Vacuum coating technology is one of the methods of gas phase physical deposition, also known as vacuum electroplating. Under vacuum conditions, the coating material is heated by an evaporator to sublimate it, and the evaporated particle flow is directly shot toward the substrate, depositing on the substrate surface to form a solid film.
Vacuum coating has a wide range of applications, such as vacuum aluminum plating, vacuum plating on plastic and other substrates, and then dyeing with different colors. It can be used in the manufacture of furniture, handicrafts, lighting, clocks, toys, automotive lamps, reflectors and soft packaging materials, and the decorative effect is excellent.
Vacuum coating products have high brightness, delicate and realistic texture, low production cost, environmental protection, and less restrictions on substrate materials. They are increasingly used in the surface treatment of cosmetic shells.
1. Basic principles of vacuum coating technology
The vacuum coating process is simply that electrons are accelerated to fly to the substrate under the action of the electric field and collide with argon atoms, ionizing a large number of argon ions and electrons, and the electrons fly to the substrate. Argon ions are accelerated to bombard the target material under the action of the electric field, sputtering a large number of target atoms, and the neutral target atoms (or molecules) are deposited on the substrate to form a film.
2.The characteristics of vacuum coating technology
Wide range of plating materials: There are dozens of materials that can be used for vacuum plating evaporation, including metals, alloys and non-metals. Vacuum coating processing can also process multi-layer composite films like multi-layer electroplating to meet the requirements of various coating properties.
Vacuum coating technology can achieve coatings that cannot be formed by electrodeposition methods: such as aluminum, titanium, zirconium and other coatings, and even ceramic and diamond coatings, which is very valuable.
Excellent performance of vacuum coating: The thickness of vacuum coating is much smaller than that of electroplating, but the coating has good friction and corrosion resistance, low porosity, and no hydrogen embrittlement, which can save a lot of metal materials compared to electroplating.
Excellent environmental benefits: Vacuum coating processing equipment is simple, small footprint, elegant and clean production environment, no sewage discharge, and will not cause harm to the environment and operators. In the situation of paying attention to environmental protection and vigorously promoting clean production, vacuum coating technology can replace electroplating in many aspects.
3. Types of Vacuum Coating Technology
1). Vacuum evaporation method
Vacuum evaporation is a technology that evacuates the vacuum chamber containing the substrate, and then heats the evaporated plating material to vaporize and escape from the surface, forming a vapor flow that is incident on the surface of the substrate and condenses to form a solid film.
It is a technology that heats the raw materials to be formed into a film in the evaporation container in a vacuum chamber to vaporize and escape from the surface, forming a vapor flow that is incident on the surface of the solid (called substrate or substrate) and condenses to form a solid film.
2). Sputtering coating
Sputtering coating refers to the technology of bombarding the target surface with energetic particles in a vacuum chamber, so that the atoms or molecules of the target material are emitted from the surface and then deposited on the substrate. In the sputtering titanium experiment, electrons, ions or neutral particles can be used as energetic particles to bombard the target. Since ions are easy to accelerate and obtain greater kinetic energy under electric fields, Ar+ is generally used as the bombarding particles.
3). Ion plating
4). Molecular beam epitaxy
5). Chemical vapor deposition
4. Vacuum coating coating
1. Primer
At present, except for a few plastic materials such as PET that do not require surface coating, most plastics, especially block engineering plastics, need primer pretreatment before vacuum coating. Primer pretreatment is a kind of pretreatment for vacuum coating, which can effectively improve the adhesion and flatness of the coating. For example, plasma treatment improves the adhesion between the coating and the substrate.
2. Topcoat
The vacuum coating is usually thin (no more than 0.2 μm) and has poor mechanical properties such as wear resistance. Topcoat not only protects the coating, but also gives the vacuum coated products good mechanical properties such as hardness and wear resistance. The main performance requirements of topcoat include:
(1) It has high adhesion to the coating, which is the basis for the coating to play a protective role;
(2) It should have sufficient wear resistance to protect the extremely thin vacuum coating from mechanical scratches;
(3) It has high barrier properties, that is, it should have good water resistance, corrosion resistance and weather resistance, prevent oxygen and other corrosive substances to the coating from directly contacting the vacuum coating, and protect the coating from corrosion;
(4) The topcoat composition itself cannot contain components or impurities that may corrode the coating;
(5) For vacuum coating occasions that need to highlight brightness, the topcoat should also ensure high transparency and surface gloss.
Some vacuum coating processes do not require topcoat. For example, when the coating material is chrome or stainless steel, the coating has good corrosion resistance, high hardness and strong scratch resistance. Therefore, when the performance requirements of the product are not high, it is not necessary to apply topcoat.
Our company's T-7128 is very suitable for vacuum plating primer on metal materials, with very good adhesion, chemical resistance and hardness. The derivative product 7128C has a higher temperature resistance and can be as high as 230℃ for 2h without affecting
