Choosing the best cooling method for your CNC machines
In order to avoid mill overheating in CNC processes while still cutting down the cost, the following techniques will be ideal choices.
Overheating of the rotary cutters or milled materials is among several mechanical, electrical and material related failure modes that cause the disadvantages of CNC compared to other machining options. Overheating causes permanent damage to the milling device as well as cause bodily harm to the machine operators. If you are looking for methods to eradicate or eliminate this weakness then this article is the right one for you.
1. Flood cooling
Flood cooling, also known as wet cooling, is probably the most commonly used cooling technique that involves spraying a constant jet of coolant onto the contact area between the tool and the milled material. It is a very safe way of mitigating heat while being extremely effective. The jet of coolant also has the benefit of washing away chips of material produced during the milling process from the contact area. Downsides include the high costs of cooling fluid and how it spreads in and around the machine, requiring more cleanup. Further, synthetic cooling fluid is often toxic and can create particles harmful to the environment and human health.
2. Cryogenic cooling
Liquid nitrogen can be injected into the tool to keep the milling surface cool throughout the process. Evidence has shown that this method produces an evener finished surface than flood cooling and that the injected tools have a longer life-cycle than their more ordinary counterparts. Considering it has relatively low variable costs since no large quantity of flood coolant is used, it is a viable option for applications in which the application of exterior coolants is not possible.
3. Solid lubrication
Strong metalworking liquids, or industrial ointments, can be used as a substitute for less viscous liquids. Water and soil can be contaminated using mineral-based cooling liquids used in flood cooling. Because less fluid is required than with flood cooling, solid lubrication is more environmentally-friendly and often more cost-friendly. Unfortunately, lubricant delivery is less efficient than a constant spray system and less frictionless, requiring a regular application to the contact area. Also, solid lubrication is not good for applications needing rapid clearing of material chips.
4. Compressed air
Compressed air is a solution that can eliminate any need for lubricant, thus dealing with disposal and variable cost issues. Using compressed air may very well be the most cost-efficient way of cooling a CNC machining process and rapidly clears chips. Regretfully, the fact that compressed air cooling has no lubricating quality makes it difficultly applicable to friction-intense processes.
Conclusion
No method is unilaterally better than all the others. Each method has pros and cons that can add value to a process depending on the specific context in which CNC milling is required. It is important to remember that choosing the right method to avoid overheating must be done first and foremost in regards to the safety of the operators. Many jurisdictions have regulations for machining processes, undoubtedly influencing the choice of a cooling process.