How to Exhaust Dye Cotton or Rayon Using Orco Reactive BF-Series™ Dyes


  1. Properly prepare substrate. Goods should have good absorbency, wet-out, and contain no residual chlorine, peroxide, or alkali.  If the substrate being processed is rayon, do not exceed a pH of 9 as it will cause saponification of the fiber.
  2. At 120°F(50°C) , add 1.0% owf Orconol CHSA Conc™, X g/L(oz/gal) of common salt* or Glauber’s salt as prescribed on chart shown below, 067 oz/gal(0.5 g/L) sodium hexametaphosphate, 1.0% owf Orcotol MN Powder™(for closed machines such as jets), and predissolved BF-Series™ reactive dye properly prepared.  Run for ten minutes.

% owf dyes                          oz/gal(g/L)

to 0.75                                   2.7-6.6 (20-50)

0.75-2.00                              10        (75)

2.01-4.00                              13.3     (100)

4.01+                                     13.3     (100)

  1. Bring dyebath to 140°F(60°C) at a rate of 1-3°F/minute.
  2. Add prescribed amount of soda ash as shown in chart below. Soda ash    may be added in portions to promote improved leveling.  Run for 10-20 minutes.
  3. Add prescribed amount of Caustic 50% as shown in chart below. This will maximize the yield of the dye.  Run for 30-40 minutes.

% owf dyes                                          Soda Ash oz/gal(g/L)                        Caustic 50% oz/gal(g/L)

10:1           20:1                                    10:1           20:1

to 0.75                                                   0.67(5)    0.67(5)                                  —                      —

0.75-2.00                                              0.67(5)       0.67(5)                               .13(1.0)    .07(0.5)

2.01-4.00                                              0.67(5)    0.67(5)                                 .27(2.0)    .13(1.0)

4.01+                                                     0.67(5)       0.67(5)                               .40(3.0)    .20(1.5)


  1. After dyeing, overflow rinse until clear using cold water. Drop bath.


  1. In new bath at 100°F-120°F(38°C-50°C), neutralize with 1.0 g/L(0.133oz/gal) Acetic Acid 56%(or more if necessary for neutralization of residual alkali) for 15 minutes. Drop bath.


  1. Soap at boil using 0.25% owf Orcopon KP™ for 10-15 minutes. Warm rinse at 140°F-175°F(60°C-80°C).  Cold rinse.


*  For shades using Orco Reactive™ Blue RW Special use Glauber’s salt in place of common salt  and use ½ the amount. Glauber’s Salt is recommended in jet-dyeing machines as common salt may cause pitting in machinery.

** For shades using Orco Reactive™ Turquoise RP, raise dyebath temperature to 165°F(75°C).

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