Single point incremental forming of PVC: Experimental findings and theoretical interpretation

The aim of the present paper is twofold; (i) to evaluate the possibility of producing low-cost, small-batch, polymer sheet components by means of single point incremental forming (SPIF) and (ii) to provide a first step towards the understanding of the fundamentals of the SPIF of polymers and the identification of the key influential process variables.The experimental research work makes use of Polyvinylchloride (PVC) sheets and was carried out on a CNC milling machine, equipped with a conventional SPIF set-up. Benchmark tests were performed on cones with varying wall angle and results confirm that SPIF of PVC sheets at room temperature has potential for the manufacture of complex parts with very high depths.The overall experimental findings are interpreted by means of an innovative extension of the membrane approach developed by Silva et al. (2008a) that is capable of modelling the cold plastic deformation of polymers with pressure-sensitive yield surfaces. Qualitative evidence of the adequacy of the model to provide explanation of the results and observations provides the link between theory and experimentation.