| Abstract: | An important problem associated with the introduction of automation in the dyehouse is that of the establishment and acceptance of numerically defined colour-tolerance limits. This is dependent not only on agreement between supplier and consumer but also on the availability of instruments that can measure colour differences with sufficient accuracy. The manner in which these differences can be used to provide feed-back information to modify dye formulations to give a more exact colour match is demonstrated. Alternatively, similar information can be fed forward to allocate material automatically into slightly ‘off-shade’ but still acceptable colour lots. Attention is drawn to the need to differentiate between colour differences caused by process variables and those attributable to dye formulation. It is suggested that a greater awareness of sources of colour variation and associated costs in the dyeing process is needed to enable the requirements and value of instrumentation and automation to be assessed. |
