1. Dyeing and sampling: dye:2%(o.w.f) (commonly choose red, black and orchid); fabric : preliminary treated woven plain. Dyeing agent is according to the dyeing and sampling method. If it is applicable test in the factory, we can choose fabric with the lower fastness in the workshop.
2. Fixing: fixation process: fixing agent: 2%-4%(o.w.f) bath ratio:1:20, temperature:
40℃～60℃(according to the actual conditions in the fabric or the suggested using index of fixing agent); time: 20min; PH value: some fixing agent need correct PH value to ensure the best fixing result and lowest colored light; Operation: immersed the dyed and washed fabric into the fixing liquid. And keep it 20 min and take out, drying in oven and for test.
3. The fixation result evaluation
①the color change in hue: compare the in-fixing fabrics and the dyeing-fixing agent with the Grey scale color assessment card and grade. And keep fixing fabric as standard, and note the tonal change. Usually n the dyeing plant, the experimental sampling workers look according to his experience and check the color change. We also can use a computer color matching color measurement, using dyed fabrics as the prototype, fixing color fabric as spline, and measure the glossiness change of solid color fabric.
② water fastness: test the fabric color fastness according to the following method.Take a piece of 250 px x 100 px dyed fabric, stitching a piece of the same standard of white cloth on the front area, immersed into 50ml distilled water, Keep (30±5)℃，6 hours later,take out and squeeze to drive out the water. Separate the sample and the white cloth, and dry in room temperature or below 60℃. And test the white cloth’s color fading grade and color staining grade using color fading and change sample card and Grey scale for staining. Please check the gb/t 5713—1997 “the color fastness test and color fastness to water test of fabric”Colorfastness to Water standard. This method is as follows: wet the sample and white cloth using distilled water, clamp between syg 631 and perspiration fastness tester,bearing 12.5pa pressure, move the superfluous water, and put the compound sample into the incubator（37±2）℃ for 4hours
③ Soaping agent fastness: test the fabric color fastness according to the following method, and compare the coefficient before and after the fastness: Take a piece of 250 px x 100 px dyed fabric, stitching a piece of the same standard white cloth on the front area, immersed into a 250ml beaker of 4g/l soap flake and 2g/lsodium carbonate solution, and then put it into 60℃ water bath, stirring a little bit, and make it wet. keeping 30 min(stirring vigorous at 10min , stirring 30 times every time).