Abstract: To extrude, for pneumatic tires, uncured tread strips composed of three different rubber or synthetic material mixtures, three extruders are used which feed to a common extruder head and are connected with the latter. The present invention utilizes the favorable flow conditions resulting from the known Y-arrangement of three extruders within the extruder head, while at the same time avoiding the previously unavoidable complex and expensive specialized construction of the extruder head. Inventively, the third extruder, which opposes the two first extruders in the withdrawal direction, is not screwed or clamped to the extruder head which is common to all three of the extruders. Rather, the third extruder is easily detachably connected via a direct metal-to-metal contact with the extruder head only by a frictional connection in a longitudinally movable arrangement.

Abstract: A screw extrusion press having a barrel temperature control means is disclosed, which press permits the inner liner or cylinder of the barrel or a portion thereof to be replaced rapidly without necessitating simultaneous replacement of the temperature control means. This object is achieved by providing intermediate rings between individual extruder barrel portions, the rings each defining annular passages and guide means for the temperature control medium.

Abstract: An extrusion device comprises feed means and extrusion means. The feed means comprises a feed hopper having a feed aperture formed therein, said feed aperture feeding material into a hollow barrel in which a single screw rotates. The single screw conveys the material to the extrusion device. The extrusion device comprises twin screws rotating in a further barrel. The two barrels are co-axial with one another and are in series with one another. The diameter of the single screw is at least twice the diameter of each of the twin screws.

Abstract: This invention, in its preferred embodiment, relates to an improved extruder screw, for plastics and like materials, wherein said screw includes, in sequence, a (1) feed section, (2) transition section, and (3) metering section, and a plurality of back flow seals to minimize the pressure flow opposing the moving materials passing therealong. Preferably, said seals comprise a first length of flighting having a reduced pitch over that preceding said first length of flighting, and a second length of flighting having zero pitch.

Abstract: A driven stirrer mounted above the melting grid in a melt grid spinning apparatus provides a means to distribute flake, descending from source of supply to the melt grid away from the center of the grid toward its sidewalls.

Abstract: Plasticating extruders in which increased melting effectiveness is attained through multiple stages including at least one inner screw conveyor within an outer screw conveyor in a barrel for receiving unmelted solid material from the channel of the outer screw conveyor and conveying the received unmelted solid material in the channel of the inner conveyor in a direction parallel to and axially coextensive with the direction of travel of the material in the channel of the outer screw conveyor and melting the received unmelted solid material to bring melted material to a downstream location where the melted material from both channels merges to deliver a flow of fully melted material to a downstream discharge outlet. A vent may be located in the barrel in the vicinity where material enters the channel of the inner screw conveyor for improved venting as a result of the diversion of material away from the vent.

Abstract: A method for generating an aerosol powder from a melt includes an atomization die having an orifice through which the melt passes to create the powder. In a preferred embodiment, the orifice has a dimension less than 5 millimeters, and may include a heater to prevent freeze-off. The die may be included in a high-temperature probe suitable for immersion on the melt, so that accumulated accretions of powder on the walls of the probe may be melted off by heating the probe.

Abstract: An object is produced from a tubular blank (10,15,17) of thermoplastic material of the type polyester or polyamide, preferably of polyethylene terephthalate by reducing the thickness of amorphous material in one or several areas of the blank by means of one single or several consecutive re-shaping operations. A mechanical shaping device (23,29,71,81) moves a transitional zone (13,14,113) situated between thicker and thinner material along the blank and elongates simultaneously the blank in the moving direction of the transitional zone. After the last re-shaping operation the thinner material has preferably an oriented state. During the re-shaping operation the temperature of the material in the transitional zone (13,14,113) is controlled at a level which, immediately before the re-shaping operation, is within or close to the range of the glass transition temperature (TG).

Abstract: An apparatus for atomization of high temperature melts to from very finely divided powder. The apparatus has a ceramic central melt delivery tube. Melt is introduced at the top and exits at the bottom. At the exit surface a high velocity gas impinges on the melt to atomize the melt into fine particles. The bottom portion of the melt delivery tube has an internal shape to expand the external configuration of the melt stream.

Abstract: Apparatus is disclosed for the separation of admixtures from contaminated thermoplastic materials. The apparatus has a distributor screw, a retainer chamber and return flow holes for contaminated materials to pass from the retainer chamber into an annular space formed between the distributor screw and the screening element within the pressure chamber. The materials circularly travel around saw-like teeth of the distributor screw and back through the flow holes into the retaining chamber. The retainer chamber and the annular space are openly connected to each other at the inlet side of the pressure chamber. Purified materials exit through one outlet exit and admixtures exit through a second exit.

Abstract: Apparatus for the manufacture of metal powder by atomization with noble gas or nitrogen, having an atomization tower, a gas recycling system, and a gas cleaning system is disclosed. The gas cleaning system is connected parallel to the atomization tower in order to shorten the start-up time without increasing the cost and complexity of the gas cleaning system.

