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How to Manage your Metalworking Fluids

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.

What are Fire Resistant Lubricants?

Fire-resistant lubricants are fluids that are used in applications and systems where the risk of ignition is high. Typically, these environments are near or contain: open flames, sparks, or hot metals. If an oil leak were to occur, the risk of injury, damage, and even death is magnified as sustained fires can occur. That is why fire-resistant lubricants have been developed and manufactured to protect personnel and equipment.

Why do I need a Fire-Resistant Lubricant?

Fire-resistant lubricants are most needed in environments need high-temperature surfaces and open flames. Regular fluids that have low flash points pose the greatest risks to fire and should be switched for fire-resistant lubricants that have higher flash points.

If using pressurized hydraulic lines, it is key to have a fluid with a high flash point as small leaks can aerosolize the lubricant easily. The lubricant spray is much more susceptible to fire. It takes much less heat to ignite and can spread to fluid reservoirs. The lubricant can ignite if it’s fire point and/or auto-ignition point is reached. The fire point is the temperature at which a fire is sustained and is typically several (50+) degrees higher than the flash point. Opting for fire-resistant fluids with higher flash points will reduce the risk of fire and damage.

Fire-Resistance Fluid Standards

The term “Fire Resistant” and “Fire Resistance” are often misinterpreted and sometimes overused. There is no single property or metric that conveys relative fire resistance. Metrics like flash point, fire point, and autoignition temperature are useful, but do not tell the whole story. Because of this, most fluids are vigorously tested and are classified as “fire resistant” if it can pass various tests and simulations.

The Factory Mutual Research Corporation (FM) developed key benchmarks for testing fire-resistance. FM tests every single commercially available “Fire Resistant” fluid to ensure it meets various benchmarks. FM 6930 is the standard for hydraulic fluids and is classified into 3 levels: 0, 1, and 2. This standard only measures a fluid’s flammability and does not consider other factors of the lubricant.

The Mine Safety & Health Administration (MSHA) has their own tests and standards for underground mines and applications. Their stringent testing produces more failures than FM. Both programs has strict auditing and inspection programs to ensure fire-resistant fluids meet performance standards.

Types of Fire-Resistant Lubricants

Oil-Water Emulsions

There are 2 types of oil-water emulsion fluids: oil-in-water and water-in-oil. Oil-in-water emulsions are formulated with oil droplets sustained in water. Approximately 95% of the fluid is made of water and the remaining 5% is composed of oil. These emulsions have excellent fire resistance and heat-transfer capabilities, but poor lubricity and poor corrosion protection.

Due to these poor lubricity characteristics, water-in-oil emulsions (also known as inverse emulsions) are better performing fluids. These are 40% water and 60% oil. It provides more balance of heat-transfer properties, lubricity, and corrosion protection. The fire-resistance primarily comes from the water, which turns into steam and reduces the oil’s combustibility.

Water Glycols

Water-in-oil emulsions have seen declining market share due to the rise of Water Glycol Fluids. Water Glycols contain 35-45% water and the remaining contents are some sort of glycol, such as ethylene glycol. These Water Glycols offer some benefits such as a lower freezing point and excellent fire resistance. Water Glycols do have drawbacks, but many of these can be mitigated by various additive packages. These fluids can be used in a variety of applications, but speed and strength ratings are reduced due to the limited performance of the fluid. Despite this, Water Glycols are one of the most popular fire resistance lubricants on the market today.

Phosphate Esters

Phosphate Esters provide the best fire resistance properties of any fluid. This is due to their natural molecular structure. They are non-corrosive, have excellent oxidative stability, great anti-wear characteristics, and are suitable for use up to 150 C. Despite this, they have been losing popularity due to stringent compatibility and maintenance concerns. They are still popular for aircraft and military applications. Additionally, they require special seals and coatings and require special care during disposal.

Polyol Esters

Polyol ester fluids have gained popularity due to its fire resistance properties, excellent lubricity, and good viscosity stability across different temperatures. These contain additive packages to impart good performance and high thermal properties. These are much more compatible and versatile than phosphate esters. This has led to their rising popularity and market share in recent years.

Maintenance and Other Considerations

When switching to fire-resistant fluids, compatibility must be considered before restarting the equipment. By carefully draining the machine, this decreases the likelihood of any incompatibility issues.

