GB/T 33075-2016

This standard specifies a test method for determining the substantivity (direct affinity) of reactive dyes to cellulose fibers under defined conditions. It is applied in the textile dyeing industry for quality control and product development, specifically to evaluate how effectively a reactive dye will exhaust onto cotton or other cellulosic substrates during the dyeing process. The method helps manufacturers and users predict dye uptake and optimize dyeing formulations.