Fatigue properties of parts printed by PolyJet material jetting

This paper aims to seek to fill a gap in the literature by characterizing the fatigue life and microstructure of a printed elastomer material, the TangoBlackPlus material.

Because the TangoBlackPlus material is marketed as “rubber-like”, the printed elastomer specimens were tested according to the ASTM D4482-11 “Test Method for Rubber Property Extension Cycling Fatigue”. The microstructure of the printed material and multi-material interface was examined by slicing specimens and examining them under an optical microscope.

Findings are developed to show the relationship between elongation and expected fatigue life. Findings also indicate that the smoother, non-support encased “glossy” surface finish option for PolyJet parts improve the fatigue life of components and that there are a number of microscopic voids in the TangoBlackPlus material that seem to be concentrated at layer and print head boundaries.

This paper provides a glimpse into the fatigue properties and microstructure of printed elastomeric parts, a previously unstudied area. This work is limited in that it only looks at specimens created in a single orientation, on a single machine, with a single material. More work is needed to understand the general fatigue properties of printed elastomers and the factors that influence fatigue life in these materials.

The authors provide several design guidelines based on the findings and previous work that can be used to increase the fatigue life of printed elastomer components.

As additive manufacturing (AM) technology moves from a prototyping tool to a tool used to create end use products, it is important to examine the expected lifespan of AM components. This work adds to the understanding of the expected product lifecycle of printed elastomer components that will likely be expected to withstand large repeated loading conditions.