Anti-wear (AW) and Extreme-pressure (EP) additives – Part 2 OilChat#57

In this two-part series of our newsletter we are looking at friction and wear reducing agents that are added to lubricants. In the previous issue of OilChat we discussed anti-wear (AW) additives and how they work. In this edition we are delving into the basics and operation of extreme-pressure (EP) additives.

Extreme-Pressure Additives are designed for higher load applications such as gears and sliding surfaces where AW compounds are not adequate. EP agents are tougher and chemically more aggressive than anti-wear additives. Extreme-pressure additives typically contain organic sulphur, phosphorus or chlorine compounds with sulphur-phosphorus (SP) additives being the most commonly used for automotive and industrial gear oils and grease.

Sulphur-phosphorus additives function in a different manner than anti-wear compounds. They form an actual chemical reaction with the metal surface to create a resilient protective layer that reduces wear between two mating metal surfaces. SP additives require temperatures in excess of 90˚C to activate the chemical reaction and the reaction is restricted to localized areas where metal-to-metal contact occurs.

The friction between sliding surfaces generates sufficient heat (hot spots) to activate the additive. The chemical reaction between the additive and the metal surface is confined to this area. If hydrodynamic lubrication (explained in OilChat 22) is maintained, the SP additive will not be activated. EP additives are often supplemented with anti-wear additives to make the lubricant effective across a wide range of pressure and temperature conditions. Depending upon the amount used  sulphur-phosphorus extreme-pressure additives may not be compatible with oils containing zinc based anti-wear additives. It is therefore not recommended to mix AW and EP lubricants yourself.

When the loading and sliding conditions become too severe, extreme-pressure additives will also be scuffed away until the protective layer is depleted. Removal of the EP layer may also remove the metal to which it is chemically bonded, resulting in micropitting of the metal surface. One normally would not find high concentrations of sulphur-phosphorus based EP additives in manual transmission oils due to their aggressive nature toward the yellow metals that are commonly used in the manufacture of transmission synchronizers. Automotive transmission fluids are therefore formulated to balance wear protection with corrosiveness.

There are various other extreme-pressure additives, such as sulphurized fatty acids, chlorinated hydro-carbons, sulfates, nitrites and phenols. Not all of these compounds are temperature-activated and can provide wear protection at all temperatures. Unfortunately some of them persist in the environment and have a strong tendency for bio-accumulation. Bar fatty acids, their role is largely restricted to cutting fluid formulations. There are currently several international initiatives to replace them with more environmentally friendly alternatives.

Regardless of their chemical composition, both anti-wear and extreme-pressure additives operate primarily in boundary- and and mixed-lubrication phases where most of the lubricant is forced out of the contact zone. The metal-to-metal interface triggers the tribochemical reaction of the AW and EP additives on the metal surfaces to control friction and wear. Should you have any further questions about wear reducing agents simply mail us at info@bcl.co.za and we will respond by return message.

Anti-wear (AW) and Extreme-pressure (EP) additives OilChat#56

Various chemical compounds are added to lubricant base oils to improve the performance of the final product. Two such compounds are anti-wear (AW) and extreme-pressure (EP) additives. Although the terms anti-wear and extreme-pressure are often used interchangeably in the language of lubrication, there are noteworthy contrasts between the two additive packages. In this and the next edition of the newsletter we will endeavor to explain the differences between AW and EP additives.

Anti-wear and extreme-pressure additives are used to reduce friction and wear between moving metal surfaces in boundary- and mixed-lubrication conditions (for details please refer to OilChat #22). AW and EP agents both function by depositing a protective barrier on the metal surfaces but their chemistries and the way they function are poles apart.

Anti-Wear Additives are often phosphorus based polar compounds with oil soluble tails and polar heads that have an affinity for metal surfaces. These additives work by the polar heads physically bonding, or adsorbing, to the metal frictional surfaces (like iron to a magnet) to form a protective film as shown in Figure 1.  Under boundary- and mixed-lubricating conditions the heat generated by metal-to-metal contact, triggers the adsorbed additive layer to bond chemically with the metal surface to form a chemisorbed film as illustrated in Figure 2. This provides a more robust protective barrier or coating on the metal surface.

