The resistance factor of polyethylene plastic mesh to ultraviolet rays
The resistance factor of polyethylene plastic mesh to ultraviolet rays
Polyethylene plastic mesh is a very common material in our production and life. Polyethylene materials will be damaged by direct outdoor ultraviolet rays, become brittle, lose color, lose toughness, weather, etc. In this article, we will discuss the principles and factors of UV damage to polyethylene materials.
Our common hail nets, shading nets, balcony nets, insect nets, bird nets, agricultural shading nets, etc. are all made of plastic products. Among these plastic products, polyethylene material occupies a higher proportion because of its super stability, especially in sunshade nets, which almost occupies more than 90%. It is very practical to explore ways to maintain a long life under ultraviolet light.
Polyethylene materials will be damaged by ultraviolet rays, what is the principle?
- We all know that plastic materials are very easy to cause static electricity, especially in winter. Plastic materials are well known because they are insulators themselves. The electrons in the insulator are very difficult to move freely, which is completely different from the conductor. Therefore, insulators are very prone to accumulating charge, storing static electricity until they reach their breakdown voltage. This is also the reason why plastics are more prone to static electricity.
- And this is the reason why ultraviolet rays destroy plastics. Ultraviolet rays have strong energy. After irradiating polyethylene plastic, free radicals will be generated, and free radicals are electrons in a free state. While pure plastics cannot absorb UV radiation, catalyst residues and other impurities act as acceptors, oxidatively degrading after absorbing free radicals. Although these small impurities are very small, such as the content of sodium in polycarbonate, which is only a few parts per billion, it can also cause color degradation.
- While the polyethylene material itself is exposed to oxygen in the air, free radicals will attract free hydrogen ions and oxygen ions in the air. This process causes the double bond of the polyethylene material to break, which in turn destroys the structure of the main chain, which is why the structure becomes brittle. This process is called photooxidation.
If you have a lot of insights on this issue, or are interested in products, please contact us.