Cloth washing skills

The linen washing process is divided into the following stages:

1. Inspection and classification: firstly, the washing money is classified to make the washing targeted. According to the color of linen, different linen treatments may cause mutual pollution, and the treatment methods of similar linen with different colors are also different; According to the scale of linen, it is classified into three categories: heavy scale, medium scale and clean scale; According to the classification of linen dirt, this classification method is aimed at the special dirt that linen has in the process of use. Generally, special stain remover is used to treat these special dirt. If heavy-dirty linen is treated with the same kind of linen with general dirt, it will only cause a lot of backwashing and waste. Classification by linen texture, such as pure cotton sheets and polyester-cotton sheets, must be handled separately. Generally, sheets with the same dirt, pure cotton ones take longer time, higher temperature and a larger proportion of washing products than polyester-cotton ones. Therefore, it is beneficial to improve productivity and save costs to classify linen according to its texture.

2. stain removal: stain removal refers to the process of applying some chemicals and correct mechanical action to remove stains that cannot be removed in conventional water washing and dry cleaning. Decontamination requires certain operating skills and professional knowledge.

3. washing and pre-washing: using the action of water and mechanical force, the water-soluble dirt on the washed fabric is washed away from the fabric as much as possible, which lays a good foundation for the decontamination of the main washing. For the washing of medium and heavy dirt, the washing step is generally adopted. Pre-washing is a pre-decontamination process by adding proper detergent. Due to the surface tension of water, only water can not fully wet the dirt. For particularly serious dirt, pre-washing is a necessary step. Pre-washing can generally be arranged after the washing step or directly into the pre-washing process.

4. Main washing: This process takes water as the medium, and closely cooperates with the chemical action of detergent, the mechanical action of washing machine, and the appropriate concentration, temperature and sufficient action time of washing liquid to form a reasonable washing and decontamination environment to achieve the purpose of decontamination.

5. Bleaching: This process is a supplementary step of main washing decontamination, and mainly removes pigment dirt that cannot be completely removed in the main washing step. Oxidative bleaching agent (oxygen bleaching powder) is mainly used in this step. Therefore, the water temperature should be strictly controlled at 65℃ ~ 7℃, and the PH value of the lotion should be controlled at 1.2 ~ 1.8, and the dosage should be strictly controlled according to the dirt type and fabric structure.

6. Rinsing: Rinsing is a diffusion process, which allows the residual detergent components containing dirt in the fabric to diffuse into the water, and a certain temperature (generally 3℃ ~ 5℃) is applied during this process. The high water level makes the concentration of washing liquid decrease rapidly, thus achieving the purpose of cleaning.

7. Over-water and dehydration: The centrifugal force generated when the washing machine drum rotates at high speed is used to minimize the moisture content of the fabric in the drum, which requires high equipment performance.

8. Neutralization by peracid: The detergent usually used in washing is alkaline. Although it has been washed for many times, there is no guarantee that there are no alkaline components. The presence of alkaline substances will have a certain impact on the appearance and feel of the washing. These problems can be solved by neutralization reaction between acid and alkali.

9. softness: this process is washable and is generally set according to customer's needs. Softening is a post-treatment process, not a decontamination process. Softening treatment can make the fabric feel comfortable, at the same time, it can prevent static electricity, play a lubricating role in the fabric, and prevent the fibers from being tightly intertwined and falling off.

sizing: the sizing step is mainly aimed at cotton products or mixed fiber fabrics such as table cloths, napkins and some uniforms in restaurants. After sizing, it can make the surface of the fabric stiff and prevent fuzzing, and at the same time, it also forms a sizing film on the surface of the fabric, which has a certain obstacle to the penetration of dirt.