What is Vacuum Metalizing: Benefits, Processes, and Applications
Every industry uses a wide range of versatile components, each having its own unique characteristics. Vacuum metalizing is a process that helps to create components of plastics with metal plating.
If you want to know more about the process of vacuum metalizing, how it works, and where it is used, the guide below can help you. So, let's read.
What is Vacuum Metalizing?
Vacuum metalizing is a process in which a layer of metal is formed on the metalized substrate. It is created in the form of PVD, and it coats a metal on the non-metallic substrate with the help of evaporation.
The metal wire is fed into a heat source using a closed vacuum chamber, and that is where the metal evaporation takes place. The temperature of the chamber is kept around 1500 degrees Celsius, and due to the low pressure in the chamber, the boiling point of the metal components is reduced. Such a reduction converts the liquid metal into a gaseous state. The metal vapor produces a metal coating on the thin film.
Benefits of Vacuum Metallization
The process of vacuum metalization has multiple benefits, some of which are as follows:
- It is a cheaper process and can help achieve the desired look in a very sustainable way.
- Vacuum metalization is safe compared to other plating methods like chromium plating, which uses a hazardous mixture of cyanide and chromium.
- The process of vacuum metalization helps meet a versatile range of decorative functional coatings, which helps to address the challenges faced by industrial coatings.
- It improves the reflectivity, tolerance, and moisture barriers of the components.
The Vacuum Metalizing Process
The process of vacuum metalization has various steps, and these are as follows:
Step 1: Tooling
Customized tools and fixtures are designed to hold the components in place so that maximum efficiency is attained at the time of vacuum metalization. The components are inspected for their defects before clamping to ensure that the metalized coating quality is balanced accordingly.
Step 2: Loading
The loading stage is where the components are prepared and cleaned so that they can be vacuum-metalized. The components are also loaded into the clamps and fixtures.
Step 3: Applying the Base Coating
The base coat involves the application of primer, which makes the surface smooth and enhances its abrasion resistance. This process helps to prepare the part for vacuum metalization.
Step 4: Vacuum Metalizing
The fixtures are kept in the vacuum chamber, consisting of a turntable. The filament is then used for the evaporation of metal, which creates vapor clouds that bond with the component.
The fixture is then rotated in the vacuum, which achieves a consistent coating. Once the process of metalization is complete, the chamber is returned to the atmosphere, and the fixture is removed.
Step 5: Applying the Top Coat
Based on the part properties, a top coat is applied so that the component can have improved resistance against chemicals, wear, and corrosion. It even helps to enhance the part's appearance. There are different types of coats that can be applied, such as ceramic, Téflon, tinted, gold, and many others.
Step 6: Quality Inspection
The components are inspected thoroughly and matched with the standards of ISO 9001 so that the defects can be identified and fixed.
Metals for Vacuum Metalizing
When aluminum and copper are compared in the context of vacuum metalizing, the electrical conductivity offered by silver and copper is excellent. However, copper can corrode, and silver is expensive. Hence, aluminum is considered to be the best choice for vacuum metalization as it offers improved reflectivity and low cost.
Aluminium
Aluminium offers reflective coating, and components that need high reflectivity are vacuum metalized using aluminum-like automobile lighting reflectors.
Cuivre
Copper offers high conductivity, and hence, it is also used in many applications. Still, because of its corrosion, it can be covered with a layer of oxide so that the coating becomes corrosion-resistant.
Vacuum Metalizing vs Electroplating
The two processes, vacuum metalizing and electroplating, differ from one another in various ways, and some of these differences are as follows:
Material of Metal Plating
The major difference is the material of metal plating; vacuum metalizing is mostly carried out with aluminum plating. In comparison, electroplating uses nickel or chrome plating.
Plating Environment
PVD vacuum metalization is carried out in a vacuum chamber, as it requires high equipment and testing, and it increases the cost. Whereas electroplating is carried out in an electrolytic solution, which is a simpler method.
Color and Durability
Vacuum metalization coating has a brighter color compared to electroplating and is more durable.
Environment Friendly
Vacuum metallization is conducted in a vacuum chamber, and hence, no steam is released outside, which makes it environment-friendly. Whereas, in electroplating, highly polluting hexavalent chromium is used, which impacts the environment.
Applications for Vacuum Metalizing
Vacuum metalization is used for various applications, and some of these are as follows:
Decoration
It adds aesthetic appeal to the components by creating a mirror-like reflective finish and varied colors, adding a decorative touch to the components. The unique colors enhance the overall look of the components and are mostly opted for in household appliances, instruments, automobiles, etc.
Insulating Applications
Vacuum metalization is used to enhance the functionality of the fabrics and films. It helps to add insulation to the components by improving their reflectivity. The barrier of insulation materials attains its functionality from the process. They can be used to protect spacecraft during space missions by adding multiple layers of metal.
Improves Barrier
To enhance the circulation cycle and improve the shelf life of the products, the role played by commodity packaging is also increasing. It is mostly considered in drugs, food, and detergents, where high-quality packaging is needed. The process of vacuum metalization helps reduce the transmission of light from the substrate and gives it a barrier that limits UV exposure.
Optical Part Reflectivity
Vacuum metalization is used for multiple types of optical lighting parts, like automobile and bicycle reflectors. This helps to create the polished surface at the stage of the prototype so that the optical reflectivity can be tested.
Conclusion
The concept of vacuum metalization is a very common one and is observed in many applications. If you are also looking forward to having your substrates and parts metallized, you can contact us at DEK. We have high-quality procedures that help to create vacuum metalized parts with enhanced reflectivity and functionality.
