Study on the Degreasing of Sheep Skin Using Subcritical Fluid Extraction

Degreasing is one of the important processes for the production of leather and fur. This study aimed to develop a degreasing method using subcritical n-pentane. Sheep skin was chosen as raw skin for this investigation. The best possible combination of degreasing parameters was found using single factor experiment and response surface methodology. The effects of temperature and pressure on the degreasing efficiency were evaluated further with histological analysis. The results showed that the optimum degreasing parameters were a degreasing time of 58 min, pressure of 0.45 MPa, temperature of 41.0°C and thus yielded a degreasing rate of 52.46％ theoretically and 51.46% experimentally. Histological sections showed that the degreasing effect of subcritical n-pentane was quite significant and the lipid droplets around the hair follicles were dramatically reduced. It has been proven that subcritical n-pentane degreasing is an effective technique for sheep skin degreasing.