Collaborative robots have become a mainstay in CNC machine tending, injection molding, painting, and general material handling applications. Their flexibility and ease of integration make them an attractive option across industries. However, there’s a common misconception that cobots can be deployed in fluid-rich environments without any additional planning. This assumption can lead to unnecessary wear, failures, or even safety hazards.
Whether you’re dealing with coolant mist from a CNC, mold release overspray from an injection molding press, or fine particulates in a painting booth, understanding how your robot interacts with liquids is critical. In this article, we’ll explore when fluid exposure becomes a concern, how to evaluate the severity, and what you can do to protect your robotic investment.
Fluid Hazards in Automation Environments
The most common fluid exposure scenario occurs in CNC machine tending applications. Machines often emit water-soluble or oil-based coolants during cutting operations, which can aerosolize into a fine mist or splatter as droplets during part ejection. Over time, these airborne particles settle on nearby surfaces—including the robot arm and cables.
Injection molding cells often present a different challenge. Mold release agents, used to help eject parts from the tool, can atomize into the surrounding air. Though less aggressive than coolants, these compounds can leave a film on exposed robot joints or affect sensors. Similarly, hydraulic fluid leaks or pneumatic venting can add to the contamination.
In painting or coating applications, overspray and volatile organic compounds (VOCs) introduce not just chemical exposure but also potential explosion risks. This makes robot selection, IP rating, and possibly hazardous location certification extremely important.
Even in relatively clean environments, moisture from cleaning processes, product condensation, or washdown zones in food production can present ingress concerns if not properly accounted for.
Do You Need to Worry About Corrosion?
Not all liquids are equally harmful. For instance, most water-based coolants are not corrosive by nature, especially when diluted correctly. However, they can become a problem if left to pool or dry in joints and connectors. Additionally, additives in these fluids—particularly in the amine family—can degrade rubber gaskets and seals over time.
Universal Robots’ e-Series, for example, is known to have gasket materials that are susceptible to swelling when exposed to certain amine-based coolants. While this doesn’t mean the robot can’t be used near coolant, it does mean operators must take precautions. Gasket swelling can lead to mechanical binding, calibration drift, or ingress that compromises internal electronics.
Similarly, mold releases or silicone-based coatings can slowly gum up mechanical joints or contaminate the robot’s end effector or vision system. Over time, this can lead to performance degradation and false positives in part detection.
Evaluating the Level of Exposure
One of the most important aspects of coolant compatibility is understanding how much and where the fluid is landing. Mist exposure is generally considered low-risk for robots with at least an IP54 rating, provided regular cleaning is part of the maintenance routine. Issues begin to arise when light droplets begin to accumulate—particularly on vertically oriented surfaces, cable junctions, or downward-facing robot joints.
Heavy dripping, especially from above, presents a more serious concern. A robot placed beneath a CNC door or mold ejector may experience direct impact from fluid, often in unpredictable spray patterns. If coolant drips onto the arm from overhead, gravity pulls it into every potential opening. If the robot is not sealed appropriately or positioned away from the source, this kind of exposure can quickly lead to corrosion or electrical failure.
In these cases, the use of protective enclosures, deflectors, or repositioning of the robot can significantly mitigate the risk. It’s also important to consider long-term accumulation: even a small amount of mist, if consistent, will eventually cause problems without intervention.
Understanding IP Ratings and Robot Design
Ingress Protection (IP) ratings are a standardized way to determine how well a robot resists solid and liquid penetration. For industrial environments, this is your first line of defense. An IP54 rating means the robot is protected from limited dust ingress and water spray from any direction. IP65 offers full dust protection and resistance to low-pressure water jets, while IP67 adds protection against immersion in water up to one meter deep for up to 30 minutes.
Most Universal Robots e-Series models, including the UR3e, UR5e, and UR10e, are rated IP54. While suitable for light mist, they may struggle in high-exposure environments. Their newer models—UR20 and UR30—feature IP65-rated arms with more robust sealing. Fanuc’s CRX series goes a step further, offering IP67 ratings, making them one of the most fluid-tolerant collaborative robot options available off the shelf.
Techman’s ruggedized TM12S also offers an IP65 rating and removes common ingress points such as the integrated camera and tool flange buttons. This version is particularly suited for environments where splash exposure is unavoidable.
Explosion Hazards: Not Just a Paint Problem
When fluids involve volatile compounds—such as solvent-based paints, adhesives, or certain aerosols—there’s more at stake than just equipment damage. These environments can pose a real explosion hazard if vapor concentrations meet the right conditions. Most standard collaborative robots are
not certified for Class I Division 1 or 2 areas as defined by NEC or ATEX standards. Deploying a standard IP-rated robot in such zones could not only damage the equipment but also endanger personnel.
Fortunately, there are purpose-built options. Fanuc now offers an explosion-proof model—the CRX-10iA/L Paint collaborative robot—specifically designed for painting applications. This unit is certified for hazardous environments, with appropriate sealing and grounding to handle flammable vapors safely.
In cases where an off-the-shelf explosion-proof robot isn’t available, some integrators offer retrofit solutions. For instance, Universal Robots can be retrofitted with sealed enclosures, positive pressure purge systems, and ATEX/NEC compliance features—though these must be carefully engineered, certified, and maintained.
No matter the path you choose, it’s essential to involve your environmental health and safety (EH&S) team early. Hazmat classification, local fire codes, and insurance requirements should all guide your robot selection and deployment process.
Protecting Your Robot
Even when an IP65 or IP67 robot is not available—or not practical—there are proven methods to protect your cobot investment. One option is a fitted protective sleeve, such as the Teflon-based Roboworld RoboSuit, which can resist aggressive coolants and prevent ingress into joints and electrical connectors. These suits are particularly useful in CNC tending and molding applications where daily exposure is expected.
Another approach is strategic shielding. Adding drip guards above the robot, tray-style bases below it, or rerouting coolant nozzles away from the work zone can significantly reduce the risk. If buttons or exposed connectors are present, cover boots or sealed caps are advisable.
Most importantly, routine inspection and cleaning must be built into the daily or weekly maintenance schedule. If fluid is pooling on or near the robot, it’s only a matter of time before problems arise.
Conclusion: Know Before You Deploy
Cobots can thrive in environments that contain fluids—but only if those environments are properly understood and managed. Don’t assume that a robot placed near a CNC or mold press will “just work” long-term. Take the time to understand the fluid exposure profile, check the robot’s IP rating, and evaluate whether protective accessories or enclosure strategies are needed.
Doing so can extend the lifespan of your equipment, reduce unplanned downtime, and ensure safe, reliable automation performance—even in messy environments.
If you’re evaluating a new cell—or troubleshooting an existing one—use the quick checklist below to identify potential red flags and confirm your robot is protected against fluid-related risks.
Coolant & Chemical Exposure Checklist for Cobot Applications
- Have you identified the type of liquid involved (coolant, mold release, solvent, etc.)?
- How frequent is the exposure — mist, splash, or direct drip?
- What is the IP rating of the robot arm? Is it adequate for this environment?
- Are there any gaskets, buttons, or sensors vulnerable to chemical ingress?
- Is there explosion potential from flammable vapors or VOCs?
- Are you using shields, guards, or deflectors to minimize exposure?
- Have you considered a protective sleeve like a Roboworld RoboSuit?
- Is there a routine cleaning or inspection process in place?
- Would an IP67 or explosion-proof model be more appropriate for the task?
Looking to automate around coolants or paints?
Contact Uchimura Robotics for a site-specific assessment or protective solution recommendation.
