Impact of Ageing, Different Share of Recycled Material and Orientation on SLS Polyamide Product Hardness

In selective laser sintering (SLS) of polymer products the price of material is not the most important factor, but it does play a significant role when analysing the overall i.e. final price of the product, and therefore recycling of material is becoming an increasingly important factor, as well as the ratio of the shares in combining the original and the already used materials. In practice it is inevitable to use the products in various atmospheric conditions (UV radiation and humid environment), intentionally or unintentionally. UV light, with sun being its most common source, and average humidity in different parts of the world can be approximately from 20% to 90%, depending on time, day and geographic location. Therefore, it is necessary to determine how UV light after a longer period of time of exposure affects the product properties. The properties of the final product are also affected by the orientation in the working area of the machine. In the paper an analysis has been performed of the impact of three different types of product orientation in the machine working area and three different ratios of the used polyamide material (100% original, combined in 50:50 ratio of original and recycled and 100% recycled material after the third cycle of usage) on hardness of the polyamide product made by selective laser sintering.