Abstract: A hot isostatic pressing apparatus having a high pressure vessel, a heat insulating layer and a heater disposed inside the heat insulating layer, the heat insulating layer and the heater being disposed within a high pressure chamber defined by upper and lower covers. The heat insulating layer is composed of at least two inner and outer inverted cup-like casings, the outer casing being metallic and having a hermetic structure and the inner casing having a hermetic structure. A passage is formed in the upper surface of the outer casing and a valve capable of being opened and closed is provided therein. Further, a mechanism for opening and closing the valve is mounted on the upper cover, and a gas passage is formed in the lower portion of the het insulating layer. The above arrangement creates a convection of gas in the cooling step after the HIP treatment whereby a remarkable improvement can be attained in cooling efficiency, cooling time and productivity.

Abstract: A dual-hopper supporting structure for the injection unit of an injection molding machine which has a transverse horizontal guide plate slidingly guiding a hopper carriage. To the upper side of the latter are bolted the base assemblies of two raw material hoppers, as well as a translation drive motor with a pinion which engages a drive rack on a longitudinal edge of the transverse guide plate. The transverse guide plate has a central charge bore coinciding with the operating position of the hoppers and equidistant evacuation bores in the two waiting positions of the hoppers. In addition to speeding up changeovers in the production setup, the novel structure gives the injection unit marbling capabilities.

Abstract: An apparatus for producing a polyacetylene film by introducing acetylene gas into a vessel for storing Ziegler-Natta catalyst to polymerize the acetylene gas with the catalyst which comprises a film forming projecting flat section having a film forming flat surface projected from the surface of the Ziegler-Natta catalyst stored in the bottom of the vessel, thereby coating the Ziegler-Natta catalyst on the inner surface of the side wall of the vessel and the film forming flat surface. Thus, the acetylene gas introduced into the vessel is polymerized with the catalyst to produce the polyacetylene film. In this manner, the polyacetylene film having a constant thickness of high quality can be produced with the Ziegler-Natta catalyst of the suitable amount by providing the film forming flat surface even in the bottom of the vessel, thereby improving the production efficiency.

Abstract: A metal mold to be used for injection-molding of a flat plastic disc. The flat, annular mold cavity has a substantially continuously increasing axial thickness away from the injection gate. The gate can be in the center or on the outer periphery of the mold. A split mold type is disclosed wherein at least one of the inner opposed surfaces tapers away from an imaginary flat center plane. Alternatively, a stamper having a tapering thickness can be used in a mold having parallel opposed inner surfaces.

Abstract: A cavity member is disclosed for use in an injection molding machine. The cavity member has one portion which includes a molding surface for forming the molded article and a second portion for reducing heat transmission to the first portion. The second portion forms a cap on the nozzle end of the cavity member and includes an aperture aligned with the gate of the cavity member so as to permit plastic from the nozzle of an injection molding machine to enter into the mold. The cap includes channels which can cooperate with pockets in the nozzle end of the second portion for liquid cooling. The nozzle is spaced from the cap by a short distance to provide a thermal break which break can be filled with plastic from the injection molding unit to provide further insulation.

Abstract: A heat insulator for a hot isostatic pressing apparatus including a plurality of non-perforated graphite sheets; a plurality of perforated graphite sheets, each one of the plurality of perforated graphite sheets being sandwiched between and making at least substantially planar contact with, but not being bonded to, adjoining ones of the plurality of non-perforated graphite sheets; and a gas having an extremely low thermal conductivity substantially confined in the perforations in the plurality of perforated graphite sheets.

Abstract: A method for generating prime powder from a material having a high melting point and apparatus for generating the powder is taught. The apparatus includes a melt delivery tube. The melt of the high melting material is introduced into the tube and exits from the tube into an atomization zone. Gas is delivered to the zone at high pressure as a stream to atomize the melt. Pursuant to the present invention, the atomizing gas is directed against the lower end of the melt delivery tube and it is deflected from the melt delivery tube into contact with the descending high temperature melt. A concave surface is provided on the end of the melt delivery tube to deflect the gas along the tube surface to minimize Eddy currents and provide better control of the atomization process.

Abstract: A reaction injection molding system including: a core and a permanent cavity at least a portion of which is elastomeric. The elastomeric portion of the cavity has a first part defining at least a portion of the floor of the cavity, a second part defining at least a portion of the wall of the cavity and a third part defining at least a portion of the upper edge of the wall and extending therefrom to define at least a portion of the top of the cavity. A finger gate interconnects the cavity with a source of molding medium; the finger gate includes a plurality of spaced fingers on the core transverse to the edge of the wall and aligned with the flow of the molding medium into the cavity for engaging the third part of the elastomeric portion and securing the elastomeric portion in the cavity.

Abstract: A platen assembly is provided having a working surface which can be mechanically converted between planar and corrugated configurations. A mat of wood wafers coated with thermosetting resin binder is deposited between upper and lower, spaced apart platen assemblies of this type. The platen assemblies, in the planar configuration, are then pressed together to a limited extent to pre-compress the mat to fix the wafers. Horizontal force is then applied to the platen assemblies to convert them to the corrugated configuration, with the pre-compressed mat retained therebetween. The mat is therefore forced to adopt a corrugated form. The platen assemblies are then further pressed together and heated, to cure the resin and produce a corrugated wafer board panel.