Processes and apparatus are disclosed which substantially eliminate the formation of oxidized indigo dye before and during dye application onto a natural fiber yarn or fabric while allowing the leuco-indigo dye molecule to diffuse fully into the natural fibers of the yarn where it can fix to the fibers prior to oxidation (i.e., exposure of the leuco-dyed yarns to oxygen). Indigo dyed textile products (e.g., dyed cotton yarns that may be twill woven to form a denim fabric) exhibit exceptionally high colorfastness as determined by the AATCC Crock Test.

A device for applying a foamed treating material under pressure to a traveling sheet of relatively incompressible textile yarns. A foam applicator unit has a nozzle with a foam dispensing slot facing across one side of the traveling sheet of yarns. A drive roll faces the other side of the traveling sheet of yarns in tangential alignment with the foam dispensing slot. The roll has a resiliently compressible, soft rubber outer layer, which compresses to conform with the surface of the relatively incompressible yarns and presses the traveling sheet of yarns against the applicator surfaces leading to and away from the slot to prevent escape of foam and to prevent passage of foam between yarns to maintain uniform distribution of foam applied to the traveling sheet of yarns.

A method for improving the colourfastness of a dyed textile is provided. The method comprises the steps of: conveying a dyed textile along a processing line in a first direction; flowing a fluid from a reservoir through the dyed textile on the processing line in a second directly substantially opposite to the first direction; subsequently removing at least 50% of the applied fluid from the dyed textile; removing contaminants from the fluid; and returning the fluid to the reservoir.

Processes and apparatus are disclosed which substantially eliminate the formation of oxidized indigo dye before and during dye application onto a natural fiber yarn or fabric while allowing the leuco-indigo dye molecule to diffuse fully into the natural fibers of the yarn where it can fix to the fibers prior to oxidation (i.e., exposure of the leuco-dyed yarns to oxygen). Indigo dyed textile products (e.g., dyed cotton yarns that may be twill woven to form a denim fabric) exhibit exceptionally high colorfastness as determined by the AATCC Crock Test.

A gel felt production system includes a conveying device including a plurality of first rotating rollers that are rotatably. The plurality of first rotating rollers are disposed at intervals along a conveying direction of the conveying device. An input end of the conveying device is configured to input a wet felt, and an output end of the conveying device is configured to output a gel felt. A method for producing the gel felt using the gel felt production system is further provided.