Coolant is an important part of cnc machining process, they help to extend the life of the tool and improve the surface finish of the processed parts. Properly maintaining the coolant concentration level can not only extend the service life of the coolant, but also extend the service life of tools and machines.
The role of coolant
Reduce and eliminate heat accumulation in the cutting area and workpiece
Provide lubrication to reduce friction between tools and chip removal
Wash away chips and small abrasive particles from the work area
Prevent corrosion
The type of cnc machining process and material determine the type of coolant to be used and the balance of cooling and lubrication required. A thinner mixture can provide you with better cooling, while a thicker mixture can provide you with more lubrication.
Coolant type
Soluble oil: the most common of all water-soluble cutting fluids, it is an excellent choice for general processing. If the coolant tanks are not properly maintained, they can easily cause microbial growth of fungi and bacteria.
Synthetic oils: These types of oils are often the cleanest of all cutting fluids because they do not contain mineral oils and will not be mixed with flowing oils. However, they have the lowest degree of lubrication.
Semi-synthetic oils: They have less oil than emulsion-based oils, less odor, and retain many of the same lubricating properties.
Straight oil: not miscible with water, with mineral oil or petroleum-based ingredients, and contains vegetable oils, fats and esters and other lubricants. They provide the best lubrication, but have the worst cooling performance.
How the machine coolant system works
During processing, the coolant mixture can overflow the entire work area. This process also flushes debris and particles from the work area. Coolant accumulates in the sump at the bottom of the machine. The coolant is drawn from the oil pan and recirculated to the work area.
Both central and stand-alone coolant systems need to be monitored, maintained and adjusted. Compared with the central system, small systems are prone to more rapid changes and greater fluctuations in consolidation levels. Therefore, the coolant used in small systems needs to be more resistant to contamination by metal chips, flowing oil and other materials.
Coolant concentration
If the proper coolant concentration level is not maintained, some problems may occur. If the coolant concentration is lower than the lowest ratio of the machine coolant supplier, it will cause the machine and the workpiece to corrode, which shortens the service life of the tool and breeds bacteria.
On the other hand, if the coolant concentration is too high, it will result in:
Less heat transfer
Blistering
Reduce lubrication
Waste concentrate
Residue formation shortens tool life
Dyeing of machinery and mechanical parts
The coolant should be checked daily to maintain an acceptable concentration level. The concentration of the machine coolant may change 5%-20% every day due to evaporation, splashing, fogging and overflow. Daily records can understand the operation mode of the system and the degree of daily concentration change.