Wet-blue hides when used as raw material usually are purchased from many sources. Although traded as a commodity, wet-blue hides can significantly vary from a physical-chemical perspective, such as color, pH, differential value, content of fixed chrome oxide among others.
The practice of an initial offer of chrome salts normally precedes the retanning process itself, and is primarily intended to level the chrome content of the leather, but other advantages can be achieved when this process is performed with the use of products which combine synthetic tannins, chromium salts and complexing agents.
Some advantages of using this type of product are:
– Process without pH adjustment at the beginning of the retanning;
– Equalization of chrome oxide, thru all cross section, to the ideal level early in the retanning itself;
– Process of chrome retanning with high float exhaustion;
– Best equalization between batches, especially when from distinct origin (here we quote the final coloration of crusts, dying equalization especially for light colors, and less presence of “shadows”, specially on grain side);
– Greater uniformity on fullness, better firmness and grain smoothness.
Unipelli´s offers to his customers Unichrom TL, a synergetic combination of chrome salts, complexing agents and synthetic tannins. Unichrome TL provides a safe retanning process with considerable improvement in equalization between all wet-blue batches.
For more information contact www.unipelli.com.br or hotline (51) 3563 3146.