Additive manufacturing is a growing field. One of the most common types of 3d printing methods is stereolithography. While the tensile properties of many stereolithographic resins are known, the compressive properties are not publicly available. In this paper, four types of resins that from Formlabs® are tested under compression to estimate their mechanical properties. Testing was performed on Clear, Tough, Durable and High Temperature resins with and without post processing. Post processing was performed in a customized curing oven following direction from the resin manufacturer. After testing, it was found that the Tough and Durable resins performed similarly when green, but the curing process stiffened the Tough Resin. Clear and High Temperature resins performed similarly after curing, whereas the High Temperature resin behaves more like an elastomer when green.
We estimated the tangent modulus of the stress-strain curve using a Polynomial fitting and were able to separate the elastic modulus from the viscous modulus. We found that the viscous modulus is non linear and depends upon the velocity of the test.
The test presented here are the first comparison of different types of Formalab resins under compression and can shed some light on the anisotropic behavior of many of these resins.