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Our Process

Mueller Corporation uses a combination of vacuum metalizing with a spray coated base and top coat to achieve the best results for our customers. Our vacuum metalizing process provides an even coating without large build ups, while our spray coatings provide an adhesive base and customizable functional and decorative top coats.

Mueller’s superior processes are executed by our team of engineering experts in our full capacity facility. To learn more about what makes Mueller the right choice for your next coating project, visit our Why Mueller page.

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Benefits of Vacuum Metalizing and Spray Coating

Vacuum metalizing is the process of evaporating metals, most commonly aluminum, inside a vacuum chamber and bonding them to the desired substrate. This is the most common PVD (physical vapor deposition) method and the coating process of choice for many industries due to its many benefits:

More cost-effective than other applications
More environmentally friendly than other coating processes
Provides a more consistent, durable application
Meets a broad range of functional and decorative coating requirements and solves particular industrial coating challenges

Industrial coating challenges addressed by the vacuum metalizing process include:

Shielding from electronic interference
Barriers against moisture or vapor
High tolerances for properties like coating uniformity and adhesion
Unique reflective qualities

Our facility is fully equipped for all of your vacuum metalizing needs, with twelve automated vacuum chambers for both thermal evaporation and magnetron sputtering, which include four different sized chambers for a variety of applications and part sizes.

Step 1: Tooling and Part Loading

Our process begins with the fabrication of custom tooling fixtures to hold and mask your parts during the vacuum metalizing and painting operations. We ensure tooling fixtures provide maximum efficiency both in the number of components on a fixture and the handling of the fixture for processing, which allows for the best possible piece price.

Our goal is to ensure masking is integrated into the tooling fixtures to minimize manual processes. Any masking that is not achievable with a tooling fixture will be completed before processing.

We follow client guidelines and adhere to strict quality standards to ensure correctly processed parts. Our machine operators take several precautionary measures to ensure that no contaminants are transferred while loading the parts. Individual parts are inspected to ensure visible defects are resolved, and then loaded onto the tooling fixtures.

Step 2: Spray Coating Basecoat Application

For reflective finishes and chrome or metallic coatings a specially formulated primer, or basecoat, is applied to promote adhesion and provide a smooth surface for the metalizing and paint finish. Mueller Corporation has developed proprietary coatings for many substrates, including flexible plastics, which are suited for both high and low-temperature applications.

All coatings are applied by High-Volume Low-Pressure (HVLP) spray guns using one of three different methods:

Six-axis robotic paint cells
Automatic reciprocating paint cells
Manual (by hand) for low volume and prototypes.

Our robotic spray cells include eight banks, allowing us to apply a variety of coatings, such as:

Conductive paint for EMI/RFI shielding
Metallic paints
Basecoats and topcoats for vacuum metalizing

After paint application, the tooling fixtures are placed into convection ovens for curing.

Step 3: Vacuum Metalizing Process

First, the tooling fixtures are placed into carousels that are loaded into the vacuum chamber. A predetermined vacuum level is reached before a current is sent to the evaporation source. The source is a tungsten filament loaded with an alloy, most commonly aluminum. The current heats the filament until the alloy evaporates, forming a vapor cloud that bonds to the parts.

The tooling fixtures rotate in front of the evaporation sources to achieve a uniform coating. Upon completion of the metalizing process, the chamber is returned to match the atmosphere, and the tooling fixtures are unloaded.

Our proprietary EMI/RFI shielding process allows us to evaporate up to 20 microns of aluminum. The typical thickness of evaporated aluminum for light reflectors and chrome decorative coatings is approximately 1,000 angstroms. In-chamber pretreatment and post-treatment processes aid in the adhesion of the coating.

Step 4: Spray Topcoating Application

When required, a topcoat is applied to enhance resistance to moisture, abrasion, and chemicals. Mueller provides several functional and decorative topcoats including:

2K urethane and UV cured abrasion resistant clear coats
Functional industrial coatings such as Teflon and ceramic coatings
Dyed and tinted topcoats giving the appearance of gold, bronze, colored chrome, and metallic satin finishes

All work is done in a clean and responsible manner to produce the best finish with the least impact on the environment.

Precision EMI shielding, RFI shielding, ESD shielding and coating services

Let Mueller Corporation Be Your Vacuum Metalizing Partner

Join the ranks of industry leaders who leverage Mueller to go above and beyond for their coating needs. Contact us to get a custom coated sample for your project, free of charge.