Abstract: A process is disclosed for the coextrusion of a multi-layered tube whereby at least one stream of molten polymer from a single-screw extruder is passed through a die; wherein the stream is divided into two concentric streams which are balanced by varying the area of a restrictor orifice placed in the central stream. Spider lines in the outer molten stream are eliminated by the use of a second restrictor means used downstream of an open chamber for reuniting the melt, which chamber is downstream of the spider legs.

Abstract: Disclosed is a process for the production of a hollow article comprised of a biaxially oriented thermoplastic resinous material, comprising the steps of heating a sheet of thermoplastic material to a temperature above the orientation temperature of the thermoplastic material; clamping an area of the heated thermoplastic sheet between a first mold half and a second mold half, the first mold half containing a pre - form mold surface having a configuration predetermined to provide for uniform wall thickness of the hollow article to be formed, the surface being at a temperature which is not higher than the orientation temperature of the thermoplastic material, and the second mold half having a cavity which corresponds to the shape of the hollow article to be produced; forcing the heated thermoplastic sheet by pressure differential into the first mold half against the surface; maintaining the thermoplastic sheet in contact with the surface for a period of time sufficient to bring the thermoplastic sheet to its ori

Abstract: Disclosed is an apparatus and process for producing multiple-layer film or sheeting which includes an improved laydown means comprising adjustable cam-actuated control means for controlling the polymer flow and individual layer thickness.

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: Methods are disclosed for the treatment of food, beverage, and medicine containers and the like, which are made of organic polymeric resins, to greatly increase the gas barrier properties thereof. The containers are ion-plated with a very thin flexible layer of an inorganic oxide.

Abstract: Disclosed is a process for extruding thermoplastic resinous compositions, comprising the steps of heat plastifying the resinous composition in an extruder; cooling the heat plastified resinous composition exiting from the extruder to a uniform temperature desired for extrusion through an extrusion die, including conveying the resinous composition through at least one enclosed flow path in a cooling device, circulating a cooling medium about the entire circumference of each of the resin flow paths and controlling by the means of orifices the flow of thermoplastic at the inlet and the outlet of the cooling device across substantially the entire cross-section of each of the resin flow paths; and, extruding the cooled thermoplastic resinous composition through an extrusion die downstream of the cooling device.

Abstract: Process and apparatus are disclosed for manufacturing foamed articles such as tubes used as pipe insulation, which tubes are of a high impermeability and flexibility and are formed of a polymer, such as polyethylene or polypropylene, containing up to about 25% of an elastomer.

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: The invention disclosed is for a method and apparatus for blow molding foam walled plastic using a quadrisectional mold. A parison of foamed plastic may be blow molded to assume the contour of the closed mold, after which the molded shape is severed into two portions and ejected. Desirably, cellular plastic is blow molded to form hot drink cups.

Abstract: The method for blow molding foam walled plastic using a quadrisectional mold. A parison of foamed plastic may be blow molded to assume the contour of the closed mold, after which the molded shape is severed into two portions and ejected. Desirably, cellular plastic is blow molded to form hot drink cups.