Recent Progress in Fatliquoring Technology of Chrome-Free Tanning Systems

Fatliquoring is an important process in leather production, which is helpful to improve the mechanical properties and sensory properties of leather, especially the softness. However, in recent years, with the urgent demand and rapid development of chrome-free tanning technology, the traditional fatliquoring agents and fatliquoring processes designed to adapt to chrome tanning technology are no longer compatible with these new tanning technologies and usually face the problems of low fatliquoring absorption rate, uneven distribution and poor binding ability. In order to better promote the integrity and commercial exploitation of chrome-free tanning technology, some fatliquoring agents and corresponding fatliquoring processes suitable for chrome-free tanned leather have been developed. This review summarizes the recent progress of fatliquoring technology suitable for chrome-free tanned leather. The properties of chrome-free tanned leather, the characteristics of different fatliquoring agents, the fatliquoring process parameters, and their influence on the fatliquoring process of chrome-free tanned leather are emphatically discussed. Furthermore, the characterization methods of fatliquoring effect are also introduced from the aspects of absorption, distribution and biodegradability of fatliquoring agent and fatliquoring mechanism. Especially, the problems faced by fatliquoring technology of chrome-free tanned leather aredescribed, and its future development direction is prospected.Finally, the reasonable assumption of fatliquoring agent and expected fatliquoring effect suitable for chrome-free tanned leather based on silicon materials developed by our group is put forward.