?EFFECTS OF CHROME-SYNTAN-VEGETABLE COMBINATION RETANNAGE AND POLYMERIZATION (IN SITU) ON THE INTERNAL MEMBRANE OF BOVINE STOMACHS FOR EXOTIC LEATHER

Abstract

Internal membrane of bovine stomach with poor hide substance (the leather making material), a solid waste
from slaughter house, was processed into exotic leather for value-added goods like ladies hand bags, purses,
wallets etc. Pure vegetable, synthetic/vegetable tanning or tanning of an unlimed membrane gave unsatisfac-
tory leather. Its thickness, hide substance, leatherity, thermal stability and strength properties were consider-
ably increased through polymerization in situ (urea formaldehyde) followed by chrome tannage and
synthetic retanning, and chrome-syntan-heavy vegetable combination retannage. Resin finishing contrib-
uted additional strength and beauty to the leather. In the former case the average thickness and shrinkage
temp. (Ts) were 0.8 mm and 135°C respectively with diminished surface area and coarse shrunken grain
affect. In the later case the average thickness and Ts were 0.7 mm and 128°C respectively with improved
stability, cutting value, better area yield with prominent natural grain patterns and about 9% more weight
gain than the former case. The tensile strength in both the cases was low i.e. 34.8 kg/ern? but was within the
limits of fancy light leathers.