A Guide to Chemical Grades

Chemicals are key for many products in commercial, industrial, and consumer industries. Creating proper formulations is merely the beginning of the process, but manufacturers need a product to use and one that meets whatever specifications necessary to ensure performance, purity, integrity, and safety. These specifications and requirements are outlined by organizations such as the United States Pharmacopeia (USP), American Chemical Society (ACS), and many others.

Why do Chemical Grades Matter?

These grades indicate the purity and quality of a chemical. Certain applications such as consumer or medical products, require stringent quality standards compared to industrial or educational applications. It is important to know what grade you need so you do not make costly mistakes or non-compliant products.

For example, all drug and drug products in the United States must be in compliance with USP-NF current standards as outlined in the USP-NF Compendium of monographs. Each chemical has a monograph that serves as a standard. These monographs provide information about a chemical’s appearance, solubility, weight, safety, and purity. Purity standards will include testing information and acceptable results. These purity standards help control quality and maintain the integrity of chemicals and end-products. The FDA approves all products and is responsible for compliance and regulation of food, drug, and other consumer products.

What are Some of the Chemical Grades?

There are a variety of chemical grades including industry-wide standards and some specialized for specific scientific applications. We will highlight some common grades used in commercial, industrial, and consumer applications. Some key grades are:

  • ACS Grade: Chemicals that are ACS grade meet or exceed standards set forth by the American Chemical Society. This is the most stringent grade and requires high purity. Products with ACS grade are acceptable for use in food, drug, or medicinal uses.
  • FCC Grade: Chemicals that are FCC grade meet standards outlined in the Food Chemicals Codex. The FCC was acquired by the USP, but still uses the Codex for food chemical standards. This applies specifically for food ingredients and includes special tests for toxicity and ensure suitability for human consumption. The FCC is not officially recognized in the United States, but FCC standards are incorporated into hundreds of FDA food regulations.
  • Lab Grade: Chemicals labelled as Lab Grade have unknown levels of impurities. These are popular for educational or demonstration purposes. However, they fail to meet purity standards for food, drug, or medicinal uses.
  • Reagent Grade: Chemicals with a Reagent Grade generally equal ACS grade standards. These are acceptable for food, drug, and medicinal use and are suitable for use in many laboratory and analytical applications.
  • Pharmaceutical Grade (USP): Chemicals with a Pharmaceutical Grade meet or exceed requirements of a national pharmacopeia. The most common pharmacopeia is USP, but these can meet the standards of the British, Japanese, European, and other pharmacopeias. Many countries incorporate USP standards into their own national pharmacopeia.
  • Technical Grade: Chemicals meeting a Technical grade are used for commercial and industrial purposes. It is not pure enough to be used in any food, drug, or medicinal applications. Like Lab Grade chemicals, these are suitable for demonstration purposes.

Considerations for Selecting a Grade

It is critical to know these grades and which one is required for you process as these grades ascertain: identity, potency, purity, and performance. Having chemicals that are certified ensure your commercial, industrial, or consumer products are in compliance of all standard and regulations. If you need to substitute for cost or availability reasons, it is important to understand these grades as well as the following considers:

  • What is the minimum grade required? Can I use a lower quality grade?
  • What are the differences and similarities of the grades considered?
  • What are the regulatory and economic consequences of the higher or lower grade?

When making a decision on chemical grades, keep these considerations in mind as well as understanding regulatory considerations. Understanding these grades will reduce headaches and confusion and ensure you are making the best product possible. Twin Specialties has a large catalog of chemicals and chemical substitutes that meet your manufacturing need.

How to Get Rid of Microbes in Your Sump

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.

Using Microbes to Improve Spill Cleanup

What are Microbes

Microbes (or microorganisms) are microscopic organisms that exist as a single cell or a colony of cells. All single-cell organisms are considered microbes. Thus, the term, microbes, is broad and encompasses a wide variety of organisms. Microbes exist in nearly every environment and can adapt to extreme conditions. Microbes are important in human life as they can perform a wide variety of tasks that are critical. These include:

  • Fermenting food
  • Treating sewage
  • Producing fuel and other bioactive compounds
  • Producing soil nutrients

We are going to focus on a developing application: consuming oil spills.

