Research physicist, National Bureau of Standards, Washington, DC
A new test method is proposed for the determination of the environmental stress-crack resistance of ethylene based plastics. The method incorporates features of both ASTM Test for Environmental Stress-Cracking of Ethylene Plastics (D 1693) and Test for Environmental Stress Rupture of Type III Polyethylenes Under Constant Tensile Load (D 2552). The specimen is constrained in a fixed geometry by bending it around a cylindrical metallic form, and it is subjected to a constant applied stress. Statistical data are presented which indicate that the coefficients of variation that can be expected from the new test are at least comparable to those reported earlier in round robin tests carried out using ASTM D 2552. The principle advantage of the proposed new test over both ASTM D 1693 and D 2552 is a substantial savings in the time required to collect the data.
Paper ID: JTE10290J