... , "jingcheng" DM series of plastic film blow molding unit, by the extruder, single-layer blow die, cooling wind ring, traction ... , complementary features: 1, screw extruder, spiral tube-based company2, by matching the high reliability of the hardened gear box, low ... channel, head for the high-quality carbon steel materials, multi-channel by heat-treatment process after deformation to a minimum. 5, ...