The simulation of the flow of polymer melt in lomolding

[摘要] ENGLISH ABSTRACT: Lomolding is a new process similar to injection moulding. In this thesis anumerical model of the polymer flow into the cavity is presented. The modelis used to compare the two processes with each other.Lomolding and injection moulding were modelled numerically with the finiteelement method. The model was an axisymmetric model and takes phenomenasuch as generalised Newtonian flow, free surfaces, moving boundariesand solidification into account.The processes' characteristics that were compared are the cavity pressure,shear rate and shear stress. Improvements in these characteristics will result inlomolding having smaller machines, less fibre breakage and a better potentialfor in-mould-decoration. The thesis shows that lomolding has substantiallylower shear rates and shear stresses than injection moulding. The model wasalso used to investigate certain machine design aspects, and to gain a betterunderstanding of the polymer flow in lomolding.

[发布机构] Stellenbosch University