Abstract

The satisfactory performance of synthetic-coated patent leathers in wear includes high resistance to flex cracking, which depends on good adhesion of the plastic patent finish to the underlying leather. Observation of wear failure shows that early delamination of the patent finish causes early splitting and cracking. While loss of plasticiser from the film may contribute, laboratory tests have shown that wetting of the leather from the flesh side can cause rapid breakdown of film adhesion and early cracking in wear. A laboratory test for wet flex resistance of patent leathers has been developed and is useful for predicting wear behaviour, and is suggested as a routine test for patent leathers. Flex tests also show that patent leathers are very susceptible to cracking from perforations and cut-outs, so it is advised to avoid such decorations in shoe areas that will be flexed during wear.