An investigation on the leathers used natural fat emulsion in fatliquoring process

The fatty spue is one of the most frequently defect appearing on finished leathers especially for sheep skins. Origins of this problem are due to insufficient degreasing process, present of excess residual natural fat in leather, quantity and quality of fatliquoring material added during fatliquoring process and faulty fatliquoring techniques. It is not easy to identify this problem during wet processes. In this research it is aimed to find out limit value of natural fat cause to fatty spue and its quality. Irish ovines which known as their high natural fat content were used. First group was processed without degreasing and fatliquoring. Second and third ones were degreased, second group was processed without fatliquoring but thirds were fatliquored by 3-5-7% their own emulsified fat. Some physical and chemical characteristics of natural and emulsified fats were found out such as density, acid, peroxide and iodine values. Visual images of crosssection of skins were obtained by Scanning Electron Microscopy (SEM). Gas Chromatography (GC) and Nuclear Magnetic Resonance (NMR) analysis were performed for determination of the fatty acids components caused to fatty spue. It was determined that excess of 3 % of natural fat emulsion could cause to fatty spue and palmitic and stearic acids were found as main responsibles.