The dyeing and finishing of clothing in our country began in the late 1970s, initially with the grinding, rinsing, and snow washing of denim clothing. In the 1980s, sand washing of silk clothing emerged, as well as washing (shrinking), softening, and sand washing of cotton and T/C clothing, and a small amount of clothing dyeing, printing, and tie dyeing. In the 1990s, the rise of enzyme treatment technology was widely used for washing denim clothing, super soft washing of pure cotton clothing, and polishing of knitted fabrics. In recent years, permanent pressing resin finishing technology has emerged for clothing impregnation treatment, which has greatly improved the stability of size and shape compared to previous fabric treatment methods. The washing industry has developed with the development of the clothing industry, and many high-end clothing cannot do without post dyeing and finishing processing, which has become a modern new technology to improve the taste and added value of clothing.
After undergoing multiple processes such as spinning, dyeing and finishing, and garment manufacturing, textiles are generally subjected to washing treatment to achieve stain removal, shrinkage prevention, softening, hair removal, or certain special visual effects, making the overall performance of the finished garment closer to normal and the color more natural.
For the current water washing industry in China, it can be roughly divided into the following types based on the purpose of washing:
Wash shrink
When the fabric shrinkage rate exceeds the standard, wash a piece of fabric sample before making clothes, measure the longitudinal and transverse shrinkage rates, convert them into clothing dimensions, and then cut according to the proportion. After making the sample, conduct a water washing test to ensure that the shrinkage rate of the clothing meets the standard. These types of clothing need to be washed after being ready to wear. And the size after shrinkage must be consistent with the test sample. This requires a unified process for washing and shrinking.
Washing and shrinking process: Place the clothing in a 40 ℃ pool of warm water, soak for half an hour (occasionally use a stick to press it halfway to make it completely wet), take it out, dehydrate and dry it.
Washing shrinkage requirement: After washing, the shrinkage rate of the clothing should be reduced to 3% (note: may vary according to customer requirements and standards).
Wash and soften
Most clothing requires softness. At the request of the customer, add a softener to adjust the feel of the clothes during washing and shrinking.
Place the clothing in a pool with warm water at 40 ℃ and 2 grams per liter of softener, wash for a certain period of time, dehydrate, and dry.
Soft washing requirements: After washing, the shrinkage rate of the clothing decreases and the hand feel is slightly soft. Soft washing is usually arranged in the last step of washing or carried out simultaneously with other washing steps.
Cleaning and upkeep
Products exported to certain countries are required to ensure formaldehyde free or low formaldehyde levels. At present, resin processing technology is widely used in the dyeing and finishing industry for wrinkle and shrinkage prevention finishing. Some fabrics with formaldehyde emit formaldehyde odor in the space, causing clothes that were originally formaldehyde free to absorb a small amount of formaldehyde. If not careful, it can easily lead to breach of contract.
Cleaning process: 40-50 ℃ soap washing (1 g/L laundry detergent, 2 g/L soda ash), water washing, dehydration, drying.
Cleaning requirements: There should be no odor or formaldehyde on the cloth.
unhair
Cotton yarn undergoes multiple production processes such as spinning, dyeing and finishing, and garment manufacturing before evolving into clothing. During various processing steps, the fabric surface is subjected to various frictions, and the feathers on the fabric surface protrude unevenly, affecting its appearance and feel. In order to improve its appearance or enhance its pilling resistance, the common processing method is enzymatic washing to achieve the purpose of removing hair.
Hair removal process: enzyme washing (under acidic conditions, 1-2g/L), water washing, dehydration, and drying.
Hair removal requirement: The fabric surface should have smooth feathers. Powerful, with colors that meet the standard.
No ironing (wrinkle resistant)
Cotton clothing, if only subjected to general washing treatment, is prone to wrinkling during wearing, affecting its appearance. The currently popular solution is to add resin during the wet processing process for heat free finishing. Ironless finishing can be performed separately during the shaping process of fabrics or the washing process of finished garments. The processing flow also varies depending on the type of resin used.
Non ironing process: resin is washed with approximately 60g/L catalyst (note: may vary according to requirements), dehydrated (maintaining a certain moisture content), ironed, and dried.
Ironing free requirements: flat, not prone to wrinkling, strong, and color standard.
Cowboy washing
The principle of using cellulase for stone like finishing of denim fabric is to hydrolyze part of the cellulose with cellulase, which causes the brominated indigo remaining in the amorphous zone of cellulose to also fall off, thus making the surface effect of denim fabric similar to stone grinding. The difference between the two is that the stone mill is a fully mechanized abrasion fiber, while the enzymatic method mainly relies on biocatalytic hydrolysis of fibers.
Cowboy washing process: enzyme washing (or adding stones), washing, drying.
Cowboy washing requirements: reduce the amount of fuzz on the fabric surface, have a stone grinding effect (fading, pilling), and prevent re dyeing.
Comprehensive washing
Combining the above washing methods, perform multiple water washes (depending on the actual effect, you can choose to do them simultaneously).