Zinc dithiophosphate (ZDP) compounds are the most commonly used anti-wear additives.  Zinc dialkyl-dithiophosphate (ZDDP) is typically used to formulate engine oils, hydraulic fluids, automatic transmission fluids and some greases. They also help to protect the base oil from oxidation and the metal from corrosion. ZDP compounds start decomposing at 130˚C to 170°C and are thus not suitable for very high temperature applications. Tricresyl phosphate (TCP) is a functional alternative for such uses since it can be used at temperatures well in excess of 200˚C. TCP is often used as AW additives in turbine oils and it is also suitable for applications with silver components because it does not contain zinc.

Some lubricant formulations and certain aftermarket engine oil additives use polytetrafluoro-ethylene (PTFE) for wear protection but its efficiency is controversial. A well-known trade name of PTFE is Teflon, a brand name of the DuPont Chemical Company.  DuPont, however, does not give an enthusiastic endorsement of PTFE as a lubricating oil additive. While DuPont says that Teflon is great for preventing food from sticking to frying pans, the company is equivocal about Teflon as an engine oil additive and they have never “promoted” such usage.

Under extreme-pressure conditions, the performance of AW additives becomes insufficient and designated EP agents are required. In the next issue of OilChat we will discuss the basics and operation of extreme-pressure additives.  If, in the interim, you have any questions concerning friction-reducing compounds, our experts are at your disposal and ready to provide you with advice and guidance. Simply mail us at info@bcl.co.za.

How the Covid-19 Pandemic impacted the Lubricant Industry OilChat#55

OilChat has been out of circulation for some time due to Covid-19 ramifications, but it is now back on track with this edition of the newsletter. In the last two issues of our bulletin (OilChat numbers 53 and 54) we have delved into the History of Lubrication. In this issue we will discuss how the pandemic is affecting the lubricants industry right now and the way forward.

Most lubricant users have recently experienced oil shortages and sharp price increases. But why is this and how has Covid-19 affected international lubricant supplies? We operate in a truly global economy and nothing has illustrated this more than the current, ongoing raw material shortages caused by the worldwide pandemic.

Base oils are the foundation of all lubricants. Lubricating base oils, both mineral and synthetics, are currently in short supply. One of the main reasons for this is that most base oils are a by-product of crude oil refining. Oil refineries distil crude oil into various streams to produce fuels such as  petrol, diesel and jet fuel, other hydrocarbon products for making synthetic rubbers, paints, plastics, and lubricant base oils.

During the global lockdown travel has been greatly reduced, both commercially and personally with many of us working from home and not commuting. There are still very few planes flying hence little demand for jet fuel, which as an industry is a major consumer of fuel. The overall demand for fuel has therefore dropped dramatically and subsequently oil companies are simply producing much less fuel. Consequently base oil production has also been slashed. This shortage has led to the sharp spike in lubricant costs and supply constraints.

Lockdowns across the globe have also reduced the number of staff working at lubricant base oil facilities, leading to bottlenecks in production and increased costs. As a result orders cannot be produced and delivered in a timely fashion.  The failure of a single production plant can significantly limit the global availability of certain commodities and components, especially since storage quantities are limited for budgetary reasons.

In addition to base oils all lubricant manufacturers are heavily reliant on the timely and full supply of additives and packaging. Since many feedstocks for for these commodities are by-products of the fuel manufacturing process, their production has been scaled down too. Lubricant manufacturers are therefore also experiencing a shortage of crude oil based additives and plastic containers.

These are just a few factors which have negatively impacted the oil industry and have primarily led to the shortage in raw materials and finished lubricants. Sadly, there is no way to predict or foresee what the future may hold and to determine when these shortages will be rectified.

At Blue Chip lubricants we have been proactive and have put strong contingency procedures in place to allow continued supply of our key products. We are pleased to advise that to date we have managed to supply all our customers OTIF (on time and in full) through all this chaos. Also, due to steel shortages the 208 litre drums are also in short supply but we have secured large volumes of these to ensure we have sufficient stock.

In addition we are importing container loads of heavy-duty engine oil directly from Q8Oils in Europe. We have ordered large volumes of the Q8 T750 SAE 15W40 engine oil at March pricing for delivery over the period June to August. This ensures adequate stock levels and extremely competitive pricing for all our distributors and customers.  These imports have also permitted us to free up the limited local base stocks to produce other key lubricant products for our customers.

At Blue Chip Lubricants we are continuously pulling out all stops to be ahead of the crisis, but the global scenario changes every day. We deliver orders on a FIFO (first in first out) basis and it is therefore in your own interest to place your orders early to ensure you are not last in the queue.

