Metallized

Metallized refers to a material that has been coated with a thin layer of metal, typically by deposition techniques, to impart reflectivity, barrier properties, conductivity, or aesthetic qualities. The metal layer is usually very thin, on the order of nanometers to a few micrometers, and the coating can be continuous or patterned.

Metallization methods include physical vapor deposition methods such as thermal evaporation and sputtering, chemical vapor deposition, and electroplating or electroless plating. On flexible polymers and films, a common approach is sputtering aluminum onto PET to produce metallized film used in packaging. Other metals such as copper, nickel, silver, or gold may be deposited depending on the properties required.

Common substrates for metallization include plastics (notably PET, polycarbonate, polyimide), paper, textiles, glass, and ceramics. Metallized films are widely used because of their high reflectivity, barrier to gas and moisture, and light weight.

Applications range from food and cosmetic packaging, where the metal layer reduces permeability and provides a shiny appearance, to electrical and optical components, where metal coatings provide conductivity or reflectivity and EMI shielding. Metallized films also serve in insulation and solar reflectors, and in decorative coatings for consumer goods.

Limitations include potential adhesion issues between metal and substrate, susceptibility to abrasion, and recyclability challenges, since the metal layer complicates processing of multi-material laminates. Some metallized devices may require careful handling to prevent delamination or tarnish; aluminum layers can tarnish in certain environments, while silver layers may tarnish without protective coatings. Quality control often involves adhesion tests and measurements of optical properties.