A novel family of ionomers boasts breakthrough performance for fresh food packaging that requires selective high permeability to oxygen and moisture.

A novel family of ionomers boasts breakthrough performance for fresh food packaging that requires selective high permeability to oxygen and moisture. Developed by DuPont Packaging & Industrial Polymers, Wilmington, Del., Selar VP resins are based on a patented technology of highly neutralized ionic compositions of ethylene ionomers modifi ed with fatty-acid salts. Thirty percent of the resin's content is from renewable sources. It can be processed on conventional cast or blown film equipment. The fi rst of the new resins boasts high oxygen transmission rates (OTR) plus tight cling to product, good machineability, and ease of cutting. Applications include multilayer fi lms for premade bags, form-fi ll-seal, and vacuum skin packaging of fresh produce and fi sh. These resins are also well-suited to monolayer thermoformed packages for single-serve fresh-fruit cups. Properties include a 0.94 g/cc density, oxygen permeation value (OPV) of 1300 cc-mil/100 in.2-day, secant fl ex modulus of 21,000 psi, and tensile strength of 24,000 psi. The modifi ed ionomers have improved heat resistance, so they can be used as the outer layer of a multilayer structure, and are stiffer than other materials with high OTR, such as EVA, EMA, and mLLDPE (especially at lower densities). Tel: (302) 999-5912 . www.dupont.com

DuPont Co., Packaging &
Industrial Polymers
Barley Mills Plaza BMP 22-1157 Wilmington, DE 19880-0022
Phone (302) 999-5912 Fax (304) 863-2779