ARS | Publication request: Composite drying with simultaneous vacuum and toggling

Submitted to: International Union of Leather Technologists and Chemists Societies
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2011
Publication Date: N/A

Technical Abstract: Drying is one of key steps to govern the physical properties of leather and it is where leather acquires its final texture, consistency and flexibility. Recently we have been working diligently to improve chrome-free leather by optimizing its drying process. We developed a drying method using a combination of toggle and vacuum drying together. This is because vacuum drying offers fast speed at a low temperature, which is particularly advantageous to heat-vulnerable chrome-free leathers. On the other hand, adding a toggle action during vacuum drying can significantly increase the area yield. We explored this composite drying method and investigated how drying variables affect mechanical properties and area yield of chrome-free leather. This study showed that the stretch applied in a drying operation significantly affects stiffness and area yield. We observed that biaxial stretch increases tensile strength but has less effect on fracture energy. Our study also showed that tensile strength increases with apparent density and decreases with drying rate. Under an optimal drying condition, a 16% increase in area yield with good properties can be achieved.