We would also like to make use of this opportunity to thank all our loyal customers for your continued support during the pandemic and for the confidence that you have placed in us and our products. We are certainly looking forward to a long and rewarding relationship with all our staunch supporters. Together we can keep the wheels of our country turning smoothly.

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The history of lubricants P2 OilChat#54

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In this issue of our newsletter we will discuss what is considered to be the modern history of lubrication.  Early machines were relatively simple and worked satisfactorily using crude oil as a lubricant. Most industrial plants kept a single drum of oil to lubricate all their machines. During the First Industrial Revolution (1760 to 1840) the development of larger machines with tighter specifications which had to run at greater speeds for mass production, triggered the search for more sophisticated and specialised lubricants.

It is impossible to discuss all the highlights in the evolution of modern lubrication in a space like this, but we consider the following milestones worth mentioning:

1848 Scottish chemical engineer James Young (founder of the first commercial oil works in the world and father of the petrochemical industry) discovered natural petroleum seepage in a Derbyshire colliery. From this he distilled a light thin oil for use as lamp oil, and at the same time obtaining a thicker oil suitable for lubricating machinery.

1859 Edwin L. Drake struck oil at Titusville in America. His oil well created a new way to supply petroleum-based oil products, which accelerated the move toward the use of mineral oil in America.

1866 – Dr John Ellis, founder of the Continuous Oil Refining Company in Binghamton, USA, developed an all-mineral, high viscosity lubricant for steam engines – previously using inefficient combinations of petroleum and animal or vegetable fats. His breakthrough oil worked very effectively at high temperatures. This meant no more gummed valves, corroded cylinders or leaking seals.

1872 Elijah McCoy, a Canadian-born American inventor and engineer, developed an automatic lubricator that was used to apply oil through a drip cup to locomotive and ship steam engines. Railroad engineers insisted on McCoy lubrication systems when buying new machines and would take nothing less than what became known as “the real McCoy”.

1885 German engineer Karl Benz produced a petrol-powered automobile. This is also considered to be the first “production” vehicle as Benz made several other identical reproductions. The vehicle was powered by a single cylinder four-stroke engine.

1908 Henry Ford introduced The Ford Model T car on October 1, 1908. During 1913 the Model T became the first automobile to be mass-produced on a moving assembly line.  By 1927, Ford had produced over 15,000,000 Model T cars.

1920 As the demand for automobiles grew, so did the demand for better lubricating oils. Lubricant manufacturers started extracting base oils under vacuum from crude oil to improve the performance of their lubricants. Vacuum distillation is still used today in modern oil refineries.

1923 – The Society of Automotive Engineers (SAE) classified engine oils by viscosity i.e. light, medium and heavy. At the time engine oils contained no additives and had to be replaced every 800 to 1000 miles.

1930s Up to 1930 there were no common standards to regulate the performance of motor oils and every vehicle manufacturer had their own set of requirements for lubricants. Vehicle manufacturers realized that there was a need for fixed standards for lubricant performance so that vehicles could be sold anywhere in the world without major modifications or embarrassing failures. The American Petroleum Institute (API) took on the task of setting common standards for engine oil. Their first attempt described three oil categories: Regular (straight mineral oil); Premium (mineral oil with oxidation inhibitors) and Heavy Duty (mineral oil with oxidation inhibitors plus detergents/dispersants). Zinc dialkyl phosphate additives were developed to provide rust and corrosion protection. The antiwear properties of zinc compounds were only recognised years later.

1940s – World War II accelerated the development of lubricant technology and the use of molybdenum disulphide as a solid lubricant dates back to the early days of the war. America and Germany started using ester based synthetic oils in fighter plane engines. Polyalphaolefin (PAO) synthetic oils were developed in the USA and their initial use was in steam turbines. Possibly the first ever use of synthetics for automotive applications was in tank engines. Sherman tanks operating in the intense heat of the Sahara Desert were enormously stressed.  The engines fried their oil and seized solid. The new PAO lubricants were tried out very successfully in the tank engines. In 1947, after the war, the API changed their Engine Oil Classification System to the format still used today.

