The line is characteristic of high-speed extruding and melting for it has been equipped with the Polyolefin special-purpose single screw extruder; It is the separate special-helix structure mixing screw rod and Spiral structure nose that enables the line a reasonable flow, so that the tubing the line makes has smooth wall, inner and outer. The line has adopted the special design and Diameter-sizing cooling way, so its Sphere of production varies from 50mm to 200mm, and its production speed has reached as high as 0.6-1.5 meters per minute.