EFFECT OF MELT TEMPERATURE ON THE FINAL THICKNESS DISTRIBUTION OF BLOW MOLDED PARTS

The extrusion blow moulding process is becoming increasingly important in the polymer industry. Parison programming is a crucial component o f the extrusion blow moulding process, since it allows for the optimiz ation of resin usage in a given part. However, the inflation of progra mmed (variable thickness) parisons is very complex and is not a well u nderstood phenomenon. The goal of this work is to present some experim ental results demonstrating the effects of melt temperature on the inf lation of programmed parisons. The inflation of parisons into a non-ax isymmetric motor oil bottle is considered. Four parison thickness prof iles are studied. These are (i) low magnitude constant thickness, (ii) high magnitude constant thickness, (iii) one step high to low magnitu de thickness and (iv) two step low to high to low magnitude thickness. Three melt temperatures were used; 180, 200 and 220-degrees-C.