Vacuum plating and water electroplating are both electroplating methods used in the rapid prototyping industry. It involves attaching a metal layer to a surface through a chemical reaction to increase corrosion resistance, alter the size, or create an aesthetic effect.
Understanding the differences between these methods can help designers and engineers choose the most suitable technique for their specific applications.
What Is Vacuum Plating?
(Vacuum-plated ABS parts. Image from the Internet)
According to different processes, vacuum plating, or vacuum coating, mainly can be divided into several types, including vacuum vapor plating, sputtering plating, and ion plating. It can also be categorized into general vacuum plating, UV vacuum plating, and special vacuum plating.
They all deposit various metal and non-metal films on the surface of plastic parts by distillation or sputtering under vacuum conditions. In this way, very thin plating can be achieved.
Vacuum Plating Process
Product surface cleaning and de-staticizing--> spraying primer--> baking primer--> vacuum coating--> spraying top coat--> baking top coat.
What Is Water Electroplating?
(Water-electroplated ABS parts. Image from the Internet)
Water electroplating, also known simply as electroplating, involves using an electric current to reduce dissolved metal cations so that they form a coherent metal coating on an electrode.
The conductivity of the product increases significantly after plating. There are two ways of insulation treatment:
- One is to apply insulating oil to the part to be insulated so that it will not be plated when plating, thus achieving the insulating effect. Of course, the component coated with insulating oil will become black, so it is unsuitable for outside surfaces.
- Secondly, protecting the part with special adhesive paper can also achieve the effect of insulation.
Water Electroplating Process
Preparation: The substrate is cleaned and submerged in an electrolyte solution.
Electroplating: An electric current is applied, causing metal ions in the solution to deposit onto the substrate.
Finishing: The plated object is rinsed and dried.
Key Differences Between Vacuum Plating and Water Electroplating
#Cost
Vacuum Plating: Generally more expensive due to the cost of equipment and materials.
Water Electroplating: More cost-effective, especially for large-scale operations.
Simply speaking, if not covered by UV oil, the adhesion of vacuum plating is weak and cannot pass the 100-gram TEST. In comparison, water plating is better than vacuum plating. Therefore, to ensure the adhesion of vacuum plating, it is necessary to carry out a special coating treatment afterward, and the cost is higher.
#Material
Both vacuum plating and water electroplating are typically used for plastic components in rapid prototyping.
Vacuum Plating: It can apply to various materials, including ABS, ABS + PC, and PC. After vacuum plating, the parts can resist a high temperature of about 200℃. For parts that require high-temperature resistance, spraying a layer of UV oil at the end of vacuum casting makes the product's surface shiny and high-temperature resistant and ensures adhesion simultaneously.
Water Electroplating: Can only plate ABS material and ABS+PC material (the plating effect for the latter is not very good) and cannot be used for parts that need to be applied at high temperatures.
#Color
Vacuum Plating: Offers a wide range of color selections. It can even plate seven colors on one part.
Water Electroplating: It is typically only possible to obtain sub-silver, gray-silver, gunmetal, gold, black chrome, semi-glossy chrome, and other single colors with water plating.
#Process Complexity
Water plating enjoys a broader application than vacuum casting because its process is less complex. And the requirements of equipment and environment are not as strict as vacuum plating.
#Efficiency
Vacuum Plating: Offers high efficiency with minimal material waste.
Water Electroplating: Efficient for large volumes but may produce more waste.
#Applications
Vacuum Plating: Ideal for high-end applications requiring superior finishes, such as in the aerospace, automotive, and electronics industries.
Water Electroplating: Commonly used in the automotive, jewelry, and hardware industries for corrosion resistance and decorative purposes.
#Environmental Impact
Vacuum Plating: More environmentally friendly with fewer hazardous byproducts.
Water Electroplating: Generates chemical waste that requires careful disposal to avoid environmental contamination.
Conclusion
Both vacuum plating and water electroplating have their unique advantages and disadvantages.
Vacuum plating offers superior quality and environmental benefits but at a higher cost, making it suitable for high-end applications.
Water electroplating, on the other hand, is more cost-effective and widely used but comes with environmental and surface quality trade-offs.
Understanding these differences can help designers and engineers select which plating method to use based on their specific needs and priorities for prototyping new products.
