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: Method for making polymer from a polymer emulsion. An extruder is provided with a screw rotating in a barrel. Means are provided for injecting a latex emulsion under pressure, directly into the barrel, and a polymer seal is formed at the injection point. Means are provided within the barrel for coagulating the latex emulsion upstream of the seal, and for providing a polymer seal and a pressure drop downstream of the seal, into a zone in which the screws are running less than full of polymer, whereby the polymer and the water separate in the spaces between the screws. The liberated water is taken off and the coagulated polymer product is continuously extruded and may be subjected to devolatilization, countercurrent washing, pelletizing and drying.

Abstract: Apparatus for making polymer from a polymer emulsion. An extruder is provided with a screw rotating in a barrel. Means are provided for injecting a latex emulsion under pressure, directly into the barrel, and a polymer seal is formed at the injection point. Means are provided within the barrel for coagulating the latex emulsion upstream of the seal, and for providing a polymer seal and a pressure drop downstream of the seal, into a zone in which the screws are running less than full of polymer, whereby the polymer and the water separate in the spaces between the screws. The liberated water is taken off and the coagulated polymer product is continuously extruded and may be subjected to devolatilization, countercurrent washing, pelletizing and drying.

Abstract: Means and method are provided for feeding through a feed port, to a plasticized polymer mass, a powdery material which contains entrapped air. An extruder is used having an entrance for feeding the polymer, and having a rotating worm, transporting the polymer from its entrance to a polymer exit; means are provided forming an entrance port for the powdery material downstream of the polymer entrance, and positive vent means are provided in the housing upstream of the powdery material entrance but downstream of the polymer entrance for drawing out the air, to prevent entrapped air or volatiles from fouling the powder feed port.

Abstract: Dilute polymer solution (about 5 to 50% by weight of solid polymer) is heated and flashed in a concentrator, is delivered to an extruder at a concentration of about 30 - 80% by weight of solid polymer, further solvent is vaporized and vented off, and the solid polymer material is subjected to counter-current fluid flow in single or multiple stages, with back pressure control at the polymer exit.