Meaning
The chemical breakdown of polymers and organic pigments under the combined action of ultraviolet radiation and atmospheric oxygen causes surface cracking and color fading. The process of ultraviolet photo oxidation alters the physical and aesthetic properties of plastic films, inks, and coatings used in packaging. This degradation occurs during outdoor exposure or under intensive artificial lighting and is halted when the light source is removed.
Implementing proper additive strategies prevents the catastrophic loss of physical strength and aesthetic quality that occurs when unprotected packaging materials are exposed to environmental stresses during transit and long shelf display.
Chemical Reaction
Absorption of UV light by the material’s polymer chains generates free radicals that react with oxygen to form hydroperoxides. This chain reaction during ultraviolet photo oxidation leads to the scission of polymer backbones, which reduces the mechanical strength of the packaging. Over time, the material loses its flexibility and becomes brittle.
Material Failure
Physical symptoms of this process include chalking, micro-cracking, and a significant loss of gloss or color intensity. When packaging suffers from ultraviolet photo oxidation, its protective barrier properties can fail, exposing the enclosed product to moisture and oxygen. This failure can shorten the product shelf life and damage the brand reputation.
Industrial Prevention
Packaging converters introduce light stabilizers and UV absorbers into plastic and ink formulations to delay this chemical breakdown. Utilizing these additives protects the material during transit and extended retail displays, ensuring that the packaging maintains its structural integrity. This protective measure is essential for products that require long-term storage or are displayed outdoors.
