Abstract

The overall objective of the study is to develop a new approach to characterizing environmental stress cracking resistance (ESCR) of polyethylene (PE) without using any pre-notch to accelerate crack growth. This paper presents a concept that uses an indenter to apply transverse loading to create local stretch in the region around the indenter. Cracks are initiated by the local stretch and time for the crack growth to the neighboring low-strain region, at a constant deflection and in a 10% Igepal CO-630 solution at 50 °C, is used to characterize ESCR for PE. The concept is verified by testing four types of PE, two high-density PE and two linear-low-density PE, of which ESCR has been characterized using ASTM D1693-A. Results show that even using much thicker specimens (10mm compared to 3mm) [1], time for crack growth based on the new concept is much shorter, especially for PE with strong ESCR. This supports the feasibility of using the new concept to characterize PE’s ESCR in a shorter timeframe than that required for ATSM D1693-A.

Keywords: Polyethylene; ESCR; Transverse loading; Mechanical testing