Finite element analysis of the thermoforming of Polypropylene

Polypropylene (PP) is typically solid phase thermoformed at temperatures close to its crystalline melting point, usually in the 150° to 160° Celsius range. In such conditions the mechanical properties of the material rapidly decline with temperature and these large changes in properties make Polypropylene one of the more difficult materials to process by thermoforming. This paper presents the findings of a study into the thermoforming behaviour of an industrial thermoforming grade of Polypropylene. Practical tests were performed using custom built thermoforming equipment at Queen's University Belfast. Numerical simulations of these processes were similarly constructed to replicate thermoforming processes using industry standard Finite Element Analysis software.