BS 5131-2.1:1991

This Section of BS 5131 describes a method for g determining the resistance of soling material to cut growth resulting from flexing.

The test is primarily intended for testing the unpatterned soling material, i.e. using a specimen of defined length, width and thickness made from the soling material. In addition however, the method sets out conditions for testing whole soles (which may also be patterned) to assess the cut growth performance of the entire sole when flexed at a critical point of the pattern.

The test gives a good indication of the performance of the soling material in normal use and a reasonable indication of the performance of whole soles in normal use. However, in the case of polyurethane soles (especially those which are patterned) the method does not always predict sole cracking. Furthermore, the method is not suitable for testing specimens of material greater than 15 mm thickness.

When carrying out this test, a decision is made as to which of two temperatures is appropriate, either room temperature or – 5 °C. The appropriate temperature is that at which the material is least resistant to cut growth. Most materials are less resistant to cut growth at lower temperatures. As a consequence, where the soling material consists of either rubber, resin rubber, polyvinyl chloride (PVC), ethylene vinyl acetate (EVA) or nylon, a temperature of – 5 °C has been chosen. However, where the soling material consists of thermoplastic rubber, room temperature has been chosen, because resistance to cut growth is less at room temperature than at – 5 °C for this material.

NOTE. The titles of the publications referred to in this standard are listed on the inside back page.