Patent attributes
An extruder includes a barrel and a kneading screw extending through the barrel in a rotatable fashion. The kneading screw is provided with a devolatilization portion. The devolatilization portion includes a kneading flight that is twisted in a direction for transferring a material downstream. The kneading flight kneads the material while transferring the material downstream and separates a volatile component from the material. Impregnation sections, which allow the kneading chamber to be impregnated with the material, are respectively disposed adjacent to an upstream side and a downstream side of the devolatilization portion so that the air-tightness of the devolatilization portion of the extruder is maintained. Accordingly, an efficient devolatilization operation of the material is achieved.
