ISO 16770:2019

Plastics — Determination of environmental stress cracking (ESC) of polyethylene — Full-notch creep test (FNCT) ISO 16770:2019

Publication date:   Sep 25, 2019

Scope

This document specifies a method for determining the environmental stress cracking (ESC) resistance of polyethylene (PE) materials in a defined test environment. The test is carried out on notched test specimens machined from moulded sheets/specimens or from finished products. The test specimen is subjected to a static tensile load when immersed into an environment such as a surfactant solution held at a specified temperature. The time to failure is measured.
The method has been specifically developed for polyethylene materials but can be used to evaluate PE products, such as pipes, fusion welds/fittings and blow-moulded PE containers to study the effect of aggressive environments, i.e. dangerous goods and chemicals.
The method is suitable for use with test specimens moulded to chosen dimensions or machined from compression moulded sheets or injection moulded specimens, or from finished products, such as mouldings and pipes. When the test specimens are machined from extruded or moulded parts, the results can be affected not only by properties of the material, but also by stresses or orientation introduced during processing.