Severe effluent pollution has set new requirements for eliminating the use of salts during the reactive dyeing of cotton. In this study, 3‐chloro‐2‐hydroxypropyltrimethylammonium chloride was used as an etherifying agent via a pad‐irradiate‐pad‐steam process with a reactive dye to cationize cotton. The fabric underwent a microwave‐assisted pad‐irradiate process, and the cationic fabric was dyed salt‐free using a reactive dye in a pad‐steam process. The influence of etherifying conditions on the nitrogen content, grafting efficiency of the cotton samples, and dyeing properties of cationic cotton fabrics were investigated. Cationic cotton samples have the same dyeability with a reactive dye without salt as with dyes used in a conventional pad‐dry‐pad‐steam process because of the increase in the electrostatic attraction between the dye and the cationic cotton. Such an approach that eliminates salts is beneficial to environmental protection. Properties of the dyed cotton (such as color evenness, washing, and rubbing fastness) obtained using the reactive dye made the cotton fabric wearable enough to satisfy standard requirements.

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Polyester fabrics are usually difficult to dye deeply due to their high refractive indexes. In this study, poly(methyl methacrylate)/polysiloxane core‐shell latex was used as a deepening agent in the colour‐deepening finishing of dyed polyester fabrics by lowering the refraction index and enhancing the diffuse reflection via the rough surface. Poly(methyl methacrylate)/polysiloxane core‐shell latex has a better shade‐deepening effect than polysiloxane latex on dyed polyester fabrics. The mass ratio of core/shell monomer and the finishing conditions of the polyester fabrics had a large influence on shade deepening. The optimum finishing conditions were obtained for a mass ratio of core/shell monomer of 1:2, a deepening agent concentration of 10 wt%, a pick‐up of 80%, and a curing temperature of 180°C. After a deepening finishing, the dyed polyester fabrics showed a small colour difference and the colour fastness barely decreased.