Abstract

Research work was carried out on recovered chrome tannin application in the processing of unsplit cattle hide tanning. In these experiments 20—80% of “Regenerate” was used in individual trials of tannings with Chromal.

Taking into consideration the tannin content in spent tanning floats from tanning trials with a changing share of “Regenerate”, a statement can be made that with an increase in the “Regenerate” share, negligible deterioration of its exhaustion occurs.

The general content of tannin in wet-blue from tanning trials with different shares of recovered chrome liquor remains on the level of 4.0—4.4% Cr,03and shows a falling tendency with the increasing share of “Regenerate”. In addition a disadvantageous effect of a different tannin distribution in the cross-section of the leather was confirmed. The content of Cr,03in the middle layer decreases with the increase in the “Regenerate” share. Distinct deterioration of both indicators, i.e. total chromium content and its distri bution in the layers of the leathers tanned exclusively with “Regenerate” was observed.

The physical test results of garment leather and footwear leather showed that all the leathers from tanning trials with a partial use of “Regenerate” comply with the Polish Standards for the parameters needed for quality leathers. Each time the leathers tanned with 100% “Regenerate” stood out from the others: garment leather with the highest tear strength values and the lowest elongation, footwear leather with the lowest strength values, the lowest extension at burst and the lowest elongation at break.