Using Microbes on Oil Spills

When an oil spill occurs, the first step is trying to absorb as many hydrocarbons as possible. In marine settings, this is crucial in stopping contamination. In most manufacturing and industrial settings, people will use absorbent pads, booms, socks, etc. These products absorb hydrocarbons and then can be disposed into a landfill (via a waste management company). However, there are some environmental issues with this cleanup process. The oil is not remediated as it is put into the landfill.

This is where microbes can help treat the hydrocarbons. After a spill, remediation companies will spray the spill with a microbe liquid suspension or spread a microbe culture powder. This occurs after the absorbents soaked up loose oil. So not all the oil is remediated by the microbes and some of it will be put into landfills. Having microbes within the absorbents and/or deployed immediately on the spill will improve the cleanup.

Eating the Oil

Microbes degrade or “eat” hydrocarbons and then break them down into water and carbon dioxide. Scientists measure oil contamination in soil or water by measuring Total Petroleum Hydrocarbons (TPH) in samples. They measure a site over time by regularly measuring TPH over time. If the microbes are doing their job, TPH should drop over time. If these microbes are present in absorbents, they can continue to degrade the absorbed oil even after the absorbents have been disposed of.

Green Boom

Green Boom manufactures 100% biodegradable oil-only absorbents that include microbes. Their proprietary biomass filler can be used to soak up oil spills and breakdown hydrocarbons all at the same time. The microbes in the absorbent products have been tested on the BP-Deepwater Horizon Oil Spill with spectacular results. After 4 weeks of testing, 95.3% of alkanes and 68.9% of PAHs were reduced. After 12 weeks of testing, 99.8% of hydrocarbons were degraded.

https://www.youtube.com/watch?v=byLert34c1E&feature=youtu.be

These absorbent products have superior absorbency and naturally breakdown. This reduces disposal costs and allows for an environmentally-friendly oil spill cleanup. All parts of the product are made with natural fibers and absorbed oil will degrade with microbes. Green Boom’s absorbents are designed to be fast wicking and will achieve up to 90% absorption capacity within the first 5 minutes of contact with oil.

Our New Partnership

Twin Specialties is proud to announce a new partnership with Green Boom to provide you 100% biodegradable absorbent products.

Twin Specialties can offer the following Green Boom absorbents:

Check out our absorbents page for technical product information. Contact Twin Specialties and we will work with you to improve your oil-spill cleanup response. Be on the lookout for more posts about our new biodegradable absorbents and case studies.

Pros & Cons of Biodegradable Lubricants

In the next installment of our Biodegradable Lubricants series we examine the pros and cons of biodegradable lubricants. How do these lubricants compare to their petroleum-based counterparts? Previously we examined: biodegradability standards, biodegradable base stocks and biodegradable lubricant products. However, are these products right for you? We will look at some pros and cons to see if biodegradable lubricants are the right choice for you.

Pros of Biodegradable Lubricants

  • Excellent lubricity; superior to that of mineral oil
  • Higher viscosity index than mineral and synthetic oils
  • Higher flash point than mineral and synthetic oils
  • Less toxic and readily biodegradable
  • Renewable and reduce dependency on imported petroleum
  • New biotechnology has produced genetically-modified seeds designed for use in lubricants
  • Metal-wetting attraction makes them good for keeping dirt and debris off metal surfaces
  • Water-soluble PAGs are ideal for fire-resistant lubricants
  • Ideal for industries and applications where oil comes in contact with the environment
  • No potential for bioaccumulation (build-up in organism fatty tissue)
  • Price premiums are expected to decline with further market development

Cons of Biodegradable Lubricants

  • Lubricity so potent, friction modifiers must be added to reduce slippage in certain applications
  • Insufficient oxidative stability; oil must be treated or modified to ensure performance (which increase costs)
  • Small amounts of water can cause serious foaming and degradation
  • Cannot withstand high reservoir temperatures (usually greater than 80 C)
  • Vegetable base stocks must be hydrogenated to combat low oxidative stability
  • Low pour point; can be improved by winterization
  • Synthetic esters can be used for cold-temperature environments, but reduce bio-based properties
  • Synthetic oils are limited to which additives they can use due to biodegradability standards
  • PAGs can emulsify water, which can cause foaming, sludge, and corrosion
  • High price premiums for synthetic-based products

