Tag: additives

How to Manage your Metalworking Fluids

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Metalworking fluids may not contribute that much to your manufacturing costs, but when fluids begin to fail or not work as intended, the costs could be astronomical. With the increasing costs of more technological fluids and rising disposal costs, managing your fluid and fluid consumption is more important than ever. Managing your fluids and dedicating a fluid management program could pay dividends by: reducing fluid usage, extending tool life, and improving manufacturing performance.

Monitoring Concentration

Fluid technology has advanced by leaps and bounds over the years and have improved performance for manufacturers. However, these advanced fluids have been engineered to work at specific concentrations. Running a coolant too thin or too rich will limit its ability to do its job. Running a coolant too rich might cause problems of over lubricity, but the main problem is overconsumption of the fluid.

The big problems occur when a fluid is too thin. This means the concentration in the sump is below the manufacturer’s recommendation. The additive packages are designed based on these minimum concentrations and provide enough of each additive to perform its function properly. Less concentrate means fewer biocides, fewer rust inhibitors, fewer emulsion stabilizers, etc. Eventually, the fluid breaks down quicker requiring more frequent change-outs. Some managing fluids, some operators use coolant additives/boosts to improve performance. If you vigilantly monitor concentration, the need for additives will lessen and thus reduce costs.

To monitor concentration, use a refractometer to measure concentration frequently. It is recommended to measure concentration every day or twice a day (depending on your operating schedule). The same person should measure to ensure consistency and ensure reliable measurements. When charging or recharging sumps, using automatic mixers helps ensure concentration is consistent. Remember, do not add just coolant or just water to the sump to balance out concentration. Some facilities use digital coolant monitoring systems to manage concentration, pH, and other factors. Facilities with large coolant systems may benefit from the technology.

Assessing Water Quality

Water comprises 90% or more of the fluid in the sump, thus it is crucial to make sure you are using good water. A common problem is hard water. The ions in hard water can cause chemical instability and increase the likelihood for emulsion splitting. Testing and treating your water is recommended to make sure your sump mix is working as intended. Twin Specialties can test samples of your tap water to ensure it is suitable for use in your metalworking fluid. If your tap water is excessively hard, installing a de-ionized water line is recommended for your facility. Coolant mixers can be connected directly to these lines to ensure proper mixing.

Once your water is deemed suitable, mixing the oil and water is all that is left in preparation. For the best performance and increased emulsion stability, follow the acronym O.I.L.: oil in last. This is an easy to remember acronym that will help you manually mix coolant; automatic mixers already mix using best practices.

Monitoring pH

Alkalinity is critical in the performance of your fluid. If the pH dips too low, it will no longer work and will need to be changed out. If pH drops below 8, it is imperative to raise it immediately. If pH drops below 7, the coolant is lost and must be changed. As the coolant gets more acidic (decreasing pH) you increase your risk of rusting problems. Some additives boost pH, but those may not be needed if you actively monitor your concentration. Monitoring is relatively easy, mix the fluid in the sump to get a more homogenized solution then dip a pH testing strip into the solution. Give the strip some time to change color and then match the strip to a reference sheet (usually provided with the strips). Then you can act accordingly armed with the pH information you need.

Tramp Oil Removal

Slideways and spindles require oil lubricants in order to function properly and ensure proper machining operations. These oil lubricants will leak into the sump and can cause havoc on your metalworking fluid. Some of the lubricant will be emulsified and disrupt the chemical composition of your metalworking fluid. The more oil content in the concentrate, the more likely the tramp oil will be emulsified.

This causes the growth of anaerobic bacteria. This bacterium creates hydrogen sulfide gas, which is the “rotten egg” or “Monday morning” smell that indicates coolant rancidity. The hydrogen sulfide in water also produces acids that drive down pH and alkalinity, which further damages coolant.

Synthetic coolants are excellent in rejecting tramp oils and prevent them from being emulsified. These floating oils can easily be skimmed and removed before causing damage. Using coolants below recommended concentrations limit the tramp oil rejecting additives and can accelerate this process of degradation.

