An empirical study into laser sintering of ultra-high molecular weight polyethylene (UHMWPE)

The feasibility of processing UHMWPE using a commercial laser sintering system has been investigated. In contrast to previously reported studies on the laser sintering of UHMWPE that were unable to produce multilayer parts, in this work the powder was heated prior to sintering. This was carried out to minimise thermal gradients during processing and resultant induced strains upon cooling. Various machine parameters, including the feed and bed temperatures, laser power, scan count, roller speed, and the direction of the scan vectors were investigated in an attempt to achieve multiple layer structures with increased mechanical properties. Fabricated parts were analysed by SEM, DSC and mechanical testing. Multilayer parts were successfully produced with accurate dimensions (±0.1 mm) and significant sintering between particles and layers. However a precise combination of processing conditions was required to achieve this; this small processing window may limit the feasibility of processing the material commercially unless the variation and inconsistencies between and within current laser sintering systems can be improved. Further investigations into secondary processing are also required to improve the mechanical properties of the UHMWPE parts produced using this method.