Investigation of interply shear in composite forming

This paper describes work carried out on investigating the interply slip phenomenon. First, rheological measurements on the PP resin have been performed, indicating a shear thinning behaviour of the resin. An Ellis model was used to describe the flow behaviour of the resin. Second, the influence of the process conditions on the interply shear properties of a glass/PP woven fabric are assessed by changing the temperature, speed and normal pressure. A peak shear stress, similar to a yield, was observed. A mild increase of the yield shear stress is observed for increasing normal pressure. The influence of both the temperature and velocity on this peak stress is related to the viscous nature of the interply shear.