web coating machine coating is a technology that applies physical vapor deposition method to continuously coat a flexible substrate. Coating on the surface of a flexible substrate has two functions: one is functional and the other is decorative. The so-called functionality is to use different coating methods to coat flexible substrates such as plastic films, paper, metal strips, cloth, etc. with semiconductor films, metal films, optical multi-layer films, etc., which can not only improve their surface hardness, mechanical strength and water resistance, but also It can also increase oil resistance and solvent resistance, improve aging resistance, and have conductivity, reflectivity, absorptivity, insulation, barrier properties and prevention of static electricity, etc., so that these flexible materials have some special functions.

Common web coating machine can be divided into: evaporation winding coating, magnetron sputtering winding coating and combined winding coating according to their working principles. Among them, evaporation winding coating is divided into three types: resistance heating evaporation, induction heating evaporation and electron beam heating evaporation; magnetron sputtering winding coating is divided into two types: DC sputtering and medium frequency reactive sputtering; combined winding coating is divided into There are many forms such as the combination of resistance evaporation and magnetron sputtering, the combination of resistance evaporation and e-book evaporation, the combination of electron beam evaporation and magnetron sputtering, etc.
        web coating machine have made great progress in the past 30 years. Coated products are widely used in decoration, packaging, capacitors and other fields, and can be used to coat a variety of optical, electrical, electromagnetic, conductive and other films. The base materials used include PE, PET, PI, PP, OPP, BOPP, paper, foam plastic and cloth, etc. Generally, the moisture content of plastic-based film materials is 1% to 2%, and the moisture content of paper is larger, generally 5%-7%. After coating and drying, the moisture content is still 3%. Due to the high moisture content of the substrate, the coating chamber has evolved from the initial single chamber to the current double-chamber or multi-chamber structure. Evaporation sources can be resistive, inductive, electronic and magnetron sputtering. The double-chamber structure is widely used. Its advantages are: ① It can evaporate paper substrates with large outgassing volume and ensure the coating quality. A large amount of gas released from the paper is exhausted from the winding chamber. Since the narrow gap in the partition between the winding chamber and the evaporation chamber is very small, it is difficult for the released gas to enter the evaporation chamber; ② The single-chamber structure must be equipped with a larger exhaust system to ensure the working pressure during evaporation, and The evaporation chamber in the double-chamber structure has a small gas volume and can be equipped with a small exhaust unit to reduce equipment costs and save energy; ③ The winding chamber and the evaporation chamber are exhausted separately, which can shorten the exhaust time.