ISO/NP 16685

Thermoplastic materials for piping systems — Determination of resistanceto slow crack growth under cyclic loading — Cracked Round Bar test method ISO/NP 16685

Scope

This International Standard specifies a method to determine the resistance to slow crack growth (SCG) of thermoplastic materials, pipes, and fittings. The test is applicable to samples taken from compression moulded sheets, extruded rods, sheets or pipes, and injection moulded fittings of suitable thickness.

This International Standard provides a method that is suitable for an accelerated fracture-mechanics characterization at ambient temperatures of 23 °C of different polyethylene grades, especially for PE 80 and PE 100 types for pipe applications. This method can also be used for other thermoplastic materials such as polypropylene (PP), unplasticized polyvinylchloride (PVC-U), or unplasticized polyamide (PA-U) by using specifically adapted testing parameters for the target stress range,. Furthermore, this test can be applied to characterise the slow crack growth resistance of virgin, as well as non-virgin (reused, recycled) thermoplastic materials [7]. [8], [9], [10].