Floating tramp oil can increase oil mist and smoke formation that can damage machines. The tramp oil mist also increases residues on the machine that can clog filters and destroy critical electronic components. Removing floating oil is relatively easy. Installing a skimmer, centrifuge, and/or coalescer will remove tramp oil from the sump and extend your coolants life.

Filtration

Metal fines and chips may find their way into the sump. It is important that they do not remain there and are not cycled through the machine. These fines can cause wear and damage to the machine and workpiece. The fines can build up and create dead-zones when additives are trapped and do not work. The trapped additives cannot work and lead to accelerated coolant breakdown.

Filtration used to be a cost-prohibitive endeavor, but the economics of coolant management and consumption make filters a worthwhile tool. The costs of filtration have come down and filtration technology has improved, thus implementing them will reduce coolant consumption and coolant spending.

Removing Foreign Substances from the Sump

Dirt and other foreign substances can cause problems such as abrasion and pump damage. Filtering solid substances and removing them will improve coolant performance. Sump cleaners might not be fully removed and can cause excessive foaming. If that happens, using a defoamer should alleviate these issues. However, be sure to properly remove the cleaner before recharging the sump. Prevention and proper preparation are usually the best maintenance.

Managing Straight Oil/Neat Oil

Neat oils require much less maintenance than water soluble coolants. This is because neat oils do not require water, which is a breeding ground for bacteria, fungi, and mold. However, there are still a few things that you should do to maintain and extend fluid life. The main thing should be done is filtering metal fines. Removing these metal fines improve finishing and fluid performance.

Takeaways

Given the rising costs and improving technology of metalworking fluids, it is more important than ever to proactively manage your fluids. This can lead to extended use intervals and improved performance. Following these steps will allow your machine to get the most out of these fluids.

Twin Specialties provides a full line of metalworking fluids and additives. Additionally, our sales team will work with you to test your fluids and water to troubleshoot the problem. Contact Twin Specialties for more information about our metalworking fluids, technical expertise, and our testing and sampling program.

How to Select the Right Grease

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Selecting a grease or lubricant is one of the most crucial decisions you make in regards to any machine. Your selection might make the difference between cost savings, reduced downtime, or significant unexpected costs and failures. For oil lubricants, many OEMs specify what product or what type of product is recommended for each component of their equipment. This simplifies the selection process. However, OEM grease specifications are much broader. Most of the time OEMs simply recommend the National Lubrication Grease Institute (NLGI) specification.

This presents both flexibility and options, but also introduces more room erroneous decision-making and poor lubrication. Simply using the NLGI grade is not enough. You have to look at other factors to ensure you grease and machine work properly and does not fail. We will look at some key factors that every operator needs to consider.

Base Oil Viscosity

A grease is composed of 3 ingredients: thickener, oil, and additives. The NLGI number indicates the thickness of the thickener, but does not specify the viscosity of the thickened base oil. The underlying base oil has its own viscosity just like any lubrication oil. If a piece of a equipment calls for a certain lubricating oil with a specific viscosity, it is easy to find a grease that has the same base oil viscosity and similar additive package.

If viscosity requirements are not specified, you can use the chart below (courtesy of ExxonMobil and Noria).

The two factors required are operating temperature and DN or NDm, which are the bearing speed factors. To calculate those speed factors, simply use the following formula:

  • DN = (rpm)*(bearing bore) and
  • NDm = (rpm)*((bearing bore + outside diameter) / 2)

The intersection of DN and Temperature will point you towards the required ISO viscosity. This chart assumes viscosity index.

Base Oil Type and Additives

Once a viscosity is identified, you need to figure out what additives and base oil you need. Similar to oil lubricants you must assess your operations and figure what additives are necessary or unnecessary. For example, light loads and high-speed applications do not require a grease with extreme pressure (EP) additives, but a heavily loaded application will need those EP additives. The chart below breaks down the needed additives for various bearings.

