Abstract: Plasticizing system for plasticizing solidified-resin particle, plasticizing system, comprising: housing assembly providing: (i) melt channel configured to receive solidified-resin particle, and (ii) opposite-facing surfaces spaced apart from each other, and defining, at least in part, convergene channel configured to receive the solidified-resin particle. Opposite-facing surfaces and the convergence channel form part of melt channel. Plunger assembly is movable, at least in part, relative to opposite-facing surfaces. Plunger assembly configured to move, at least in part, solidified-resin particle relative to opposite-facing surfaces along, at least in part, convergence channel. In response to relative movement between solidified-resin particle and opposite-facing surfaces, solidified-resin particle receives, in use, plasticization-inducing effect from opposite-facing surfaces.

Abstract: A device for producing plastic moldings has an extruder and a molding tool arranged downstream of an extruder discharge opening. A screw is rotatably guided in the extruder and is axially displaceable to transfer liquid polymers, prepolymers or monomers present in the extruder into the molding tool. A nonreturn valve adjacent to a free end of the screw has a locking ring in contact with the inner circumferential wall of the extruder that includes a seal, which is applied to at least part of its outer circumference and which seals the locking ring against the circumferential wall of the extruder. The sealing material of the seal is selected from the group of the polymers, copolymers and polymer blends with a hardness lower than that of the circumferential wall of the extruder. A nonreturn valve and method of processing liquid prepolymers or monomers into plastic moldings is provided.

Abstract: The invention relates to methods for producing annular moldings subjected to tensile or pressure loading from plastic by using an injection mold having a main cavity, at least one extra cavity is incorporated in the injection mold. The at least one extra cavity is joined to the main cavity by a connecting duct. The main cavity is filled with plastic melt so a flow line is formed in the vicinity of the connecting duct between the at least one extra cavity and the main cavity, wherein the cross section of the connecting duct is dimensioned such that, during the filling of the main cavity, no plastic melt flows into the extra cavity. The filling pressure is increased until plastic melt flows into the extra cavity; flow taking place through the flow line produced during the filling of the main cavity. Subsequently, the injection mold is opened and the molding removed.

Abstract: An injection molding machine includes a hydraulic driving system providing hydraulic power; a molding system configured for molding a workpiece; and an injection system configured for injecting a molten material to the molding system with the hydraulic power. The injection system includes a cylinder and a piston movably received in the cylinder. The cylinder is surrounded by one of an alternating current-charged coil of wire and a closed-loop coil of wire, and the piston is surrounded by the other, whereby the piston receives acceleration for movement in the cylinder.

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: An injection molding machine capable of accurately detecting a rotational force exerted on a screw by resin backflow to easily evaluate states of resin backflow and closure of a check valve. In a state where the screw is stopped axially and rotationally after metering is finished, a load exerted on the screw in the rotational direction is detected. This load is a rotational force exerted on the screw from resin remaining between flights of the screw (resistance torque component). During injection, a load T exerted on the screw in the direction of rotation is detected, and the resistance torque component is subtracted from the detected load T to obtain a backflow torque component generated by resin flowing back through the check valve. By simultaneously displaying waveforms of backflow torque components in a plurality of molding cycles to be overlapped, stability of closure of the check valve is readily evaluated.

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: In repeating strokes for injecting a resin material, a piston (13) is slid to an inlet position (P2) within a cylinder (12). Accordingly, when the piston (13) is moved backward further, the resin near the piston (13) is replaced with a fresh resin supplied from a resin reservoir section (RT). Therefore, in the subsequent injection stroke, only the fresh resin can be always injected. Thus, there is no possibility that the rein stays beyond the pot-life and starts to cure or causes an increase in viscosity within the cylinder (12). Further, any foreign matter such as a semi-cured resin is not produced. Therefore, clogging of the resin passage and the flow of the foreign matter into a molding cavity can be suppressed. As a result, given molding conditions can be always ensured, and, thus, highly accurate molding products can be produced with high reproducibility.

