... level b) The adoption of professional screw ensures good plastificationc) Adopts compound screw type head to clear memory function effectivelyd) ... 75, 90c) Cylinder heating power (kW): 23, 34, 48 d) Length-diameter ratio: 30:1, 30:1, 30:1e) Vacuum ... Plastic tube extrusion line:Vacuum feeding machine---- Dry hopper ----- Single screw extruder----- Mould ----- Vacuum tank ----- Water tank----Haul off ...