High-water content fluids require a lot more maintenance and care to ensure they perform properly. Water provides a great medium for bacteria and biocide treatments are recommended to prevent bacteria growth. As temperatures rise, water evaporates and needs to be replaced to ensure the fluids cooling properties are not compromised. pH levels should be monitored along with corrosiveness and wear protection. It is important to follow proper storage practices to maximize efficacy and shelf life.

Like any other oils, fire-resistant fluids degrade in heat and reduce oxidative stability. It is important to note rotating pressure vessel oxidation test (RPVOT) values to ensure your fluid has enough oxidative stability.

Conclusion

Fire-resistant fluids are great options for equipment and environments that are susceptible to fires. If you have high-pressure machines, it is imperative to consider fire-resistant fluids to prevent potential sprays that can ignite. Twin Specialties offers both water glycols and polyol esters to meet your needs. Contact Twin Specialties for product information.

Why is it difficult to source Chemicals?

Throughout the last few months, there have been numerous disruptions across various supply chains, often occurring consecutively or even simultaneously. With COVID lockdowns in China, the war in Ukraine, truck driver shortages, and port congestion, some chemicals are still difficult to source.

Below are three different direct impacts the chemical industry is experiencing that will affect you and your business:

Allocation & Force Majeure

Due to natural disasters, staffing shortages, raw import shortages, and plant shut downs, lead times have more than doubled for almost all products. Products sold and transported by the tanker, truck load, and shipping container are facing longer lead times due driver shortages. Read more to learn more about the shortages and lead times.

Container Crisis & Container Shortages

Importing goods is more costly due to several reasons.

  1. There is a shipping container shortage.
  2. Shipping containers are stuck at ports due to trucking shortages.
  3. Some ports are shut down due to staffing shortages, leaving cargo ships anchored at sea for weeks on end.

Due to these interruptions, raw materials are harder to import, causing a shortage in finished goods (chemicals, containers, etc.) As we are seeing costs increase for all products and services, we are seeing large swings in our container costs as well. Read more for additional info and more can be found here about container shortages.

Lead Times & China Power Outage Mandate

The government of China has mandated power outages in an effort to save energy and cut carbon emissions. These power outages halt production for plants within the JiangSu, Zhejiang, Guangdong and other provinces. Shutting down these plants is causing a shortage in chemicals, clothing, and various other goods and raw materials. Read more about the forced shutdown period in China. In addition, to environmental requirements, certain provinces shut down business due to spikes in COVID case counts. This put pressure on other manufacturers to fill demand.

What is Twin Specialties Doing?

We look to serve our customer the best way possible. These challenges force us to think differently and try new things. We are continuously looking to expand our relationships with our current suppliers and grow our network of suppliers. This allows us more options to source chemicals that you need at the best price possible. If you are looking for chemicals, fill out the form below and Twin Specialties will help you find the exact product you are looking for.

How to Select the Right Grease

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 Respond to the EPA Solvent Assessment

In 2020, the EPA determined that 4 common parts-cleaning degreasing solvents pose “unreasonable risks” to workers. Not only, do they pose risks to workers, they also pose significant environmental risks. By 2022, there should be new rules and restrictions governing the use of solvents. This will have significant impacts on your surface finishing processes and your operations. We also do not know what the exact nature of the EPA’s decisions yet. It is crucial to take proactive steps to educate yourself about alternative cleaners and processes to mitigate worker and environmental risks.

What Solvents are the EPA Evaluating?

In 2016, the Frank R. Lautenberg Chemical Safety for the 21st Century Act became law with broad support from Congress. The law, referred to as “Lautenberg”, amends the Toxic Substances Control Act (TSCA). TSCA focused primarily on environmental impacts of chemicals and solvents, Lautenberg expanded the TSCA’s scope to include worker exposure: previously, worker exposure was solely under the jurisdiction of OSHA. Lautenberg also ordered the EPA to conduct a new review of chemicals and solvents and their impacts on human health and the environment.

At the end of 2020, the EPA issues a final risk assessment on 10 high priority chemicals. 4 of the 10 chemicals include the following degreasing solvents:

  • Methylene Chloride (MC)
  • Trichlorethylene (TCE): In 2016 EPA placed an alert on TCE as a known carcinogen
  • Perchloroethylene (PCE)
  • N-propyl Bromide (nPB)

The EPA found “unreasonable risks” to workers for all 4 solvents used in vapor degreasing operations. Additionally, trans-1,2-dichloroethylene (trans-DCE) has not yet been evaluated, but will be in the next tier of priority chemicals.