Abstract: A plasticizing and injecting device for a plastics injection molding machine includes an axially fixed and rotationally driven plasticizing screw, and an injection plunger movable forwards and backwards inside the plasticizing screw by a linear drive and including, at its front end, a non-return valve. An injection cylinder is provided anteriorly of the plasticizing cylinder. The non-return valve can be moved by the injection cylinder forwards and backwards inside the injection cylinder between a rear position at the beginning of the injection process and a front position after completion of the injection process. In addition, a melt chamber is formed between the front end of the plasticizing screw and the non-return valve, and forms, during the injection process and during the holding pressure phase, an annular gap between the injection plunger and the injection cylinder for receiving plastic melt as the plasticizing screw continues to rotate during injection.

Abstract: A tool for a resin transfer moulding method comprises a cavity, a resin trap and a transition region, wherein the cavity is designed such that a component can be accommodated in it. Furthermore, the resin trap is integrated in the tool, and the transition region is designed such that with it a connection between the cavity and the resin trap can be established.

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: An improved precise control non-return valve assembly which is mounted on the front end of a helical rotating plasticating screw of an injection molding machine or the like that is surrounded by a heated elongated barrel and end-cap that forms a distribution chamber, whose purpose is to allow means for passage of molten plastic fluid in the downstream direction while preventing it in the opposite direction. The valve having an outwardly extended portion of a shaft and has a means to accept a ring that is sandwiched between a bushing assembly and a rear seating area. The bushing assembly consists of at least two bushings and one pin whose dual purpose is to govern the forward movement of the ring and to absorb the force that is being applied to it. The non-return valve assembly when moved forward with the screw, forms a seal, builds pressure, and displaces molten plastic fluid from the distribution chamber through a discharge chamber passageway and into a 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: A discharge apparatus for a two-stage injection molding machine, includes a check shaft seat having a runner, and disposed between a feeding portion and an injection portion of the two-stage injection molding machine, for allowing a plastic material in the feeding portion to enter the injection portion via the runner; at least one check shaft disposed in the check shaft seat, and for opening and closing the runner via movement of the check shaft; at least one cover provided at a side of the check shaft seat, and having at least one discharge hole for discharging residues of the plastic material between the check shaft seat and the check shaft; and at least one adjustable unit for adjusting a discharge speed of the residues of the plastic material. The discharge hole and the adjustable unit can prevent locking of the check shaft and pollution from degraded residues of plastic material.

Abstract: The present invention relates to a non-return valve that can be configured for use anywhere along a molding material flow path in a molding system. The non-return valve of the present invention includes an improved means to restrict the backflow of melt therethrough during injection. In particular, a spigot-seal is configurable, during injection, between overlapping, closely-spaced, and mutually parallel complementary male and female spigot portions that are configured between complementary valve members. The spigot-seal advantageously maintains an effective backflow restriction even in the eventuality of transient movement between the spigot portions during injection. Preferably, the non-return valve of the present invention is also configured to include a means for mutually aligning and/or guiding the complementary valve components that ensures a proper alignment between the complementary spigot portions, and may also serve to improve the function and longevity of a face-seal, when present.

Abstract: A method for making foam products steps of preparing variety of foam materials with different colors, mixing the materials in a final tank, feeding the materials in a mold, heating the materials which are then foamed to form a product which is then removed from the mold and cooled. The method is proceeded by a device which includes first tanks for receiving the variety of foam materials, second tanks for being fed with pre-set amount of the variety of foam materials, and a final tank which has mixture of the variety of foam materials. The mixture is then sent to a mold to be heated and foamed.

Abstract: An apparatus for injection molding comprises an injection unit comprising a plunger, the plunger being translated with accumulation of plasticized material in preparation for injection and being advanced to inject the accumulated plasticized material into mold cavities. At least one electric motor is engaged with the plunger to resist translation as melt is accumulated and to inject plasticized material into the mold cavities. At least one hydraulic actuator selectably operates the plunger during a pack and hold interval to supply supplemental force when force supplied by the electric motors is limited to maintain the operation of the motors within the applicable continuous duty rating thereof. The electric motors are advantageously selectably operatively engaged with the plunger to inject plasticized material into the mold cavities and the hydraulic actuators are operated to inject plasticized material into the mold cavities when the motors are not engaged therefore.

