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Understanding limitations of finishing agentsYellowing , change of shade, loss of strength in the substrate, odour etc are some of the shortcomings to be expected while choosing the finishing agent. Certain cases some of the deficiencies may be acceptable and certain other cases may not. As already mentioned it is necessary to understand and be fore warned. Yellowing Yellowing is associated with cationic finishes of quaternary ammonium compounds with free hydrogen attached to the nitrogen atom that can bind with chlorine to form ‘Chloramines’, the main cause for the colouration. Cationic finishes where the quaternary compound based on tertiary amines has no free hydrogen or groups that are likely to bind chlorine are not likely to cause yellowing. It is therefore necessary to choose the right cationic-finishing agent. Relative resins like DMDHEU, DMEU though they do not contain free hydrogen attached to the N of the ethylene urea, also cause yellowing and chlorine damage due to chlorine retention after several washes, as they are prone to cleavage and partially reverting back to give ‘NH’ The triazone based reactive resins have better resistance to cleavage and there fore perform better with respect to chlorine retention and degradation.
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