Application Practice of Potassium Permanganate White-out Printing Thickener

When the corduroy fabric is dyed with sulphur dyes and the denim fabric is dyed with indigo dyes, the oxidizing agent sodium hypochlorite or potassium permanganate can be used as a whitening agent for white printing. This has the advantage of a simple and cost-effective reduction compared to using a reducing agent as a whitener. The key is to have a good thickener, it must use less, does not react with the oxidant, made the slurry rheology is good, the stability is good, the quality of the pull-out printing is good, and the price is cheap.

Zhejiang Yuxi Xuxiao Auxiliary Factory of Cixi City cooperated with related universities and research institutes. After many years of research, it successfully developed S88-1 thickener for sodium hypochlorite and S88-2 thickener for potassium permanganate. After many years of use by many factories, they have obtained very good economic benefits. Sodium hypochlorite paste made with thickener S88-1 is suitable for rolling machines. Potassium permanganate whitening paste made with thickener S88-2 is suitable for rotary screen, flat screen, rolling machine and hand. The potassium permanganate pull-out printing process is briefly described as follows:

First, color dye selection

Satin dyes are used for the dyeing of corduroy fabrics and indigo dyes are used for denim dyeing.

Second, the applicable models:

Rotary net, flat net, rolling machine, manual apply.

Third, the process flow:

Retort bleach → vulcanized (or indigo) dyeing → Drying → Pull white printing → Ventilation → Acid reduction → Wash → Soft → Dry

Fourth, process requirements:

1, decoction bleaching in the premise of satisfying the dyeing process conditions do not have to be too strong.

2, dyeing according to the conventional process, requiring drying.

3, rotary screen pull white printing process:

(1) According to the pattern requirements, the rotary screen generally uses 80-120 meshes; (2) Speed: 40m/min - 50m/min; (3) Drying room temperature: 100°C-110°C; Should not be too high, pay attention to the clean room to prevent fire.

4, after the release of cloth in a timely manner, hot cloth can not be stacked long-term. The ventilation is carried out on the air permeable frame, so that the oxidant and the dye are fully applied, and the speed of the penetration of the wind is required to be constant, so that the frost carving effect is uniform.

5, pickling reduction and washing soft:

(1) promptly pickle reduction after ventilation to avoid excessive oxidation; (2) with a good reduction liquid dropping into the pickling tank through the high slot, and maintain a constant level; (3) under the conditions of the reduction, the concentration of oxalic acid solution and The temperature can not be too high (60-70 °C can be used, can be 2-3 tanks; and interconnected, the acid from the last tank to join (the purpose of adding acetic acid is to stabilize the acid, to prevent fiber damage); (4 ) Acid residues remaining on the surface of the cloth are washed with soda ash to prevent fiber damage; (5) Washing tank arrangement; Pickling → Washing → Neutralization → Soaping → Washing → Softening.

Fifth, process prescription:

(a) pull white pulp:

1, recipe:

Thickener S88-2 8kg

Potassium permanganate 8kg

Water 100kg

2, pulping method:

(1) Prepare 100 kg of hot water at a temperature higher than 60°C in a plastic bucket, place 8 kg of potassium permanganate, and stir for a while to dissolve.

(2) Add thickener S88-2 8kg to the plastic bucket. When the above potassium permanganate solution is cooled to about 50°C, use wood pulp first, and then slowly pour in high manganese with a beater. The potassium acid solution is slow and fast first, so that it is always in a thick state (when the previous solution is not completely mixed with the thickener, it cannot be rushed to add liquid; late attention should not be given to undissolved potassium permanganate crystals).

(3) The above-mentioned pre-paste is left to stand for more than 2 hours to allow it to thicken sufficiently, and is naturally cooled to room temperature in order to prevent the photo-resist from corroding. Before the machine according to the flower type requirements, add potassium permanganate solution under stirring, adjust the consistency and filter after use.

Source: Dongguan Printing