Abstract: The invention includes a method and an extrusion apparatus for shaping plastic materials particularly those of high molecular weight, whereby the temperature distribution in an extrusion cylinder allows for the build-up of very high pressures and all axial pressure forces are absorbed by a two-sided extruder screw, the extrusion cylinder and, in some instances, the therein contained plastic material. In practicing the method, the plastic material in a flowing state, and at a positive pressure, is continuously conveyed to an extrusion apparatus, and subsequent to its entrance in an extrusion cylinder and before its discharge is cooled to a temperature below the solidification point, not only from the outside by a cooling source in the extrusion cylinder but also from the inside by a cooling source in the interior of the extruder screw.The present invention makes possible the production of materials of improved strength and elasticity, which can be molded to synthetic threads, films and splittable films.

Abstract: An improved machine for the production of foamed plastic molded parts, including soft foam plastics, i.e. for processing particles without foaming capacity, and including the processing of greatly frothed plastic foam particles, i.e. particles with but little foaming capacity, is obtained in that a pressure equalization system is provided which creates virtually equal pressure conditions while the mold cavity is being filled, i.e. the same overpressure in the material supply line as in the mold cavity. This makes it possible to introduce the foam particles, already compressed in the material supply system, into the mold cavity in a continuous flow by means of an injector, with excess foam particles being blown back into a tank provided in the material supply system by the injector after the mold cavity is filled.

Abstract: Method of production of a reflector wall having a core of thermosetting material enclosed in a skin of thermoplastic material, by two-material injection molding. Between a concave mold face having projecting points and a convex mold face, a thermoplastic skin material and a thermosetting core material having a polycondensation temperature greater than the plasto-elasticity temperature of the thermoplastic skin material are successively injected, while holding a temperature intermediate between the two temperatures; the points cause in the skin material interruptions permitting the emergence of the core material to the concave mold face, in localised zones of this in which open vents; the polycondensation of the core material and the hardening of the skin material is successively caused.

Abstract: The molding machine of the present invention comprises a screw extruder for extruding plastic material. A plurality of molds are moved one at a time to the outlet end of the extruder for receiving the plastic material therefrom. One end of the mold is open for receiving the plastic material and the opposite end of the mold includes a closure plate covering the end of the mold. The closure plate has a small fill sensing aperture therein. A sensing switch is mounted adjacent the fill sensing aperture and is adapted to sense when molded plastic exits from the fill sensing aperture so as to shut off the extruder and cause the mold to move away from the extruder so that an additional mold can be filled. A cylinder operated closure device clamps the opposite ends of the mold after the mold has moved away from the filling station so as to contain the plastic material within the mold while the plastic material cools and hardens.

Abstract: An apparatus for producing articles by molding of mixtures of at least two flowable reactive components comprises respective metering units for displacing the components to a mixing head from respective storage vessels with the working pistons of these units being displaced by hydraulic fluid from a common pump through servocontrolled valves respectively following the working pistons to maintain the velocities thereof constant.

Abstract: A hydraulic press for non-refractory material consisting of a rigid framework and a vertically moveable press pad and horizontally moveable box section. A mold cavity is defined within framework and the press pad is contained within. Moveable box section delivers stock to mold cavity, forms cover over mold cavity during manufacture, and ejects formed unit from framework. A hydraulic cylinder is provided for movement of press pad during compression of unit and to raise unit for ejection from framework. A separate hydraulic cylinder is provided for movement of box section through framework. Both cylinders are fixedly connected to the framework. Hydraulic fluid, directed by solenoid-activated valves, provides movement of cylinders. Control means include an electrical circuit using relays, timmer, pressure actuated valve, and mechanical trip switches.

