... -plating. Screw: 38CrMoAl Motor, air blower, up traction unit: inverter controlled automatic SJ series co-extrusion double layer film ... used for packing liquid, industrial products, garments and textile, with two layers film, it can protect the products better. ... roller pneumatic typeDouble layer Co-extrusion Film Winding unitExtruding unit with two main motor, two screw.Double layer Co-extrusion ...