Metalized BOPP film is a type of polypropylene film that has been coated with a thin layer of metal, typically aluminum. The metal coating gives the film a metallic appearance and provides it with certain properties such as increased barrier strength and improved heat reflectivity. The metalized BOPP film is mainly used in packaging applications, such as flexible packaging, lamination and labels, to provide a barrier against light, moisture and gases. It is also used in decorative applications, such as gift wrapping, and in insulation products.
There are several processes for creating metalized BOPP film, but the two most common methods are vacuum metalization and sputter coating.
Vacuum metalization: This process involves depositing a thin layer of metal onto the surface of the BOPP film in a vacuum chamber. The film is placed on a spool and is passed through a chamber that has been evacuated of all air. The metal, typically aluminum, is heated until it vaporizes, and the vapor is then deposited onto the film as it passes through the chamber. The thickness of the metal layer can be controlled by adjusting the amount of time the film is in the chamber.
Sputter coating: This process uses a sputter coating machine to deposit a thin layer of metal onto the BOPP film. The film is placed on a spool and passed through a chamber where it is bombarded with ions of the metal, typically aluminum, which causes the metal to be deposited onto the film. The thickness of the metal layer can be controlled by adjusting the amount of time the film is in the chamber.
Both of these processes are designed to create a very thin, uniform layer of metal on the surface of the film that is tightly adhered to the BOPP, and it's possible to get different thicknesses of metalization.