Abstract: A machine has a nozzle formed with an annular passage centered on an axis and having at an outer axial end an annular mouth. A plastic mass is introduced under pressure into the inner axial end of the passage at two diametrally opposite locations and mixes and passes outwardly along the passage to emerge from the mouth as a tube. The axial outward flow of the mass along the passage is impeded upstream of the mouth to pressurize the mass with a pressure substantially greater than atmospheric. Such flow is impeded either by restricting the passage or by allowing the volume of the passage to increase against a predetermined counterforce. The mass will form when it leaves the nozzle a tube of almost perfectly uniform wall thickness.

Abstract: Process and apparatus for producing a sheet or film exhibiting a colored band of varying color intensity, with an extruder for melting a stream of a thermoplastic synthetic resin and with a slot die tool (e.g.

Abstract: A food processing apparatus having an extrudate outlet nozzle, an extrudate receiver, the nozzle and receiver being movable to discharge extrudate in a preselected two dimensional line configuration on the receiver, and a programmable controller for controlling the movement to achieve the configuration.

Abstract: A method of moulding by low pressure moulding wherein a passage from the mould cavity is bridged by the molten material during filling and in which the moulding pressure is too low to cause the material to flow down the passage. After the mould is completely filled, the pressure increases to cause penetration of the molten material along the passage to a switch operating position to operate a switch to stop further flow of material into the mould.

Abstract: Disclosed is a process and apparatus for extrusion of multiple-layer sheeting comprising an improved co-extrusion feedblock and valve plate for laying down co-extruded resin streams onto a main extruded polymeric resin. The new design provides advantageous external control of the layer number as well as a more refined control of layer thicknesses.

Abstract: An apparatus for controlling extrusion back-pressure in a face cutting apparatus having an extrudate feed means, a die and a cutter is provided. The apparatus consists of a pair of nested dies, one upstream and one downstream, each die having a plurality of areas, each of the areas having a plurality of extrusion orifices. The nested dies are movable relative to another. In one relative position, the orifices of the upstream die exactly aligned with the orifices of the downstream die. Means are provided for relative movement of the dies in response to a change in the pressure adjacent the extrudate delivery end.

Abstract: Disclosed is an apparatus and process for the production of multiple-layer film or sheeting having desirable surface characteristics, especially including uniformity of layer thickness and width. The apparatus includes a feedblock which selectively splits the coextruded streams, controls the flow thereof and applies the layers in a manner such that the thickness of the various layers can be more easily and accurately controlled across the width of the sheeting.

Abstract: An adjustable die mechanism (10) for extruding a profiled strip of plastic or elastomeric material wherein a plurality of adjacent segments (44) is located upstream and in spaced relation from a final extrusion die assembly (32), having a predetermined profiled opening (38), with this plurality of segments (44) being mounted for individual and independent adjustment thereof, each segment having one end (46) capable of extending into the extrudate flow channel (26). Means for actuating (64) move the segments (44) relative to the profiled opening (38) in a predetermined manner such that moving the segments (44) into the profiled opening (38) modifies the flow of the extrudate material downstream of the segments (44) as the profiled strip emerges from the die assembly (32). The die mechanism includes control means (82) for selectively operating the means for moving the segments so as to produce a strip of material having the desired characteristics.

Abstract: An extruder system has an extruder provided internally with a worm. A source of an additive fluid under pressure is connected to a conduit opening into the barrel. An upstream valve and a downstream valve are provided in this conduit and a pressurizable fluid reservoir is provided in the conduit between the valves. The extruder is continuously rotated in the barrel to plastify a resin therein. The valves are alternatively opened and closed, that is one is open when the other is closed and vice versa, so that a fluid first flows from the source through the upstream valve into the reservoir and then from the reservoir through the downstream valve into the barrel to be mixed by the worm with the plastic resin therein. The reservoir can be a cylinder having a piston advanced when the downstream valve is opened to force the charge of additive fluid in the reservoir into the barrel.

