As rapid prototyping (RP) moves closer toward direct manufacturing, stereolithography (SL) resin leader DSM Somos is working to increase industry awareness around the impact testing of SL resins for the better evaluation of material performance. At the recent 2008 3DSUG conference in Costa Mesa, CA, DSM Somos made the information tangible with live test demonstrations in which RP users were invited to put various materials up against Somos’ latest high-impact SL resin, DMX-SL™ 100, in Gardner impact tests*.

“We used a Gardner impact tester to demonstrate the wide range of impact resistance currently exhibited by today’s RP materials,” says DSM Somos Marketing Manager Eva Montgomery. “In all, over twenty different materials were tested, ranging from 3D-printing resins to SL resins to laser sintered resins. Each material was ultimately compared to the unprecedented stiffness/toughness performance of Somos DMX-SL™ 100.”

Nonofficial data gathered at the live demonstrations showed DMX-SL to have as much as four times the impact resistance of all other stereolithography and 3D-printing resins tested. It also demonstrated up to twice the impact resistance of fused ABS, polycarbonate and some laser sintered nylons, with a performance similar to high-strength laser sintered nylons.

Introduced in March 2007, DMX-SL 100 is the industry’s first SL resin targeted for high durability applications. Based on unique chemistry platform which produces an unprecedented stiffness/ toughness combination, DMX-SL demonstrates the stiffness of standard ABS-type resins but with more than twice the impact strength. More information about DMX-SL, as well as video footage of the live test demonstrations held at the 3DSUG conference, can be found here. More information about the impact testing of SL materials can also be found online in Somos’ April 2008 newsletter, “The Part We Play.”

*Important note: the true Gardner test method (ASTM 5420) allows designers to compare the relative impact resistance of materials under controlled laboratory conditions and, consequently, is often used for material selection or quality control. The results obtained in Somos’ live demonstrations at the 3DSUG Conference were used only to stimulate industry understanding and discussion of impact strength and how it can be used in the selection of RP materials for either functional testing or direct manufacturing applications.