1950s – It was only during the nineteen-fifties that the antiwear properties of zinc chemistry were fully understood and it became an integral part of many oil formulations. To this day zinc dialkyl phosphates remain the backbone of antiwear additive technology. Solvent oil refining emerged and replaced traditional petroleum distillates owing to their improved lubricant properties. This eventually led to the introduction of API Group 1 lubricating base oils. The world’s first successful multigrade engine oil was launched in 1953. Fire Resistant Hydraulic Fluids were invented in 1958. The first Jet Engine Oil based on polyol-esters were developed and patented in New Jersey, USA. This decade also saw the development of superior grease types, i.e. urea and aluminium.

1960s – Food grade lubricants were introduced and used since the early 1960s.  The Jost Report in 1966 (click to follow link) led by Dr Peter Jost, included the first mention of the term “tribology”.

1970s – The first 100% synthetic di-ester based engine oil passed the API sequence tests and received API qualification in 1972. The following year the first PAO based synthetic engine oil was launched commercially.

1980s – A low-wear tractor hydraulic fluid (THF/UTTO) with satisfactory wet brake performance in a wide variety of tractors was introduced in 1980. The development and design of American and European engines and their appetite for lubricants departed from each other and the CCMC (Committee of Common Market Automobile Constructors) promulgated oil specifications for European automotive engines. 1984 saw the introduction of all-hydroprocessed base oils in the USA. This process combined catalytic dewaxing with hydrocracking and hydrofinishing, which set a new standard for performance (API Group II) in the lubricating base oil industry.

1990s – Germany pioneered SAE 0W-60 engine oil during 1992. The European Automobile Manufacturers’ Association (ACEA) Oil Sequences were introduced in 1996 when they superseded the outdated CCMC

Sequences previously used to define European petrol and diesel engine oil performance.  A revolutionary base oil dewaxing process (hydroisomerization) was commercialized in Richmond, California. Hydroisomerization converts petroleum wax to very high-quality base oil. This represented a major improvement over Group I and II base stocks and allowed the introduction of superior quality Group III base oils. Although these oils were (and still are) produced from mineral feed stocks,
Group III oils closely mirrored the characteristics of PAO synthetic base oils. In fact, during 1999 the National Advertising Division (NAD) in America ruled that hydroisomerized Group III base oil can be classified as ‘synthetic oil’.

2000 and Beyond

The lubricant evolution continues as increasingly advanced products are developed to meet the rising demands of modern machinery for better productivity, performance reliability, energy efficiency and environmental responsibility.  To meet these requirements the trend is towards lower viscosity oil grades, alternative additive technologies and base oils with higher purity and lower volatility. Many modern engines are now calling for SAE 5W-30 and even SAE 0W-20. In fact the SAE (Society of Automotive Engineers) has recently promulgated a new SAE 16 grade as a lighter alternative to SAE 20 engine oil grade. In the interest of the environment, focus has shifted to low ash oil additives with little or no metallic compounds. New Group III base oils have been developed that can actually outperform a full synthetic PAO in several areas important to lubrication, such as additive solubility, lubricity and antiwear performance. Group III base oils can now also rival PAO stocks in pour point, viscosity index and oxidation stability and can be manufactured in volumes and at a price unachievable by PAOs.

With the support of Q8Oils, Blue Chip Lubricants are at the forefront of new product development. Our vast experience, well equipped laboratory and modern production facilities ensure that you always receive a tailor-made solution for your specific lubrication requirements. To learn more please contact us today by visiting https://www.bcl.co.za

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The history of lubricants P1 OilChat#53

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In a world that depends a great deal on machines, lubrication is absolutely essential. The science of tribology has advanced significantly in recent times, but the roots of lubrication extend back further than one might imagine. Lubrication in simple form has been in existence at least since the beginning of documented times. In this issue of our newsletter we will delve into the ancient history of lubrication.

lubricant is a substance introduced between two surfaces in relative motion to each other to reduce friction (and consequently wear) between them. Our forefathers first became familiar with friction in the Stone Age, when they discovered that they could create fire by rubbing pieces of wood against each other. We do not know for sure exactly when they mastered the art of making fire, but indications are that it was approximately 400,000 years ago.

Man’s search for effective lubricants and lubrication technologies has a colourful past, going back as far as the recorded history of humankind. Water was probably the first documented lubricant. The Egyptian mural on the right shows a statue being dragged along the ground. A man can be clearly seen on the leading end of the transporting sledge pouring a liquid (water?) on the ground in front of it, presumably as a lubricant. To learn more visit
https://www.youtube.com/watch?v=tR3MnyWD5gE

It is impossible to list all the milestones in the colourful history of lubrication in a condensed publication like this, but the following fascinating highlights are worth mentioning:

4000 B.C. to 3500 B.C. Indications are the Chinese made use of the lubricating properties of water earlier than 3500 B.C.

