Study on torsion of PVC part formed by incremental sheet forming

The development of plastic product prototype by incremental sheet forming (ISF) has attracted extensive attention. Forming polyvinyl chloride (PVC) sheet into parts by ISF has a wide application prospect in many industrial fields. However, torsion is a problem that needs to be solved. In this paper, some truncated pyramids were formed by different feed speeds and tool paths with a certain spindle speed of the tool. Torsion angle of central line and accuracy of each formed part were measured. In addition, numerical simulation was also used to get the influence of tool path on the torsion of PVC parts. The results show that PVC part appears torsion around the central axis when it was formed by the unidirectional direction tool path, and torsion increases and accuracy reduces with increment of feed speed of the tool. Otherwise, the alternating bidirectional direction tool path can effectively eliminate the torsion of PVC part.