HNBR release. (Materials).

Xtend W-3201 semi-permanent release is specially formulated for hi-nitrile butadiene rubber (HNBR) as a low friction, 87 durometer rating automotive seal that allows easy release from the mold with minimal flash residue, according to the manufacturer. Prior to using Xtend W-3201, the automotive seal producer relied on a fluoropolymer-based mold release. The HNBR bonded tenaciously to the steel molds and required four steps to complete, according to the company. As a result of the fluoropolymer release being applied heavily for each cycle, the molds turned white from excessive release buildup. With the Extend W-3201, first one coat of release is sprayed on a clean mold, and it is allowed to dry slightly. Secondly, polishing is done with a soft cloth. After repeating this same procedure three to four times and allowing 10-15 minutes between application for drying and curing at 86 [degrees] F/30 [degrees] C, the molds are ready to go into production. After a six-minute pressing cycle, the parts are said to actually fall out of the mold, and the flash residue is released by simply blowing it off. (Axel Plastics Research Laboratories, P.O. Box 77 0855, Woodside, NY 11377)

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