cylinder, wherein the valve exerts pressure on resin in the mold independently of the injection cylinder or plasticizing unit. The valve is actuated by relative movement between the mold and one of the injection cylinder and the plasticizing unit.

Abstract: The installation contains means (1) for continuous production of a paste made of a thermoplastic material, means (8) for accumulating and temporarily storing the paste thus produced and means (15) for taking the paste out of the accumulating means and storage means and introducing it into a first mould comprising thermoregulated means in the form of a syringe. The invention is characterised in that the output of the accumulating means and storage means comprises a distributor (12) that has at least two outputs (13, 14) and can be controlled in order to deliver the paste to one of the two outputs, whereby one of said outputs (13) is adapted in order to be coupled to thermoregulated means (15) in the form of a syringe and the other output (14) is adapted in order to be permanently connected to the charging orifice of a piston (17) that injects the paste at a high pressure into a second part-forming mold (17), whereby one output thereof (19) is adapted in order to be permanently coupled to the second mold.

Abstract: The injection molding machine has an extruder for providing molding material, a cavity for retaining the molding material prior to injection into a mold, a plunger within the cavity to move the material out of the cavity, and a check valve. The check valve has separate means to permit the material to flow from the extruder to the cavity and from the cavity to an adjacent mold. By having separate flow channels for molding and recharging, the injection molding machine may be recharged on the fly.

Abstract: An injection-molding process including kneading functional particles with a binder resin in a kneader, temporarily storing the kneaded material supplied from the kneader in a reservoir device and feeding the kneaded material stored in the reservoir device to an injection device, the reservoir device including a pair of reservoirs, the kneaded material stored in one reservoir device is fed to the injection device where the kneaded material is then injection-molded, and simultaneously the kneaded material is fed from the kneader to another reservoir device and stored in it. Then, the kneaded material stored in the other reservoir device is fed to the injection device where the kneaded material is then injection-molded, and simultaneously the kneaded material is fed from the kneader to the one reservoir device and stored in it, so that the injection molding process is conducted by alternately repeating the above steps by switching operations.

Abstract: The injection molding machine has an extruder for providing molding material, a cavity for retaining the molding material prior to injection into a mold, a plunger within the cavity to move the material out of the cavity, and a check valve. The check valve has separate means to permit the material to flow from the extruder to the cavity and from the cavity to an adjacent mold. By having separate flow channels for molding and recharging, the injection molding machine may be recharged on the fly.

Abstract: A method and apparatus for runnerless injection molding of plastic materials utilizing a novel valve stem for controlling the opening and closing of at least two gates in a single injection nozzle The method and apparatus includes at least two separate melt streams whose flows are not obstructed by the valve stem. These melt streams may contain the same plastic material or different plastic materials and the injection nozzle may be either simultaneously or sequentially activated for filling the mold cavity.

Abstract: A two-stage, electrically-powered injection unit for an injection molding machine is disclosed. The injection unit includes an extruder for plasticating material, and a separate melt accumulator to receive the plasticated material. The accumulator includes an injection plunger that is slidably positioned to inject the plasticated material from the accumulator into a mold. The plunger is rotated and translated by an electrically-driven linear actuator, such as a roller screw mechanism. The plunger extends outwardly of the accumulator barrel at the commencement of an injection stroke and is peripherally supported by a bushing at the outer end of the accumulator barrel. The outwardly-extending portion of the plunger can also be supported by a movable intermediate support member to minimize lateral deflection of the plunger and enable a longer injection stroke to be employed.

Abstract: The invention is directed to a two-stage, all-electric injection unit. More specifically, an injection unit in which the feed screw is preferably used only for plastication and the injection of the plasticized material is accomplished by a separate accumulator having an electrically driven linear actuator, such as a ball screw mechanism. The plunger of the accumulator is configured with a helical flight and is rotatable by way of a one-way clutch interposed between the plunger and the ball screw.

