The amount of natural fat in sheep’s skin varies significantly, and this depends upon the animal origin, sex, age, etc. In wool acquired from sheep’s skin from Australia and New Zealand, this content can account for up to 50% of dry skin weight. Fats are triglycerides of saturated fatty acids. These fats can cause complications in the presence of excessive natural fat, rancidification and oxidation; due to tanning, dyeing and finishing operations become tedious. The defects reveal themselves in the form of spume and objectionable odor in leather. If the natural fat content in the raw material is high, as is usually the case with sheep’s skin, it must be removed. The process of fat or grease removal is called degreasing which is best carried out after pickling process. Fat dissolving solvents such as kerosene, methylene chloride, and trichloroethylene are employed for degreasing. Since these solvents are water insoluble, they cannot be effectively used for degreasing wet pelts. These solvents are therefore used along with emulsifiers (preferably non-ionic), which disperse the solvent in water, thus facilitating its entry inside the pelt. This paper attempts to study the degreasing action of secondary butyl ether and formulation (solvent and emulsifier) in comparison with a commercial product which is the global market leader in leather degreasing segment. This experimental study shows that an improved degreasing action was achieved with the formulation comparable to the commercial degreasing agent.

The hides and skins of animals are a source of leather. The hides are first trimmed and soaked to remove salt and other solids and to restore the moisture lost during curing. After the hide has been removed, it is fleshed (removing any remaining meat tissue or fat). Freshly fleshed hides are shipped in refrigerated trucks to a tannery for immediate processing into leather. If this is not possible, the fleshed hides are cured or preserved by immersion in agitated salt or brine for 12 h.After curing, the hides can be stored for several months without rotting and can be shipped to tanneries throughout the world. Cured hides arriving at a tannery are rehydrated or resoaked and washed in large rotating drums. ‘Unhairing’ is done by chemical digestion using a solution of lime and sodium sulphide with occasional rotation. Deliming is then performed to make the skins receptive to the vegetable tanning process.

Degreasing is done to remove grease, oil, wax, and other contaminants from the skin using organic solvents, enzymes, etc. After the hair has been removed, the hides are neutralized with acids and treated with enzymes to remove any deposits and to increase softness. This process is known as bating.

The next operation is called ‘pickling’ which involves soaking the hides in a solution of water, salt and hydrochloric or sulphuric acid. The purpose of these operations is to increase the amount of water in the hide to the amount close to that of the living hide, remove foreign bodies and loosen the structure. This loosening makes it easier for the tanning agents, fats, dyestuffs and other substances, to penetrate into the hide.

Chemical Engineering Journal, Metal Ions Onto Eggshell Powder, Heavy Metal Contamination, Water Resources, Traditional Treatment Techniques, Aquatic System, Equilibrium Biosorption Data, Biosorption Processes, Biomass Concentration, Biosorption Equilibrium, Biosorption Isotherm, Redlich Peterson Models.