Ecotan Tanning Processes

Tanning is a process in which leather is chemically treated to strengthen it, make it more flexible and resistant to deterioration.

This process strengthens the protein structure of the putrescible hide, creating a bond between the tannins and the peptide chains.

Hide is made up of three layers: the epidermis, the dermis and the subcutaneous layers. The dermis is 30–35% protein — mostly collagen — with the rest mainly fat and water. The dermis is what is used to make leather once the other layers are removed chemically or mechanically.

Throughout the full tanning process, acids, alkalis, salts, enzymes and tanning agents are used to dissolve unwanted fats and proteins and to chemically bind the collagen fibers with the tanning agents.

Thanks to 160 years of history in vegetable extracts and its experience supplying low-impact wet-white tanning solutions, Silvateam's R&D laboratories developed Ecotan: a set of new technologies for manufacturing sustainable leather.

Vegetable tanning (chrome-free)

The most traditional and oldest way of tanning leather. This system is used especially in Italy, where expert artisans combine their knowledge and history with high-quality raw hides and modern, innovative technologies. Vegetable tanning uses natural ingredients such as the tannins/polyphenols extracted from bark, wood, fruit and leaves. As a result, the finished product usually has warm, rich tones in the natural brown range.

Wet-white tanning (chrome-free)

Refers to leather pre-tanned with tannins that give a white or pale-cream color. This relatively new method has gained popularity, partly due to growing concern about water treatment and the environment, and partly due to the demand for recyclable, chrome-free leather. The main products used for wet-white tanning are synthetic tannins — mainly phenolic, disulphonic and naphthalene derivatives — aldehydes, metals (zirconium, aluminium, etc.) and oils.

Hybrid chrome tanning

Silvateam's latest solution is an innovative tanning process using a combination of chrome salts with Blancotan CAT, a new cationic synthetic tannin obtained from the condensation of dihydroxydiphenyl sulphone.