EXTRUDER Russian patent published in 2010 - IPC B29C47/76 

FIELD: machine-building.

SUBSTANCE: invention related to extruder. Technical result achieves with extruder, containing process part with a case, where at least one screw shaft located. The case has processing material inlet hole at one end, processed material outlet hole. Between the inlet and outlet holes intermediate hole located for gas withdrawal form a process part, where holdback device located. The holdback device contains at least one screw shaft in the intermediate case, which passes from the intermediate hole to intermediate case gas discharge hole. The screw executed with transportation ability of material penetrating from the intermediate case to the process part. At that faced to the process part screw section of the screw shaft has uplift direction, which allows material transportation backwards to the process part. And faced backwards form the process part screw section of the screw shaft has oncoming uplift direction.

EFFECT: creation of the extruder with a holdback device on a gas discharge hole, which significantly excludes black dots formation.

9 cl, 5 dwg