Patent ID: 7419295

Claim:
An 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.