Abstract: A method for injection molding a material consisting of a suspension of particles. The suspension of particles moves through convergent passages in an obturator and an injection channel so that the particles remain in suspension. The press has a head in which a portion of the feed channel and a portion of the injection channel, when the channel is open, is formed by a passage in an externally controlled obturator, the controlled obturator for the feed channel and the one for the injection channel being one and the same or adjacent, and disposed close to the injection orifice.

Abstract: The invention is directed to a two-stage, all-electric injection unit. More specifically, an injection unit in which the feed screw is preferably used only for plastication and the injection of the plasticized material is accomplished by a separate accumulator having an electrically driven linear actuator, such as a ball screw mechanism. The accumulator is configured so that the ratio of the piston stroke to the piston diameter is preferably in the range of ten to fifteen. In the preferred embodiment there are separate motors for rotation of the screw and operation of the accumulator. An alternate embodiment is disclosed wherein the system is driven with a single motor and one-way clutches.

Abstract: A pre-plasticizing injection molding machine includes a plasticizing and flow regulating assembly connected to the tip of an injection chamber or shooting pot having an injection cylinder. A distributor valve allows the transfer of plastic resin into the shooting pot at low pressure and prevents the backward flow of resin to the plasticizing unit when the injection plunger injects the resin. A plurality of distribution channels in communication with either the distributor valve or a separate valve, and having outlets in the shooting pot angularly equispaced in proximity to the perimeter of the conical tip of the plunger uniformly distributes new resin behind resin retained in the shooting pot from the previous injection cycle, thereby obviating stagnation zones.

Abstract: An injection molding apparatus for processing thermoplastic materials has at least one plasticizer unit, at least one injection molding cylinder with associated emptying piston, and at least one injection molding mold. The injection molding cylinder is provided with a sleeve which is arranged reciprocally between a position in which communication with the injection molding mold is interrupted and a position in which communication with the injection molding mold exists. In the position in which the communication with the injection molding mold is interrupted, a passage is provided between the sleeve and the housing which is connected between the feed conduit from the plasticizer unit and a storage space defined on the inside by the sleeve. The outside diameter of the ejection piston is slightly smaller than the inside diameter of the sleeve so that remaining between the two is an annular gap through which the plastic material passes into the storage space from one end of the sleeve.

Abstract: The invention pertains to an apparatus and method of using the same. This apparatus includes a mold defining a mold cavity and an inlet through which molten material can pass. Also included is at least one feeder for preparing a molten material. This feeder has an outlet through which molten material can pass. There is also at least one accumulator spaced from the feeder and the mold. This accumulator has an inlet through which molten material can enter, and an outlet through which molten material pass. The accumulator also is designed such that it can introduce a molten material through its outlet into the mold cavity and exert a shear stress, compressive force or stress tensor on the molten material contained within the accumulator and/or within the mold cavity. The apparatus also includes a flow control mechanism is designed to prevent the flow of molten material from the accumulator back into the feeder.

Abstract: A process for injection molding a multi-colored article in an injection mold, in which a) a desired initial quantity of a first-colored material is metered to a first desired portion of the cavity; b) a desired quantity of a second-colored material is supplied to the cavity, contiguously with the first-colored material, and is metered to a second desired portion of the cavity. The location of the first and second desired portions within in the cavity being controlled by providing the first and second-colored materials with appropriate melt viscosities and controlling the temperature and rate of supply of the first and second-colored materials. A multi-colored preform formed by the process that is suitable for blow molding a multi-colored container, and a multi-colored container blow molded from such a preform are also provided.

