Accelerated method to determine or predict failure time in polyethylenes
Patent
Overview
Overview
abstract
An accelerated method of determining the failure time of a polyethylene resin by determining the minimum displacement rate, or the time at minimum displacement rate, using ASTM F 1473-01, then following one of these routes: (1) If failure has not yet occurred, cryogenically fracturing the resin specimen and examining it for slow crack growth to determine whether the anticipated, or desired, failure time is generally before or after the predicted failure time; or (2) Applying the minimum displacement rate, or the time at minimum displacement rate, in the appropriate mathematical formula to predict the failure time for the resin. The mathematical formula is derived from the discovery of a power law relationship between the failure time and minimum displacement rate, or between failure time and the time at minimum displacement rate. Thus, it is not necessary to actually test all the way to failure using ASTM F 1473-01, thereby accelerating testing capability and consequently enabling more rapid development of new resins.
