How to color cotton fabric?

How to color cotton fabric?

The cotton plain introduced here includes twill type, poplin plain type. And elastic and non - elastic varieties. All cotton fabric dyeing to go through pre-treatment, dyeing, finishing, finished product inspection four processes. In the pre-processing part, pay attention to wrapping the edge of the joint of the fabric, because the following process is basically long car production. The consequence of not wrapping the edge is that if the joint of the fabric is broken in the steam box in the production process, it will be very troublesome.

Wool burning, cotton fabric need to be fired to remove the length of hair on the yarn, thin fabric fire burning on the line, such as 7*7 yarn card need to add iron plate (also called cylinder) to burn fresh.Desizing, remove the size on the warp when weaving, thin fabric can be removed by direct desizing machine, after heavy and elastic fabrics had better choose the method of cold pile desizing, enzyme desizing will be more thorough.

Finalize the design, the pre-processing finalize the design only for the elastic fabric, and is the size of the door is different after the bleaching hair, less than the finished door to finalize the design, the pre-processing finalize the design can not be greater than the finished door, it is best to be close to and equal to the finished door.

Bleaching, as long as pay attention to the unity of whiteness on the line, cotton generally choose hydrogen peroxide bleaching, also called oxygen bleaching.

Mercerization, mercerization should pay attention to the door, the door mercerization is too small, do not open, after finishing is not pulled open, too big, back and can not come back, mercerization is the best control and finished door width, so when dyeing will shrink some, after finishing in open, pre-shrink just control. (Note: dyeing vulcanized fabric before treatment can not mercerization, because there is alkali in mercerization, dyeing vulcanization will occur fabric flowers) mercerization end, if there is a requirement for grinding requirements, then grinding, the end of the pretreatment. Attention points: thin and thin fabric, grid fabric pay attention to control weft Angle, curling, etc., when large grid hair, pay attention to the direction of the fire, can not burn through, that is, the fire should not be perpendicular to the fabric, so as not to damage the strength.

The finished product is black. Pay attention to baking fiber after singeing. Dyeing part of cotton fabric dyeing is now based on long car continuous rolling dyeing, cylinder dyeing is no longer the mainstream, not introduced here. Dyeing is a simple process, because only through a rolling car is ok, but it is also the most difficult a process, because of the color of the dye control in addition to the known, there are many unknown things inside, such as the stability of the dyes in different temperature, control of the steam car rolling pressure control, etc., is a very fine work.

The dyed long cart is divided into two parts, the front cart is dyed and the rear cart is fixed. Dyeing method according to the selection of different types of dyes and differences, dyes are generally active, silin, vulcanization, coating. They each have advantages and disadvantages, generally look at the color of the guests, and can not be replaced with each other. Among them, shilin color fastness is the best, but the price is expensive, not suitable for dark color, light color is not bright enough. In addition to dyeing dark will increase the cost, there are dark dyeing relative reactive dyes teach difficult to control, prone to fabric flowers and other phenomena. The active color fastness is worse than the shilin, but the light color is more gorgeous, the dark color is easy to control, and the cost is correspondingly less. Vulcanization worst, color fastness is not good, banned AZO is not standard, but now there is a liquid vulcanization (also called water vulcanization) banned AZO can be standard, but the price is close to Shulin, dyeing is not easy to control is not popular, only a few people pursue its fading effect and use. Paint is not comparable, its fading is very serious, is the best choice for clothing after washing the pursuit of fading effect. Can be used with shilin, active flexible application, get different washing effect (general shilin or active base, coating cover face, can solve the single dye coating white point problem, the cost increases accordingly).

Activity, shilin and vulcanization of the dye before the car is basically the same, to say the difference, is infrared pre-baked open a group, two groups or not open. The car behind was completely different. The active use of salt and soda solid color, shulin using hydrogen peroxide reduction solid color (so shulin is also called VAT dye), vulcanization to high temperature cooking solid color, water temperature must be more than 95 degrees. After dyeing the coating according to the color fastness of fading requirements to determine whether to bake solid color. Bake at about 195-210 degrees. Dyeing can not be 100% good, repair color, stripping color is inevitable. Minor adjustments such as a shallow coat of paint, deep with soda wash. If it's too deep, only peel it off and redye it or go back to black. After finishing part because cotton fabric in the pre-treatment and dyeing of a lot of long car, warp length. Zonal shrinkage, feel is rough, after finishing is to solve these problems. Softness and tensioning, softness and tensioning should be carried out separately if there is no setting machine, softness first to improve the feel, before tensioning. Pull out the shrinking latitudes. There is a molding machine can be accomplished at one go. But the stretchcloth is best to finalize the design process.

Pre-shrink, the production process of the elongation of the fabric through the pre-shrink machine rubber blanket, the principle of heat expansion and cold contraction of the fabric to clothing cutting within the allowed range, elastic fabric control at 3%, 5% weft. The control of unelasticity is 3% warp and 3% weft. According to the requirements of the guests, we should pay attention to whether the twill needs to be pulled and whether the weft of plain weave is up to the standard (the weft of plain fabric should be controlled within 3%, and the weft of checked fabric should be controlled and it is best to be close to 0). Factories can also according to their own equipment, but also air soft washing fabrics. There are extra costs, of course.

After finishing the finished product inspection, the fabric shall be tested for shrinkage, color fastness, and other internal indexes required by the customer. If the color indexes are qualified, the finished product can be inspected. General customers tend to agree with the four-point standard inspection of the United States (China's national standard is similar, but the defects are too fine to be easy to remember and use), so qualified products can be packaged. At this point, the dyeing process is over and the fabric can be sent to the garment factory.