Abstract: A liquid reaction mixture from which soft cellular material is derived is poured into a moving mold where it begins to expand. Beyond the point at which the reaction mixture is poured, the bottom wall of the mold is deformed between its sides and this causes the expanding mixture to flow laterally so that the mixture expands into a desired configuration. The foregoing process is carried out on a conveyor having an endless belt and rollers for deforming the upper pass of the belt between the sides thereof. The mold is a flexible film material which is supported on and propelled by the belt.

Abstract: A product comprising a cellular plastic material is extruded from a modified conventional extrusion head by injecting a gaseous expanding medium into advancing fluent plastic material through porous material forming at least a portion of a section of the core tube in an extrusion chamber. By controlling the interrelationship between various process parameters such as the speed and pressure of the advancing fluent plastic material, the rate of injection of expanding medium into the advancing plastic material, the place where the expanding medium is injected, and the amount the extruded product is allowed to expand before cooling, it is possible to extrude, from a single source of fluent plastic material, a product comprising many different configurations of cellular and solid plastic material such as a uniform cellular structure throughout, or a cellular plastic inner section with a more dense outer covering.

Abstract: Thermoplastic foam plank is prepared by extrusion from a slotted die between a pair of generally parallel opposed forming plates. A substantial improvement in physical properties is obtained by using curved supports which engage the foaming gel generally adjacent the ends of the die opening and edges of the freshly extruded sheet.

Abstract: An apparatus for extruding a tubular article from a cellular plastic compound comprising a bushing defining a passage extending therethrough, an internal mandrel within the passage of the bushing and cooperating therewith to define a die passage, and an external mandrel downstream of the internal mandrel. The die passage has a tapered section and an outlet section with the overall width of the tapered section reducing as it extends toward the outlet. The outlet section terminates in an outlet. The gap dimension of the tapered section is greater than the gap dimension of the outlet section. The die passage has a transition section which is of progressively reducing thickness to smoothly blend the tapered section and the outlet section.

Abstract: An apparatus for the production of extruded profiles of foamed thermoplasts consisting of an extruder having an extrusion screw or helix and a form-giving extruder head having a flow channel there-through, at least part of the length of said flow channel being divided by separating walls having a thickness of 0.2 to 3 mm arranged in the axial direction into individual channels of such a length and cross-section area whereby each individual channel has a nozzle coefficient k of from 0.1 to 2mm.sup.3, characterized in that thorn-like pins are inserted into some of the individual channels; as well as the process of extrusion.

Abstract: Continuous foam blocks with rectangular cross-section are produced on a side-limited conveyor band by feeding a foamable mixture to a cover foil travelling with said conveyor band and covering the free surface of the mixture with a bearing layer not earlier than immediately after the supply of the mixture and not later than before the zone in which a skin would be formed on the free surface of the block.

Abstract: An apparatus for use as an extruder die is disclosed. The die comprises a cylindrical housing surrounded by heating means. Within the die is provided gas injection means which can be used to expand the hot extrudate.

Abstract: A foamable synthetic plastic composition such as a polyurethane is foamed in place around a pipe within a tubular former disposed concentrically about the pipe while the former moves longitudinally along the pipe. Conditions are regulated to form an external skin on the foam. A hot melt glue or similar composition is applied as an outer sealer onto the foam within the tubular former. Preferably a spiral wrapping of polyethylene film or the like is applied while the sealer is still hot and adhesive, and an aluminum jacket may be applied on top of the spiral wrapping.

Abstract: An apparatus for the production of extruded profiles of foamed thermoplasts consisting of an extruder having an extrusion screw and a form-giving extruder head having a flow channel therethrough characterized in that at least part of the length of said flow channel is divided by separating walls having a thickness of 0.2 to 3 mm arranged in the axial direction into individual channels of such a length and cross-section area whereby each individual channel has a nozzle coefficient k of from 0.1 to 2 mm.sup.3 ; as well as the process of extrusion.

Abstract: The invention pertains to a process for the continuous production of thin polyurethane foam layers, in which a band-like supporting layer is moved longitudinally and locally guided so as to take a nearly cylindrical shape, the axis of which is horizontal and perpendicular to the general direction of the band motion, and a reacting mixture is projected on the supporting layer by means of a vertical, rotating projection disk, reciprocating along the axis of the said cylindrical shape.

Abstract: An automated system for fabricating a lead pencil in which the lead is securely bonded to a sheath formed of foam plastic material and having a smooth skin. In the system, individual pieces of lead which are pre-treated with a heat-activatable adhesive layer, are sequentially fed into an extrusion die in which the lead is ensheathed by molten foam plastic material whose heat serves to activate the adhesive. The string of ensheathed lead pieces emerging from the die are advanced through a sizing jig in a cooling station wherein the diameter of the sheath is rendered uniform and the surface thereof is formed into a smooth skin, the sheath being rigidified in the station and the activated adhesive being set to strongly bond the lead to the sheath. The resultant rod is fed to a cut-off station which serves to sever the rod into individual pencils.