Aluminum coating process

The aluminum plating process of plastic film generally adopts the direct plating method, that is, the aluminum layer is directly plated on the surface of the substrate film. BOPET and BOPA film substrates do not need surface treatment before aluminum plating, and can be directly evaporated. For non-polar plastic films such as BOPP, CPP, PE, etc., corona treatment or glue coating is required on the surface of the film before evaporation to make the surface tension reach 38-42 dynes/cm or have good adhesion. . When evaporating, place the roll film in a vacuum chamber and close the vacuum chamber to evacuate. Adjust the unwinding speed, rewinding speed, wire feeding speed and evaporation capacity, turn on the cold source, make the aluminum wire continuously melt and evaporate on the evaporation boat, and form a bright aluminum layer after the surface moves. Film cooling. Aluminum coating.

Principle of Vacuum Evaporation

Install the coating substrate (cylindrical) in a vacuum evaporator, vacuumize with a vacuum pump to make the vacuum inside the coating reach 1.3×10-2～1.3×10-3Pa, heat the crucible to make high-pure aluminum. The metal wire is melted and evaporated into gaseous aluminum at a temperature of 1200 ℃ ~ 1400 ℃, and the gaseous aluminum particles are deposited on the surface of the moving film substrate, and after cooling and reduction, a continuous bright metal aluminum layer is formed. form. The thickness of the aluminum plating layer is controlled by controlling the evaporation speed of metal aluminum, the moving speed of the film substrate and the vacuum degree of the coating chamber. Generally, the thickness of the aluminized layer is 25-500nm, and the width of the aluminized film is 800mm-2000mm.