Method for dyeing a nonwoven fabric and apparel formed therefrom
View Patent ↗A method is provided for dyeing a nonwoven fabric comprising a blend of fibers to a single color shade. The method includes selecting a nonwoven fabric formed of a blend of polyester and nylon fibers, where the polyester fibers comprise about X percent by weight of the fabric and the nylon fibers comprise about Y percent by weight of the fabric. A single bath is formulated having about X percent by weight disperse dye and about Y percent by weight acid dye, adjusted for the desired color shade/depth. The nonwoven fabric is then dyed to obtain a dyed fabric having a single color shade of at least Grade 4 when measured in accordance with AATCC Test Method 153 and a colorfastness of at least Grade 4 when measured in accordance with AATCC Test Method 61.
1. A method of dyeing a nonwoven fabric comprising a blend of fibers to a single color shade, the method comprising:
selecting a nonwoven fabric formed of a blend of polyester and nylon fibers, the polyester fibers comprising an amount of about X percent by weight of the fabric and the nylon fibers comprising an amount of about Y percent by weight of the fabric;
formulating in a single bath an amount of dye comprising about X percent by weight disperse dye and about Y percent by weight acid dye, wherein the percentage by weight of each type of dye is equal to the percentage by weight of each type of fiber, the amount of each dye adjusted for the desired color shade; and
dyeing the nonwoven fabric to obtain a dyed fabric having a uniform color shade throughout of at least Grade 4 when measured in accordance with AATCC Test Method 153 and a colorfastness of at least Grade 4 when measured in accordance with AATCC Test Method 61.
2. The method of claim 1 further comprising the step of adjusting the pH of the dye bath to a value of less than 4.0.
3. The method of claim 2 wherein the pH is adjusted to a value of less than 3.5.
4. The method of claim 3 wherein the pH is adjusted to a value of about 3.3.
5. The method of claim 2 wherein the pH of the bath is adjusted by the addition of an acidic material.
6. The method of claim 5 wherein the acidic material is a citric acid added in an amount of between about 0.1 percent and 1.0 percent by weight of the nonwoven fabric.
7. The method of claim 6 wherein the citric acid is added in an amount of about 0.3 percent by weight of the nonwoven fabric.
8. The method of claim 1 wherein the dyed fabric has a crock rating of at least Grade 4 when measured in accordance with AATCC Test Method 8.
9. The method of claim 1 wherein the nonwoven fabric comprises about 70 percent polyester fibers.
10. The method of claim 1 wherein the nonwoven fabric is dyed at a temperature between about 250 degrees Fahrenheit and 270 degrees Fahrenheit.