Abstract

A study has been made of the effects of two test methods and three synthetic perspiration solutions on the properties of four types of upper leather.

The test methods involved either a simple soak procedure or a process in which the solid components of the perspiration solutions accumulate in the leather, especially in the grain. The test solutions included two new formulations, the composition of which closely resembles that of natural perspiration except for concentration, and one which differs markedly in composition from natural perspiration. The leathers used were full-chrome, chrome plus glutaraldehyde, chrome plus syntan, and chrome plus vegetable tannin. Assessments of strength, flexural fatigue, shrinkage and hydrothermal stability were made after various days or cycles of treatment. The results show that detannage alone does not necessarily cause the loss of strength and flex endurnce associated with perspiration damage of worn footwear, and therefore a simple soak treatment will not give the same results as are obtained in wear. The loss of strength consequent on the accumulation of the soluble solids of perspiration indicate that the causes of perspiration damage to upper leather are less related to detannage than to the physical effects arising from the accumulation of perspiration residues, and the test method and the synthetic perspiration used for assessing perspiration resistance must take this major factor into account.

The L.I.R.I. flesh pad treatment method in combination with the L.l.R.l. test solution are shown to give results consistent with those anticipated from the examination of worn footwear.

The results also show that the resistance to perspiration damage of footwear uppers is likely to be enhanced by a periodic washing of the grain surface in water, followed by waxing and polishing.