What Happens after the EPA Final Assessment?

Now that the EPA has issued a final assessment, it must now propose a rule with 1 year and finalize the rule within 2 years (end of 2022). What will the new look like? We do not know and the rules will be unique to each solvent as each solvent will present varying levels of risk to workers and the environment. An outright ban of on all 4 solvents is possible, but highly unlikely. A more likely scenario is increasing restrictions on the systems and operations in which these solvents can be used.

Trends indicate that these solvents can and will be used in airless systems. Airless systems prevent aerosolized degreaser to escape and increase worker exposure to droplets. The EPA may also consider the risks to be excessive even in the use of an airless system for 1 or more of the solvents. In the case of nPB, the toxicity limits have been reduced, but the exposure levels can be controlled given the right system. Using aerosol cans may overexpose workers to unreasonable risks, but airless systems might limit exposure to toxicity levels within regulations. Other implementations such as better ventilation, training and PPE could also reduce exposure and help you maintain compliance.

On the other hand, it is possible, but unlikely, the EPA would allow the use of an open top degreaser in certain situations. Whatever the EPA proposes and implements, it is important to be proactive now to ensure a smooth transition to changing products and processes.

What Can You Do Now?

Being proactive will ensure a smooth transition to life under new guidelines. There are many options and alternatives that can replace open top vapor degreasing. Each option has its costs and benefits and it is up to you to decide what is best. Some options include:

  • Implementing an airless system to limit exposure
  • Switching to an environmental, health & safety (EHS) preferred product such as trans-DCE or a “designer solvent”
  • Switching to a new vacuum degreaser using modified alcohol or hydrocarbon blends
  • Using an aqueous cleaning process and alkaline cleaners

These solutions account for the incoming rules, but there are many performance and economic factors to consider. If you plan to switch to an aqueous or airless system, investment in equipment and facilities are necessary and those costs have to be considered. Aqueous cleaners also may not perform as well as solvents in certain instances. This is why the government recognizes the need for solvent cleaning and enacted laws to preserve this process until a better method is discovered.

If you are planning to switch to another solvent, it is important to make sure that is works with existing systems and the cost increases are not substantial. Designer solvents are modified to perform safely, but they are costly. Having an efficient system to use these solvents will save you money in the long run. Solvent manufacturers are aware of these changes, but it is important for you to be proactive and informed too. This testing will vary from job to job and being proactive will allow you to monitor performance and compatibility and select the best solvent.

How Twin Specialties Can Help You?

In addition to provide solvents, Twin Specialties has alternative solvent degreasers, degreaser cleaners, and alkaline cleaners. Our sister company, Gemini Disposal Services, can handle disposal and treatment of used solvents and waste water generated in aqueous cleaning. We are here to help you find manufacturing, cleaning, and disposal solutions. Contact us for more information.

Used Oil vs. Waste Oil

The life of your oil-based lubricant does not end when it is time for a change. In fact, after draining a used lubricant, the oil will begin a new lifecycle thanks to advancements in recycling and recovery technology. 800 million of the 1.3 billion gallons of waste oil produced in the United States is recycled every year. To increase the amount of recyclable oil, manufacturers must collect and disposed of used and waste oil in safe, sustainable, and environmentally way. To achieve this, it is essential to follow best practices for used and waste oil management. However, there are key differences between “used oil” and “waste oil.”

Used Oil Defined

“Used oil” and “waste oil” are often used interchangeably, but the EPA defines them differently. The EPA defines used oil as:

“Used oil is any oil that has been refined from crude oil or any synthetic oil that has been used and as a result of such use is contaminated by physical or chemical impurities.”

This does not include any vegetable or animal-based oils. Simply, this is any petroleum or synthetic oil that has been used in operations and have reached the end of its service life.

Waste Oil Defined

Waste oil is much broader in its definition. Waste oil is “oil that has been contaminated with substances that may or may not be hazardous.” A lot of waste oil has not been used and was contaminated before use. A common example is a loose drum cap leaked and the oil mixed with water, rendering it unsuitable for use in lubrication.

