ISO 18488:2025

This document specifies a method for the determination of the strain hardening modulus, which is used as a measure for the resistance to slow crack growth of polyethylene. This document specifies how to obtain a strain hardening modulus measurement from “true stress vs. draw ratio” curves on compression moulded samples. Details of the necessary equipment, precision and sample preparation for the generation of data are given. This document provides a method that is valid for all types of polyethylene, independent from the manufacturing technology, comonomer or catalyst type used for pipes and fittings applications.