Because most retanning agents, dyes and fatliquors have been developed for application on wet-blue leathers, the main problems with conventional wet-white leather have been associated with the reactivity of the wet-white itself and the fixation of post-tanning products. Often, due to the desired characteristics of the final articles, an excess of these products is necessary to approach chrome leather characteristics. This has a severe impact on the wastewaters with unfixed products and on the physical properties of the final leather produced. EasyWhite Tan, however, has a cationic character and presents new opportunities for retanning, dyeing and fatliquoring of chrome-free leathers with appropriate post-tanning products and treatment. The leathers produced with Clariant’s new tanning process have less stretch and elasticity, with fewer wrinkles and flatter growth marks. Besides having a tight, fine grain, 20% less dyestuffs are required than with conventional wet white. They also have higher light and heat resistance and have no negative influence on water resistant leather if re-chroming is applied.
The EasyWhite Tan process has multiple advantages for processing raw hides; it uses less water, reduces environmental load and wastewater treatment, requires no added salt, and it removes two or three process stages, including the pickle and basification steps. It is also metal, aldehyde and phenol free.
The processing of chrome-free or wet-white leather, however, was, until the advent of the new tanning system, considered to be somewhat difficult. EasyWhite Tan is based on Clariant’s Granofin Easy F-90, a single, easy-to-use liquid tanning agent.
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