... to the large L/D ratio of the screw in the extrusion unit.2. Advanced net-electrically-changed device in the die ... -roller calendar, traction, rewinding and electric control box..etc7. The screw, material barrel, screen changer, measurement pump, die head are made ... life after nitrogen treatment.8. The die head adopts hanger-type branch pipe decreasing-style construction, so the flow passage is ...