Basic knowledge of washing raw materials (1)
Performance characteristics of washing materials and additives
First, surfactants and their effects
(1) Wetting effect Textile fibers have obvious hydrophilic properties and are easily wetted. The wetting of the surfactant is closely related to the decontamination process of the fabric. Due to the participation of surfactants, the surface of the fabric fiber is easily wetted by the washing liquid and penetrates into the capillary of the fiber to expand the fiber; at the same time, the surfactant can penetrate between the hydrophobic dirt particles to pulverize the particulate dirt. Colloid-sized microparticles, so that the original structure between the fabric fibers and the dirt is destroyed, and the dirt is easily separated from the fibers.
The wetting action of the surfactant does not directly decontaminate during the washing process, but plays a very important role in the decontamination of the fabric.
(2) Dispersion Insoluble solids such as dust and soot cannot sink and sink in water. When a detergent containing a surfactant is added, the hydrophobic hydrocarbon chain of the surfactant is easily adsorbed on the surface of the solid particles, and the hydrophilic group at the other end is extended into the water to form a hydrophilic adsorption around the solid particles. The membrane, when the surface tension between the washing liquid and the solid particles is smaller than the surface tension inside the solid particles. At this time, the wetting action of the surfactant molecules destroys the cohesive force between the solid particles. At the same time, due to the extremely strong impregnation of the surfactant molecules, the solid particles are broken into tiny particles, surrounded by surfactant molecules, and dispersed in water. Since the surfactant is a polar substance, it can be ionized in water and has different charges. Therefore, the molecular enveloping ring usually carries a charge, so that the dispersed particles are not easily recondensed to form a precipitate, and can only be suspended in water.
(3) Emulsification After adding a surfactant to the liquid in the oil moisture layer, the oil is divided into extremely fine droplets dispersed in water to form an emulsion, which is less likely to cause delamination. The emulsification of the surfactant plays a very important role in washing the oil on the laundry. After the grease becomes emulsified, it is not easy to aggregate and precipitate on the clothes.
(4) Solubilization There are three ways of solubilization: one is that non-polar substances such as oil and mineral oil are dissolved between the micelle hydrocarbon chains of the surfactant molecules and sandwiched between the hydrophobic groups. One is a substance having both polar and non-polar groups, and the surfactant molecules are aligned together. Another type is a hydrophilic substance that is adsorbed on the polar surface of the surfactant micelle.
(5) Foam effect When a certain amount of surfactant is added to the water, the hungry foam formed by the external force is relatively stable. The main reason for the formation of foam is the directional adsorption of surfactant molecules, resulting in a decrease in the surface tension of the gas-liquid two-phase interface.
Second, detergent additives and their effects
(1) Inorganic additives
1 , phosphate Main role: metal ion chelation, improve degumming, emulsifying and dispersing, alkaline buffering.
2 , sodium silicate Main role: buffering effect, sodium silicate can keep the pH value of the solution unchanged, has a buffering effect; has a certain protective effect on the fabric, in the synthetic washing powder, with a certain amount of sodium silicate, can maintain the strength of the fabric To reduce the damage rate of the fabric; anti-corrosion effect, sodium silicate can effectively prevent corrosion of metal parts; effect on suspension force, emulsifying power and foam stability; can keep the finished washing powder loose and prevent agglomeration.
3 , sodium carbonate Has good adsorption properties and promotes foam formation
4 , sodium sulfate Decontamination, increase the adsorption speed and adsorption capacity of the detergent on the fiber, can improve the decontamination effect of the detergent; shape the washing powder and prevent caking, help the molding of the washing powder, and prevent agglomeration.
(2) Organic additives
1 , anti-redeposition agent It can prevent the dirt that has been washed off the fabric from being deposited on the fabric again, so that the white fabric is washed many times and then thrown to keep it white, so that it will not turn yellow and gray.
2 , fluorescent whitening agent Enhance the look and feel of the washed fabric, make the white fabric whiter, and the color fabric is more vivid and pleasing.
3 , enzyme preparation It can decompose the corresponding dirt, reduce the washing temperature and improve the washing quality.
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