Nine are Hytrel thermoplastic polyester elastomers with hardness values of 40 to 82-Shore D. They can replace flexible plasticized PVC, conventional rubbers, and thermoplastic elastomers used in soft-touch surfaces, valves, seals, springs, shock absorbers, tubing, and noise-management parts. Three additional engineering plastics come from grades of Delrin polyacetal, Zytel nylon, and Zenite liquid-crystal polymer (LCP). All medical-grade polymers have been or are being tested according to ISO 10993-1 and USP Class-VI test criteria. Many grades comply with U.S. Food and Drug Administration and European Union requirements for contact with specific kinds of foods under defined conditions.

DuPont Engineering Polymers, Box 80713, Chestnut Run Plaza 713, Wilmington, DE 19880, (800) 441-0575,