Mechanical properties of glass fibre reinforced polypropylene disks produced by rotating, expansion and compression injection moulding

A special mould (RCEM, rotation, compression and expansion mould) intended for inducing complex stress fields during the filling stage of injection moulding was used to manipulate the microstructure of a short fibre reinforced polypropylene. Centred gated discs were injection moulded with different filling sequences (stationary, expansion, compression, expansion with continuous rotation and compression with continuous rotation). The mechanical behaviour of the mouldings was characterized in tensile and flexural loadings on specimens cut at different locations along the flow length. Complete discs were also tested in 4-point support flexural test at low velocity and at impact. The respective results are analysed and discussed in terms of the developed fibre orientation morphology.