An integrative simulation concept for extrusion blow molded plastic bottles

It is well known that the mechanical properties of extrusion blow molded plastic bottles are influenced by the process conditions, which leads to local orthotropic process-dependent material parameters. In this study, these parameters as well as local orientation effects are for the first time considered in the structural analysis of extrusion blow molded products. Furthermore, an integrative simulation concept has been worked out which combines process simulation and structural analysis to take the process history of the plastic bottle into account. The elastic modulus is described as a function of process parameters like the local degrees of stretching and the mold temperature. Because the local degrees of stretching differ considerably, a new algorithm was developed which identif ies the local degrees of stretching as well as their orientation using the results of the process simulation. For the data mapping between the process mesh and the structural analysis mesh, the self-developed MpCCI Mapper software was used. In a simulation of a top load test, the integrative simulation model was compared with the conventional model as well as with experimental data. Although in this particular case the influence of the orthotropic material model with respect to the local degrees of stretching is rather low, the general use of process dependent material parameters leads to much better results.