Abstract:

Biaxially oriented polyvinyl chloride （PVC⁃O） pipes were prepared through one⁃step extrusion based on a pure formula using polyvinyl chloride resin as a main raw material. PVC⁃O pipes were prepared using the same formula through axial tensile at stretching temperatures of 80， 85， 88， 90 ºC and a radial stretching ratio to 1.8/1 （the outside dia⁃meter of the feedstock pipe： 63 mm and wall thickness： 5.2 mm） and 1.9/1 （the outside diameter of the feedstock pipe： 60 mm and wall thickness： 6.0 mm）. The mechanical properties of the pipes produced through different processes were characterized through hydrostatic， falling⁃weight impact， tensile， and ring stiffness tests. The results indicated that the optimal tensile temperature of the PVC⁃O pipe extrusion was determined to be 85 ºC， and its optimal radial tensile ratio was 1.9/1.

Key words: biaxially oriented unplasticized poly（vinyl chloride） pipe, tensile temperature, radial tensile ratio, mechanical property