Abstract

Leather processing involves diffusion of various chemicals through the pores of skin/leather matrix. Pore-size of the matrix has significant impact on the diffusion rates of the substances involved. The determination of pore-sizes and related parameters is necessary for an understanding of the diffusion phenomena in leather processing and related techniques. There are some limitations in existing poresize measurement techniques for natural fibrous materials like leather; hence there is a need for development of novel techniques with non-influencing character on structure of materials like leather. In this regard, a capillary flow porosimetry technique for pore-size measurement has been applied to two types of leather viz., full-chrome crust leather (FCC) and vegetable-tanned crust (VTC). By utilizing the capillary flow porosimetry technique, important pore-size parameters such as smallest, largest and mean pore-size plus porosity and average Darcy permeability have been determined. The respective values are 0.04μ, 0.93μ, 0.13μ, 59.1% and 0.027 respectively for FCC leather and 0.04μ, 0.67μ, 0.11μ, 49.9% and 0.021 for VTC leather. The results indicate that FCC leather has greater porosity compared to VTC leather; possibly due to chrome tanning providing less filling effect compared to vegetable tanning.