| 摘要 |
<p>A method for making a plastic blow molded product (62) is performed by extruding a hollow parison (56) of hot polyethylene terephthalate from an extruder head (54) at a predetermined speed in a vertical direction and by longitudinally stretching and blow molding the parison by molds (30) of a rotary wheel (22) that rotates the molds at a faster speed than the speed of extrusion such that the blow molding provides a biaxially oriented polyethylene terephthalate product (62). The parison (56) has an intrinsic viscosity greater than 0.9 and its wall thickness is varied to control the wall thickness of the resultant blow molded product (62). Both upward and downward extrusion of the parison (56) is disclosed. Pressurized gas is supplied to the interior of the extruded parison (56) and the pressure thereof is varied by increasing the pressure just prior to the mold closing to provide lateral stretching that permits handled containers to be blow molded from extruded polyethylene terephthalate.</p> |
