Rapid-prototyping resins imitate PP and ABS. (Keeping up with Materials).

Five new polyurethane materials are designed for rapid vacuum casting of prototypes and short-run parts that mimic properties of polypropylene and ABS. These are additions to the Parts-in-Minutes family from the Ren-Shape Solutions Tooling Group of Vantico, Inc., East Lansing, Mich.

Grade RO 6489 R/H produces tough parts resembling PP. It combines high impact strength, high HDT (185 F @ 66 psi), and nearly 200,000 psi flex modulus. Parts can be demolded in less than 30 min. A developmental version with slightly longer pot life is suited to casting large parts.

Also in testing are two ABS-like PUR grades with high flex modulus and HDTs near 212 F. The fifth grade, RR 6488 R/H, is Vantico's first developed specifically for use with vacuum-casting machines from MCP Systems Inc., Fairfield, Conn., which Vantico began distributing on June 1. This material performs like PE or other polyolefins, with a combination of extremely high impact strength (5 ft-lb/in, notched Izod), 200 F HDT, and 95,000 psi flex modulus. It has a 15-min pot life and 8-hr demold time suitable for large parts. Parts can also be cured at 120 F to reduce demold time to 1 hr. Tel: [phone], www.vantico.com