Vat dye is a major dye dyeing for dyeing of current color fabric cotton yarn. After dyeing, the yarn is not only bright in color, but also very good. Most of the daily exposure is above 6 or more, and some varieties are as high as 8. Therefore, all color woven fabrics such as cooking, bleaching, silk, and thermal shapes can be sorted out. There are many varieties of reduced dyes. According to their chemical structures, they can be divided into pupae and crickets. The reducing dyes used for yarn dyeing are mostly based on mackerel.
1. Basic way to dye
The total color sodium salt of the dye is easily adsorbed by the cotton yarn, and the upper dye rate is fast. Therefore, the uniform dyeing is poor, and the alkali and insurance powder required for the dye baths are also higher. During the dyeing process of the yarn, 1g -cricket reduction dye often consumes 5 ~ 6g of alkaline and insurance powder in the dye bath. The dyeing rate is conducive to the diffusion of the internal dye to the fiber and improves the effect of the uniform dye. The dosage is 0.2 ~ 0.5g/L. The dyeing time in daily dyeing is generally 15 ~ 20min. To improve the uniformity of the color yarn and the staining fastness, the dyeing time can be appropriately extended to 20 ~ 30 minutes. For a small amount of reducing dye that needs to be dyed at lower temperatures, the sodium salt of the hidden color is adsorbed by the yarn, and it is not easy to oxidize in the air. It can choose the appropriate oxidation method and oxidant to promote the conversion of dye hidden colors and hair color. Then use water to wash or dilute acid solution to remove residual alkali agents and impurities. Finally, soap and water washing are performed to complete the yarn dyeing. Due to the different dye dyes that have different dyeing properties, when the yarn dyeing, the difference between the amount of alkali, insurance powder, the amount of the auxiliary, and the dyeing temperature, time and other conditions of the gauze Essence
2. Darum process and operation
(1) Handmade yarn dyeing. When the handmade yarn is dyed, the white yarn should be continuously lifted 7-9 times (about 5 minutes) after the tank of the white yarn, but the interval is evenly consistent.
(2) Deductive gauze dyeing. Use a reciprocating gauze to dye the yarn. When the lower cylinder, the two people are lifted in turn. The machine should be in a state of only swinging. When the white gauze is soaked by the dyeing liquid (equivalent to the time to swing 3 times), it can only be possible. Roll the screens. Some well -dye -in -laws require high -silk yarn. It also needs to be manually operated in the white gauze cylinder to swing the yarn to the left and right, and make it rolling continuously for 4 ~ 5 minutes, and then stop operation. Perform, change every 1min in the future and fall. After the dyeing is 10min, it will be changed every 2 to 3 minutes. When you fall, you must re -immerse the color gauze of about 1/3 of the exposed liquid surface to the dye solution to prevent early oxidation and produce deep -shaped head color flowers.
(3) High -temperature and high -pressure dye dyeing machine dyeing. The tube gauze staining can be promoted by the circulating pump in the positive and negative direction. Each time the time is changed to the flow, the spray from the center to the surroundings (that is, the positive cycle), the time is 0.5 ~ 1.5min, and then spray it from the surrounding area to the center to spray the liquid to the center. (That is, anti -loop), the time is 4.5 ~ 3.5min. If the twisted gauze is stained, it can always be stained with a positive circulation liquid, which is not suitable for reverse circulation. If the dyeing fluid circulates from the surrounding area to the center, the upper density of the twisted gauze is getting smaller and smaller, and the lower density of the lower layer is getting more. The larger the short circuit of the liquid flow, the gauze dyeing is not transparent, causing defective diseases such as white core, white spots and light spots.
Before the yarn dyeing, the quality of the white gauze should be inspected. The appearance of the white gauze is clean and non -spots, and it is neutral. The stacking time must not exceed 8 hours, and it must be covered with a wet cloth. When the yarn dyeing is installed, it should be filled according to the requirements of different dye equipment to prevent staining defects caused by improper yarn loading.