| 摘要 |
PURPOSE:To obtain a thin pipe, in which the ratio of an outside diameter to wall thickness is a specific value or more and thermal shrinkage is reduced, by using ultra-high-molecular polyethylene having limiting viscosity (mu) of a specific value or more. CONSTITUTION:A screw extruder 1 is supplied with ultra-high-molecular-weight polyethylene, and the melt is extruded continuously from a die 2 and molded to a cylindrical composition, thus acquiring a thin pipe. Limiting viscosity (mu) is 5.0dl/g or more, preferably 8-30dl/g from the viewpoint of the acquisition of the uniform thin pipe in ultra-high-molecular-weight polyethylene as the blank of the thin pipe. The ultra-high-molecular-weight polyethylene thin pipe has an outside diameter (D) of 10mm or more and wall thickness (t) of 0.5mm or more, favorably 25-100mm and 1-5mm respectively. The ratio of the outside diameter/wall thickness (D/t) is ten or more, and it is favorable that the ratio is 15-50 from viewpoint of the acquisition of the pipe having excellent rigidity. |