Waste oil is considered a hazardous waste. In terms of regulations and compliance, that makes it a completely different product than “used oil.” That brings more liabilities and procedures needed to ensure it is handled properly. Additionally, used oil with certain additive mixtures and water can be classified as waste oil. Off-spec oils with exceeding amounts of arsenic (5 ppm), cadmium (2 ppm), chromium (10 ppm), lead (100 ppm) and halogens (> 4000 ppm) and a flash point above 100 F will also qualify as waste oil.

Best Practices for Storage and Removal

Even though the contents of waste oil may be similar to used oil, it is still classified as waste oil due to the method in which contamination occurred. Used oil is a by-product of doing business, thus allowable to be stored onsite. One mandatory practice for used oil is labelling the storage tanks correctly. Used oil tanks, drums, totes, containers, etc. must be labelled “Used Oil” in order to be in compliance with environment regulations.

By ensuring not cross-contamination, clearly label containers for waste oil and used oil. This prevents potentially spoiling non-hazardous used oil. Waste oil and used oil may be contain similar content mixes, but whether it is used makes all the difference. If an open or leaking drum is contaminated, it is considered waste oil as the contaminant is not known and not incurred during the course of operations.

One way to avoid accumulation of waste oil is ensuring storage best practices are maintained and the integrity of your drums and totes is maintained. If you store your oil near chemicals and solvents, potentially hazardous contamination can occur and proper waste oil procedures must take place. To save on handling costs of waste oil, consider a lubricant storage program and dedicate space for lubricants away from already-hazardous materials.

Learning from your Used Oil

Before dumping your used oil, it is advised to take a sample of the used oil and used oil filters. You can test the used oil and learn a lot about contamination and oil life. This can be a key part of your oil analysis program and help extend your service life and improve lubrication-related decision making and handling.

Key Takeaways

Proper planning and storage of unused lubricant will reduce the accumulation and likelihood of waste oil. Clearly labelling “Used Oil” and “Waste Oil” tanks will keep your facility in compliance and ensure used oil is not contaminated with hazardous materials. By using certified haulers, like Gemini Disposal Services, and recyclers more oil can be recycled and reduce harmful environmental activity like drilling and pipelines. For example, 1 gallon of used motor oil can provide the same 2.5 quarts of lubricating oil as 42 gallons of crude oil.

How to Monitor Alkaline Cleaning Tanks

After machining parts, manufacturers have to clean them. Once clean, the parts may be painted, assembled, or stored with a rust inhibitor coating. That makes cleaning crucial. Poor cleaning could lead to rust, uneven painting or failure in assembly. Many manufacturers do not have the time or budget to rapidly change out (1-day to 1-week intervals) cleaning tanks; if you are fortunate to have short intervals, little maintenance is required as there is limited time for problems to arise. However, you should still perform basic tests to ensure your cleaner is working properly.

For manufacturers with longer tank life, there are 2 main properties to monitor to ensure the performance of your alkaline cleaner: pH and concentration. When the pH and concentration change, the efficacy of the cleaners can decline and lead to more frequent change-outs and greater cleaner consumption. Basic monitoring can prove to be highly cost effective and extend tank life. 

pH Testing

The ability to remove soils declines as the cleaner’s pH drops. The recommended pH for cleaning non-aluminum parts is > 9.0 and > 9.5 for aluminum parts. Additionally, many corrosion inhibitors have a pH-dependent solubility curve. As the pH drops, less inhibitor is incorporated into the solution and the more likely corrosion on cleaned parts can occur. These inhibitors start to drop around 10.2 pH, but do not cause significant issues until the pH drops below 9.5.

Maintenance programs typically attempt to adjust the pH back into range after falling out rather than monitoring the pH for remaining in range. We recommend the latter method as this ensures the pH does not drop dangerously low and potentially renders the solution unusable. Trying to keep the pH between 9.5 (or higher) and 10.5 is ideal. Adding a caustic to boost pH could cause problems as you will get a false concentration reading. If you plan to adjust the pH, have a qualified on-site analytical chemist perform the adjustments.

To measure the pH, pull a sample of agitated solution and wait for it to cool to room temperature. Once cooled, use a narrow range pH strip to test the pH. Higher temperatures can render pH tests unreliable and measuring in the tank could capture the pH of contaminants on the strip.

Concentration Testing

The other key test involves testing the concentration using titration. Titration is used to find the tank strength (concentration). Titration involves adding an acidic reagent to a know volume of tank solution until a defined pH is reached. This can be done simply by adding drops of a reagent to the tank solution. This process involves a dye that changes colors at the defined pH endpoint. This is useful for finding the concentration with a +/- 2% tolerance.