Abstract: A gate for a mold comprises a plunger member mounted in the molding compound inlet conduit and adapted to prevent flow through the conduit in a first longitudinal position and to permit flow through the conduit in second longitudinal positions. The plunger defines an enlarged sealing end which is proportioned to prevent flow through the conduit on the first position. The sealing end defines a mold cavity-facing surface which is of larger cross-sectional area than the surface of the plunger opposed to the mold chamber and subject to contact with pressurized molding compound in the compound. The plunger member is longitudinally expansible and contractible so that even though one end may be rigidly mounted in the conduit, the enlarged sealing end is longitudinally movable to open and close the mold gate in a manner purely responsive to pressures therein. Thus, spontaneous gating of a mold may be provided.

Abstract: This invention is an improved injection molding nozzle whereby the shut-off plunger is operated by a fluid and the opening of the nozzle is accomplished by the flow of plasticized material through the nozzle. A control rod internal to the nozzle controls the movement of the plunger shut-off member and is adjustable so that the amount of plasticized resin flowing through the nozzle can be accurately controlled.

Abstract: A gate for a mold comprises a molding compound inlet conduit for communication of molding compound to the mold cavity. A plunger member is slidably mounted adjacent the inlet conduit and adapted to prevent flow through the conduit in a first sliding position and to permit flow through the conduit in a second sliding position. The plunger defines a slidable shaft and an enlarged end proportioned to prevent the flow through the conduit in the first position. The enlarged end defines a mold cavity-facing surface of larger area than the opposed surface on the enlarged end, which opposed surface communicates with the conduit. Accordingly, pressurized molding compound presses against the opposed surface, to spontaneously open the plunger into a second sliding position to admit molding compound to the mold cavity. Upon essential equalization of the pressures in the mold cavity at the conduit, the plunger is spontaneously moved hydrostatically to its first closed sliding position.

Abstract: An apparatus and method utilizing pressurized air discharged through positionable outlets is adapted to blowing core mark material from freshly molded, uncured concrete blocks of either the rib or flute type designed to be split or conventional unsplit blocks so as to prevent the core mark material associated with such blocks from being trapped and hardening in recesses or on surfaces of the blocks.

Abstract: The force applied to a ram is controlled so that the ram moves at a controlled speed while propelling material to be extruded through a die.

Abstract: A plastics extruder in operative association with a control arrangement is disclosed. The plastics extruder includes a screw extruder, a screen downstream of the screw extruder, a throttle located between the screw extruder and the screen, a moulding tool downstream of the screen, and a melt index measuring device. The measuring device includes a metering pump whose rotational speed is controllable and which is provided with a rotational speed indicator, a measuring nozzle disposed in a sample flow channel, and pressure and temperature sensors connected to the sample flow channel directly upstream of the inlet of the measuring nozzle. The sample flow channel is adapted to be located downstream of the screen pack and upstream of the moulding tool. For the purpose of regulating the viscosity of the plastics material melted in the screw extruder, the throttle cross-section is variable by a servomotor connected to the output of a programmable two-coordinate controller.

Abstract: Gas-flow control apparatus for delivering a constant volumetric flow of gas to an extruder through which a molten thermoplastic resin is being processed. The gas-flow control apparatus consists of a compressor having an intake and a discharge and is operable to produce a constant volumetric gas flow output. A discharge conduit connects the compressor discharge with the extruder and a feedback loop system consisting of a feedback conduit connects the compressor discharge with the compressor intake and includes a bypass valve. The feedback loop system thus is operable to divert a selected fraction of the compressor output back to the compressor intake thereby to control the volume of gas supplied to the extruder. Flow measuring apparatus measures the volume of the supply gas delivered to the compressor which is equal to the volume of the gas delivered to the extruder and regulates the bypass valve so that a predetermined volumetric flow of gas to the extruder is maintained.

