What causes the pillow core to turn yellow?

Pillow is an essential item on the bed. It is used every night when sleeping and resting, but the pillow will inevitably turn yellow after being used for a long time. So what is the reason for the yellowing of the pillow core?

1. The human body secretes oil, which absorbs a lot of sweat, sebum, dandruff, and other dirty metabolic wastes from the head. All pillows will turn yellow after some time.

2. The yellowing of the pillow is caused by water stains or accidental dripping, which causes the pillow to become damp and yellow.

3. It may be cloudy and the weather is damp, and it is stored or used in a press box without drying in time, which will cause yellowing.