Specification_ASTM D2768.pdf

This document is an ASTM International Standard Specification (Designation D 2768 – 95) for general-purpose ethylene-propylene rubber jackets used on wires and cables. The specification covers a weather and ozone-resistant crosslinked compound primarily composed of ethylene-propylene copolymer (EPM) or ethylene-propylene terpolymer (EPDM). Key technical requirements include a minimum surface resistivity of 200,000 MV, no cable failure during U-bend discharge testing, and retention of at least 80% of unaged tensile strength and elongation after 720 hours of exposure in a dual carbon-arc apparatus. The physical properties table specifies minimum unexposed tensile strength of 1,500 psi with 200% elongation, and after air oven aging at 121°C for 168 hours, a minimum tensile strength of 1,200 psi with 175% elongation, applicable to jackets with a nominal thickness of 0.030 inches (0.76 mm) or more.