Anomalous Fluidity of Cellulose Dyed with Certain Reactive Dyes and its Significance to the Practical Dyer*

The apparent chemical damage caused to cellulose by dyeing with reactive dyes, as assessed by determining the fluidity of the material in cuprammonium hydroxide, was examined. High values of fluidity were obtained, although tensile‐strength tests show that this parameter is not adversely affected by these dyes. The possible causes of these high values are discussed. The influence of pH on fluidity values and colour is also discussed. Significant variations in colour are encountered when the pH is not carefully controlled.