Conclusion

Biodegradable lubricants have significant potential to perform better than mineral oils. Developments in biotechnology could allow for specially formulated base oils that will address the current short comings of vegetable oils. As demand increases, price premiums will decrease and the we will become less dependent on petroleum. Synthetic oils already provide superior performance, albeit at a higher cost. Environmental concerns will drive these developments and shift the lubricant market towards biodegradable and environmentally accepted lubricants. To learn more, check out this EPA report on Environmentally Accepted Lubricants (EALs).

Twin Specialties Offers Biodegradable Lubricants

No matter your application or environmental requirements, Twin Specialties can meet your manufacturing, marine, or agricultural needs. We offer a variety of lubricants including: Shell Naturelle, Castrol Performance Bio, and various Food Grade lubricants. Contact Twin Specialties for a quote.

What is Moly?

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 Biodegradable Lubricants?

As the world’s petroleum reserves are extracted, scarcity increases, thus driving oil and lubricant prices higher. This economic burden will force end-users and manufacturers to develop alternatives that are cost effective, readily available, and sustainable. The answer to these concerns are biodegradable lubricants.

Biodegradable Lubricants Defined

Biodegradable lubricants have the ability to degrade naturally by the actions of biological organisms. Petroleum is naturally occurring and is considered inherently biodegradable. However, that does not mean they can be marketed, sold, and treated as biodegradable. When we refer to biodegradable lubricants, we are discussing lubricants that are readily biodegradable.

Determining Biodegradability

Biodegradable lubricants must meet the ISO 9439 or OECD 301B standards. These standards state that a lubricant that has degraded by more than 60% within 28 days is readily biodegradable. The tests involve treating a lubricant sample with microorganisms in the presence of oxygen and measuring the CO2 produced by the microorganisms. As mentioned before, petroleum-based lubricants are inherently biodegradable, but not readily biodegradable because they fail to meet these standards. Petroleum-based lubricants naturally degrade at a rate of 15-35% in 28 days, falling short of the required 60%.

Additionally, the lubricant must be of “low toxicity.” There are a variety of tests used to determine toxicity. These tests involve fish, daphnia, and other organisms. In their pure form, mineral oil and vegetable oil show little toxicity, but lubricants are not just pure oil. As additives are incorporated into formulations, the toxicity increases. Additives are added to make up for any performance shortcomings of biodegradable base stocks.

Types of Biodegradable Base Stocks

Most biodegradable lubricants use vegetable oil, synthetic esters, polyalkylene glycols (PAGs), or a combination of these as base stocks. Vegetable oils have been used for years when petroleum was in short supply. They were popular during World War I and World War II due to oil rationing and came back in popularity during oil embargo in the 1970s. Vegetable oils declined in popularity due to the availability of low-cost oil after Desert Storm. Their popularity is beginning to rise as more manufacturers and end-users are faced with climate change and sustainability concerns. Some common vegetable oils used are soybean oil, cottonseed oil, olive oil, sunflower oil, and canola oil. To improve performance, farmers are beginning to grow genetically modified crops that are designed and engineered for use in lubricants.

Synthetic base stocks, such as esters and PAGs, are also used to boost performance when vegetable oils cannot get the job done. PAGs are effective, however they have a few issues that should be considered. PAGs are incompatible with other oils and can cause problems if inadvertently mixed with non-PAG oils. PAGs can also react poorly with seals and paints. This is why synthetic esters are preferred for biodegradable lubricants. Synthetic esters are typically added to vegetable-oil based lubricants to improve low temperature properties. These serve better than light mineral oils as synthetic esters are less toxic and more biodegradable.

