Inflation of a variable thickness parison in blow moulding: experimental and theoretical study

Optimal resin use in extrusion blow moulding entails the use of a process known as parison programming. Parison programming involves varying the die gap during the extrusion and results in a variable thickness parison. The inflation of a variable thickness parison is a complex phenomenon involving the interaction of many process variables. The final thickness distribution and radius inflation patterns are obtained for various programmed parisons. Constant, one step and two steps thickness parisons were looked at. The radius inflation patterns are monitored by employing a transparent mould in conjunction with a video camera. Theoretical predictions of the final thickness distribution and the radius inflation profiles are also obtained for some of the cases.Peer reviewed: YesNRC publication: Ye