Abstract: Disclosed is a device configured for a valve. The valve has a valve structure that is configured to include an outlet body configured to define an outlet. The outlet body is also configured to attach to a melt processing screw of a molding machine. The valve structure is also configured to include an outlet cover configured to selectively close and open the outlet. The device includes a brake configured to decelerate the outlet cover responsive to deceleration of the outlet body, and the decelerating outlet cover maintains the outlet substantially closed.

Abstract: A screw tip for use in a molding system apparatus is disclosed. The screw tip includes a connection section and screw tip head section. The screw tip head houses an entry port, or entry ports, an accumulation chamber, and a check valve chamber. A check valve is provided when assembled with the screw tip. The check valve may be a cylindrical plate or a spherical member or a conical member.

Abstract: An injection molding apparatus which includes a check valve assembly mounted at the forward end of a feed-screw, the valve assembly having forward and rearward valve seat surfaces which co-act in a first position to allow a plasticized polymeric material to enter and flow through the valve into an injection chamber and which co-act in a second position to stop any additional material from entering the valve assembly. The second valve position is effected by a feed-screw injection stroke which generates a back pressure to close the valve, the back pressure moving a check ring of the valve assembly into a position to block entry into the valve. Part of the valve seat surfaces are covered with a plurality of ceramic disks and other valve seat surfaces are covered with a metal alloy which effectively increases the abrasion resistance of the valve seat surfaces and thus also increases the wear service life of the check valve assembly.

Abstract: A screw tip is provided in front of a screw with a shaft interposed therebetween, and a check ring is fitted around the shaft. The check ring is separated from a front end portion of the screw when the screw is rotated in a forward direction. The check ring contacts the front end portion of the screw when the screw is advanced. A front end surface of the check ring is provided with teeth, and a rear end surface of the screw tip is provided with grooves with which the respective teeth are engaged. Respective one side surfaces of the grooves and the teeth which are pressed against each other when the screw is rotated in the forward direction are formed vertical to the front end surface of the check ring, and side surfaces thereof located on the reverse sides of the above respective one side surfaces are inclined.

Abstract: An injection molding apparatus includes an injection piston that is slidable within a nozzle having a movable valve gate pin. The injection piston is movable from a retracted position to an extended position in order to force melt towards a mold cavity. A valve is located at a forward end of the piston to selectively block communication between a recess, which is provided in an outer wall of the piston adjacent the valve, and a melt chamber of the nozzle. Movement of the injection piston from the retracted position to the extended position causes the valve to close so that the predetermined volume of melt located below the valve is forced into the mold cavity, when the valve gate pin opens the mold gate.

Abstract: An injection unit for an injection molding machine includes a plasticizing unit in the form of an extruder, a plunger-type injection device, which can be connected to the injection molding machine by an injection nozzle. The plunger-type injection device defines an injection space. The extruder has a forward portion which is connected to the injection space by a melt through channel in which a shutoff valve is disposed. The extruder is operated continuously and includes one or more plasticizing screws, wherein the extruder is configured in such a way that the backup length can expand backwards into the extruder, when the shutoff valve is closed.

Abstract: An injection unit for injection molding machines includes an extruder as plasticizing unit and a plunger-type injection molding device that can be coupled to the injection molding machine by an injection nozzle. The plunger-type injection molding machine has an injection plunger, wherein the area in front of the injection plunger forms an injection space which is connected to a forward end of the extruder by a melt channel, with a shutoff valve disposed in the melt channel. The extruder can be continuously operated and has one or more plasticizing screws for plastification, wherein the extruder is so configured that a backup length is able to increase backwards into the extruder, when the shutoff valve is closed.

Abstract: An injection molding shooting pot 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 injection molding shooting pot includes a shooting pot piston having a proximal end and a distal end. A shooting pot piston extension is disposed at the distal end of the shooting pot piston, and is configured to dislodge a check valve moving element during a discharge cycle of the shooting pot piston.