This method is rather crude, but can be highly refined by having a trained chemist use lab equipment to run the test. Lab equipment is required for tests that require tighter tolerances than +/- 2%. Look for a constant concentration over time. If the concentration drops, some likely suspects are: cleaner carry-out, leaks, overly aggressive oil skimming, pH degradation by contaminants, and excessive raw material stripping. If the concentration increases, some likely suspects are: excessive add-back of cleaner or the presence of metalworking fluids. Sometimes soil could affect the strength reading and could indicate rising concentration or stable concentration when the strength is actually dropping.

Takeaways

The pH and concentration tests should be conducted each shift in the manner described above. Investing in lab equipment may prove worthwhile if you have stringent tolerances. If the concentration is too low, add some cleaner to put the solution in the proper range. If too high, add water to bring solution within the proper range. pH adjustment is not recommended unless you have a trained chemist on-site. For more information on cleaner management, contact Twin Specialties and ask about our “Coolant Management Guide” that includes tips and information for aqueous cleaners.

7 Steps for a Successful CNC Restart

After an extended production shutdown, it is imperative to get restarted quickly and efficiently. Maintaining your coolant can be the difference between success and failure. It is key to clean, refill (if necessary), and run according to the manufacturer’s recommendation.

These steps will depend on whether you emptied the sump before the shutdown. If you have emptied the coolant, ensure that the machine is cleaned out; Astro-Clean A can be used to clean the machine and remove and residual coolant and contamination in tough to reach places.

If your coolant remains in the sump after the shutdown, follow these steps for a successful restart:

  1. Inspect the coolant sump/tank for any problems.
    • Remove any tramp oil by using skimmers.
    • Remove any swarf or solids with filters or skimming nets.
    • If there are significant solids, the tank and machine should be cleaned out before proceeding.
  2. Do not add any coolant unless there is not enough to circulate through the machine. If you need to add coolant, add coolant at or above the target concentration.
  3. Circulate coolant through ALL pumps for 60 minutes to ensure all nozzles are flushed out.
  4. Check the concentration from the nozzle using a refractometer (either manual or digital).
  5. Top off the sump to 95% capacity to the target concentration + 2%.
  6. Check the pH and odor. Test the pH from the nozzle.
    • If it is too low (8-9 pH), add 3% volume of coolant and circulate for 30 minutes. Repeat until pH is acceptable.
    • If pH is below 8, the coolant is spent and must be replaced. Use Astro-Clean A to clean out machine.
  7. Add fresh coolant to bring tank/sump volume to 100%.

Bonus Tip: To keep coolant fresher during shutdowns, run skimmers and fish-tank fans to prevent tramp oil contamination and coolant breakdown. Circulating the sump coolant may reduce odor.

Following these steps will ensure a successful restart. Equally important is continuous monitoring of the sump/tank. One individual should check concentration daily and pH weekly. If something is off, act accordingly and quickly. Keep records in a coolant log for each machine to ensure continued success.

Contact Twin Specialties about our coolant guide for information about success coolant management. Twin Specialties has over 65 years of experience with metalworking fluids and is your go-to source for metalworking fluids, cleaners, and rust preventatives/inhibitors.

5 Factors for Drawing Fluid Selection

In drawing processes, there two main types of lubrication. Firstly, there is fluid or hydrodynamic lubrication, which is the separation of metal surfaces with a continuous film of lubricant that prevents contact of those metal surfaces. Secondly, there is boundary lubrication, which is separating metal surfaces by a film only a few molecules thick.

The drawing process generates extreme pressures and the lubricant needs to perform to ensure proper separation of metal surfaces.

Factors for Drawing Fluid Selection

There are many factors that will affect lubricant selection. We will examine these factors and how they may affect lubricant selection and use. Considering these factors will ensure proper separation and excellent performance.

Type of Metal

Not all metals are alike. The first classification for metals is whether it is ferrous, non-ferrous, or an alloy. The hardness of metal will also be a key factor. Harder metals will require higher pressures, thus higher operating temperatures. A harder metal will need a lubricant that provides excellent cooling to prevent poor finishes or melting. Resistance to rust and corrosion varies metal to metal. Porous metals, such as cast iron, are porous and can rust quickly during annealing. Applications with those kinds of metals may require a lubricant that has rust/corrosion preventative additives.

