| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially oriented polyolefin pipe, which has a uniform pipe wall thickness and not only has a high pipe strength required for the pipe used as an underground pipe but also can be easily manufactured, and its manufacturing method. SOLUTION: In a biaxially oriented polyolefin pipe, which is made of polyolefin resin and oriented axially and peripherally, the difference between the first temperature, at which the crystallinity of the polyolefin resin is 25%, and the second temperature at which the crystallinity of the polyolefin resin is 10%, is 8 deg.C or higher and the difference between the greatest wall thickness of the biaxially oriented polyolefin pipe and the smallest wall thickness is 1 mm or less. |