Abstract: A standard injection molding machine is combined with an auxiliary plasticizing unit having a hot runner manifold that can be alternately connected with or disconnected from the main injection unit of the molding machine to perform sandwich molding. The injection unit retracts from the mold to connect with a hot runner and receive skin material from a non-reciprocating screw extruder directly into the barrel of the injection unit. The injection unit then disconnects from the hot runner and moves back into position for injection into the mold. Simultaneously with this movement, the injection unit plasticizes sufficient core material to complete the stacked arrangement of skin and core material necessary for sandwich molding. In an alternate embodiment, the sandwich molding apparatus includes an accumulator with a suitable valve and connections to the other components to supply a final shot of skin material into the mold, as well as provide the pack and hold functions of the injection cycle.

Abstract: In a method and device for mold press forming involving distribution of molten resin within a mold including a plurality of valve gates, deformation of the product and generation of excessive burrs and voids are prevented by accurately distributing a prescribed amount of resin material to each valve gate by detecting the amount of molten resin supplied from an injection unit and controlling the opening timing and period of each valve gate. The amount of molten resin supplied from the injection unit can be conveniently evaluated by detecting the displacement of an in-line screw used in the injection unit. By providing a metering arrangement for each of the valve gates, the molten resin can be even more accurately distributed to each of the valve gates.

Abstract: Apparatus and method for molding plastic articles including oscillating the molten plastic in the mold cavity. The method and apparatus is particularly suitable for use with a plurality of mold cavities supplied from a single feeding means or extruder. The disclosure teaches alternately feeding molten plastic to the mold cavity from at least one shooting pot while the flow of molten plastic to the mold cavity from the feeding means is discontinued.

Abstract: Apparatus and method for molding plastic articles including oscillating the molten plastic in the mold cavity. The method and apparatus is particularly suitable for use with a plurality of mold cavities supplied from a single feeding means or extruder. The disclosure teaches alternately feeding molten plastic to the mold cavity from at least one shooting pot while the flow of molten plastic to the mold cavity from the feeding means is discontinued.

Abstract: In the injection molding of a hollow shaped article by the injection of not only molten synthetic resin but also compressed gas into a die, a method is provided by this invention which effects the supply of the compressed gas with a multistage compressor and the injected compressed gas is recovered in a recovery container connected to the suction side of the multistage compressor. For the injection molding of a hollow shaped article by the injection of not only molten synthetic resin but also compressed gas into a die, an apparatus is provided by this invention which has a gas nozzle for injecting the compressed gas into the die connected through a first switching valve to the discharge side of the multistage compressor and, at the same time, has the gas nozzle connected through a second switching valve to a recovery container connected to the suction side of the multistage compressor.

Abstract: Apparatus for forming multilayered articles including a nozzle communicating with the mold cavity. The nozzle includes a first nozzle channel for feeding a first thermoplastic material to the mold cavity and a second nozzle channel communicating with the first nozzle channel for feeding a second thermoplastic material to the mold cavity. A metered amount of second material is fed from the second nozzle channel to the first nozzle channel and subsequently to the mold cavity by the first material from the first nozzle channel.

Abstract: Apparatus and method for molding plastic articles including oscillating the molten plastic in the mold cavity. The method and apparatus is particularly suitable for use with a plurality of mold cavities supplied from a single feeding means or extruder. The disclosure teaches alternately feeding molten plastic to the mold cavity from shooting pots while the flow of molten plastic to the mold cavity from the feeding means is discontinued.

Abstract: An apparatus for the extraction of melt samples, particularly from continuously operating plastics processing plants, has a test sample mould which is connected to a melt channel via a transfer channel. There are provided a shutoff device and a device for transferring the melt into the mould. In the transfer channel there is arranged a suction piston which sucks the melt out of the melt channel into the transfer channel which in this case is opened simultaneously. In addition, there is provided a pressure piston for injecting this melt into the moulding chamber. An apparatus of particularly simple construction is created in this way and permits extraction of melt samples without the melt coming into contact with the atmosphere, no dead spaces at all being created at the same time in the melt channel during the time when no melt samples are extracted.