Severity of Operations

The severity of the operation will be key to determining what kind of lubricant you need. Operations with extreme pressures may require lubricants with extreme-pressure and anti-wear additives to maintain proper lubrication. Operating speeds play a key role in determining the viscosity needed. Higher speeds will require lower viscosities so that the lubricant will adequately circulate. As temperatures rise, viscosity can degrade quickly. When the lubricant becomes too “thin” or “runny”, proper separation may be lost. Some lubricants will include viscosity index (VI) improvers to help maintain proper fluid thickness as temperatures rise.

Tooling

The tooling used in drawing may affect the lubricant selection. Some of the tools used in drawing include:

  1. Dies for cold drawing
  2. Rolls for forming strips and shapes
  3. Cutting tools
  4. Extrusion dies
  5. Heading dies
  6. Plugs
  7. Mandrels

The material of the tools also matters. In high temperatures, tool life may diminish and a lubricant that extends tool life improves performance and reduce costs. Tooling can be made of the following materials:

  1. Steel
  2. Carbide
  3. Diamond (synthetic or natural)

Subsequent Processes and Applications

Once a workpiece has completed the metal working process, most likely it still has to go through more manufacturing processes. Some of these include: annealing, cleaning, painting, and assembly into the final product. Cleaning the workpiece is import for final assembly as you want to avoid rust and corrosion. Drawing fluids that are emulsifiable are easier to clean and are preferred by some manufacturers. The cleaning process used also matters. Whether you use a dip tank, spray washer, or vapor degreaser, selecting a fluid that can wash away while also reducing rust and corrosion will be dependent on the cleaning process. Many fluid manufacturers, such as Twin Specialties, supply cleaners that are developed with their drawing fluids in mind.

Economic Considerations

With limited budgets, manufacturers must be pragmatic in selecting a fluid. Opting for a less expensive product may have hidden costs that are not realized at time of purchase. Lower quality fluids may reduce tool life and the fluid itself may need to be changed more frequently. These costs can add up and may not be realized until the job is completed. If your budget allows for it, opting for a synthetic fluid may prove to be a smart choice. Even though lubricants do not make up most of the budget, selecting the right lubricant can create tremendous cost savings on other parts of the income statement.

Takeaways

Each manufacturer has unique conditions and budgets; thus, no lubricant can be a one-size-fits-all product. Analyzing your metal workpieces, operations, tooling, cleaning and assembly processes, and budget will provide clarity. That clarity can aid lubricant selection and allow you to focus more on your manufacturing.

Working with manufacturers and distributors to determine the proper lubricant is the best strategy to maximize efficiency and boost the bottom line. Twin Specialties can analyze your processes and budget considerations to find the optimal lubricant.

What is DEF?

DEF Defined & EPA Requirements

DEF, also known as Diesel Exhaust Fluid, is an aftertreatment fuel system liquid that is used in diesel engine vehicles to reduce air pollution. Specifically, DEF is designed to reduce the concentration and emission of nitrogen oxides (NOx), by converting nitrogen monoxide (NO) and nitrogen dioxide (NO2) molecules into:

  • Harmless nitrogen molecules, which are the most abundant in our atmosphere
  • Water
  • Carbon dioxide, which is harmless to humans, but still plays a role in climate change

By transforming harmful emissions into harmless gases, DEF plays a key role in reducing emissions over the past few decades. The 2010 EPA Emission Requirements for diesel engines are:

  • 0.2g/HP-hr of NOx
  • 0.1g/HP-hr Particylate Matter

Looking at the chart to the right, DEF has helped reduce emissions by 98% since the late 1980s. This has led to a cleaner environment with less “black” fuel exhaust. These results have made DEF and essential fluid for all diesel engine vehicles.

Ingredients & DEF Standards (ISO 22241)

Sometimes to solve complex problems, all you need is a simple solution. DEF is a simple product consisting of only 2 ingredients: urea and deionized water. With such a short ingredient list, why would it be tough to manufacture DEF? In order for DEF to work effectively and protect your engine and fuel system, DEF must be made with extremely pure urea and water. These purity requirements are clearly defined in ISO 22241, Diesel Engines – NOx Reduction Agent, Aqueous Urea Solution (AUS 32). Additionally, DEF products that meet ISO 22241 may be licensed to display the API DEF Certification.