Abstract: A feedblock fashioned from a plurality of plates is disclosed which distributes two flows of dissimilar synthetic resinous materials into a radially stratified annular form for extrusion by a pipehead die. The feedblock is mounted on a pipehead with the plurality of plates defining material flow channels for three strata. Independently operable valves vary stratum thickness and assure radially matched flow conditions between strata at confluence. Each stratum is independently accelerated through a convergent channel to assure that a uniform circumferential distribution of flow conditions develops. Moreover, two strata are developed through channel systems which do not induce circumferential maldistribution. The third stratum is handled to eliminate circumferential maldistribution. Accordingly, the process and apparatus develop stable annular flow with radial stratification having neither radial nor circumferential maldistributions that may later interact to distort the strata.

Abstract: A method for pressure buildup in a pressing cylinder of a press for a plastic or elastic material, wherein the material, under the influence of the advance of a plunger, is initially precompressed slowly to reach a pre-extrusion pressure and then the pressure is raised and adjusted to the extrusion pressure for the material and maintained at this level. The differential quotient of the pressure rise as a function of time is predetermined as a criterion for reaching the pre-extrusion pressure, and compression is carried out up to this point at a constant low plunger advance rate, with a constant rise in pressure thereafter up to the extrusion pressure.A circuit for carrying out the method includes at least one valve incorporated in the hydraulic feed line to the hydraulic cylinder in which the piston is positioned. The valve is controllable initially by a volume sensor and then by a pressure-rise control means for the hydraulic fluid.

Abstract: A control device connected to rotational speed measuring means for an extruder screw, to a filling level monitor in a degassing opening of the extruder, to a cut-off in a filling container for the extruder, to vacuum means connected to the degassing opening and to a source of gas under pressure such that upon receipt from the speed measuring means or the filling level monitor by the control device of an indication of probable filling of the degassing opening with melt, the control device closes the cut-off, disconnects the vacuum means from the degassing opening and connects the gas pressure source thereto.

Abstract: A vibrating apparatus for forming a concrete block by a vibration compaction method. The apparatus has a mold box for contouring a concrete block to be produced, a receiving plate which is detachably and resiliently attached to the bottom of the mold box, a device for vibrating the mold box, and an air spring device which permits a close and resilient contact between the mold box and the receiving plate. This close contact permits the receiving plate to effectively follow the vibration of the mold box. The vibration of the mold box is effectively transmitted to the concrete block material.

Abstract: The instant invention relates to a method and an apparatus for the production of a foam-forming reaction mixture or homogeneous material-forming reaction mixture from at least two liquid reactants and for the subsequent introduction thereof into a cavity, and in particular into the cavity of a mold. The reactants are introduced into a mixing zone where they are mixed together. The mixture is subsequently fed through an outlet of controlled cross-section and charged into a cavity. In order to carry out the method, an apparatus is provided which comprises a mixing chamber arranged in a housing and having inlet openings for the reactants and an outlet opening for the reaction mixture, wherein an adjustable baffle plate is arranged opposite the outlet opening axially of the outlet opening.

Abstract: Plastic materials are dewatered in an extruder by applying heat and pressure and venting out vaporized water; before the plastic is extruded through the die orifice a gas is injected under high pressure into the plastic and this causes gas explosions when the plastic is released through the die orifices. The particles produced have micropores which provide improved workability, and form bales of controllable density.

Abstract: The stability of a flash fibrillation process for converting thermoplastics materials into fibrils by flash extruding a hot pressurized dispersion of thermoplastics material in liquid through an orifice is improved by inserting a pressure-responsive valve in the orifice which ensures the dispersion is at a specified minimum pressure before it is extruded through the orifice. The minimum pressure should be sufficient to ensure the liquid does not volatilize prior to its extrusion through the outlet.

Abstract: A gate of a mold for an injection molding machine comprises a valve cone having a circular cone shape or a pyramid shape and a valve seat corresponding to the valve cone wherein the valve cone is pushed toward the valve seat by a spring in the direction reverse to the injecting direction.

