TREATMENT OF FIBERS FOR IMPROVED DYEABILITY
The present technology is directed to devices and methods for dyeing a fiber, including pretreatment of the fiber before contacting it with a dye. The present technology is also directed to methods of improving the dyeability of a fiber, as well as increasing the efficiency of the dyeing process and minimizing waste and loss of dye.
1 . A method of treating a cellulose fiber, the method comprising the steps of:
(a) obtaining a sample of the fiber;
(b) contacting the sample of the fiber with a solution, the solution comprising:
i. about 0.5 to about 15 g/L of a wetting agent;
ii. about 5 to about 300 g/L of an alkaline composition; and
iii. about 5 to about 200 g/L of an ammonium salt; and
(c) providing for the solution to react with the fiber.
2 . The method of claim 1 , wherein the wetting agent comprises a nonionic surfactant.
3 . The method of claim 1 , wherein the wetting agent comprises an anionic/nonionic blended surfactant.
4 . The method of claim 1 , wherein the alkaline composition comprises sodium hydroxide or potassium hydroxide.
5 . The method of claim 1 , wherein the ammonium salt comprises 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC).
6 . The method of claim 1 , wherein step (b) comprises immersing the sample of the fiber in the solution.
7 . The method of claim 6 , wherein step (b) comprises immersing the sample of the fiber in the solution for a period of about 10 to about 60 seconds.
8 . The method of claim 1 , wherein step (b) comprises contacting the sample of the fiber with a saturation pad that contains the solution.
9 . The method of claim 1 , wherein step (c) comprises removing the sample of the fiber from the solution and storing the sample of the fiber in a closed container for a period of about 8 to 24 hours.
10 . The method of claim 1 , further comprising the step of:
(d) contacting the fiber with an acid in an amount sufficient to maintain a pH of less than about 7.0 on the surface of the fiber.
11 . A method of minimizing the amount of dye required to dye a fiber to a desired color, the method comprising the steps of:
(a) treating the fiber by contacting it with a solution comprising a wetting agent, an alkaline composition and an ammonium salt;
(b) removing the fiber from contact with the solution;
(c) storing the fiber in a closed container for a period of about 8 hours to about 24 hours;
(d) removing the fiber from the closed container;
(e) contacting the fiber with a dye until the fiber reaches a desired color; wherein the fiber is dyed to the desired color using up to 50% less dye by volume than required for an untreated fiber.
12 . The method of claim 11 , wherein after step (d), the fiber is contacted with an acid solution in an amount sufficient to maintain a pH of the fiber of below about 7.0.
13 . The method of claim 11 , wherein the fiber is dried between steps (d) and (e).
14 . A method of optimizing the retention of a dye in a fiber, the method comprising the steps of
(a) treating the fiber by contacting it with a solution comprising a wetting agent, caustic soda and an ammonium salt;
(b) removing the fiber from contact with the solution;
(c) extracting the fiber to a wet pickup of 65-150%;
(d) storing the fiber in a container for a period of about 8 hours to about 24 hours;
(e) dyeing the fiber;
wherein after step (d), the fiber is contacted with an acid in an amount sufficient to maintain a pH of below about 7.0.