Leading dyehouses specialising in the exhaust dyeing of Cellulosic fibres have been reviewed across Europe, Asia and the Americas. The study as a whole took place in a series of completely independent dyehouse audits, each as part of agreed quality and productivity improvement programmes with the managements concerned.
The study in its entirety covered a wide range of different types of reactive dyestuff, applied on a complete spectrum of exhaust dyeing machinery types, and across a diverse range of cellulosic knitted fabrics and yarns, on cottons of different origins. The study as a whole has led to some startling conclusions.
The industrial concerns studied in depth shared two common features which are relevant to the subject of sequestrants. They all used softened water; but had failed to recognise the danger of hardness from other sources. Hard water, containing both alkaline earth and heavy metals, is known to cause processing problems with reactive dyes. The manufacturers of reactive dyes themselves issue very clear warnings to such effect.