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Innovative processing for tanning leather

Convert all types and kinds of untanned skins in their
bated, drenched, or pickled condition via a one-stage
process into into pure white, full, plump or grain leather
by treatment with modified melamine formaldehyde resins.

Leather is one of the oldest commodities on today's world market. It has been called "the most historic of useful materials". Samples of the art of leather manufacturing from hides and skins have been found which are claimed to be at least 6,000 years old. Leather is produced from hides and skins and is used for shoes, upholstery, gloves, cases and other purposes. It is formed from a natural hide and becomes a dry, stable material after tanning, retanning and finishing. These processes prevent putrefaction and rotting under humid conditions. Tanning stabilises the collagen fibres. Chrome tanning was introduced in about 1900 and is now the principal tanning process. Soft leathers are first chrome tanned corresponding to a content of at least 3% chromium oxide. Chromium (III) has a remarkable complex-forming capacity. The binding of Chromium to collagen takes place within the carbodyl groups of the amino acids side chains. Exhaustion of the tanning bath under normal conditions is far from complete which is a drawback from the pollution standpoint. Residual chromium concentrations of 50-100 mg/L are obtained in tanning baths. Chromium (IV) is a toxic irritant and carcinogenic; it is formed from Chromium (III) under alkaline oxidizing conditions. Therefore Chromium residues must be precipitated to form a sludge and discarded under carefully controlled conditions. In this project water-soluble melamine-formaldehyde resin which is a partially etherified and anionically modified form will be synthesised to produce an environmentally acceptable, one-stage tanning process without using chromium as a tanning agent. In the following Table some estimated figures can be found for leather production in Europe. Since soft leathers are first chrome tanned to a state of boilfastness corresponding to a content of at least 3% chromium oxide, the total amount of chromium oxide used for the leather production can be calculated. Therefore the Research and Development programmes of the EUROPEAN UNION have to give some attention and support the leather industry to produce environmentally clean chemicals to keep our world clean. Table: Economic data (in 1O(3) t) for hides estimated by the U.S. DEPARTMENT OF AGRICULTURE ___________________________________________________________ Country Production Imports Exports Utilization ___________________________________________________________ BELGIUM 30 26 38 18 FRANCE 191 25 162 47 GERMANY 212 78 127 163 GREECE 11 14 2 23 ITALY 101 380 27 454 U.K. 92 37 79 50 PORTUGAL 9 55 5 57 SPAIN 43 70 5 108 ROMANIA 31 40 0 70 TURKEY 62 10 0 70 __________________________________________________________ Keywords: tanning agent, leather syntans, melamine- formaldehyde.
Acronym: 
LEATHERSYNTANS
Project ID: 
2 040
Start date: 
01-04-1999
Project Duration: 
43months
Project costs: 
1 220 000.00€
Technological Area: 
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.