Application of Novel Method of A Blend of Acacia nilotica Pods Powder and Neem Bark in Full Vegetable and Semi_chrome Tannage

Abstract

Vegetable tannage is an eco-friendly method compared with environmental polluting chromium based method of tanning that is commonly used in commercial tanning and which prevents the collagen fibrous protein in animal skins from putrefaction and produces hydrothermal stable product commonly known as leather. Thus study was conducted to improve the tanning efficiency of locally available tanning in the Sudan 'Garad', applying blending method, physico-chemical properties of 'Garad', bark and leaves of 'Neem' and 'Karkady' bark was determined, hide powder method was used in determining the tannins content whereas the analysis t-test and Anova were used to compare the mean values of the physico-chemical properties of vegetable tanning materials, the physico-chemical properties results of 'Neem' bark, crushed 'Garad' and pure powder were found to be acceptable and utilized as raw materials for commercial manufactory purpose, screening results of 'Karkady' calyxes and bark show that they contain oxalate organic salts 0.5% which were used to chelate the iron from the tanning liquor the results showed high efficiency, whereas used 5% dry leaves powder of 'Neem' at 60°C eliminated the mould growth for one month and also dropped the viscosity to opposite level and subsequently the liquor of improved indigenous tanning material was produced by blending 80% Acacia nilotica pods with 20% azadirachta indica barks' and then in spray-drying, various physico-chemical properties were studied and compared with those of conventional indigenous and myrobalan tanning materials. The results showed that the physico-chemical properties of modified indigenous materials are comparable with the myrobalan tanning material and even better than indigenous tanning in total soluble solids (93%), tannin contents (56%), non-tannins contents (36.7%), tannin/nontannins ratio (1.5) and pH (4.6). The results also showed that the material has bright and light brown colour which is consistent with the Indian Standards as required for industrial usage, yielded powder was used for full vegetable and semi chrome tanning to produce shoe upper leathers. The physico-mechanical properties of improved tanned leather were compared with conventionally tanned leather. Parameters of full vegetable tanned leather were tensile strength (20.0 N/Cm2), tear strength (4.4 N/cm), stitch tear strength (11.8 N/cm), elongation (40.5%), distension and strength of grain (8.9 mm) and shrinkage temperature (>82°C). Whereas factors of semi-chrome tanned leather were tensile strength (21.2-22.0 N/Cm2), tear strength (4.3-5.2 N/cm), stitch tear strength (12.6-11.8 N/cm), elongation (59-57%), distension and strength of grain (9.5-10.6 mm) and shrinkage temperature (98-100°C). The results showed that the ‘Garad - Neem’ blend significantly enhanced the quality of tanned leather to almost double the level of the leather tanned by conventional pure Acacia nilotica pods ‘Garad’ power. Physico-chemical properties of wastewater of tanning trails showed that the employment of improved powder to produce shoe upper leather is very eco-friendly.