Influence of different retanning agents on the physical and structural properties of chrome leather

Thirty-two ovine clothing leathers in the wet-blue state were treated in a pilot plant. A standard process of neutralisation, dyeing and fatliquoring was applied to the left halves of the leathers; the right halves were processed in the identical way but, were retanned after the neutralisation step. Eight different tanning agents at four different levels were used. The following parameters were measured to characterise the structural and mechanical properties of the leather: tensile strength, tear strength, distention at grain crack in the ball burst test, apparent density, water absorption and water vapour permeability.