I don't know if you have noticed that the collar and cuffs are the most prone to yellowing on our white clothes, because these two parts are most susceptible to the sweat on our bodies. These sweat and grease are left on clothes, and if they are not cleaned in the cleaning process, they will easily turn yellow.
Second, clothes are poorly kept or kept for too long.
There is another reason why clothes turn yellow, which is related to water quality. If the water quality at home is hard, once the water penetrates into the clothes, the clothes will turn yellow. Next, it is related to washing products. If the foam in the washing powder is not washed clean with water, the remaining substances will also make the clothes hard and yellow.
Third, the fluorescent agent becomes weak.
In order to cover up the stains on clothes, some businesses will add a lot of whitening agent or washing powder to the water to make the clothes look like new after washing. But these clothes will lose luster and turn yellow as long as they are left for a period of time, which is caused by the accumulation and residue of fluorescent agents.
As long as the time is longer, the more fluorescent agent will accumulate. These things can't be washed away, which not only affects the beauty of clothes, but also does great harm to the body.