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.
Unusual. Chrom-Crust weiterverarbeitet. Die Färbung ist so nicht ansprechend. Daher eher eine "Billig-Lösung".
Crusting
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
a kotori web solution