| Résumé : |
The bulk of chamois leather is used as wash leather for cleaning windows, car bodies and similar surfaces where its particular merit is its softness, high water absorbence and "wringability" ; some eight million skins are processed annually.
The traditional method ofmaking chamois leather was to impregnate the damp flesh splits of sheepskins with cod liver oil in fulling stocks and then hang them up in warm stoves to allow oxidation of the oil to occur, the products of which reaction had a tanning action. These two processes might be repeated two or three times until a satisfactory leathering was achieved.
Surplus oil was removed by hydraulic pressing (to yield a by-product known as Dégras or Moellon) followed by a final wash in warm alkaline water. The skins were then hung to dry and finished. The process is dirty and labour-intensive. For a production of 1000 skins per day, 75 mean hours were needed and 20 000 ft2 of warm stove area, with a high fire risk.
The modern system described herein and largely innovated by tha author as commercial process in Europe and the USA, loads the damp flesh splits into a large rotating drum along with the cod liver oil. Whilst this is rotating, a controlled blast of warm air is blown in, which effects some drying of the skins and suitable oxidation of the cod oil, so that complete tannage may be achieved in 12 h. Subsequently, surplus oil is removed by a solvent degreasing plant to yield a dry, tanned chamois leather.
The merits of this system are a reduction to nine man hours only, elimination of the warm stoves, a big improvement in cleanliness of working conditions, a yield of superior anhydrous Dégras, and the elimination of effluent problemsn incidental to the use of alkaline, aqueous wash liquors. The practical development of these systems was carried out by the author over a number of years and the back-up research performed under his guidance by a number of his students in the former Leather Department of the College of Technology, Northampton (now the Leathersellers' Centre, Nene College). |
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Theory and practice of modern chamois leather production in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 69 (Année 1985)
