Automated manufacturing has made it easier than ever to access products at affordable prices. The secret behind that success is the efficiency of modern CNC tools and machines, which is largely thanks to innovations such as coolant.
Coolants are used throughout the CNC manufacturing world. The right coolant works to increase efficiency, reduce costs and help operators deliver higher quality results than they could otherwise achieve.
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What Is CNC Coolant?
CNC coolant is a special category of liquids that are used to cool and lubricate tools and workpieces during machining. CNC coolant allows operators to manage heat build up when processing hard materials like metal or composites. Coolant systems are a popular solution that help with:
- Providing lubrication for tools
- Providing lubrication for workpieces
- Improving chip management
- Controlling heat build up
- Improving the quality of surface finishes
- Avoiding heat deformation, especially in soft materials like plastics
Used correctly, CNC coolant will greatly improve the quality and efficiency of your manufacturing processes. Coolant directly addresses heat build up, which is one of the main challenges with CNC machining, allowing operators to improve results and push their equipment to the limit.
When Is CNC Coolant Used?
Coolant systems are found on a huge range of CNC machines used for metalworking, timber manufacturing, machining, fabrication and beyond. The ability to continuously cool tooling and materials delivers significant improvements in quality, making cooling systems a critical part of most machining processes.
Depending on the industry, it’s common to see CNC coolant being used with milling machines, grinders, lathes and 3 and 5 axis CNC machines.
The Common Types of CNC Coolant
CNC coolants are available in a number of different formulations and varieties. The coolant you use depends on your equipment, the materials you’re machining and what you are trying to achieve. There are four main types of CNC coolant:
Synthetic
Synthetic coolants are polymer-based fluids that improve lubrication. Fully synthetic lubricants contain additives and rust inhibitors that make them some of the best performing coolants on the market.
Semi-synthetic
Semi-synthetic coolant is a blend of polymer-based lubricants and mineral oil. The low concentration of mineral oil means semi-synthetics benefit from the best of both worlds.
Soluble oils
Soluble oil coolants are a mix of oil and water. The higher concentration of mineral oil means soluble oil coolants are suitable for heavy-duty machining that requires greater heat dissipation.
Insoluble oils
Insoluble oil coolants are 100% mineral oil. These provide the best lubrication for metalworking, although they offer less heat dissipation than synthetic fluids.
The Dangers of CNC Coolant
On their own, the chemicals that make up CNC coolant are often harmful to machinists that are in regular contact with the fluid. Small concentrations of CNC coolant are unlikely to cause any serious harm. But regular, prolonged exposure to CNC coolant can lead to skin irritation, bacterial infections, breathing difficulties and other long-term side effects.
The dangers of CNC coolant largely come from the mineral oils and synthetic fluids they use, as well as additives like biocides and rust inhibitors. Rust inhibitors are a particular concern, with many reported cases of long-term complications due to prolonged exposure.
Adding to these issues is the fact that CNC coolant systems are run on a closed-loop. This reduces waste and expense, but it means that CNC coolant tanks are prone to growing bacteria. Many suppliers add biocides to their coolant to reduce bacterial growth, but it’s still up to machinists to manage the risk.
CNC Coolant Maintenance Procedures
Most types of CNC coolant are harmless when exposure occurs in small concentrations. That means it’s important for operators to use the correct PPE – such as ear, eye and breathing protection – whenever coolant systems are active.
It’s strongly recommended that you develop your own guidelines that help employees reduce the risk and manage CNC coolant properly. There are a few best-practice guidelines you can follow when dealing with CNC coolant:
- Test the coolant to check that it is maintained at the correct concentration
- Change the coolant at regular intervals
- Flush the coolant sump with every fluid change
- Filter used coolant to remove debris and bacteria before returning it to the sump
- Provide training and education to staff on the dangers of coolant
- Supply appropriate PPE
- Install machine cabinets and fume extractors to minimise the amount of coolant in the air
Using CNC coolants can provide a world of benefits to your manufacturing operations. From extended tool life to reduced expenses, higher quality finishes and greater efficiency, coolant systems are critical upgrades for all machining work. As long as staff are provided with PPE and training, CNC coolant poses no serious risk, and it can be a major boon to your business.