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

Abstract: A backflow prevention device for an injection molding machine includes a screw tip having a tip end, a central body member connected to the tip end, a thrust ring at a rear end of the body member, and a mounting end for attachment to a plasticizing screw. A locking ring is arranged at a distance to the body member to define an annular gap and is axially movable between an open position, in which a first sealing surface rests against a shoulder of the tip end, allowing passage of material, and a closed position, in which a second sealing surface rests against a shoulder of the thrust ring, prohibiting entry of material. Disposed in the annular gap coaxial to the locking ring is at least one mixing element in the form of a circular ring which has circumferential bores in spaced-apart disposition for axial material transport.

Abstract: An injection molding device includes a continuously operating extruder and a discontinuously operating injection unit receiving plastic material from the extruder. The extruder has an extruder barrel which includes a plasticizing zone and a discharge zone, whereby the discharge zone is configured to provide an intermediate storage space and has a cross sectional area which is greater than a cross sectional area of the plasticizing zone. In this way, the discharge zone provides a buffer volume which is filled during the injection process and then emptied again.

Abstract: An injection unit for an injection molding machine includes an injection device in the form of a plunger/screw, which is driven axially and rotationally in a housing, and a device intended for mixing and metering plastic melt and including an inlet for introduction of an additive. A spacer element is disposed between a backflow prevention assembly of the screw and the plunger, with the spacer element having a length, which corresponds at least to the stroke of the injection device. The spacer element has a first flow channel for establishing in each position a fluidic connection with a second flow channel which initially extends radially in an outward direction and then parallel to the movement and guide area of the plunger to an area between a nozzle and the plunger. The second flow channel extends through the mixing and metering device arranged adjacent to a movement and guide area of the plunger.

Abstract: A form, fill and seal packaging machine for forming, filling and sealing a carton, molds a closure directly onto the carton. The machine includes a carton erection station adapted to receive a carton in a generally flat form and to erect the flat form carton into a tubular form defining an internal carton region. A direct injection molding station has an internal mold tool and an external mold tool. The internal mold tool is configured for receipt within the internal carton region and the internal mold tool and the external mold tool are configured to receive and clamp the carton therebetween. The direct injection molding station further includes a polymer injection system for injecting polymer from a location external of the carton to the internal mold tool. The closure is directly molded in place on the carton. A mold tool set, a method for carrying out the molding and a closure molded thereby are also disclosed.

Abstract: An injection molding apparatus includes an injection piston that is slidable within a nozzle having a movable valve gate pin. The injection piston is movable from a retracted position to an extended position in order to force melt towards a mold cavity. A valve is located at a forward end of the piston to selectively block communication between a recess, which is provided in an outer wall of the piston adjacent the valve, and a melt chamber of the nozzle. Movement of the injection piston from the retracted position to the extended position causes the valve to close so that the predetermined volume of melt located below the valve is forced into the mold cavity, when the valve gate pin opens the mold gate.

Abstract: A backflow prevention device for a plasticizing and injection screw axially movable in a plasticizing cylinder of an injection molding machine, includes a base body having a leading head portion and a trailing neck portion and formed with a channel for passage of plastic melt by the screw to an anterior screw space, whereby a check valve is disposed in the channel. Bearing against an inner wall of the plasticizing cylinder and axially moving between open and closed positions is a locking ring so positioned behind the head portion in the area of the neck portion as to define a gap with the base body.

Abstract: A form, fill and seal packaging machine for forming, filling and sealing a carton, molds a closure directly onto the carton. The machine includes a carton erection station adapted to receive a carton in a generally flat form and to erect the flat form carton into a tubular form defining an internal carton region. A direct injection molding station has an internal mold tool and an external mold tool. The internal mold tool is configured for receipt within the internal carton region and the internal mold tool and the external mold tool are configured to receive and clamp the carton therebetween. The direct injection molding station further includes a polymer injection system for injecting polymer from a location external of the carton to the internal mold tool. The closure is directly molded in place on the carton. A mold tool set, a method for carrying out the molding and a closure molded thereby are also disclosed.

