In the summer, when the room temperature is high, laundry plants commonly face the problem that the linen tends to have stubborn stains more easily. Why does linen tend to have the yellow stains issue? How should people prevent it?
Water Quality Change
In summer, the water temperature rises. The dissolving capacity of water rises, too. The water can dissolve more minerals (calcium, magnesium, iron) and impurities. If the water hasn’t undergone advanced treatments such as reverse osmosis, this kind of water, when combined with the alkaline components in detergents, is easy to form “soap scum” that deposits on the fibers of the linen, creating yellow spots.
● Water softening
In summer, laundry plants should ensure the high-efficiency operation of water softening equipment. If the ion exchange method is used, industrial salt should be used regularly and in sufficient quantities to regenerate the resin (note to reserve time for resin recovery).
● Detergents
During washing, choose washing products rich in chelating agents and highly effective anti-redeposition agents. Chelating agents can effectively complex metal ions in water, preventing them from reacting with detergents to form precipitates. Anti-redeposition agents can prevent the already formed dirt from reattaching to the linen, effectively preventing rust and scale spots.
Increased Human Secretions
In summer, people’s secretion of sweat and sebum increases. Linen that directly contacts human skin, like bed sheets and pillowcases, can easily be contaminated. These stains are rich in protein. If they are washed directly at high temperatures, the protein will denature and solidify and form yellow stains, which are very difficult to remove.
● Pre-wash
As a result, there must be a pre-wash link. During the pre-wash process, some water-soluble stains and salt can be removed primarily.
● Main wash
During main-wash, after adding the detergents, people should wash the linen in water at about 40 degrees Celsius for about 5 minutes. At this temperature, protease and other ingredients can effectively dissolve protein stains and prevent them from denaturing and solidifying at subsequent high temperatures. Then, raise the temperature and wash the linen according to the regular procedure.
Increased Pigment Stains
In summer, fruits, cold beverages, and ice cream are quite popular. The rate of linen being contaminated with a large amount of fruit juice and beverages significantly increased. This will easily form pigment stains.
● Minor stains
The color-safe bleach powder/liquid (oxygen bleach) should be used first. Its oxidation can effectively dissolve some natural pigments, and it causes little damage to linen.
● Stubborn stains
Chlorine bleach powder/liquid may be considered. Its concentration should be strictly controlled according to product instructions. If the concentration is high, it will severely damage fibers, and the linen will be yellow, stiff, and brittle. After using the chlorine bleach, the linen must be rinsed thoroughly to ensure there is no chlorine residue. The residual chlorine may oxidize the linen and cause secondary yellowing and hardness.
Conclusion
The yellow stains on linen in summer mainly result from three major factors: water quality change, increased human secretion, and contamination by juice and beverages. Adopting targeted solutions can significantly reduce the formation of the yellow stains on linen in summer.
Post time: Aug-06-2025