| 摘要 |
PURPOSE:To ensure a minimum wall thickness and keep the stability of a parison by a method wherein blow molding is performed by leading high density polyethylene resin composition having the specified value intrinsic viscosity, zero viscosity, R value and density in a mold without substantially controlling the circumferential wall thickness of parison. CONSTITUTION:At the manufacturing of a blow molded container, high density polyethylene having an intrinsic viscosity of 2-6dl/g, a zero shear viscosity at 190 deg.C of 2X10<7>-3X10<8> poise, a R value (or index of uniformly stretching properties) of 2.5-4 and a density of 0.94-0.97g/cm<3> is extruded into parison. Without substantially controlling the circumferential wall thickness of the parison at the extrusion of the parison, the minimum wall thickness can be ensured and the stability of the parison is also kept. |