What requirements are needed to meet the ISO 22241 standard? Each ingredient has the following requirements:

  • Technically Pure Urea with traces of biuret, ammonia, and water only. Urea that is free of aldehydes or other substances such as anticaking agents. The urea is to be free of contaminants such as sulfur, chloride, nitrate, or other compounds.
  • Water with very low inorganic, organic, or colloidal contaminants. This is achieved by single distillation, deionization, ultra-filtration, or reverse osmosis.

Using these purified ingredients, DEF must have a urea concentration of 32.5%. This ensures that enough urea is present to convert the NOx and ensures reliable operation of the selective catalytic reduction (SCR) systems. It is also the concentration that produces the lowest freezing temperature of 12 F. If the fluid does not meet these ISO 22241 standards, it cannot be classified or called a diesel exhaust fluid.

How does it Work?

Now that we have found the fluids needed to convert the NOx, we need the technology and equipment to catalyze those chemical reactions. The most common systems used are Selective Catalytic Reduction systems (SCR). The SCR allows the following chemical reaction to occur:

  1. Water evaporates and urea decomposes into ammonia and isocyanic acid
  2. Isocyanic acid reacts with the water vapor and hydrolyzes into carbon dioxide and more ammonia
  3. In the presence of oxygen and a catalyst, ammonia reduces NOx into nitrogen and water

SCRs have proven to be the most effective solution in reducing NOx emissions. SCRs are the only solution that curbs emissions without compromising fuel efficiency and engine performance. As an aftertreatment system, a system that does not work within the engine, SCRs allow engineers to tune engines that can help performance and efficiency. All diesel vehicles produced today have some sort of SCR built in.

SCRs also have safeguards in place to ensure a diesel engine is not operating without a proper amount of DEF. Many vehicles have warning systems to warn operators to refill their DEF tanks. If those fail, engines will shut down and will not engage until there is a sufficient amount of DEF in the tank to reduce any NOx produced by the engine. It is important for operators to monitor the DEF tank just like they would their fuel tank.

Benefits and Costs of DEF

With increased fuel efficiency, many fleets are noticing around a 5% fuel savings compared to older models. Off-road vehicles and equipment that use SCRs and DEF can see fuel savings well beyond 5%. With large fleets, that 5% can add up significantly over many vehicles and miles.

The DEF needed to properly reduce NOx is generally 2-6% of a vehicles fuel consumption (e.g. 2-6 gallons of DEF needed for every 100 gallons of diesel fuel consumed). To figure out your DEF needs, simply determine: miles driven by your vehicle, miles per gallon (MPG), and DEF dosing rate (2-6%). By dividing miles driven by the MPG, you find your fuel consumption. Multiply your fuel consumption by the dosing rate to get your required DEF volume.

The cost of the DEF is the only extra cost to SCR systems, but those costs can easily be offset (and then some) with the 5% fuel savings. The weight of a full DEF tank is only 5-9 lbs., which is negligible in large commercial vehicles. In passenger cars with diesel engines, typically you need to fill your DEF tank at each oil change. Fortunately, a 2.5-gallon container of DEF can be found for under $20 at most retailers.

Storing and Handling DEF

DEF has a freezing/crystallization point of 12 F. As DEF freezes into a crystalline slush, its volume can expand as much as 7%. Many vehicles have heating elements that ensure in-tank DEF does not freeze or threaten vehicle failure. Freezing does not affect the efficacy of the product, but it is important to store it in tanks at appropriate temperatures.

The shelf life of DEF is about 1-2 years, but could be reduced if the fluid is exposed to direct sunlight or stored at temperatures above 86 F. The water can evaporate in tanks, so it is important to keep the tanks sealed and at an ambient temperature around 75 F. If the fluid evaporates, do not add your own mixture as that can upset the precise chemical balance of manufactured DEF.

Where to get DEF

For commercial fleets and clients, speak with a distributor about solutions and certified products. Twin Specialties offers DEF in drums, totes, and bulk. Additionally, we can work with certain businesses interested in buying larger amounts of retail/consumer-packaged DEF products. Individuals who drive a diesel-engine vehicle can purchase bottles or DEF at gas stations, hardware stores, or auto shops. As diesel-engine vehicles become more popular, especially in Europe, many gas stations are adding AdBlue pumps where drivers can pump DEF directly in their car from the pump for cost savings.