Funcitions and construction The series Extruders with apporpriate screws,dies and other auxiliaries can directly convert thermoplastic expecialy PVC powder into Pipe,plate sheet,film and profile,and also Proved function of modifying and Pelleting. The extruders drivd by D.C motor with a thyristor to stepless regulte.It also equiped with the over-load protection and stoppage alarmingsystem.The screws core and the outside of barrels are cooled by the circulation of oil,ther fuctions include vacuum wenting and forced feeding