Why does woolen sweater turn yellow after cleaning?
The sweater is more durable and the price is moderate. If woolen sweaters are not properly handled and maintained, they will turn yellow, especially light-colored sweaters, which is a headache for us. Why does it turn yellow?
We sweat a little every time we finish exercise. If your woolen sweater gets wet with sweat, our first reaction is to take it off and change it. Did you soak the sweater in hot water for a while, then wash it? Everyone thinks that this can remove the sweat from the sweater and wash it very cleanly, but in fact we did this inadvertently damage the sweater.
We all know that sweat is salty, because it contains a certain amount of salt, and the rest is urea, protein and other elements in it. Both salt and urea can be dissolved in water and are easily decomposed in high-temperature water.
But this protein is different. If the temperature is low, it will dissolve in the water in a gelatinous form. If it is affected by the heat, it will solidify immediately, so that it is not easy to dissolve in the water. If the protein coagulated on the fiber is exposed to sunlight or oxidized in the air, it will turn into yellow dirt and adhere to the woolen sweater fiber, so it is difficult to wash it off with hot laundry detergent. Therefore, if the sweater is wet with sweat, it is best not to soak it in too hot water, let alone wash it.