Abstract: An injection assembly for an injection molding machine, with a continuously operating plasticizing unit, includes a piston-type injection unit and an arrangement for intermediate storage and discharge of melt. Several melt reservoirs with melt inlet openings are provided between the plasticizing unit and the piston-type injection unit. Melt lines that connect the melt reservoirs with each other and with the plasticizing unit extend to the melt inlet openings. The melt reservoirs include actuatable work pistons for discharging the melt, wherein the work pistons can open and close the melt inlet openings in the melt reservoirs to divert the melt flow. The disclosed injection unit increases the total volume of bufferable melt and allows individual and separate adjustment of the reservoir volumes and the discharge velocity of the individual melt reservoirs. In addition, switching valves can be eliminated since the melt flow is switched by the work pistons.

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 an injection chamber unit with a horizontal channel, a vertical channel, and a transitioning passage interconnecting the horizontal and vertical channels. The transitioning passage has an innermost turning side and an opposite outermost turning side longer than the innermost turning side. The transitioning passage includes at least two turning corners of obtuse angle at the outermost turning side and adjacent to the horizontal channel and the vertical channel, respectively. The transitioning passage further includes a tapered passage section which tapers toward the vertical channel, and a wall part which partially Ago confines the tapered passage section at the outermost turning side. The wall part has a shape conforming to a segment of a truncated cone-shaped face which extends angularly by an angle of less than 360 degrees.

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: The invention relates to a plasticizing unit in injection-moulding machines, in particular for processing thermoplastics, with a plasticizing cylinder in which a rotatable and axially displaceable screw is arranged, at the head of which a non-return valve is provided, which has an axially displaceable barrier sleeve which encloses with radial play a tapered region which belongs to a basic body fixed in the screw head and is present between blades and a stop ring. The basic body has at least three blades, in that supporting elements provided on the surfaces of the blades facing the barrier sleeve, wherein at least the supporting surfaces of the supporting elements are made of a hard-wearing material.

Abstract: In a compounder-type injection molding machine having an extruder for continuously producing a melt and at least one injection device is fluidly connected to the extruder to receive melt, a reservoir is provided which is in fluid communication with the extruder as well as with the injection device for temporary storage of melt. In order to maintain a pressure at a desired level at the outlet of the extruder, a pressure sensor is provided for ascertaining a melt pressure state downstream of an outlet of the extruder. The pressure sensor outputs a signal, commensurate with the melt pressure state, to a control unit for activating a drive in the reservoir or a drive in the injection device in response to the signal according a predetermined algorithm.

Abstract: A screw injecting apparatus includes a check valve mounted on the tip end portion of a screw and adapted to be opened and closed in response to rotation of the screw, and a control for controlling operation of the screw such that in a metering phase of molding process, the screw rotates in one direction to feed a melt of molding material toward the nozzle while the check valve is in an open state, when a metered amount of melt is accumulated forward of the tip end portion, the screw moves backward by a predetermined distance to reduce a reaction from the melt accumulated around the tip end portion, thereafter, the screw rotates in the reverse direction to close the check valve and cause the screw to advance until the amount of forward movement of the screw becomes substantially equal to the predetermined distance of backward movement achieved previously.

Abstract: An injection moulding machine for producing small plastic components with a drive unit (6, 84), a plasticizing device (4, 42) and a hot channel nozzle (1) having a collection chamber (10) for the molten plastic. An injection ram (35) projects into the hot channel nozzle (1) and can push the collected plastic out. In an embodiment, the plasticizing device (4, 42) and the drive unit (6, 84) are secured to a movable bearing housing (85) and can move the injection ram (35).

Abstract: A conveying device that permits the continuous accumulation and intermittent injection a molding material is herein disclosed. The conveying device comprises a housing having a bore with an inlet and an outlet and a shaft reciprocable disposed within the bore. The shaft and bore are constructed and arranged to form an annular space therebetween. A slip ring is slidably captured on the reciprocable shaft and may travel longitudinally on the shaft between a forward position and a rearward position. When the shaft is retracted from the bore, the slip ring moves to its forward position on the shaft and the molding material may flow between an inner surface of the slip ring and the shaft. When the shaft is inserted into the bore, the slip ring moves to its rearward position and the slip ring acts as a piston head and forces the molding material from the bore and into a downstream molding or handling mechanism.