3500 B.C. Wheels are an example of primitive, caveman technology. It was, however, so ingenious for those times that it took thousands and thousands of years for someone to invent it circa 3500 B.C. Evidence indicates they were first created to serve as potter’s wheels in Mesopotamia (Iraq).

3200 B.C. It took another 300 years before it was figured out how to use wheels on carts to transport objects. Wheels of the era were made of a solid piece of wood or stone with a hole in the centre for a wooden axle. The earliest ‘vehicles‘ were probably ox carts. The use of the wheel spread fast throughout Eurasia (including the Middle East) and the earliest images of wheeled carts surfaced in the remains of Slavic settlements in present-day Poland. It has been speculated that water was initially used to prevent the hubs of wooden wheels from becoming charred as a result of frictional heat.

3000 B.C. Wheeled carts were now in extensive use in the Middle East, although few traces of lubricant materials have been associated with remnants of such vehicles from that era.

3000 B.C. to 2000 B.C.  It was finally discovered that smearing a lump of animal fat or bitumen (black viscous oil seeping out of the ground) on the dry and squeaking parts made the wheel run quietly and cooler, but without scientific knowledge of friction, no one knew why.

2000 B.C. The invention of the spoked wheel allowed the construction of lighter and faster ‘vehicles’.  The earliest known chariots have been found in the Sintashta burials in Russia. The technology spread rapidly throughout the Old World and played an important role in ancient warfare.

2000 B.C. to 1650 B.C. The advent of high speed horse drawn chariots could possibly be seen as the birth of ‘Tribology’. Experimentation at the time led to the use of more sophisticated lubricants, including olive oil and other vegetable matter. The Egyptians discovered that some of the more viscous liquids not only dissipated heat better, but also prevented much of it from forming in the first place. At the same time, they observed that the wheels were turning more freely. These early discoveries marked the dawn of machinery lubrication.

1650 B.C. Olive oil appeared to be a lubricant of choice at the time. The grave of Egyptian king Tehut-Hetep was found to contain a description of the application of olive oil to reduce friction.

1400 B.C. Compounded lubricants have been identified on the axles of Egyptian and Roman chariots dating back to this age. The lubricant was most probably prepared by combining olive oil with lime.

1200 B.C. When metal replaced wood as moving parts in machinery during the Iron Age, crude chunks of animal fat or bitumen became inadequate lubricants. A next generation of lubricants were developed using fatty and oily substances derived from animal fats and vegetable extracts.

780 B.C. The Chinese discovered the friction-reducing properties of a mixture consisting of animal fats or vegetable oils and lead which resulted in the development of a new generation of compounded lubricants.

1760 A.D. to 1840 A.D. The increased demand for animal-based products as lubricants, and also as illuminating oil, during the First Industrial Revolution almost had disastrous consequences. The sperm whale was almost hunted to extinction to meet the demand for sperm oil. This, and the increasing difficulty to obtain other bio-based oils, triggered the search for alternative lubricants, especially petroleum (mineral) oils.

Many things have changed since the early days of lubrication, but machines and tribology endure in our modern technological world … a tribute to the true significance of these early achievements. In the next issue of our newsletter we will look at the modern history of lubrication.

industry-metal-fire

Air Tool Lubrication OilChat#52

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An air tool or pneumatic tool is a type of power tool driven by compressed air supplied by an air compressor. Air tools come in various shapes and sizes, ranging from small hand tools to jackhammers (paving breakers) and powerful rig mounted units used in the mining and quarrying industry. General grade air tools with a relative short life span are less expensive and are considered “disposable tools” in the tooling industry.  Industrial grade pneumatic tools are amongst the most indestructible power tools available and yet many of them ‘die at a young age’. To understand why this happens one must first look at the way pneumatic tools operate.

An air compressor is the starting point for any pneumatic circuit. A compressor is a machine that converts ordinary air into compressed air as discussed in OilChat #20. The compressed air delivers potential energy (via a flexible hose) to the actuator at the business end of the pneumatic circuit. The actuator turns the potential energy stored in the compressed air back into kinetic energy and movement. In short, the actuator is the tool that does some or other useful mechanical work for us. Actuators may move back and forth in a straight line (reciprocate) or deliver a rotary motion. Linear-action (percussion) tools like jackhammers typically employ a piston-type actuator. Rotary-action tools such as air-driven drills and grinders use a geared or turbine type motor to do the job.

