ISO 18488:2015 PDF

Scope: This International Standard 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. The strain hardening modulus is obtained from stress-strain curves on compression moulded samples. This International Standard describes how such measurement is performed and how the strain hardening modulus shall be determined from such a curve. Details of the required equipment, precision, and sample preparation for the generation of meaningful data are given. This International Standard provides a method that is valid for all types of polyethylene, independent from the manufacturing technology, comonomer, catalyst type, that are used for pipes and fittings applications. NOTE This method could be developed for materials for other applications.

ISO 18488:2015 Referenced Document

ISO 16241:2005 Notch tensile test to measure the resistance to slow crack growth of polyethylene materials for pipe and fitting products (PENT)
ISO 37:2011 Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties
ISO 527-1:2012 Plastics - Determination of tensile properties - Part 1: General principles
ISO 7500-1:2004 Metallic materials - Verification of static uniaxial testing machines - Part 1: Tension/compression testing machines - Verification and calibration of the force-measuring system
ISO 9513:2012 Metallic materials - Calibration of extensometer systems used in uniaxial testing

2015 ISO 18488:2015 Polyethylene (PE) materials for piping systems - Determination of Strain Hardening Modulus in relation to slow crack growth - Test method