US 4,845,789 AGranted

Dyeing of garments with low-substantivity vat dyes

AssigneeCotton Incorporated

InventorsGlenn P. Morton, George A. McFadyen, Rob L. Stone

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Abstract

The present invention provides a process for the rapid dyeing of a series of successive garments or batches of garments with a vat dye, preferably indigo dye, wherein the garments while contained are submerged in and impregnated with the dyeing solution in a first bath, then removed from it while draining the dyeing solution and conserving it for re-use, then promptly immersed in an oxidizing solution in a second bath so as to shock oxidize the dye present in the garments, then removed from the oxidizing bath while draining the oxidizing solution and preserving it for re-use, and then washed and dried, and wherein the time elapsed between removal of the garments from the dyeing solution and their immersion in the oxidizing solution is less than 5 minutes.

Claims21

Dependent claims

A process for dyeing a series of successive garments with a vat dye of low substantivity, comprising the steps of:

(a) placing a batch comprising at least one garment made of cellulose fiber in a first container;
(b) submerging the garment batch in said container at ambient temperature in a first bath comprising a solution of low-substantivity vat dye in its leuco form and agitating said garment batch while keeping the same submerged in said first bath until each garment in the batch is substantially uniformly impregnated with the aqueous dye solution;
(c) separating the said batch comprising said at least one impregnated garment from said first bath and retaining the first bath for later use;
(d) promptly after said separation submerging said batch comprising said at least one impregnated garment while in a container in a second bath comprising an aqueous solution of an oxidizing agent and agitating said garment batch in said second bath until substantially all the vat dye in the garment is oxidized;
(e) separating the batch comprising said at least one garment containing the oxidized dye from said second bath and retaining said second bath for later use;
and
(f) thereafter washing said separated batch comprising said at least one garment.

4 more elements

A process for dyeing a series of successive batches of cotton garments with indigo, comprising the steps of:

(a) placing a batch of said garments in a first foraminous container;
(b) submerging said garments in said first container at ambient temperature in a first bath comprising an aqueous solution of an indigo dye and agitating said garments while substantially completely submerged in said dye solution for about 10 to about 30 minutes until all parts of each garment are impregnated with said dye solution;
(c) removing said first container from said impregnated garments from said first bath while said dye solution drains from said first container back into said first bath for re-use in another dyeing cycle;
(d) promptly discharging said separated, impregnated garments from said first container into a second foraminous container and submerging and thereby shock oxidizing said impregnated garments in said second container in a second bath comprising an aqueous solution of an oxidizing agent for about 2 to about 20 minutes at a predetermined temperature and agitating said impregnated garments in said oxidizing solution until substantially all of the indigo dye in each garment is oxidized;
(e) removing said second container with said oxidize garments from said second bath while draining the oxidizing solution back into said second bath for re-use in another oxidizing cycle;
(f) discharging said removed garments from said second container to a washing zone and washing the oxidized garments with water;
and
(g) transferring the washed garments from the washing zone to a drying zone and drying the washed garments.

5 more elements

A cyclical process for dyeing a series of successive batches of cotton garments with indigo, wherein each cycle comprises the steps of:

(a) placing a batch comprising a plurality of garments in a foraminous container;
(b) immersing said container in a first bath comprising an aqueous dyeing solution consisting essentially of indigo dye, caustic soda, and hydrosulfite at ambient temperature and agitating said garments while substantially completely submerged in said dyeing solution until each garment is uniformly impregnated with said dyeing solution;
(c) removing the foraminous container with the impregnated garments from said first bath while draining dyeing solution back into said first bath for re-use;
(d) thereafter promptly discharging the impregnated garments from said first container into another foraminous container and immersing said other container with the garments at a predetermined temperature in a second bath comprising an aqueous solution consisting essentially of water, of hydrogen peroxide and sodium carbonate and agitating said garments while submerged in said second bath until substantially all of the indigo dye in each garment is uniformly oxidized;
(e) removing said other container with the oxidized garments from said second bath while draining oxidizing solution back into said second bath for re-use;
(f) discharging the oxidized garments form said other container to a washing zone and washing the oxidized garments with water;
and
(g) transferring the washed garments to a drying zone and drying the same.

5 more elements

Dependencies are inferred from the claim text.