After a period of use and washing, the linen turns gray and yellow. If you put the new linen and old linen together, you will know the obvious color difference. This condition will have a bad impact on customer experience. There are many reasons for linen to turn gray or yellow, like substandard water quality, residual chemicals, and excessive softeners. Below are some common causes and solutions.
Iron Ion Buildup
● Water
Laundry plants need to use softened water for laundry. Iron in the water is in the form of ions or ionized compounds, so the deposit will form brown spots on the fabric, and the white fabric will be turned red and grey. As a result, the water in the laundry factory needs to be softened.
● Alkaline concentration
When choosing detergents, it is best to select a neutral product with a pH value lower than 10. Low alkaline concentration can reduce its combination with iron ions, thereby reducing their deposition on the linen. The alkalinity’s real ability to remove stains is not strong. Its main role is to assist the active agent in exerting a greater effect. Excessive alkalinity will increase the stubbornness and variation of dirt, making it difficult to remove.
● Detergent
Use the detergents with an active content of more than 10%. If the linen becomes red, gray, or stiff, you can use the corresponding detergents to solve it. Strong reducing chemicals like oxalic acid and sodium hyposulfite are not recommended for use because improper concentration control can easily damage the linen.
Residual Chlorine from Bleach
● Proportion
Before using chlorine bleach, you must inquire with the factory about its dosage and proportion, and strictly add the bleach according to the proportion. Otherwise, the residual chlorine. After using chlorine bleach, the rinse time should be at least 3 times. The water temperature should be maintained around 40℃. Each rinse should be at a high water level, and the duration of the rinse should be at least 2 minutes.
● Neutralizer
When washing linen with chlorine bleach or bleach water, you can properly add more neutralizer during the neutralization stage to prevent the linen from turning yellow after drying and ironing.
● High-temperature washing
If there is the phenomenon of linen turning yellow after being ironed, the linen should be rewashed at a high temperature without chlorine-containing detergents.
● Use other methods to improve linen cleanliness
Try to reduce the frequency of using chlorine bleach as much as possible. You can improve the cleanliness of linen from other aspects, like water quality, standardized washing processes, and the selection of equipment with strong mechanical force.
In the next article, we will continue to discuss with you how to solve the problem of dull and hard linen.
Post time: Jul-02-2025