Tear strength and tear resistance need to be measured, not only to make sure a product doesn't unintentionally rip but also to verify it does actually tear where it is intended, e.g. along a crease or perforation.
In some materials, a tear will propagate rapidly, predictably or evenly. In other materials, it will be more unpredictable.
Tear testing methods set standard conditions under which a product or material specimen can be measured in a repeatable way. Usually, the tear is initiated with a cut or notch in the specimen, which is held at each end by tensile grips. The material is torn at a constant rate of extension (CRE) to ensure optimum repeatability and the maximum peak tensile force is recorded.
There are various methods of tear testing but they all require both ends of the material specimen to be held in tensile grips and to be torn apart. The tensile force-extension values are continuously recorded to obtain precise data for calculating tear values. The main differences between the methods are the specimen shapes and the angle of tear.
Some tear test methods use a falling pendulum to create impact, but most apply a tensile force, for which Mecmesin meets these standards with its range of universal testers.