Courtesy of Noria

Most greases use mineral oil and only require mineral oil. However, synthetic base oils are recommended for certain extreme temperature applications. Applications with low or high operating temperatures or a wide range of temperatures, a synthetic base oil is recommended. Synthetic base oil greases are also recommended for users who want to longer regreasing intervals.

Grease Thickener

Unlike lubricating oils, greases include thickeners. The two factors that distinguish grease are type and consistency. As mentioned earlier, consistency is based on the NLGI scale. The scale ranges from 000 (most fluid) to 6 (least fluid). The most common and most recommended NLGI grade is #2. Most OEMs specify the NLGI grade and matching that number is a simple process (especially if you require a NLGI 2 grease).

The other factor for thickeners is the type of thickener. The differences between each type of thickener are present pros and cons for each application. The most common types are lithium soap, lithium complex, and polyurea. Lithium soap greases are low-cost general-purpose grease and perform well in general applications. Lithium complex is similar to lithium soap, but is preferred for applications with higher operating temperatures. Polyurea greases have good high-temperature properties and have high oxidation stability and bleed resistance. When switching greases, it is important to understand thickener compatibility to make sure the new grease does not fail.

Cost and Other Considerations

When purchasing a grease, a basic lithium grease will be cheaper than a sophisticated polyurea grease. It is up to you to determine the tradeoffs between grease costs and performance gains/losses. Purchasing a higher quality grease may lead to longer regreasing intervals and less machine failure.

To save costs, consolidating greases may be wise, but be wary of over-consolidation. This may result in some machines not using an appropriate grease.

Other attributes should be considered depending on the application. Some grease exclusive attributes include:

  • Drop Point
  • Mechanical Stability
  • Water Washout
  • Bleed Characteristics
  • Pumpability

Certain attributes are focused specifically on heavy loads and should be considered for heavy load-low speed applications. These include:

  • Four-Ball Tests
  • Timken OK Load

Additionally, industry specific requirements will also dictate grease selection. These industries have strict requirements and require greases to be certified by certain 3rd-party regulators:

Conclusion

Unlike oils, greases have many more factors for product selection. These factors should be considered for each application as each grease is designed and manufacturer specifically for each application and have a delicate balance of thickener, oil, and additives.

Twin Specialties carries a wide variety of greases to meet you application needs. We work directly with you to make sure we provide the right product that delivers performance while being mindful of the total cost of grease and maintenance. Contact Twin Specialties to learn more about our grease product lines.

How to Get Rid of Microbes in Your Sump

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Bacteria or Fungus in the Machine Sump

At some point, your metalworking fluid will go bad. Hopefully, in most cases it has ran through its effective life and can safely be removed or recharged with a fresh batch. However, sometimes a fluid’s life will be cut short due to unforeseen circumstances. This may involve machine leaks, breakdowns, or outside contamination. In some instances, your fluid and machine may be filled with bacteria or fungus. When this happens, it is imperative to stop operations and remove all fluid from the sump to prevent any further issues.

If there is any remaining contaminated fluid still in the machine, it will decrease the life and effectiveness of the new charge as the fungus and bacteria will continue to thrive in the existing fluid. It is best to also run a cleaner through the machine to help clean hard-to-reach areas such as pumps and hoses. In addition to cleaning out the contaminated fluid, the cleaner removes process oils, gummy deposits or oil, grease, swarf and other outside contaminants. Monroe Fluid Technology’s Astro-Clean A contains special additives designed to render the machine neutral of bacteria and fungus.

Bacteria and fungi grow in the presence of increased surface area in a fluid. As more bacteria and fungus are in the machine, the faster the growth. This exponential growth problem can wreak havoc on your machine and lead to serious problems. That is why it is important to be proactive in managing your fluid. This will lead to reduced down time and increased performance. The main component of fluid maintenance is following the manufacturers recommended concentration and regularly checking the fluid and adding any additives necessary to maintain the highest performance.

