Abstract

The process, already described in J. Soc. Leather Tech. Chem. (1974), 58, 88, for making standard segments of chrome tanned upper leather, has been modified by the introduction of selected variants. The subprocesses which have been varied are: (i) liming; (ii) staking and conditioning; (iii) retannage and fatliquoring. Control segments made by the unmodified standard process have been included as a part of each pack. In addition to measurements made during processing, the leathers produced have been assessed for their main mechanical properties, using both subjective and objective methods. The results show the exceptional reproducibility of the standard process itself and so enable the effects of the variants to be reliably assessed. The marked effect of increased duration of liming on subjective properties is not reflected in all the physical test results. The degree of staking employed (Mollisa) resulted in significant differences in subjective properties and in the stress/strain properties for low strains. The use of glutaraldehyde retannage and of a higher level of fatliquor produced significant differences in certain of the mechanical properties which were measured or assessed. Statistical analyses have been applied to the results of the factorial designs employed.