Abstract: An improved positive control non-return valve assembly which is mounted on the front end of a helical plasticating screw of an injection molding machine. The valve assembly comprises a thread retainer with means for attachment to the plasticating screw. The valve assembly also comprises a distribution chamber that has an annular shaped flow gap and a cylindrical passageway that leads to a plurality of discharge ports. The non-return valve assembly forms a seal, builds pressure, and displaces molten plastic fluid from the distribution chamber through a discharge chamber passageway, and into a mold.

Abstract: A shooting pot actuator for an injection molding machine having two plates carrying pusher rods for pushing against injection plungers within the shooting pots. The plates are mounted outside the mold and the clamp unit, and the pushers extend through bores in the stationary platen of the clamp unit to reach the injection plungers. The actuator reduces the cost and complication of mold design and production, and permits simplified adjustment of the injection plunger stroke.

Abstract: An injection assembly for an injection molding machine, with a continuously operating plasticizing unit, includes a piston-type injection unit and an arrangement for intermediate storage and discharge of melt. Several melt reservoirs with melt inlet openings are provided between the plasticizing unit and the piston-type injection unit. Melt lines that connect the melt reservoirs with each other and with the plasticizing unit extend to the melt inlet openings. The melt reservoirs include actuatable work pistons for discharging the melt, wherein the work pistons can open and close the melt inlet openings in the melt reservoirs to divert the melt flow. The disclosed injection unit increases the total volume of bufferable melt and allows individual and separate adjustment of the reservoir volumes and the discharge velocity of the individual melt reservoirs. In addition, switching valves can be eliminated since the melt flow is switched by the work pistons.

Abstract: The invention relates to a method and an apparatus for injection molding parts, which comprises a mixture of at least one plastic material and at least one additive in the form of fibrous or powdered fillers or reinforcement materials.

Abstract: A method for injecting plastic material or another injectable material into an injection molding tool comprises the following steps: plasticizing the plastic or other injectable material in a plasticizing apparatus (2); transporting the plasticized plastic or the plasticized other injectable material into a dosing apparatus (3), which has a fluidic connection (4) to the plasticizer apparatus (2), and specifically in essentially precisely the quantity that is to be introduced into the injection molding tool (1); transporting the plasticized plastic or the plasticized other injectable material, essentially in that quantity which is to be introduced into the injection molding tool (1), from the metering apparatus (3) into an injection apparatus (5), via a fluidic connection (6), while at the same time preventing the plastic or other injectable material from backflowing from the metering apparatus (3) into the plasticizing apparatus (2); injecting the entire quantity of plastic or the entire quantity of another i

Abstract: A screw injecting apparatus includes a check valve mounted on the tip end portion of a screw and adapted to be opened and closed in response to rotation of the screw, and a control for controlling operation of the screw such that in a metering phase of molding process, the screw rotates in one direction to feed a melt of molding material toward the nozzle while the check valve is in an open state, when a metered amount of melt is accumulated forward of the tip end portion, the screw moves backward by a predetermined distance to reduce a reaction from the melt accumulated around the tip end portion, thereafter, the screw rotates in the reverse direction to close the check valve and cause the screw to advance until the amount of forward movement of the screw becomes substantially equal to the predetermined distance of backward movement achieved previously,

Abstract: The present invention includes a filtration apparatus for an injection molding machine where the injection molding machine includes a screw housed within a bore for generating molten polymer. A tip member extends axially from the screw. The tip member has radially extending upstream and downstream flanges positioned axially apart from each other. A filter encircles the tip member and is capable of filtering the molten polymer. An annular ring member encircles the tip member and is slidably positioned within the bore between the upstream and downstream flanges. The ring member is capable of sliding between the flanges for directing the molten polymer through the filter or preventing back flow of the molten polymer past the upstream flange.

Abstract: A molding machine for molding microparts containing between 0.001 to 3.5 cubic centimeters of plastic shot volume includes a plasticizing portion operatively connected to an injection portion and a mold portion. A valve member is provided to open and close the connection between the plasticizing portion and the injection portion. A linear motor member is associated with the injection portion to permit molding times of 0.01 seconds at pressures up to about 100,000 psi during injection of the molten plastic into the mold portion.