... of colorvest bag(Procurement bags),do not need color printing can be achieved,and has a colorful uniform lines,reasonable ... extrusion die at the same time,coiling traction device that can effectively improve colorfilm production.2. Screw,cylinder used 38CrMoAl, ... structure mandral spiral type,melt extrusion material uniform,thin-film-blowing finish well, air-cooled structure of the maze-type devices ...