ISO DIS 16770

Description / Abstract: This document specifies a method for determining the resistance to slow crack growth (SCG) 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 surfactant solution held at a specified temperature. The time to failure is measured.

The method has specifically been developed for polyethylene materials but can also be used to evaluate PE products, such as pipes, fusion welds/fittings. The method is also suitable for blow moulded PE containers to study the effect of aggressive environment, i.e. dangerous goods and chemicals. The method may also be adopted for other thermoplastic materials, e.g. polypropylene (PP).

The method is suited to the use of 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 parts, it shall be taken into account that the results may be affected not only by properties of the material, but also by stresses or orientation introduced in during processing.