Abstract

The work reported in this paper deals with the measurement of the resistance of leather fibres to bending, and the permanent deformation or set resulting from that deformation. Individual fibres from leathers of different tannages were mounted in a specially constructed apparatus so that trans verse bending of the fibres could be measured with accuracy. Measurements were made under a variety of conditions of temperature and relative humidity, ranging from 3°c to 55°c and 20 r.h. to 65 rh.

The results of measurements of bending modulus confirm some of the known facts about leather behaviour, showing that this property of leather fibres is of importance when leather is stressed. However, set of leather does not appear to be dependent on the permanent deformation of fibres when bent, since certain factors, namely, tannage and humidity, which are known to affect the values of set in leather, have the opposite effect when the set of individual fibres is considered.

Stretch in leather is likely to be a complex function of fibre extension, fibre bending and fibre slip, each of these properties being affected in the same way by factors which are known to affect the extensibility of leather.