Abstract: An automatic device for supplying an elastomer or like material for an intion machine comprising an injection cylinder and a piston, wherein the piston is controlled by a hydraulic multiplier device formed by two stages, the first stage being called the downstream stage and the second stage being called the upstream multiplier stage, and wherein the device comprises a sensor for controlling the supplying of the cylinder with material so as to stock said cylinder by an electrically driven tape advance unit, the sensor being brought into play when the piston is moved in the forward direction, a pressure controller for tripping the upstream multiplier stage to multiply the pressure in the injection cylinder, the pressure controller being controlled from a pressure threshold of the fluid supply of the first downstream stage and an end of travel sensor for tripping the return of the first and second stages to make the piston return at the end of the injection.

Abstract: A rotary tabletting machine comprises a rotor with press tools for compression of tablets arranged around the periphery thereof. Pressure rolls contacting said press tools are mounted on both sides of the rotor. The machine is provided with a means for batching tablet material, a means for controlling said means for batching tablet material, and a hydraulic stabilizer of compressive pressure. The hydraulic stabilizer is equipped with a hydraulic pressure regulator connected with said controlling means and incorporating a check valve, a hydraulic damper and a capillary, the inlet of said check valve being coupled to the hydraulic stabilizer, and the outlet thereof being coupled to said controlling means through the hydraulic damper and to a drain through the capillary.

Abstract: The specification discloses a system and process for producing discrete chilled products having preselected weights from a semi-fluid mixture. The semi-fluid mixture is pumped along a distribution path to an extruding manifold which extrudes a plurality of parallel continuous lengths of the mixture. The continous lengths are directed through a chilling station in a parallel relationship in order to chill and firm the lengths such that the lengths maintain their extruded cross-sectional configuration. A cutter periodically severs the continuous lengths at predetermined intervals to provide a plurality of discrete products having predetermined weights. The pumping rate, rate of travel through the freezer and periodic severing of the continuous lengths may be selectively varied in order to maintain any desired weight of the discrete products.

Abstract: Disclosed is a screw extruder apparatus, having passages to drain melt as formed into a central bore of the screw, which is physically separated by seal means into a first zone on the feed side advancing plastic toward said seal and a second zone on the opposite side of said seal means into which drained melt passes from the bore and is pumped back toward said seal and out a lateral exit orifice adjacent said seal means. The temperature of the melt in the second zone can be independently controlled. In one embodiment means are provided to maintain an essentially constant pressure in said second zone.

Abstract: A continuous mixing method and system for preparation of syrup employed as a starting material for continuously manufacturing plate products therefrom are disclosed. The syrup is prepared by a method in which at least one additive is incorporated into at least one master batch of methyl methacrylate or a monomer mixture of methyl methacrylate and a copolymerizable unsaturated compound or a syrup of a monomer-polymer mixture thereof and the flow of the resulting liquid mixture is continuously combined with the flow from another batch of a syrup of the monomer-polymer mixture in a proportion such that the master batch is less in amount than said other batch, and the combined flows are continuously blended with each other.

Abstract: A nozzle shut-off valve for an injection molding machine has a plunger mounted to reciprocate in a bore so as to block the passageway of the plastic through the nozzle, a single-acting pneumatic piston and cylinder to reciprocate the plunger, to block said passageway, and a pilot passage connecting the underside of the plunger to a location upstream of the intersection of the bore and the passageway for plastic through the nozzle.

Abstract: A method of injecting a molten material such as molten metal or plasticizing resin under pressure and an apparatus performing the same wherein the piston speed of a cylinder for injecting the molten material is made to decrease before the mold cavity is filled up to the full with the molten material, thereby peak pressure generated in the molten material filled up to the full being eliminated and further pressure vibration occurred in a pressurized oil being obviated.

Abstract: A vertical underwater type pelletizer-cutter apparatus utilizing a hydraulic suction force for pelletization of thermoplastic polymers comprising a nozzle portion having a plurality of nozzles through which a thermoplastic polymer in a melt state is extruded in strands, an injector portion having a plurality of injectors through which the strands are introduced with water, a cooling portion comprising a plurality of guide tubes through which the strands pass together with said water which cools and solidifies the same and a cutter portion which cuts the cooled and solidified strands into pellets, wherein means are provided for monitoring the pressure at the space in the upper part of the guide tube and for automatically stopping the extrusion of the thermoplastic polymer when the monitoring means detects an abnormal reduction in the pressure.

