The first step is pretreatment, which is to remove stains. It uses artificial additives to pretreat seriously polluted dirt and stains insoluble in dry cleaning solvents (such as juice, nail polish, paint, ink, etc.) ) without water.

The second step is the main washing. Put the pretreated clothes into a dry cleaning machine, wash them thoroughly with dry cleaning solvent, and spin them dry.

The third step, post-treatment, the main purpose is to remove the residual dry cleaning solvent in clothes and irons and shape them.

You should check your clothes first to see if there are any parts or parts that are not suitable for dry cleaning. For example, plastic buttons that may dissolve will be removed or covered. Wash clothes that fade easily separately from other light-colored clothes. For specific stains, a treatment agent can be added in advance.

Dry cleaning uses a special dry cleaning machine. Its specific structure usually varies with the solvent. Tetrachloroethylene is still the most common solvent. In addition, there are various hydrocarbon solvents such as petroleum and liquid carbon dioxide.

The principle of dry cleaning machine is similar to that of domestic washing machine and dryer. The fabric to be washed is packed in an open inner rotating cage/drum with a capacity of 9-36kg, and the outer rotating cage contains about 1/3 volume of solvent. Cleaning is carried out under the condition of strictly controlling the temperature, the inner and outer cages rotate relatively, and at the same time, fresh solvent is constantly replacing the parts containing dirt. The common washing time is 8- 15 minutes.

After the solvent is finally rinsed clean, the outer rotating cage is emptied, and then the inner rotating cage begins to rotate (the rotation speed is generally 350-450 rpm), and the clothes are dried by centrifugal force. Then hot air is introduced, and the residual solvent is volatilized during the rotation of the inner rotating cage.

The dirty solvent in the dry cleaning process is purified and recovered through filtration, adsorption and other processes. The remaining residue still contains a small amount of solvent, which will cause pollution if it is directly discharged into nature, so it needs further treatment.

Extended data:

Advantages and disadvantages of dry cleaning clothes

With the development of chemical industry and clothing industry, clothing fabrics are constantly updated, and many of them need dry cleaning. Dry cleaning generally does not deform clothes, and it is very convenient and popular, but it also has health hazards.

Generally speaking, dry cleaners use high chloride chemicals as active solvents when dry cleaning clothes. This high chloride is harmful to the human nervous system. Long-term exposure to this chemical is likely to lead to kidney cancer.

In the process of dry cleaning clothes, this chemical will be absorbed by the fibers of clothes, and then released into the air from clothes when clothes are dry, thus affecting human health.

Many people don't know that dry cleaning will release harmful substances, so when they get their clothes back from the dry cleaner, they either wear them immediately or put them in the closet. In fact, this is very unscientific. The result of taking clothes back and wearing them immediately is that harmful substances on clothes can't be released immediately, so it directly hurts the body.

Although the clothes put in the closet are not worn immediately, they are poorly ventilated, and high-concentration harmful chemicals will spread in the closet. The clothes stored in the closet may be infected by harmful substances to a certain extent, and it is also harmful to health to take them out of the closet.

In view of this, clothes should be taken back from the dry cleaners and put in a ventilated place to dry, so that the chemicals released by clothes can be dispersed in the wind before being worn or put into the wardrobe for collection. Children are particularly sensitive to high chloride.

So dry cleaning clothes should be kept away from children. Because different dry cleaners use different doses and methods of high chloride, the damage to health is also different. Proper consideration should be given when choosing a dry cleaner.

References:

Baidu encyclopedia-dry-cleaning