Crust leather
Crust leather
Crustleder ist Leder, das nach der Gerbung getrocknet, aber noch nicht gefärbt ist. Bei chromgegerbten Ledern spricht man dann von "Chrom-Crust" oder bei pflanzlich gegerbten Ledern von "Pflanzen-Crust". Ein weiterer Begriff für "Crustleder" ist "Borke" oder "Borkeleder".
Crustleder wird nur selten weiterverarbeitet. Meist werden die Leder vor der Verarbeitung noch gefärbt und zugerichtet.
"Pflanzencrust" - "Chromcrust"
Pflanzliche Crustleder verarbeitet.
Sehr selten. Chrom-Crust weiterverarbeitet. Die Färbung ist so nicht ansprechend. Daher eher eine "Billig-Lösung".
Crusting leather
Crusting is when the hide/skin is thinned, retanned and lubricated. Often a coloring operation is included in the crusting sub-process. The chemicals added during crusting have to be fixed in place. The culmination of the crusting sub-process is the drying and softening operations. Crusting may include the following operations:
wetting back - semi-processed leather is rehydrated. sammying - 45-55%(m/m) water is squeezed out the leather. splitting - the leather is split into one or more horizontal layers. shaving - the leather is thinned using a machine which cuts leather fibres off. neutralisation - the pH of the leather is adjusted to a value between 4.5 and 6.5. retanning - additional tanning agents are added to impart properties. dyeing - the leather is coloured. fatliquoring - fats/oils and waxes are fixed to the leather fibres. filling - heavy/dense chemicals that make the leather harder and heavier are added. stuffing - fats/oils and waxes are added between the fibres. stripping - superficially fixed tannins are removed. whitening - the colour of the leather is lightened. fixation - all unbound chemicals are chemically bonded/trapped or removed from the leather setting - area, grain flatness are imparted and excess water removed. drying - the leather is dried to various moisture levels (commonly 14-25%). conditioning - water is added to the leather to a level of 18-28%. softening - physical softening of the leather by separating the leather fibres. buffing - abrasion of the surfaces of the leather to reduce nap or grain defects.
Additional information