LEI ‘How To’ Guide – Machine Coolant

The weather is reaching the warmest peak of the season, but our team is staying quite cool inside our temperature-regulated workspace – and so are our machines! Machine coolant is a vital part of all of our machines here at Leading Edge Industrial, and we’ve spent a significant amount of time researching and testing different ways to make our machine coolant most effective. There are a few questions you need to ask yourself when choosing the best coolant for the job. These include:

What metals are you planning on machining?
What options do you have?
What are your top preferences?
What product are you currently using

Answer these questions to get an idea of where to start. We can help you take it from there! Here are a few of our solutions:

Reducing the Lube

While reducing the lubrication may seem counterproductive upon first thought, minimum quantity lubrication (MQL), or near-dry lubrication, is a method that’s been practiced throughout the manufacturing industry for nearly 15 years. MQL uses the minimal amount of cutting fluid mixed with air as an aerosol to control the lubrication and provide reduced friction at the cutting-edge zone. This not only allows your machines to run more effectively but reduces the need to buy cutting fluids and minimizes disposal costs. Additionally, the aerosol is nearly completely used up in the machining process, which diminishes workpiece, tool, and machine cleaning-cycle times. Shops that practice cutting lubrication produce clean, dry chips that can be recycled.

MQL mixing systems take precision and efficiency to a new level. The systems deliver a precise amount of aerosol while controlling the diameter of the droplets. The flow can range from 3-ml/hour to 500 ml/hour. Tools for MQL delivered internally will need special consideration, as the channels used to transport aerosol through the tool are designed to have a minimum change of direction as to increase efficiency. This proves to be challenging in large diameter tools that require a lot of flow change to reach their outside diameter and the cutting zone.

Cutting Dry

Cutting dry (or even cutting dry with pressurized air for cooling) has been a regular practice throughout the manufacturing industry for years and is used for the machining of hardened steel parts. During these applications, heat is generated, and the cooling effect of the air that is pressurized will reduce the change of thermal shock. Temperatures generated by dry cutting are usually higher than those made when wet cutting is used. The variation in temperature during a dry machining cycle is low, which means that the tool’s cutting edges experience less stress.

Many different types of companies in the manufacturing industry can benefit from cutting dry. Machinists can eliminate the added costs and tedious nature of using, recovering, and recycling with cutting fluids. In fact, operations that expose tool materials to heat loads that tend to be inconsistent can significantly benefit from cutting dry. Some of the more brittle materials (such as coated carbide, ceramics, cermets, cubic boron nitride, and polycrystalline diamond) are highly at risk for chipping and breaking due to thermal stresses that occur in face-turning and milling operations that are incredibly rough on carbide cutting tools. In milling, the differences in temperature can cause rapid and repetitive periods of expansion and contraction due to the edges heating and cooling while they enter and exit work and those fluctuations form a series of thermal cracks perpendicular to the tool’s edge, causing it to begin to deteriorate.

Wet Cutting – Weighing the Pros and Cons

While we certainly aren’t hating on wet cutting, we realize that both methods come with a list of pros and cons. In fact, wet cutting can be an incredibly useful solution for the right company. Cutting fluids, or the formulations of lubricants and fluids, provide many critical functions in machining. For instance, cutting fluids remove chips from the point of the cut and provide corrosion protection for the workplace and machine. They clean the tool as well as the workplace and reduce tool wear in the process. Additionally, cutting fluids bind dust and microchips made in the cut, and they improve cutting accuracy, reduce friction, increase tool life, and improve the workplace surface. However, cutting fluids can bring disadvantages to the workplace in the form of hazards, allergic reactions, respiratory irritation, and even poisoning or infection in predisposed individuals. One should carefully weigh the pros and cons of cutting fluids before choosing to use them in the workplace, as dry cutting could present a successful alternative.

Flood vs. Mist

Many industry professionals are familiar with both flood and mist coolant options, but which option is preferred? Believe it or not, the difference is nearly entirely of a function of which method will better clear the chips.

Consider a low-performance coolant system. It may put out a slow trickle of coolant, but the chips are not being cleared successfully. This is because the pool of coolant on the workpiece is protecting them from removal since the sheer force of the flood alone is not strong enough to blast them out of there.

In contrast, a misting system doesn’t have a pool for the chips to hide under. It’s easy to see if the chips are being cleared or not, and whether you need to crank up the air pressure. The mist is much less messy and doesn’t require an attire of oversized ponchos just to avoid getting drenched beyond recognition! Though, if you are not careful with your MQL mixture settings, a coolant fog can form as the lubricant mixes with the surrounding air.

How do we make sure our flood coolant system isn’t mediocre?

First, we need to make sure that sufficient pressure can be generated by the flood system to ensure the chips are cleared. Second, the coolant must be appropriately aimed at the chips to be successful. Aim for the bottom of the cup or the top of the material if the nozzle can’t “see” the bottom of the cut.

LEI Upcoming Events

Conference season is quickly approaching! At the end of next month (June 25-29) our team will be attending the SkillsUSA National Leadership and Skills Conference in Louisville, Kentucky. This conference will allow us to showcase our upcoming products as well as learn from other industry professionals and leaders. Soon after, we will be attending the IMTS conference held in Chicago (September 10-15). This event takes place every other year and is considered the “Olympics” of the manufacturing industry. We are looking forward to compelling discussion and engagement, and we hope to see you there!