Driving down the High Cost of Overspray in Automotive Paint Processes

By designing automated paint systems with superior control behavior, OEMs can improve transfer efficiency and minimize overspray and its heavy costs for automotive companies.

April 18, 2025

Christopher Logue

Between material waste and paint sludge treatment, automotive manufacturers have a significant opportunity to reduce costs by minimizing overspray. (Emerson)

When painting automotive exteriors, automotive paint robot arms quickly move around the body to deliver paint. As the arm constantly changes position, the angle of delivery changes too. The paint must be directed toward the surface according to each angle. Otherwise, the paint droplets will miss the vehicle body and instead drift through the air. To direct the most paint toward the vehicle exterior, the atomizers in the arm must spray in a specific pattern according to each angle the paint is delivered.

The Emerson plug-and-play paint arm panel solution includes all automation components, providing hassle-free installation. (Emerson)

As previously stated, the spray itself is made up of compressed air combined with paint media inside the robotic arm. The flow and pressure of this shape air determine the spray pattern of the media. To achieve the necessary spray pattern each angle requires, proportional technologies in the sprayer arm must quickly change compressed air pressure and flow rates.

Transfer efficiency is the way to measure how efficiently automated paint systems use paint media. It’s a ratio that describes how much paint adheres to an intended surface compared to how much paint was sprayed. High transfer efficiency results in a low amount of overspray, while low transfer efficiency results in a high amount of overspray. The faster proportional technologies can control compressed air pressure and flow rate changes to match the spray pattern to the angle, the higher the transfer efficiency of the robotic arm.

Improving transfer efficiency

In automotive applications, automated paint systems with high transfer efficiency ensure that the paint that is sprayed effectively and coats the desired surface rather than become overspray. This minimizes media consumption and waste for automotive manufacturers and reduces their related costs.

To help automotive manufacturers maximize transfer efficiency and minimize overspray during automated paint processes, it’s critical that automated paint system OEMs engineer robotic paint arms with highly responsive and consistent proportional technologies.

Most proportional technologies used in robotic paint arms have a reaction time of 130-150 milliseconds. However, there are now direct-acting pressure regulators with a response time of 80 ms. This higher level of sensitivity can respond to necessary compressed air pressure and flow rate changes significantly faster than conventional proportional valve technologies as robotic arms move around vehicle bodies.

Christopher Logue has 10 years of industry experience across a variety of disciplines, businesses and world regions within Emerson. He currently leads global business development activities for the Emerson Factory Automation and Transportation industries. (Emerson)

What makes this level of shape air control possible is the regulatorIt has double solenoid coils on both sides and is programmed with software that features a self-adapting control algorithm. The valve can directly connect to flow sensors that calculate the exact flow and pressure data that is coming through the valve. Using a self-adapting algorithm, the valve can immediately adjust. This closed feedback loop between the valve and sensors shortens the path that sensor data must travel, skipping the robot controllers altogether.

This closed feedback loop and level of responsiveness mean that paint robots equipped with these regulators are significantly more efficient at changing spray patterns to deliver the precise flow and pressure required for the angle of spray. Self-adapting control algorithms make it possible for robotic arms to detect and quickly adjust if flow and pressure rates deviate from what the process requires.

Some suppliers offer the advanced pressure regulator and flow sensors as part of a pre-engineered, pre-programmed panel. In addition to these components, the compact panel also includes a proportional valve for atomizer control and lightweight valve terminal with AES I/O. All components are attached to a metal plate that machine builders can install inside a robotic arm and simply plug in pneumatic tubing and electrical connections.

By using plug-and-play offerings when manufacturing automated paint systems, OEMs can streamline component sourcing and minimize in-house engineering. This gives OEMs an advantage by speeding up production, getting to market faster and meeting demand.

Achieving superior media control

With a response time of 80 ms, the Emerson AVENTICS ED07 pressure regulator can respond to compressed air pressure and flow rate changes much faster than conventional proportional valve technologies. (Emerson)

Whether cars, buses or planes pass through the paint booth, overspray is a challenge that results in multiple and expensive issues. It uses excess media, generates paint sludge that must be treated and results in inefficient processes. Precision automation technology can ensure the accurate application of paint with tight controls on material usage, significantly reducing sludge disposal costs, media costs and environmental impact while improving the quality of paint finishes.

By designing automated paint systems and robotic arms with superior control behavior, OEMs can help automotive manufacturers optimize paint processes and minimize overspray. Equipped with highly responsive and consistent proportional technologies, robots can monitor and adjust the paint process in real time, ensuring optimal material usage from start to finish.

Christopher Logue is global director of Business Development, Factory Automation and Transportation Industries at Emerson.