Leather affinity testing for leather dyes - using ground leather paste for colorimetry and spectral photometry

摘要

In a dye analytical process to determine the affinity of leather dyes to grades of leather, the latter matl is ground and converted into a homogeneous fibres paste. Its dry residue is adjusted to 10g/1 and its pH-value is set to over 7 (7.3) by adding borax/formic acid. After dyeing at pH-values of 7, 5.5 and 4, the filtrate is tested colorimetrically and the dried leather fibre mat is checked by spectral photometry. This testing procedure requires only 1-10% of the leather, compared with that needed for due tests on leather samples. This method is better reproducible over long periods of time. Time savings of up to 50% have been recorded. No fulling (which is difficult to reproduce) is required.