No, they do not. Diapers mainly have a three-layer structure: the surface covering layer, the absorbent core layer and the bottom cloth. The material of the surface layer is mainly non-woven, the absorbent core layer is composed of absorbent beads and fluffy fibers, and the material of the bottom layer is usually made of PE film or PE film + non-woven. The surface layer of non-woven fabric is easy to harden after exposure to the sun, making the original soft and comfortable material hard, which can lead to injury to the baby's little butt. The bottom layer of PE film is used to prevent leakage of urine. This material is prone to photo-oxidation and thermal oxidation, and strong ultraviolet light will lead to its degradation. After exposure to the sun, the bottom layer is prone to aging conditions and thus urine leakage.