Indigo dye process
AssigneeAllegro Natural Dyes LLC
InventorSally Gurley
Life of this patent
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Abstract
An improved nonpolluting method of dyeing fibers or fabric, including natural cellulose fibers such as cotton or linen, using indigo dye. The improved process preferably includes pretreating the fibers with a mordant solution, preferably a natural nonpolluting mordant solution. The fibers are then treated with a reduced indigo liquor in an inert atmosphere, preferably nitrogen. The indigo is then oxidized by flooding the dyed fabric with water. This indigo dye process can be adapted to conventional garment, package and piece dye processes and machinery, which has not been possible with existing indigo dye processes. The improved process results in a consistent and even dyed material which is color and washfast.
Claims19
A method of dyeing fabric with indigo dye in a conventional piece dye machine, said piece dye machine including a dye tank within a contained enclosure and means for continuously moving the fabric into and out of the dye tank within said enclosure, said method comprising the following steps:
- (a) placing the fabric to be dyed within said dye tank of said piece dye machine and adding water to said dye tank to at least partially cover said fabric;
- (b) displacing oxygen from said contained enclosure of said piece dye machine with an inert or non-oxidizing gas creating an atmosphere within said enclosure which is substantially free of oxygen;
- (c) introducing an indigo dye liquor containing indigo in its reduced leuco state into said dye tank and agitating said fabric within said contained enclosure while maintaining said enclosure substantially free of oxygen;
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- (d) oxidizing said indigo dye on said fabric and thereby permanently dyeing said fabric with indigo dye.
A method of dyeing fabric with indigo dye in a conventional piece dye machine, said piece dye machine including a dye tank within a contained enclosure and means for continuously moving the fabric to be dyed into and out of said dye tank within said enclosure, said method comprising the following steps:
- (a) placing the fabric to be dyed in said dye tank of said piece dye machine and adding water to said dye tank to at least partially cover said fabric;
- (b) introducing a non-oxidizing or inert gas under pressure into said contained enclosure of said piece dye machine displacing oxygen from said contained enclosure and creating an atmosphere within said enclosure which is substantially free of oxygen;
- (c) introducing an indigo dye liquor containing indigo in its reduced leuco state into said dye tank and agitating said fabric within said contained enclosure while maintaining said enclosure substantially free of oxygen;
- (d) draining said dye liquor from said dye tank;
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- (e) flooding said fabric with water containing oxygen, thereby oxidizing said indigo dye on said fabric and permanently dyeing said fabric.
A method of dyeing yarn with indigo dye in a conventional package dye machine, said package dye machine including a perforated tube having the yarn to be dyed wound on said tube within a contained enclosure and means for pumping liquid under pressure into said perforated tube and through said yarn wound on said tube, said method comprising the following steps:
- (a) introducing an inert gas under pressure into said contained enclosure displacing oxygen from said enclosure and creating a nonoxidizing atmosphere within said enclosure;
- (b) pumping indigo dye liquor containing indigo in its reduced leuco state into said perforated tube and through said yarn wound on said tube, thereby causing said yarn to absorb said indigo dye while maintaining said nonoxidizing atmosphere within said contained enclosure surrounding said yarn;
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- (c) oxidizing said indigo aye on said yarn, thereby permanently dyeing said yarn.
Dependencies are inferred from the claim text.