In the after-treatment process of fabric, the washing process is now widely used in many clothing because it can get some special effects and increase the design comfort and beauty of clothing.
Clothing washing process refers to the semi-finished clothing through some manual processing and mechanical washing methods, the use of some washing solvents to make the clothing reach the size of the stable and soft touch and special color and texture effects. Here is a look at the common washing process of denim:
1, Enzyme wash: enzymes, can be used to degrade cellulose in cotton fibers. Because the color of the denim is actually attached to the outer layer of the yarn, the enzyme wash water can wash off the fiber and the indigo dye attached to it. When the desired color is obtained, the enzyme washing water can be stopped by changing the alkalinity of the water or increasing the water temperature. Then the next step is rinsing and softening. Enzyme washing is milder than stone washing because no sharp stones are used in the enzyme washing process. Denim washed by enzyme has uniform color, soft feel and is suitable for home textiles and clothing.
2, Stone wash: stone wash is through physical methods to fade denim, and increase the color contrast effect. A 30-yards-long, 60-inches-wide roll of cloth is placed in a 200-pounds washing vat with pumice stone , then washed by stone mill (it works best when 35% of the vat capacity is used). In the washing vat, denim and stone mix and roll, rubbing each other, the length of rolling time determines the depth of color after washing denim, the longer the washing time, the lighter the color, the stronger the color contrast effect. Denim is washed and then rinsed, soft treatment and drying. The soft denim with rich color layers after stone mill washing has become the preferred fashion fabric for home textile industry and clothing industry.
3, Stone mill washing with enzyme: In the process of washing, pumice stone and enzyme are used to make denim obtain nostalgic effect. First, only the pumice stone and fabric are put into the washing tank, and then the enzyme is put into it in the next step, and the pumice stone and fabric are rolled together until the natural nostalgic effect is produced. Blue denim is most commonly washed in this method.
4, dry grinding (stone mill) : also known as stone mill, the use of special stir-frying machine, the model is like no shell only rotary cage washing machine. Its principle is to put the pumice before frying machine, pouring into the dilution water drift (sodium hypochlorite solution), uniform absorbed through rotating the pumice, put in cowboy clothing for rotation, through the wall friction between pumice, clothing, machine, partially worn off on the surface of the garment dye, at the same time of pumice ash, covered the surface of a garment The bleaching water contained in ash and slag will destroy the indigo or vulcanized dye on the clothing through oxidation, and play a certain role in stripping and bleaching.
* The specific operations are as follows: put the pumice stone and rubber ball in the frying machine, pour diluted water, turn a few minutes to make the pumice stone evenly absorbed → Put into the denim clothing, grind for about 20 minutes → Take out an object in the washing machine with clean water to wash off the ash on the clothing → Change the water to add "sodium thiosulfate" dechlorination → Change the water to add caustic soda, whitening agent and other yellow and brightening → water washing → softening agent.
5, Sand washing: The method is to use a row of horizontal roller, the roller can be wrapped with sandpaper, or the use of chemical treatment of abrasive. Denim is placed on the roller, and the protruding part is frosted. This after-treatment will fade part of the denim and produce a velvet feel on the surface of the denim, giving it a soft, delicate hand feel. The sand washing method can also make the jeans produce wrinkles, cat whiskers and other fashionable appearance effects.
6, Hand grinding (hand sanding) : also called Hand grinding, which is relative to the machine grinding, the common way has the hand brush grinding method, sandpaper grinding method and knife grinding method ,later break away from the original intention, it became a general term for many small processes, such as the ordinary cat is a kind of hand grinding, it is just through mechanical equipment ground into the shape of the cat beard. Hand grinding generally refers to the processing technology of physical damage and degradation of fibers on the surface of clothing through sandpaper, blade, small grinder and other tools.
7, Mechanical grinding: use electric brush or grinding wheel directly on the surface of the fabric for grinding treatment, so that the surface of the clothing to achieve local whitening effect, suitable for the front leg, knee, rear hip and other large area of position. This process usually uses a trouser blower (such as an upright trouser grinder) to inflate and fix the trousers using an inflatable model "glue wave". Then use electric equipment to grinding, and finally use hand to trim pants seam edge, bag edge, trouser bottom fold and other small parts, in order to achieve a special effect.
8, Sandblasting: it is powered by compressed air, with a special spray cylinder high-speed injection of emery to the surface of jeans, using the grinding effect of emery to form the effect of wear and fade on the surface of clothing. Emery can be recycled and added to the sand cylinder for further use. The working environment of sandblasting is relatively harsh, and the operator needs a full set of dust-proof equipment.
9, Bleach washing: In order to make the clothes have a white or bright appearance and soft feel, it is necessary to rinse the clothes, that is, after ordinary washing water, the temperature rises to about 60 ° C, according to the depth of the bleaching color, add an appropriate amount of bleaching water (sodium hypochlorite solution) rinsing for a certain time, then check and confirm with sample, and the bleaching of the clothing is completed, and the residual chlorine in the water is neutralized by adding sodium hypochlorite, so that the bleaching is completely stopped. After the water, add detergent, fluorescent whitening agent, hydrogen peroxide, etc. to the water temperature of 50 ° C to do the final washing to neutralize the PH value and fluorescent whitening, etc., and finally perform soft treatment. It should be noted that during operation, the direction of adding bleach should be consistent with the turn of the cylinder to avoid dilution of bleach. the bleach washing can be divided into oxygen bleaching and chlorine bleaching. Oxygen bleaching is the use of hydrogen peroxide bleaching, generally bleached cloth surface will be slightly red. Chlorine bleaching is bleaching with sodium hypochlorite. Chlorine bleaching has a rough fading effect and is used for rinsing indigo denim.
10, Resist-dye: cowboy often to resist-dye, commonly used dyes are VAT dyes, sulphur dyes, reactive dyes, direct dyes. Reducing dyes and sulphur dyes can not be dyed by industrial washing machine, and can only be carried out in a specific dyeing tank, which has certain difficulty requirements for operation, so it is rarely used at present. Reactive dyes use low-temperature dyes in one bath, but must be fully washed to neutral and dried in time to avoid sealing and other defects; At present, direct dyeing is commonly used in middle and low grade clothing, and the process is relatively simple, but the color fastness is not ideal. It is also mentioned here that "blue cloth" provides the effect of "blue cloth" after garment production is finished by washing it.