Preparation of leather Fat liquor cum filler from fleshing waste for Retanning process in leather manufacture
Creators: name: Kassahun, Wintana
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2014

description: Skin/Hide fleshing wastes are the day to day activities to remove the flesh from the pelt, from tanneries are generated during leather processing when flesh of the soaked or limed hides skin/hides is removed with the fleshing machine. These skin/hide fleshing wastes from tanneries contain significant quantity of protein and fat content and are currently being wasted into dumping sites or in open areas, consequently creating the fleshing waste disposal major environmental problem of the tanning industries throughout the world. Approximately, 9-14 tonnes of fleshing waste are being generated from Ethiopian tanneries per day. The objective of this work is to elaborate a method/technique to develop fatliquor cum retanning agent for use in leather industry from the waste (fleshing) generated by the tanning industry. Skin/hide fleshing is source of fat/oil and protein matter. The extracted fleshing fat was first emulsified by adding emulsifier. Then the fleshing hydrolysate, containing the protein fractions was prepared by alkaline hydrolysis in the presence of sodium hydroxide at a pH of 5.6. The hydrolysate and the extracted oil were further characterized to find the suitability of production of fatliquor cum filler for retanning process. The fatliquor cum filling product was prepared and used in leather processing during retannage stage. Physical characterization of the leathers were carried out and compared with that of control leather processed with commercial fatliquors and retanning agents. Moisture, protein and fat content of the fleshing from cow hide were found to be 63.30, 12.82 and 4.84%, respectively. Similarly, the fleshing of sheep and goat skins have also been characterized and reported in the results and discussion section. The fat extracted from the fleshing was characterized for iodine, saponification and acid value. The fleshing hydrolysate was characterized for degree of hydrolysis, solid content, molecular weight, and particle size and zeta potential measurement. For making upper leathers, 8% of the fatliquor cum retanning agent per weight of skins/hides was employed, which gave better results. Similarly, for making nappa leathers, 16% of the prepared fatliquor cum retanning agent per weight of skins/hides was employed. Data from physical testing was quantified with statistical analysis and it was found significant. The leathers were not found greasy, indicating that the product penetrated into the leather matrix. The particle size of the prepared product was also determined and was found in the range of the commercially available retanning agents. xiv Organoleptic properties such as colour uniformity and intensity, roundness, softness and fullness properties of the two leather articles prepared using the developed product were evaluated by experts and found to be on par with that of the control leathers. This study represents that the waste protein and fat from skin/hide fleshing wastes can be utilized as a beneficial product after some chemical modifications. Waste skin/hide fleshing is a good alternative source for preparation of fatliquor cum retanning agent. This project also answered the disposal problem associated with the solid wasted (fleshing) generated form tanning industries. The proposed methodology could be easily adopted by all leather industries. Key words: Hydrolysis, Fleshing wastes, Fatliquor cum filler, Extraction, homogenization,