Traditional stereolithography materials use an acrylate-epoxy building block, which has produced some outstanding SLA resins. This chemistry is limited, however, in its ability to minimize water absorption and maximize dimensional stability. In 2001, DSM Somos (Elgin, IL) created oxetane, a cousin to this building block that uses a similar cure mechanism to epoxies but also offers low viscosity for faster processing, faster cure rates for quicker builds and higher green strength, and low moisture absorption.

Based on this platform, the company recently introduced three new ABS-like resins representing the second generation of Somos Oxetane Advantage materials. Designed for general, multipurpose use, the ProtoGen O-XT series of materials uses oxetane chemistry for extra performance in such areas as heat deformation (74°C with UV postcure) and low water absorption. ProtoGen O-XT 18120 is a clear material, while ProtoGen O-XT 18420 resembles white injection molded plastic.

The third introduction, ProtoCast AF 19120, offers high performance in investment casting applications. Improving upon the performance of WaterShed 11120, ProtoCast AF boasts ultralow ash (<.01%) due to the elimination of heavy metals.

?Most epoxy-based SL resins contain an antimony-based catalyst that contributes to ash content after burnout,? says Somos technical service manager Brian Bauman. ?ProtoCast AF is antimony free.?

?These three resins expand the property range of Somos? earlier oxetane materials by adding new levels of accuracy and temperature performance to their already high green strength and dimensional stability,? says Somos marketing manager Eva Montgomery. ?As a result, RP users now have even more latitude in selecting robust materials that effectively model end-use conditions.??MM

DSM Somos
(847) 697-0400
www.dsmsomos.com

IMM - October 2006