Abstract

It is generally recognized that, in an industrial process, drying is the most energy-consuming step. It occurs several times in the leather processing. Leather production, accordingly, involves a crucial intensive energy use during this process to remove residual moisture. Additionally, the drying steps also necessitate substantial periods with respect to the total time required for tanning. Drying by hot dry air requires shorter times compared to moist air; whereas the impact of the convective drying on the dried quality of leather remains unclear. Regarding these facts, the main objective of this study is to focus on improving the influencing factors – mainly the drying temperature, air velocity and humidity which impact on certain criteria in the leatherʼs quality, especially the tensile strength, extension at break and tear. The leather used in the work is from cattle, a crust black leather, taken just prior to finishing. Experiments have been carried out at a temperatures varying between 40, 45, 50, 55 and 60°C, performed at three levels of air velocity (1, 1.5 and 2m/s) and with humidity at 15%, 30% and 45%. The results obtained make it clear that drying at 50°C with injected humidity of 15% and an air velocity of 1.0m/s seems the most optimal in our case, as it gives a better quality leather.