Biocides and Metalworking Fluid Additives

One key additive is biocide. Biocides are designed to kill bacteria, fungus, and other living microbes that will damage the fluid. These additives can simply be added to any sump or central system. Grotan is designed specifically for metalworking fluids to extend fluid life. Grotan is meant to be added at 0.15% (1500 ppm) and will fight bacteria and fungus. Many products are formulated with a biocide, like Grotan, to help protect machinery, tools, and work pieces.

Metalworking fluids with biocides are constructed with recommended concentrations in mind. This matters when a machine may be running “lean” on a fluid. If the manufacturer calls for 4%, but the machine is running at 2%, the machine only has half as much additives as needed. There must be a minimum level of biocide present in a solution in order for it to be effective. If there is not enough biocide, the bacteria will not disappear and slowly but surely repopulate. Therefore, it is imperative to follow manufacturer guidelines to enough there is enough biocide and other additives in your solution.

To ensure proper performance, it is important to regularly check the concentration of the solution to ensure the product performs as expected. Using refractometers to measure the Brix/concentration is crucial in maintaining an aqueous solution. This allows users to see the exact concentration and make adjustments as necessary. It is recommended to record the concentration level daily. Due to water evaporation, it is important to add concentrate to your sump to maintain recommended concentration. Never add just water or concentrate, it is recommended to add both to maintain the sump for longer tool life. Mixers are recommended to ensure consistent refills and measurements.

Cleaning Best Practices

It is also important to hand-wash/hand-wipe reachable areas of the machine to remove any solids from the sump. If these solids are not removed, it can result in continued growth of fungus or bacteria. Fungus typically grows by attaching itself to a solid in the sump or system. Theses solids may be outside contamination or smaller clusters of fungus. Therefore, it is crucial to remove solids and deposits before AND after running a cleaning solution through your machine.

If you are unable to dedicate a time to clean and service the machine, the cleaner can be added to the metalworking fluid solution at a concentration of 1-3%. This allows for cleaning while machining parts. Build-up will release from the machine as production continues. It is important to remove these residues and solids after the system is drained. As new fluid flows through the machine after recharging, some deposits may dislodge and appear in the sump. This is normal and should occur during the first week of a new charge.

Contamination that Grows Bacteria and Fungus

In addition to using a cleaner after draining the sump, it is important to follow fluid maintenance best practices. For example, it is recommended to have some method of skimming tramp oil. This can be done by hand or by having an oil skimmer installed in your tank or sump. When tramp oil gets into the mixture, contaminants from the oil can become “food” for bacteria. The tramp oil will also sit on the top of the sump and provide a “seal” which will allow anaerobic bacteria to thrive and multiply. This results in rancidity, which can create less than ideal work environments.

Sometimes outside contaminants can get into the sump and can create surface areas for bacteria and fungus to attach themselves and grow. This build-up can lead to dead zones in the machine where fluid flow is limited or halted completely. It is important to have mechanisms in place to regularly remove solids from the sump. Some examples of tools include: magnetic wheels, conveyors, and indexable filters. In the case of fungi, the fungal mass will remain in the system since it will not disintegrate in the fluid. Therefore, it is important to remove any fungal mass to prevent future growth. Having these items in the machine allow for solid removal and higher performing fluids.

Twin Specialties Can Help

If your sump is filled with harmful microbes, we are here to help. Twin Specialties has a variety of products and resources available to help get rid of microbes. We offer cleaners and biocides that can be incorporated into your sump and metalworking fluids. Contact us for a coolant management guide, a site visit, or fluid testing. We can discuss how to fix your sump and establish practices to uphold the integrity of your metalworking fluids.

What is Moly?

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What is Moly?

Molybdenum Disulfide, simply known as Moly, is used both independently as a dry lubricant and as an additive in lubricating greases. Dry lubricants reduce friction between two sliding surfaces without the need for an oil medium. Dry lubricant molecules have a natural attraction to metal and adhere themselves to metal surfaces. These molecules create a layer of protection that prevents wear and tear as well as significantly improve lubricity of metallic surfaces.

