Dégras
Dégras (French) is the name given to tannery fat or waste fat in tannery . The degreasing of leather won fat consists of Tran , which is more or less changed by exposure to the air. Depending on the oil from which it comes, it forms a thick or thin, brown, gray or yellow, cloudy oil.
Manufacturing
Dégras can be obtained in the manufacture of soft leather. The leather is treated with oil and milled through , hung up in between and piled up in a warm room. The oil combines with the animal fibers through oxidation and gives the leather its special texture. The excess fat is then removed, for example by wringing or pressing. This is how the dégras is created. An inferior variety can be obtained by washing the pelts and treating them with warm potash solution. In addition, an artificial dégras could be obtained from the olein from stearin production , to which tannic acid or lime soap was partially added.
application
To use it, 3 parts dégras and 1 part melted sebum can be mixed together. The mixing ratio depends on the application or the properties of the water used in the tannery. If this is very calcareous, more sebum is required, but if it is iron-rich, the proportion of dégras is increased. The finished mixture should stand for a few days before use and is applied cold to the inside of the fur. This results in an even color. The cold smear will make the leather smoother.
literature
- Richard Brunner: The manufacture of lubricants, shoe waxes, leather varnishes, leather greases and dégras. in: Chemical-technical library. Volume 18. A. Hartleben, Vienna 1916, OCLC 41546019 .
Web links
- Dégras on elexion.ch
Individual evidence
- ↑ World Food Organization of the United Nations (FAO) - Dégras
- ↑ Dégras on elexion.ch, accessed on May 22, 2014.
- ↑ About Dégras (leather smear). In: Polytechnisches Journal . 205, 1872, Miszelle 9, pp. 275-276.
- ^ Franz Sünn: Application of the Dégras. In: Polytechnisches Journal . 192, 1869, Miszelle 9, pp. 343-344.