PET5840001600-AAR 5/8″ x 1600 lb Break x 4000 ft. Green Machine Grade Smooth Extruded Polyester Strapping. Polyester is the most rigid of all strapping materials. It elongates significantly less than polypropylene and retains tension over a longer period. Polyester is nick resistant and can be sealed with seals, heat or friction welds. Frequently used on heavy duty loads that need high initial tension along with high retained tension. Common applications are empty cans and bottles, lumber, and heavy, rigid palatalizing. Polyester is available in both machine grade and hand grade and is easy to dispose of and to recycle.