How Does Moly Work?

When used on its own, Moly is impregnated into the surfaces of metal parts to improve the lubricity and protect the parts themselves. When used in greases and lubricants, the Moly attracts itself to the metal surfaces as an anti-wear surface coating. When used in lubricants, Moly’s efficacy is limited if the additive remains suspended. It is important to ensure that the Moly is compatible with the oil or grease. If it is not compatible, the compounds could drop out and plug oil passages and filters.

Moly has a variety of unique properties that distinguish itself from other solid lubricants and solid additives. These include:

  • An inherently low coefficient of friction
  • Strong affinity for metallic surfaces
  • Film forming structure
  • Stability in the presence of most solvents
  • Effective lubricating properties from cryogenic temperatures to 350 C in air
  • Efficacy in vacuum and aerospace applications

Moly Greases

Moly greases can have concentrations from anywhere from 1 to 20%. Typically, Moly greases typically contain 3 to 5% Moly. Moly greases are generally used in operations where high pressure metal surfaces are sliding against each other. These include roller bearings that have very heavy loads and shock loading. Moly greases are also recommended in slow or oscillating motion that is used in universal and CV joints. Moly greases used in high-speed bearings can create problems such as “skidding,” where a bearing roller fails to rotate a full 360 degrees.

Due to its lubricating abilities in vacuums, Moly and Moly greases are popular in aerospace applications. Temperature limitations for Moly are much higher in space (1200 C compared to 350 C in air) thus can withstand extreme temperatures in space. Moly is used for low speed systems such as solar array drives, sensors, and antenna scanners.

Conclusion

As a solid lubricant, Molybdenum disulfide (Moly) serves as a better lubricant and additive than graphite because of its ability to operate under very heavy loads and in vacuum environments. If your machine’s manual calls for a moly grease, it is important to ensure a moly grease is used and the moly grease is compatible with other lubricants in your equipment.

What are Friction Modifiers?

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What are Friction Modifiers?

Friction modifiers are mild anti-wear additives used to minimize light surface contact, such as sliding and rolling. These can also be referred to as boundary lubrication additives. These additives are used in lubricants to modify the coefficient of friction (hence the name, Friction Modifiers). Friction modifiers are deployed to prevent wear on metal surfaces. Mostly used in transmission fluids and engine oils, these additives help slow down wear and increase fuel economy.

How do Friction Modifiers Work?

Source: Machinery Lubrication – Noria

A friction modifier molecule consists of two parts: a polar end (head) and an oil-soluble end (tail). The head attaches itself to the metal surface to create a cushion for the metal surface against another metal surface. The tails stand up like a carpet; vertically stacked besides each other in a Nano-sized sheet covering the metal surface. These molecules hold up when cushioned surfaces come in light contact with each other. This forms a thick boundary film that is softer than metal surfaces.

These additives have multiple functions beyond friction modification. They work as antioxidants and corrosion inhibitors as well. As the contact or load becomes heavier, the polar molecules are brushed off, thus rendering the additive useless in reducing friction.

Friction Modifier Applications

Friction Modifiers are typically used in engine oils and automatic transmission fluids. In engine oils, friction modifiers are deployed to improve fuel economy by reducing friction. In transmission fluids, friction modifiers are deployed to improve engagement on clutches. Some situations require some traction to operate properly.

Their use in engine lubricants increased in the 1970s due to the oil embargo. The lack of fuel led the automotive industry to improve fuel economy, thus reducing fuel usage. Continuous development has led to lower viscosity lubricants. Now, lubricants require robust friction modifiers to reduce wear and friction to offset the lower viscosity.

However, friction modifiers in these applications act differently based on shear conditions. This ensures equipment does not wear while also preventing too much slippage. This smooths the transition from a dynamic condition to static condition. For example, this is used in a gear change in a transmission.

