What are the reasons for the yellowing of silk pillowcases?

1. Sweat residue
The human body sweats during sleep. If the components in the sweat remain on the silk pillowcase for a long time, it is easy to cause yellowing.
2. Grease and dirt
The grease on the hair and skin may be contaminated on the pillowcase, which will cause the pillowcase to turn yellow over time.
3. Detergent residue
If the cleaning is not thorough, detergent residue will remain on the pillowcase, which will cause yellowing.
4. Exposure
Direct sunlight will cause the silk fiber to age and discolor, thus turning yellow.
5. Long-term use
As the use time increases, the silk pillowcase naturally ages, the performance of the fiber decreases, and it is easy to turn yellow.
6. Contact with cosmetics
The cosmetics on the face may rub onto the pillowcase during sleep, and some components will cause yellowing.
7. Humid environment
The storage environment is humid, which is easy to breed mold, causing the pillowcase to turn yellow.