Biodegradable Lubricant Products

Many applications and machines now can be lubricated with biodegradable lubricants and meet all performance requirements. Products that can be composed of soybean oils include:

  • Food grade hydraulic fluids and greases
  • Automotive, railroad, and machine greases
  • Tractor transmission and industrial hydraulic fluids
  • Chainsaw bar oils
  • Gear lubricants
  • Compressor oils
  • Transmission and transformer line cooling fluids

Many more products are in development and could become viable in lubricant markets soon. These include:

  • Two-cycle engine oils
  • Metalworking fluids
  • Specialty lubricants

With more resources and demand for biodegradable lubricants, engineers and manufacturers can research and develop more products that perform more applications, perform better than mineral oils, and remain price competitive.

Biodegradable lubricants are highly popular in applications and industries where environmental and safety concerns are high. Marine and agricultural industries need these lubricants as contamination could have devastating effects. According to Total Lubricants, a single liter of oil can pollute as much as 1,000,000 liters of water. In those applications, biodegradable lubricants are essential. Some government regulations ensure that these industries use biodegradable lubricants that do not harm consumers and operators in the event of leakage.

Twin Specialties Offers Biodegradable Lubricants

No matter your application or environmental requirements, Twin Specialties can meet your manufacturing, marine, or agricultural needs. We offer a variety of lubricants including: Shell Naturelle, Castrol Performance Bio, and various Food Grade lubricants. Contact Twin Specialties for a quote.

What are Aerospace Lubricants?

On May 30, 2020, NASA and SpaceX partnered to send American astronauts from US soil to the International Space Station for the first time since 2011. As a new era spaceflight begins, government entities like NASA and private enterprises like SpaceX will work to innovate their rockets and push boundaries for human space flight. Lubricant manufacturers are tasked with the same challenges to create lubricants that will aid in the journey to reach our ambitious goals.

What are Aerospace Lubricants?

Lubricants in used in aerospace applications such as, space travel, commercial airlines, and defense, are like other lubricants, but face more stringent performance demands. In order to be classified as an aerospace lubricant, products must pass tests that are created by the Department of Defense (DoD) known as “MILSPECS.” To ensure safety and performance for aerospace applications, the MILSPECS create standardization to meet DoD objectives. These MILSPECS test different performance factors such as: corrosion protection, shear stability, compatibility, and water sensitivity.

What Differentiates Aerospace Lubricants?

In addition to meeting various MILSPECS, aerospace lubricants are engineered specifically for aircraft engines and fuel systems. The key difference between aerospace lubricants and non-aerospace lubricants is weight. In space operations, weight is crucial because more fuel is needed, which can become costly. It could also put a strain on how many other supplies could be included in the launch. As the safety of astronauts and functionality of equipment is vital, these lubricants cannot fail.

In space applications, lubricants face the most demanding tests. With temperatures in space at near Absolute-Zero and reentry temperatures reaching 5000 F, lubricants must perform in a wider-range of temperatures than their Earth-bound equivalents. Additionally, lubricants must be able to operate in a vacuum environment. This is on top of all of the crucial navigational and life-supporting machines that make space travel possibly. These machines cannot suffer any breakdowns or down time as they support life and other functions both in space and on Earth. Aerospace lubricants must have a long life to maintain these critical operations.

In defense operations, completing the objective is key and your lubricant must perform to ensure the objective is met. These lubricants have to: withstand extreme-temperature jet engines, cargo aircraft landing gears, precise navigational tools, and other wide-temperature components. By selecting lubricants that meet the right MILSPECS you can ensure proper performance and success in your aerospace operations.

Aerospace Lubricant Manufacturing

Aerospace lubricants in today’s markets can be in the form of liquids or greases. Most use synthetic base oils to achieve desired results and improve efficiency. Most of these lubricants are made of perfluoropolyether (PFPEs) or Multiply Alkylated Cyclopentane (MACs). Several large manufacturers produce these products that meet various MILSPECS. Twin Specialties has access to a wide variety aerospace and MILSPEC lubricants from Shell and Castrol. Contact us to learn more about our catalog.

What are Friction Modifiers?

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.

