Process for reinforcing SLS parts by epoxy resin

Abstract

Purpose – The purpose of this paper is to report on the use of a combination of selective laser sintering (SLS) and vacuum casting to create plastic composites made by additive manufacturing. Design/methodology/approach – The research has been carried out by approaching a new concept of the final part consistent in a plastic component, where the main body is made by SLS and the internal long fibres for reinforcing are made by vacuum casting of high-resistance epoxy resin. The part is designed for optimal number and distribution of the internal fibres taking into account the target relative stiffness (N/mm*kg). The methodology is applied to a pedal clutch of a car which has been tested in an equipment for fatigue and durability, being compared to the correspondent design for injection moulding. Findings – Research has proven that the approach introduces relevant improvement in mechanical properties of the base resin consistent in PA 3200GF (EOS), reinforced by internal long fibres of resin VG SP5. Experiments showed significant increase of stiffness in the pedal clutch made under this procedure, where the stiffness was 77 per cent higher than the conventional SLS part and only 11.7 per cent lower than the one made by injection moulding of PA 66 with 50 per cent fibreglass. Originality/value – The developed method introduces an alternative procedure for increasing the mechanical properties of plastic parts developed in SLS. Optimal orientation and distribution of long fibres clearly achieves better mechanical properties at low cost.