Numerical optimization of the parison thickness of oil drum in extrusion blow molding

The optimization parison thickness can reduce the oil drum weight and meet the requirement of the minimum thickness. The profile thickness of the extruded parison can be optimized by simulation. Under different blowing pressures, extrusion blow molding non-isothermal process of the high density polyethylene oil drum with a handle was simulated by using Polyflow. The initial parison was respectively divided into 11, 51, 101 and infinite segments. After seven optimizations, the oil drum wall thickness was equal or larger than 2 mm. An appropriate inflation pressure of 0.6 MPa was obtained. The results show that the production efficiency increases with the inflation pressure increasing. With the parison segments increasing, the oil drum thickness distribution inflated from the optimized parison is more uniform and approaches to the required thickness. The oil drum mass is decreased with the segments increasing. It is necessary that the non-uniform thickness parison was produced by injection molding.