Blogs

Ultraviolet rays can destroy the polymer structure of plastics, leading to chain breakage, cross-linking reactions and oxidative degradation, which ultimately cause the following problems:

1.1 Degradation of mechanical properties

Material becomes brittle and strength decreases: UV radiation can cause molecular chain breakage, making plastics brittle, easy to break or powderize.

Degradation of impact toughness: Plastic sheets exposed to UV rays for a long time will significantly reduce their impact resistance and easily break or crack.

1.2 Color change (fading, yellowing, whitening)

Ultraviolet rays can destroy pigments and dyes in plastics, causing the color to fade or turn yellow.

For example: white HDPE sheets tend to turn yellow under UV irradiation, while black HDPE has a higher UV resistance due to its high carbon black content.

1.3 Surface aging

The surface of plastic sheets may crack, powder, roughen, and peel, affecting appearance and function.

For example: If UHMWPE or HDPE sheets are not UV-treated, the surface will become powdery after a few years of outdoor use, resulting in an increase in the friction coefficient.

1.4 Chemical degradation

UV can cause oxidation reactions in plastics, forming free radicals that gradually degrade the material.

Typical manifestations: The plastic surface becomes brittle, cracks, and even small holes appear.