Zinc Aluminum Metallized Films Profile

     Initial period, people in the manufacture of thin film capacitors aspects mainly aluminum metallized film. Needless to say, the adhesion of aluminum metallized film is better, and the production process is easy to handle. Due to the chemical reaction of a dense oxide layer that prevents the inner layer of Al₂O₃ is to oxidation, and therefore, aluminum metalized film deposited for a long period of time the aluminum layer on the surface of the oxygen in the air will not change due to oxidation its electrical parameters. But for aluminum metallized polypropylene film capacitors, high voltage and high current AC work, due to the generation of Al₂O₃, particularly in the edge of a large part of the electric field strength, often leading to rapid decline in capacity of the capacitor, the loss increases rapidly. Larger capacity capacitor, such as capacitor electric fans, washing machines, electrical cabinets and other compensation are based on the use of basic aluminum metallized polypropylene film.

     In order to find the remedy defects in aluminum metallized polypropylene film approach, it was found by experiment galvanized metal film is the best way to solve this problem. Use of metallized polypropylene film capacitors made from galvanized, working at AC high voltage high current, increasing its capacity and loss of loss is almost negligible. However, compared with aluminum metallized film, metallized film adhesion galvanized relatively poor, but also in the production process is not easy to deal with. When the oxidation of the zinc layer is exposed in a very short period of time in the air into the ZnO. ZnO is eleven kinds of semiconductor materials, and very loose, in humid conditions but accelerated oxidation coatings, often within a few days destroy the entire coating. This not only caused great inconvenience to the production and oxidation of the film capacitor made at work will also be fever, and even breakdown.

    Zinc aluminum Metallized films is the first in the metal thin film of aluminum on a base film, thereon and then galvanized. In the deposition process, the part of the aluminum atoms in motion by diffusion dialysis to zinc coating surface. Additionally, there is no gap between the two evaporation sources of zinc, aluminum, aluminum evaporation source of aluminum atoms can be deposited directly to the zinc coating surface. Of course, between the layers and no strict boundaries, most of the mixture is contained in different layers of a certain amount of atoms only. This particular structure fully integrate the aluminum and galvanized metal film metalized film respective advantages. The first is to ensure that aluminum composite metal layer and the base film with good adhesion; galvanized zinc layer in order to maintain good electrical parameters; As the surface of the aluminum layer is a protective effect. In order to ensure that the internal zinc oxide surface layer is not due to the depth of the aluminum layer to the detriment of the effective electrode area must be strictly controlled zinc, aluminum ratio. If the aluminum content is too large, it will lose galvanized metal film of good electrical properties; If the aluminum content is too small, will cause deep oxidation, affect the life of the capacitor. How much Additionally, zinc and aluminum metallized film composite aluminum content is also needed to determine the local climate at the time, or the production, storage environment of the film. In general, if the ambient temperature is low and humidity is small, then the aluminum content can be smaller. On the contrary, it should be slightly larger. The content ratio is substantially: Zn; Aluminum = 9: 1. From current production point of view, this ratio must be controlled by a computer, as zinc, aluminum evaporation control methods are not the same, zinc evaporation by temperature changes, aluminumEvaporation is determined by the wire feed speed. When the computer is given a proper ratio of zinc and aluminum, the content of the coating machine is automatically corrected, thereby ensuring that the composite film has excellent properties. Practice shows that the composite zinc aluminum metallized film stored in a sealed plastic bag more than six months will not be oxidized.