Abstract: An injection molding machine comprising an injection cylinder; a displacement element axially disposed in the injection cylinder; one of the cylinder and displacement element being movable with respect to the other; an injection nozzle on one end of the injection cylinder and a feed device including a feed hopper and a plunger reciprocally mounted in the hopper on the other end of the cylinder; a pressure source for driving the plunger; and switches for varying the working position of the plunger, the plunger stroke, the stroke frequency of the plunger and the pressure of the pressure medium.

Abstract: In a batcher plant at least one pair of reciprocable pressure cylinders are provided one of which as a first pressure cylinder is connected to a source of pressure medium while the other one as a further pressure cylinder is supplied with pressure medium in dependence on the number of strokes per minute of the first pressure cylinder. Both pressure cylinders drive delivery pumps. The total amount of delivered material is controlled by the speed and the number of cycles of the piston of the first pressure cylinder while the mutual proportions of delivered material are controlled by varying the length of stroke of the further pressure cylinder. Thus, on the one hand, mutual proportions of delivered substances can be finely adjusted within very wide limits and, on the other hand, the pressure cylinders of the various batcher units may be located in considerable distances from one another so that the plant is suitable to perform the most various functions.

Abstract: A method of extruding plastic film is provided which employs a die comprising a die body having an inlet therein for receiving a plastic melt under pressure and having an annulus in the die in flow communication with the inlet and having a discharge orifice for extruding the plastic melt therefrom in tubular form. A heat conductive band is provided and supported by the die body and such band has a circumferential heat conductivity which is better than its radial heat conductivity; and, a heater is employed for heating the band with the band assuring heat is transmitted so that practically all points of an annular portion of the die body located immediately adjacent the band are substantially at the same temperature.

Abstract: An injection-molding machine has a drive ram with a pressurizable chamber that can be connected either to the high-pressure side or the low-pressure side of a source of fluid under pressure. A control system operating this machine has a pressure-reducing valve with an inlet port connected to the high-pressure side of the source, an outlet port connected through a cut-off valve and a throttle to the chamber of the ram, and a pilot port pressurizable to control the pressure at this outlet port. A pressure-relief valve has an inlet port connected to the pressurizable ram chamber, an outlet port connected to the low-pressure side of the pressure source, and a pilot port pressurizable to control the pressure differential across this pressure-relief valve.

Abstract: A system and method for controlling the injection of material through two or more gates into the cavity of injection-molding apparatus. In this system, a sensor develops an indication of unbalanced flow conditions produced by the injection of the material into the cavity of the mold. A regulator also forms part of the system and serves to adjust the relative amounts of material passing through the gates. The method includes sensing unbalanced flow conditions produced by the material injected into the cavity and adjusting the relative amounts of materials injected into the cavity through the various gates.

Abstract: An injection nozzle for plastics material comprises a rear tubular body and a hollow front body with a nozzle orifice at one end and detachably connected to the rear body at the other end, an elongate body being provided within the front and rear bodies and mounted thereon by having radially extending arms extending into an annular V-shaped groove formed by chamfers in the engaging surfaces of the front and rear bodies, the elongate body carrying a slidable closure member biassed to close the nozzle orifice.

Abstract: A method of and apparatus for injection molding of materials such, for example, as thermoplastic resinous material, utilizing a rotatable and reciprocal screw extruder for plasticizing and injecting the material into a mold cavity, and wherein an injection piston in a cylinder is operatively connected to the plasticizing screw to push the screw forward to effect injection into a mold of plasticized material in front of the screw. A supply of fluid pressure is positively applied to the injection piston to provide a back pressure to act against the reaction caused by the rotation of the plasticizing screw, and this back pressure may be regulated to correspond with the rearward displacement, of the screw.