BOPET film can be subjected to surface treatment for special purposes. A thin layer of metal can be applied to its surface.
Applying a very thin layer of aluminium to the film surface by vacuum evaporation technology lends an attractive appearance to the film and changes its physical and mechanical properties – oxygen and gas permeability is reduced and protection against ultraviolet radiation is achieved. Therefore, the metallised film is often used as a base material for laminates in the packaging of foodstuffs (coffee, spices, confectionery). The reflective properties are employed, for example, in materials for thermal insulation.
Metallization is a technically demanding technology. The whole process takes place under high vacuum conditions.