Abstract: A system for distributing wax or a similar substance in semi-solid form is provided which includes a liquid wax supply system, a wax conditioning system including a heat exchanger which cools the wax to a semi-solid state and an accumulator for storing conditioned wax until needed, and a die press or similar work station which receives semi-solid wax from the accumulator in a continuous stream or flow. Such a system allows a lost wax die press to operate without need to manually open and reload the press with wax. An automated control system according to the invention allows die press reloading to occur automatically when needed, and operates the wax conditioning system as needed to maintain a supply of wax in the accumulator. Wax tunneling problems are avoided by means of a piston disposed in the heat exchanger which is movably interposed between hot liquid wax entering the heat exchanger and cooler, semi-solid wax leaving the heat exchanger.

Abstract: A method, system and device utilized therein for the injection molding of plastic articles of enhanced surface quality using pressurized fluid. The fluid is prevented from contaminating the molten resin in the nozzle from which it was injected to thereby eliminate splay. The method involves the initial step of injecting molten resin at a nominal injection pressure from the nozzle of an injection molding machine through a resin injection aperture at an upstream position in a mold. The resin travels along a resin flow path in the mold to a mold cavity defining the shape of the molded article at a downstream position. The device at least partially defines the resin flow path in the mold. A charge of fluid pressurized at a predetermined level is communicated to the resin flow path through an orifice in the device which opens to the resin flow path.

Abstract: A plastic material molding apparatus, wherein when the pressure at a material inlet of a cylinder of a material holding mechanism increases as a piston in the cylinder compresses a resilient member provided in the material holding mechanism, the speed of a motor for driving a material fluidizing mechanism is reduced. A servo motor for intermittently driving a plastic material metering and delivering mechanism is controlled according to the revolution speed and a predetermined total number of revolutions of the servo motor and to the number of pulses from a pulse generator provided in the servo motor. A relief valve is interposed between a material delivery port and a delivery nozzle of the metering and delivering mechanism, the relief valve being adapted to open when the material pressure at the delivery port is higher than the relief pressure, the relief pressure being set higher than the vapor pressure according to the temperature of the material at the delivery port.

Abstract: A multi-cavity mold in combination with a hot runner system wherein the hot runner system includes metering means individual to each mold cavity for feeding precisely measured quantities of thermoplastic material to each cavity.

Abstract: A method of injection molding of plastic parts in a mold in continuing cycles including the plasticizing of a moldable plastic and injecting the moldable plastic into a mold cavity characterized in that after the mold cavity is charged with plastic, pressure is maintained on the mold through an accumulator, with the accumulator being completely purged and refilled during each cycle thereby avoiding having in the accumulator static or stale plastic.

Abstract: The present invention increases the shot capacity and the screw recovery time of an injection molding machine without increasing hydraulic pump capacity or motor horsepower. In accordance with one aspect of the invention, an existing injection molding machine is retrofitted with two cylinder and piston arrangements which are bolted onto the machine between its plasticizer barrel and its melt manifold. One of the cylinder and piston arrangements is employed to perform a mold-filling operation, whereas the other cylinder and piston arrangement is employed to perform packing and suck back operations.

Abstract: Apparatus for coinjecting a plurality of thermoplastic materials to mold an article having a layered wall structure using thermoplastic material having different optimum processing temperatures including the maintenance of the optimum temperatures in flow paths individual to each material from its source to a mold cavity.

Abstract: An apparatus and method are disclosed which greatly facilitate molding of plastic material in the form of structural foam. The invention contemplates the provision of a valve-like mixing nozzle assembly which is selectively operable to control the flow of plastic material into an injection mold. Significantly, the nozzle assembly includes a mixing turbine rotatably mounted in the flow path of the plastic material. Notably, the turbine is driven by the plastic material itself as the material is driven into the mold assembly, and thus desirably provides intense mixing of the material during injection. This mixing action can be advantageously employed for effecting dispersion and/or expansion of the blowing agent carried by the plastic material for greatly enhanced control and flexibility in molding structural foam articles.

