Effect of Syntan to Fatliquor Ration on Porosity and Mechanical Properties of Wet-blue Leather

Abstract

Different types of leathers with varied end applications can bemade from same raw material. Post-tanning is the operation,which imparts the functional properties required for the finalleather. The amount of post-tanning auxiliaries such as syntan(S) and fatliquor (F) used in the leather making, make it possibleto convert the same animal skin into various leather types. Inthis work, the sheep wet-blue has been converted into garment(S:F 1:2) and upper (S:F 2:1) leather by varying the S to F ratio.Here, an attempt has been made to study the influence of S to Fratio on the porosity and mechanical properties of garment/upper leather with respect to sheep wet-blue as a control.Thermoporometry results show that the reduction in poredistribution of garment leather with respect to wet-blue leatheris about 62.3% and that of upper leather is 83%. Capillary flowporometry results show that the maximum distribution ofthrough pore throat diameter of upper leather is found to beshifted towards 0.1-0.2 ?m from 0.3-0.5 ?m (wet-blue leather),whereas in the case of garment leather pores are uniformlydistributed in the range of 0.1-0.5 ?m. The influence of posttanningauxiliaries on air permeability reduction is higher forupper leather (83%) than garment leather (41%). Morphologicalanalysis using SEM shows that loosely packed arrangement ofwet-blue leather becomes cemented fiber structure in case ofupper leather and uniform fine fiber splitting has been observedfor garment leather. Tensile strength of wet-blue leather isdecreased by about 23% when it is converted into upper leatherand that of garment leather is increased to about 16%.