Brushed stretch denim fabric and process therefor: indigo dyeing

• US 4,283,194 A
• Filed: 08/20/1979
• Issued: 08/11/1981
• Est. Priority Date: 08/20/1979
• Status: Expired due to Term

• Current Assignee: Burlington Industries LLC
• Original Assignee: Burlington Industries LLC
• Inventors: Teague, Edward W., Hance, Max H., Neal, Carl R.
• Primary Examiner(s): Clingman, A. Lionel
• Application Number:
  US06/068,277
• Time in Patent Office: 722 Days
• Field of Search: 8/653, 8/494, 8/653, 8/532, 8/918
• US Class Current: 8/494
• CPC Class Codes: D06P 1/228 Indigo
• CPC Class Codes: Y10S 8/918 Cellulose textile
• CPC Class Codes: Y10T 428/2395 Nap type surface

Abstract

The invention concerns an improved stretch denim fabric dyed with hot indigo dye and strengthened by incorporating a filament filling yarn without obtaining whitening or crease wear problems. The invention also concerns a novel hot indigo dyeing process as well as an improved finishing process for this fabric.

Claims

1. An improved indigo dyeing process comprising the steps of preparing an aqueous solution of a completely reduced indigo dye, caustic and hydrosulfite having an oxidation reduction potential ranging from about 850 mv to about 1200 mv, forming a dye bath and heating the dye bath to a temperature within the range of about 130°

F. to about 190°

F., and while maintaining a substantially constant level of indigo dye concentration and substantially the desired oxidation reduction potential of the aqueous solution, immersing a relatively dry cellulose-containing textile product into the aqueous solution for a period of time sufficient to substantially penetrate the textile product.

2. A process for effecting the penetration of a cellulose-containing textile product with an indigo dye comprising the steps of preparing an indigo dye bath comprised of a reduced indigo dye, caustic and hydrosulfite, holding the indigo concentration substantially constant, maintaining the oxidation reduction potential of the dye bath within a range of from about 850 mv to about 1200 mv, heating the dye bath to a temperature within a range of from about 130°

F. to about 190°

F., and immersing a relatively dry textile product in the heated dye bath for a period of time sufficient to substantially penetrate the textile product.

3. A process for dyeing a cellulose-containing textile product with indigo dye wherein the indigo dye penetrates the textile product comprising the steps of scouring the textile product at a temperature ranging from about 180°

F. to about 210°

F., rinsing the textile product in water at a temperature ranging from about 110°

F. to about 180°

F., drying the textile product so that it has a moisture content ranging from about 1% to about 6%, immersing the textile product in a bath of aqueous indigo dyestuff solution having an oxidation reduction potential ranging from about 850 mv to about 1200 mv and heated to a temperature ranging from about 130°

F. to about 190°

F., reoxidizing the indigo dye, rinsing the textile product in water ranging in temperature from about 80°

F. to about 140°

F., and drying the textile product.

4. A process as in claim 3 wherein the textile product is comprised of a plurality of individual ends of yarn.

5. A process as in claim 3 wherein the textile product is a fabric.

6. A process as in claim 3 wherein said dyeing process is a continuous process.

7. A process as in claim 3 wherein the indigo dye bath is composed of a dyestuff mixture including a completely reduced indigo dye, caustic and hydrosulfite, the mixture having an oxidation reduction potential ranging from about 900 mv to about 1000 mv.

8. A process as in claim 3 wherein the preferred oxidation reduction potential ranges from about 950 mv to about 960 mv.

9. A process as in claim 8 wherein the preferred temperature for the indigo dye bath ranges from about 130°

F. to about 190°

F.

10. A process as in claim 8 wherein the preferred temperature for the indigo dye bath is 160°

F.

11. A process as in claim 7 wherein the dyestuff mixture is continuously fed into the dye bath during dyeing to maintain a substantially constant indigo concentration.

12. A process as in claim 3 wherein the textile product is immersed for a period of time ranging from about 5 seconds to about 20 seconds.

13. A process as in claim 12 wherein the textile product is immersed for a period of about 8 seconds.

14. A process for finishing a stretchable fabric woven from cellulose-containing warp yarns dyed with a hot indigo dye solution that penetrates substantially there through, and stretch filling yarns, comprising the steps of washing the fabric in a series of baths maintained at about 200°

F., drying the fabric and applying a finishing and tinting solution to develop the desired hand to tint the filling yarns, thereafter drying the fabric to a moisture content of about 6% to about 8%, then stretching the fabric to an extent ranging from about 0% to about 5%, and shrinking the fabric to an extent ranging from about 8% to about 10%.

15. The process as in claim 14 further including the steps of brushing the fabric to raise a nap on the fabric face and thereafter compressively shrinking the fabric to an extent ranging from about 2% to about 8%.