Abstract: This invention relates to an injection molding system having a valve pin which is hydraulically actuated between an open and a closed position in which its tip end is seated in a gate leading to the cavity. The actuating mechanism includes a piston secured to the driven end of the valve pin which reciprocates in a cylinder. The cylinder has an inner cylindrical member which is brazed in an outer member with a flanged portion. Separate hydraulic fluid ducts extend from the flanged portion through the outer member, along grooves in the outer wall of the inner member and then through holes through the inner member to conduct hydraulic fluid to opposite sides of the piston. The flanged portion of the outer member has a pair of passages extending through it, each connected to one of the ducts. Alternate ends of the passages are sealed off so that hydraulic fluid may be received either from supply lines drilled through the back plate in which the cylinder is seated or an abutting top plate.

Abstract: The apparatus molds during each cycle homogeneous plastic material and foam plastic material. It includes a barrel member, a main passageway therein in which is located the screw member. A pair of injecting means for filling molds are provided, one having a homogeneous plastic injection chamber and the other having a foam plastic injection chamber. The first injection means is connected to the screw and barrel member upstream of the place where the inert fluid is introduced into the main passageway whereby homogeneous plastic material is discharged from the main passageway into the first injection means. The apparatus includes means for introducing an inert fluid into the main passageway whereby the rotating screw member mixes the gas with the molten plastic as it moves towards the discharge port which is connected to the second injection means whereby foam plastic material is injected into the foam plastic injection chamber. Each injection means has one or more nozzles connected to a mold located in a press.

Abstract: A method and apparatus is provided for making a composite structural homogeneous resinous article having (a) a smooth, shiny non-cellular or homogeneous relatively thin injection compression molded liner on the outer surface and (b) a cellular relatively thicker injection molded core integral with the molded liner. One extruder is connected by valve controlled passages to a pair of injection devices, each device having an injection chamber. One chamber stores the homogeneous plastic resin and the other chamber stores the foam plastic resin. A first mold assembly having a movable upper mold part and a stationary lower mold part form a cavity, with a gap opening, at a first molding station. The cavity is in communication with the first injection chamber.

Abstract: A machine for treating or processing, e.g. injection moulding or extruding, plastic material which is available in packaged form said machine comprising, in a manner known per se, an extrusion nozzle (7, 9) and a feed channel (23) connected thereto, is combined with a device (31) for emptying the packages into said feed channel by deformation of the package (71). Before the emptying exit openings may be provided in the packaging material by means of special perforating members (93 to 97). The deformation and the emptying of the package takes place in a cylinder (47) by means of a piston (45) fitting therein and driven by means of pressurized fluid.

Abstract: An injection molding device for molding shaped bodies of natural or synthetic rubber comprising a heatable mold for shaping and vulcanizing therein the bodies to be molded and an elongated feed duct communicating with the mold via an injection nozzle. Plasticized material is fed into the duct by a plasticizing device and injection is effected by a piston-type injection device, both communicating with the duct. There is provided in the duct a valve which in its closed position blocks ingress of plasticized material into the duct but opens the duct for ingress of the material to be pressed by the injection means into the mold via the nozzle. The valve head is axially displaceable in the duct and mounts a member so dimensioned that in the open position of the valve it fully closes the nozzle opening, thereby pushing any residual plasticized material into the mold and in the closed position is completely withdrawn from the nozzle opening.

Abstract: A molding apparatus in which a slider is slidable in an inclined channel into which a passage opens at one side for communication with a mold cavity while a pair of passages open at the opposite side for communication with a plasticating (worm) cylinder and a further cylinder provided with a plunger or piston. The slider has a U-shaped passage, the arms of which are positioned to interconnect both of the passages on the other side of the channel in a position of the slider in which the passage to the mold is blocked but which connects only the accumulating cylinder passage through the bight of the U-shaped passage to the mold in another position of the slider. A check valve is provided in the passage of the worm cylinder.