If you've ever detected that unpleasant odor akin to "rotten eggs" or a lingering stench reminiscent of "Monday morning" when returning to work after the weekend, you've likely encountered the telltale signs of bacterial growth in your water-based metalworking fluids. Neglecting to address this issue can lead to severe consequences, including operators refusing to work due to the overpowering smell. By the time the situation reaches this point, resolving it entails significant expenses and disruptions.

Many individuals opt to address the "ODOR" problem by simply changing the cutting oil. However, this approach fails to resolve the underlying issue. Even the most superior coolants can fall victim to microbiological attacks without proper maintenance. While most coolants are designed to create an alkaline, high-pH environment that deters microbiological growth, some incorporate biocides to eradicate microorganisms. Therefore, effective coolant maintenance commences with consistent concentration control.

■Manage concentration and pH value
Monitoring coolant quality via pH levels is crucial. The pH scale indicates coolant acidity or alkalinity, typically ranging from 9 to 9.6, although some products may exhibit lower pH during use. Ideally, coolant pH should fall between 8 and 9. Regular pH checks are recommended, preferably daily or at least weekly, using either a refractometer or test strips.

Test strips are immersed in the coolant, and the resulting color is compared to a chart to assess acidity, with a pH below 7.0 indicating acidic coolant requiring replacement. Refractometers offer another method, where a few drops are placed on the window, and the scale is read through the eyepiece after closing the cover.

A pH drop below 8.0 signifies diminishing coolant efficiency, increasing the risk of corrosion and microbial contamination, leading to odor issues. Conversely, a pH above 9.5 poses risks of dermatitis and skin irritation. Regular pH monitoring ensures optimal coolant performance and prolongs its lifespan.

In summary, the key factors affecting coolant performance are concentration control and daily makeup. Water-based coolants typically comprise 90% water, with a working solution concentration of less than 10%. Maintaining the proper concentration is crucial for effective lubrication, cooling, rust prevention, and bacterial control. Regular monitoring and adjustment can prevent these issues from occurring.

Ensuring the coolant concentration remains optimal requires daily additions of coolant at the appropriate makeup concentration. Due to ongoing evaporation and carry-off, machine sumps need regular refilling. Incorporating fresh coolant with water during refills helps restore the product's properties, maintaining its effectiveness.

■Optimize Filtration Systems
Efficient filtration systems are essential for maintaining peak performance in machining operations. CNC machines equipped with "through tool" coolant systems rely on effective filtration to prevent sump debris from obstructing coolant flow, safeguarding against equipment damage and bacterial buildup.

■Remove tramp oil promptly
When hydraulic and way oils flow into the sump and mix with the cutting fluid, it can lead to the cutting oil's inability to breathe, fostering the growth of bacteria. This can create anaerobic conditions, resulting in foul odors.

Moreover, it can lead to false concentration readings, causing the cutting oil to be improperly diluted, leading to increased tool wear and poor workpiece finish.

Therefore, timely filtration is crucial! Cutting fluid can be separated from hydraulic and way oils through an oil-water separator to stabilize the quality of the cutting oil and extend its lifespan. Proper filtration helps prevent bacterial growth, ensuring optimal performance and longevity of the cutting fluid.

For inquiries or assistance in developing a comprehensive fluid maintenance strategy, feel free to reach out to us at service_dept@hljh.com.tw or dial(+886-4-25332210).

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