Anti-Wear and Extreme Pressure (EP) Additives

As loads become heavier, engineers must adjust their lubricant to meet the tougher demands of heavier loads and higher temperatures. You should switch to a modifier that is classified as an anti-wear additive. A common and effective anti-wear agent is Zinc dialkyldithiophosphate (ZDDP). These additives react with metal surfaces once the environment reaches a high enough temperature.

As loads continue to increase, in addition to metal contact, the friction modifier must become more robust. In this instance, your lubricant must include extreme pressure (EP) additives. These additives are either temperature-dependent or not. Temperature-dependent EP additives activate as the metal surface temperature increases due to the extreme pressure. The reaction is driven by the heat produced from friction.

Final Thoughts

Lubricants with friction modifiers create more efficient operating environments. This leads to less wear, downtime, and carbon dioxide emissions. As friction modifier additives improve, lubricant manufacturers will aim to reduce to viscosity to reduce shear conditions. Conversely, this creates more components operating in thin boundary lubrication conditions. We will see continuous innovation of these additives to meet the performance and efficiency demands.

What are Lubricant Detergents?

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Detergents Defined

Detergent additives perform two key functions. Like household detergents, the additives keep metal components clean and free of deposits. Additionally, detergents neutralize acids that form in the oil. This is key for systems where component cleanliness is essential. Originally developed for engine oils, detergents addressed carburetor deposits that could hamper performance. Detergent additives were also found effective in fuel injectors. The detergents reduced deposits that affected fuel spray patterns.

How do Detergents Work?

Detergent additives are basic in nature, thus serve as a neutralizer for acidic contaminants that may arise in your lubricant. In the past, these detergents were barium-based, however modern chemistry has allowed manufacturers to move to different formulations. Today, most additives use either calcium-based chemistry or magnesium-based chemistry. As an oil is subjected to oxidation, it will start to collect acids. As these acids build up, the oil’s Total Acid Number (TAN) will increase. The basic and alkaline detergent will neutralize the acids and reduce the TAN. However, as the detergent is used, the Total Base Number (TBN) will decrease to point where the oil will need to be replaced. Therefore, measuring TBN is crucial to engine performance and lubricant effectiveness.

In high-temperature applications, metal compounds leave an ash deposit when burned. This residue buildup requires many OEMs to require low-ash oils. Detergent additives are used to clean these deposits. However, dispersants are included as well to help clean the engine. Dispersants are used to keep engine soot particles suspended and prevent agglomeration (forming larger soot deposits). The dispersant and detergent work together to suspend contaminants and neutralize acids. Eventually, the additive capacity will exceed its limit and require users to change the oil and replenish the additives.

Detergent v. Non-Detergent Oil

How do you know if you need a lubricant with detergent additives? Usually, an OEM will specify whether the equipment needs a detergent oil or non-detergent oil. Applications that could face high levels of water and contamination are good fits for detergent oil. Some examples include: off-road equipment, marine equipment, trucks & fleets, and many more. The high levels of contamination need to be neutralized with dispersants in order to keep pumps and valves clean and running.

Sometimes, OEMs require oils to not have detergent additives. Some manufacturers will produce special Non-Detergent oil to meet these specifications since, most oils now have detergent additives for better performance. Non-detergent oils are used in bearings and chains in non-critical once-through systems. It is also recommended for gas-powered appliances such as lawnmowers and tractors. Some non-detergent oils are not recommended for automotive gasoline engines (detergent oils are recommended).

Detergent Oil Today

With the developments in detergent and dispersant technology, most oils now have some sort of detergent additive to help combat high TANs and prevent sludge build-up. Even though non-detergent oil is still marketed today, it is only required for a few specific applications and not recommended by many OEMs. When selecting your lubricant, detergency is important to consider because high detergency will protect your parts, keep your system clean, and maximize performance. If you are using non-detergent oil, consider making the switch to an oil that has detergent additives.

Twin Specialties offers both detergent and non-detergent oils to meet your specifications and OEM requirements. We also offer a variety of motor oils and heavy duty engine oils with high-quality detergent additives to meet your specifications and budget. Contact us today for more information.