How Mineral Base Oils are Made

Oil-based liquid lubricants are composed of two (2) key ingredients: base oil and additive packages. Additive packages in a lubricant will tend to vary based on applications. This post will focus on the main ingredient, base oils. Base oils will comprise typically 80-99% of an oil-based lubricant. Before we look at the base oil in a finished lubricant, we have to understand how oil gets from a drilling site to a refinery and finally into your lubricant.

Extracting and Transporting Crude Oil

After crude oil is extracted from the ground at wellhead or platform drilling sites, it is transported via rail, ship, or pipeline. It is then stored at a terminal or hub. Oil & Gas Manufacturers then take the crude and refine it to meet product specifications. Some of these products include gasoline, heating oil, fuel oils, asphalt and road oil, and lubricants.

Separating the Crude Oil

The typical barrel of crude is 42 gallons. According to the American Petroleum Institute, only 0.5 gallons of crude oil in each barrel are used to make lubricants.

This is because lubricants require longer chain hydrocarbons. Most lubricants have hydrocarbon molecules with 26-40 carbon atoms. Crude oil is heated and vaporized then condensed; this process is known as distillation. The distilled oil is easily separated by hydrocarbon chain lengths. Shorter molecules rise to the top and longer molecules sink to the bottom. After the hydrocarbons with 26-40 carbon atoms are separated, they are sent to a refining process specific to lubricants.

Refining the Crude Oil

The distilled oil is refined using two different processes: extraction and conversion. Extraction involves four steps:

  1. Deasphalting: Takes residue at the bottom and separates into tar and compounds similar to lube distillates.
  2. Solvent Extraction: Remove most the aromatics and undesirable constituents of oil distillates. Results in neutral oil base stocks called reaffinates.
  3. Dewaxing: Reaffinates are dewaxed to produce a wax and dewaxed oil. The dewaxed oil becomes base stock for lubricants.
  4. Hydrofinishing: Changes polar compounds in oil by a chemical reaction. Oil becomes lighter in color and exhibits improved chemical stability.

The conversion process involves three steps and is becoming popular for refining. This process involves converting undesirable products into desirable products using hydrogen, heat, and pressure:

  1. Hydrocracking: Distillates are subjected to a chemical reaction at high temperatures and high pressure. The aromatic and naphthene rings are broken and joined using hydrogen to form an isoparaffin structure.
  2. Hydrodewaxing: A hydrogenation unit is used to deploy a catalyst that converts waxy normal paraffins to desirable isoparaffin structures.
  3. Hydrotreating: The first two processes broke chemical bonds, therefore it is necessary to saturate unsaturated molecules. By adding more hydrogen, the molecules saturate and become more stable and better able to resist oxidation

Classifying Refined Oil

This results in mineral oil base stocks that are classified into three different groups. API Groups I, II, and III are all mineral oil-based, but differ based the level of refining. The chart below gives a breakdown of each of the 3 mineral groups.

The key factors are: sulfur (%), saturates (%), and viscosity index. Some refer to Group III base stocks as “synthetic” due to the chemical processes they undergo. The natural chemical structure is altered from the natural structures found in mineral oil. However, the API classifies Group III oils as mineral because they originate from crude oil

The conversion process is more effective in reducing aromatic content, but the process is more expensive. Typically, the costs are passed along to end-users, but they get a higher quality base oil and better performance. Group II and Group III are becoming more prevalent as preferences shift towards conversion processes rather than extraction processes. Once refined, base stocks are blended with additives and additive packages to form a final product lubricant.

A Guide to Grease Thickeners

Used for over 3000 years, grease is a key lubricant used to operate a variety of machines and bearings. Over 80% of the world’s bearings are lubricated with grease. Grease is an excellent lubricant to use when liquid lubricants fail to do the job. Greases are made of three main components: base oil (70-95%), thickener (3-30%), and additives (up to 10%). We are going to examine the second component: thickeners. Thickeners are essential as they are the “sponge” that holds the base oil and additives.

What are Thickeners?

When combined with the base oil and additives, the thickener forms a semi-fluid structure. Conventional thinking suggests the structure indicates the grease is mainly thickener, however, the thickener is a material that holds the lubricant until it is dispersed. As mentioned above, the overwhelming majority of any grease is composed of base oil. There are many types of compounds that can be used as thickeners.

