Forming limit curves in blow molding for a polymer exhibiting deformation induced crystallization

摘要

We address in this paper the problem of blow molding for a polymer exhibiting a deformation induced crystallization (e.g. Poly Ethylene Terephthalate or PET). In a first part, we give the equations of a model that couples the mechanics to the crystallization for a class of molecular models (e.g. Maxwell or POM-POM models). In a second part, without a real stabilities analysis, we follow the Swift analysis for biaxial deformations. We conclude this study in showing that it is possible to quantify how crystallization during the process stabilizes it. In enhancing strongly the strain hardening, crystallization is namely a stability factor against necking.