How to graft printing on real silk

The silk-based protein fiber, when treated with sulfamic acid, reacts with the amino group of sulfamic acid at the terminal carboxyl group to form a sulfonate group, thereby giving the silk fiber a good dye-resistance against acid dyes, and increasing its resistance to salt The dyeability of the dye.

The graft printing method is a silk twill scouring, bleached and treated with 1 g/L acetic acid and 2 g/L nonionic surfactant Detergent JU, printed in white pulp containing sulfamic acid, urea and starch syrup, 80 °C drying 15min, steaming or baking, washing, dry.

The above sulfamic acid grafted silk is dyed with an acid dye or a basic dye. The dyeing methods of acid dyes were as follows: dye 1%, acetic acid 1.5%, Yuanmingfen 10%, bath ratio 1:80, temperature rise to 95°C for 30 minutes, and dyeing for 45 minutes. The basic dyeing method is: dye 1%, acetic acid 2%, sodium acetate 1%, surfactant 0.5%, bath ratio 1:80, dyeing temperature, time and acid dye staining.

The method of coloring and dyeing is to print real silk with printing paste consisting of dye, sulfamic acid, urea and pulp. The post-treatment is carried out in the same manner as described above, and further dyed with an acid dye or a basic dye.

Can also be grafted to sulfaal acid silk, with a color paste containing acid dyes or basic dye cover printing. After drying, it was treated with a high-temperature steamer at 130°C for 45 minutes, washed with water, and dried.

As a result, the grafted silk fabric can have good anti-dyeing effect on acid dyes and a deepening effect of cationic dyes, and multi-color printing effect can be obtained with anti-dyeing printing, and a "stereoscopic" printing effect can be obtained on cationic dyes. Grafting silk fibers dyed with cationic dyes, the light fastness has been greatly improved, basically up to the acrylic level.

The relevant parameters are discussed below:

(1) Concentration effect of sulfamic acid: As the concentration of sulfamic acid in the graft printing paste increases, the adsorption amount of the acid dye decreases and the adsorption amount of the basic dye increases. For example, when the amount of sulfamic acid is 0 g/L, the adsorption amount of CI Acid Red 85 is 7.71 g/kg, and that of CI Basic Violet 14 is 6.23 g/kg; when the amount of sulfamic acid is 1 g/L, CI Acid Red 85 is adsorbed. The amount was 1.35g/kg, CI basic violet 14 was 7.63g/kg; when the amount of sulfamic acid was increased to 5g/L, the adsorption amount of CI Acid Red 85 was reduced to 0.050, and CI Basic Violet 14 was increased to 8.57g/ Kg. The composition of printing paste is: urea 2g, starch slurry 25g, total 40g, steamed at 130°C for 40 min.

Sulfamic acid-grafted silk fabrics have increased affinity for salt-based dyes and have reduced affinity for acid dyes. The results of the dyeing with acid dyes showed that the dyeing resistance was good, but there was some contamination. On the other hand, when the surface of the silk fabric was dyed with a basic dye, the adsorption of basic dyes on the grafted real silk was 1.37 to 1.53 times greater than that of the ungrafted silk fabric.

(2) Effects of steaming and curing: In steaming and baking, sulfamic acid migrates from the slurry to the fiber and reacts with the fiber. Compared with baking, steaming temperature is low and the effect is good. This is because when steaming, there is a lot of water and it takes a long time. At 140-145°C, the silk yellowed, with the increase of temperature, the yellowing was remarkable, and when the temperature was above 170°C, the silk began to char. Therefore, steaming is more suitable for the sulfamic acid treatment of silk than baking. Steam temperature is generally suitable for 120 ~ 130 °C, time is 20 ~ 30min.



Source: China Washing & Dyeing Industry Information Center