Greases are classified into two major families: soap and non-soap thickeners. Over 90% of greases worldwide are classified as soap thickeners. Soap-based thickeners are produced via an acid-base reaction known as saponification. The end-result is a soap and water mixture. The water is removed and the remaining soap is used as a thickener for grease. The type of soap thickener will depend on which acids and bases are used in saponification. Some common compounds used are:

  • High molecular weight fatty acids: Stearic and 12 Hydroxy Stearic Acid (12 HSA)
  • Short chain complexing acids: Tallow, Azelaic, and Sebacic Acid
  • Most bases are a metallic hydroxide compound (i.e. lithium, calcium, etc.).

Types of Soap Thickeners

Simple Soap: This results from the reaction of one fatty acid and a metallic hydroxide. The most common soap, lithium soap, is produced

Types of Soap Thickeners – Source: NYE Lubricants

with 12 HSA and lithium hydroxide. The metallic hydroxide defines the thickener and other types besides lithium can be used.

Mixed Soap: Less common than simple soap, mixed soap is created in similar fashion as simple soap. However, the “mixed” characteristic is derived from mixing multiple metallic hydroxide compounds with a fatty acid. A common mixed soap is Ca/Li soap, which is made with calcium hydroxide and lithium hydroxide.

Complex Soap: Like simple soaps, complex soaps use a single metallic hydroxide. In order to create the complex-thickened grease, a fatty acid is combined with a short chain complexing acid. The acid mixture is then combined with a metallic hydroxide to for a complex thickener. Lithium complex grease, the most popular in North America, is made with lithium hydroxide, 12 HSA, and azelaic acid. These thickener types have an advantage over simple soap because of better high-temperature properties.

Types of Non-Soap Thickeners

Urea: Also known as polyurea, these thickeners are a reaction product of di-isocyanate combined with mono and/or diamines. The ratios of the ingredients will determine the characteristics of the thickener. This classification includes diurea, tetraurea, urea-urethane and others. Since there are no metallic elements in polyurea grease, the grease is ashless and subsequently more oxidatively stable. Polyurea greases are the most popular non-soap grease today.

Organophilic Clay: Also referred to as organo clay or clay thickeners, these thickeners are mineral based usually made from bentonite, hectorite, or montmorillonite. The minerals are purified into a clay and treated to be compatible with organic chemicals. The clay is dispersed in a lubricant to form a grease. Clay greases have no melting point and are traditionally used in high-temperate greases (however the oil will oxidize quickly at elevated temperatures).

Other: Polyurea and clay thickeners are the most used non-soap greases, but there are some other specialty thickeners that are used. These include:

  • Teflon
  • Mica and silica gel
  • Calcium sulfonate
  • Polytetrafluoroethylene (PTFE)
  • Carbon blacks
NLGI Grades – Source: Noria

NLGI Classifications

In addition to composition, the other key classification for grease is quite obvious: thickness. Defined as consistency, a grease’s consistency is its resistance to deformation by applied force. This is measured by penetration. A standard test, specifically ASTM D217, measures cone penetration after five (5) seconds for a grease at 77 F (25 C). The unit of measure is tenths of a millimeter and the NLGI classifies grease based on its penetration. The range of grades is 000 to 6. See the chart to the left for a full breakdown NLGI grades.

Most greases today fall in between the 1 and 3 grades with NLGI 2 being the most common. High penetration greases such as 00 and 0 can be used in central systems and colder environments.

Selecting the Appropriate Thickener and Grade

The right grease could vary greatly depending on your application, operating environment, and other factors. High temperature environments may require firmer (higher NLGI grade) greases and certain thickeners with high-temperature properties. It is best to consult OEM guides or speak with your grease manufacturer or distributor to get a recommendation.

Switching and mixing greases could either prove to be extremely costly. Most thickeners do not mix together and there are specific greases that are not compatible with others. It is recommended to match “like-for-like.” If you plan to make a switch, it is best to completely drain your equipment before applying new grease.