A dyeing process is the interaction between a dye and a fibre, as well as the movement of dye into the internal part of the fibre. Generally, a dyeing process involves adsorption (transfer of dyes from the aqueous solution onto the fibre surface) and diffusion (dyes diffused into the fibre).

Measurement and control of dyeing
Abstract:
The traditional dyeing process is described as a black box, in which the amount of dye on the fabric is not known until the dyeing is completed. Advances in spectrophotometry and computation have enabled an indirect determination of the amount of dye on fabric during the dyeing process based on Beer’s law. The principles of a dyebath monitoring technology that allow the analysis and control of the dyeing process are introduced. This measurement technology can aid in troubleshooting root causes in shade reproducibility that can occur from variability in dye strength, the fabric or the dyeing process.

Publisher Summary
Dyeing processes with indigo are carried out all over the world. However, dyeing of textiles with indigo in a reproducible way is complicated. Several reasons for errors and irreproducible dyeing can be found, including a lack of quality control during the dyeing itself and also in the preceding textile-finishing processes. Ab- and adsorption of dyestuff by the textile is strongly dependent on the nature, source, and properties of the fiber and its surface activity. These properties are determined by the preceding textile-finishing processes such as bleaching and mercerization. Optimization of these processes can result in a vast improvement of the dyeing process. In this context, a sensor has been developed for the continuous and online detection and control of hydrogen peroxide concentrations in textile bleaching baths in order to improve the quality and reproducibility of the bleached textile fabric.