Abstract

The leather market is becoming more demanding in terms of quality and competitive cost. Thereby, leather producers are searching for efficient processes, in order to reduce the waste load and improve the quality of the final product. For the production of garment and upholstery leather (automotive and furniture), fatliquoring is a fundamental stage, since it provides characteristics such as softness, pleasant feel and strength. Fatliquors are offered to the leather as emulsions and they are incorporated into the structure, influencing its properties. This work presents a study of the fatliquoring process, aiming at the evaluation of the amount of oil absorbed by the leather and its physical-mechanical characteristics.

The process formulation used was appropriate for the production of furniture upholstery leather, which demands high amounts of fatliquoring products. Fatliquoring parameters of temperature, pHof neutralization, pH at fixation and fixation time were studied. Experimental design and analysis of variance (ANOVA) have been used as statistical tools for determining the parameters’ effects. The process efficiency and the leather quality were measured by oil concentration and chemical oxygen demand (COD) in residual baths and oil content, softness, tensile strength, elongation and tear load of the leather. The process variables have not influenced the physical resistances. However, the temperature made a significant contribution and enhanced the oil content in the leather and softness, as well as helped to diminish the oil concentration and COD of the residual baths. The pHat fixation significantly enhanced the oil content in leather and diminished the oil concentration and COD of the residual baths. The fatliquoring effect on physical-mechanical resistance (tensile strength, elongation and tear load) has been compared to samples that were only pre-fatliquored.