Nanjing GIANT Machinery Co.,Ltd.

A twin screw extruder comprising: a barrel having a kneading chamber therein; a kneading screw comprising plural segments, said kneading screw extending through said kneading chamber in a rotatable fashion, said kneading screw being rotated so as to knead a material and to transfer the material from an upstream side of the extruder towards a downstream side of the extruder; a devolatilization segment section in said kneading screw, said devolatilization segment section being provided with a kneading flight twisted around said devolatilization segment section so as to transfer the material downstream, said kneading flight kneading the material while transferring the material downstream and separating a volatile component from the material; a feeding section disposed adjacent to a downstream side of said devolatilization segment section, said feeding section including a screw segment; a vacuum suction hole at a position corresponding to a position of said barrel where the feeding section is disposed, said vacuum suction hole communicating with a portion of said kneading chamber through which said devolatilization segment section extends; and impregnation sections disposed adjacent to an upstream side of said devolatilization segment section and to a downstream side of said feeding section, said impregnation sections for impregnating said kneading chamber with the material such that air cannot leak past the impregnation sections.

The single screw extruder, wherein said devolatilization segment section includes a double-blade rotor segment comprising a pair of kneading flights provided in said at least one double-blade rotor segment, the pair of kneading flights being projected in opposite directions from each other with respect to a diameter direction of said at least one kneading screw, and wherein each of the kneading flights is provided with a low tip and a high tip for facilitating the separation of the volatile component, the low tip having a large tip clearance with respect to an inner surface of said at least one kneading chamber so as to enable a thin-film formation of the material on the inner surface, the high tip having a small tip clearance with respect to the inner surface of said at least one kneading chamber so that the thin film of the material is scraped off the inner surface by the high tip.

Generally, a composite resin material, such as a plastic compound, is manufactured by injecting a polymeric resin material and a powdery additive into a barrel of a continuous kneading unit, and then extruding the two downstream while they are kneaded with sheet production extruder extending through the barrel. Furthermore, a granulator, for example, is disposed adjacent to the downstream side of the continuous kneading unit, such that the granulator forms the composite resin material into pellets.