COMBINATION OF WHITE MINERALS WITH NATURAL TANNINS CHROME-FREE TANNAGE FOR GARMENT LEATHERS

摘要

There is a growing need for eco-benign tanning systems owing to stringent environmental regulations. In this present study, a new combination tanning system using zinc, tannic acid and silica has been explored for the manufacture of garment leathers. The amounts of zinc, tannic acid and silica used have been optimised as 10, 10 and 5% respectively. The shrinkage temperature of the leathers obtained is 85℃. The impact of this tanning system on the environment has been assessed by analysing the effluent liquor for zinc, sulphate, BOD, COD and TDS. A significant reduction in BOD, COD and TDS loads has been achieved and the exhaustion of zinc is about 90%. The organoleptic and the strength properties of the garment leathers made using this combination system are generally comparable to those of conventional chrome tanned leather.