One step dyeing process of a polyester/natural fiber blended fabric
AssigneeDow Global Technologies LLC
InventorsSandeep Nikam, Siddhartha Ghosal, Amit Barun
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Abstract
The current invention provides methods provides a novel process to dye polyester/natural fiber blends in an all in one step dyeing process. This all in one step dyeing process is enabled by pre-treatment of the fabric using one or more synthetic cationizing agents. The all in one dyeing is then able to be carried out at a lower temperature and a neutral pH, using a combination of disperse and reactive dyes.
Claims6
A method for dyeing a fabric comprising polyester fiber and natural fiber comprising the steps of:
- a. pretreating the fabric with an aqueous solution comprising an alkali metal hydroxide and a cationizing agent, where the cationizing agent comprises either a halogenated compound capable of generating two epoxide groups in the presence of the alkali metal hydroxide or a mono- or di-quaternized cationizing agent;
- b. immersing the pretreated fabric in an aqueous bath comprising a reactive and a disperse dye at a temperature in the range of from 80 to 100° C. for a time of from 30 minutes to 60 minutes, where the aqueous bath is at a pH of from 6-7
- c. washing the dyed fabric with water at a temperature 30° C. to 40° C. for at least 20 minutes
- d. washing the dyed fabric resulting from step c. with water at a temperature of 50 to 70° C. for at least 10 minutes;
- e. washing the dyed fabric resulting from step d. with an aqueous solution comprising from 0.5 to 2 grams per liter soap, 1 to 3 grams per liter 50% hydrogen peroxide, and 1 to 3 grams per liter sodium hydroxide at a temperature in the range of from 70° C. to 90° C. for at least 10 minutes;
- f. washing the dyed fabric resulting from step e. with water at a temperature of 50° C. to 70° C. for at least 10 minutes;
- and
- g. washing the dyed fabric resulting from step f. with an aqueous solution at a pH in the range of from 4 to 6 and at a temperature in the range of from 30° C. to 40° C. for at least 10 minutes.
A method for dyeing a fabric which has been cationized and which fabric comprises polyester fiber and natural fiber wherein the method comprises the steps of:
- a. immersing the cationized fabric in an aqueous bath comprising a reactive dye and a disperse dye at a temperature in the range of from 80° C. to 100° C. for a time of from 30 minutes to 60 minutes, where the aqueous bath is at a pH of from 6 to 7;
- b. washing the dyed fabric with water at a temperature of from 30° C. to 40° C. for at least 20 minutes;
- c. washing the dyed fabric resulting from step b. with water at a temperature in a range of from 50 to 70° C. for at least 10 minutes;
- d. washing the dyed fabric resulting from step c. with an aqueous solution comprising from 0.5 to 2 grams per liter soap, 1 to 3 grams per liter 50% hydrogen peroxide, and 1 to 3 grams per liter sodium hydroxide at a temperature in the range of from 70° C. to 90° C. for at least 10 minutes;
- e. washing the dyed fabric resulting from step d. with water at a temperature in the range of 50° C. to 70° C. for at least 10 minutes;
- and
- f. washing the dyed fabric resulting from step e. with an aqueous solution at a pH in the range of from 4 to 6 and at a temperature in the range of from 30° C. to 40° C. for at least 10 minutes.
Dependencies are inferred from the claim text.