Yellowing of plastics

Yellowing of plastics

Plastics, as compounds of different chemical substances have their characteristic internal structure and composition, which determine their physical properties and their resistance to external influences, also UV radiation. Depending on the power of internal bonds, ageing of plastics can be determined. The stronger (better quality) the bonds are, the slower the ageing process is. As regards the impact of UV radiation, it is characterized by affecting the erosion of polymerization bonds, creating carbonyls, which bind light - absorb it and thus produce certain characteristic color. Generally speaking, the better the quality of the plastic, the greater the resistance. In order for plastics to turn brownish, certain minimum dose of UV radiation operating for some amount of time is required. This fact needs to be taken into account, especially when installing UV sources indoors or at places where there are particularly sensitive materials - think foils etc.

Yellowing of plastics can be avoided as follows:

• Only high quality, resistant materials will be exposed to UV radiation
• The materials will be exposed to UV radiation only for the necessarily required time
• The materials will be protected by (protective) foils, or by coatings resistant to UV radiation