Abstract: The process of modifying yarn and then dyeing or over dyeing with pigment was realized on continuous pad dyeing with sizing machine. The yarn treatment, dye liquor preparation and process design in the process were reasearched. The process could meet the demands on dyeing of various fibers. The process not only enriched dyeing methods of denim, but also had advantage on energy conservation and emission reduction.

Key words: denim; over dyeing with pigment and indigo; modification; energy conservation and emission reduction