Surlyn® is the trade name for Du Pont Company's Ionomer resins. The long-chain semi-crystalline polymer structure imparts characteristics normal to a polyolefin. The upper usable temperature range of unreinforced Surlyn is 120 degrees F to 170 degrees F. The reduction of crystalline structure produces good optical clarity. Surlyn® is processed using the same techniques as low- density polyethylene. Surlyn® can be used for fitting modules and socket liners. Typical shrinkage is 1 percent to 2 percent.