So what then is maiming, crippling and killing those ’indestructible’ pneumatic tools? The most lethal killer is dirty air. If the air going into the system is not properly filtered, grinding grit is introduced into the moving parts inside the actuator. Moisture is another air tool killer. If you impel wet air into a pneumatic tool, you are spraying rust-promoting water right into the guts of the tool. It is therefore good practice to fit an airline filter cum water trap between the compressor and the pneumatic tool. It removes impurities and most of the humidity (moisture) from the air in the line. Perfectly dry air is not always delivered to air tools.

The moving parts of air tools, regardless whether the tool is of a reciprocating or rotary type, require consistent lubrication just like a car engine. The problem is that air tools do not have a sump for the lubricant, so it needs to be fed into the tool with the compressed air that powers the tool. To do this airline lubricators are fitted to the air supply hose. Almost all pneumatic tools perform better when lubricated with oil. Injecting an oil mist into the air-stream lubricate valves, cylinders, and air motors for proper operation and long service life. Locating the lubricator properly in the airline is important to ensure that the correct amount of lubricant reaches the tool. Too little oil will allow excessive wear and can cause premature failure. Excessive oil in the airline is wasteful and can become a contaminant in the ambient area as it is carried out of the tool by the exhaust air.

 

A cross-section of a typical airline lubricator is shown on the right. Airline lubricators dispense oil from a reservoir in the lubricator into the moving airstream. As high-velocity air passes through a venturi inside the airline lubricator, it draws oil from the reservoir through a capillary tube and then drips it into the airstream. The moving air breaks the oil up into a mist or fog, which is then carried down the air line into the air-powered device. The oil feed rate can be controlled manually with an adjusting valve. A sight glass enables the operator to monitor the oil output. A filler plug allows the reservoir to be refilled in situ. Lubricators are generally selected based on pipe connection size, oil reservoir capacity and acceptable pressure loss versus flow rate. Manufacturers usually recommend a minimum air flow rate at which the venturi will function properly.

 

Pneumatic tools are precision built units with close tolerance parts. Many of them operate under heavy loads in adverse conditions. During operation temperatures may vary widely from low ambient to localized hot spots inside the air tool, particularly in reciprocating type tools. Boundary lubrication conditions often prevail due to the sliding action of heavily loaded pistons, which is further accentuated by their reciprocating motion. Moisture in the compressed air can cause rusting and washes the lubricant from critical areas. Adequate lubrication is therefore essential to keep pneumatic tools out of the repair shop.

To ensure extended equipment life air tool lubricants must control wear, protect against rust and corrosion, resist foaming and prevent water wash-off from critical areas when operating with wet air. In addition pneumatic tool lubricants must have low carbon forming characteristics and prevent the formation of sludge and deposits.  Oil fogging can be a health hazard when working in mines and enclosed spaces and the oil must therefore also resist fogging.

The heart and weak link of pneumatic tools are the rubber “O” rings (seals) inside the tool. These need to be lubricated, but many lubricants may attack the rubber. It is thus essential to use a lubricant specifically formulated for pneumatic tools. Such oils are typically blended with highly refined mineral base oils, antiwear, oiliness and tackiness additives, emulsifiers/surfactants, rust and corrosion inhibitors plus antifoam and antifogging agents.

Equally important is the viscosity of the oil. The amount of oil picked up in airline lubricators, depends largely on the viscosity grade of the lubricant and the temperature surrounding the lubricator. Equipment manufacturers’ guidelines on viscosity selection should always be followed. In the absence of such viscosity recommendations the following ambient temperature guidelines may assist in ensuring that adequate atomization is obtained in the airline lubricator:

–  Small hand-held tools: ISO Viscosity Grade 32 will suffice for the majority of applications.
–  Larger industrial tools: ISO Viscosity Grade 100 for temperatures below 20˚C
ISO Viscosity Grade 150 for temperatures between 20˚C and 25˚C
ISO Viscosity Grade 220 for temperatures between 25˚C and 30˚C
ISO Viscosity Grade 320 for temperatures between 30˚C and 35˚C
ISO Viscosity Grade 460 for temperatures above 35˚C

When operators’ health and comfort are the prime considerations when selecting air tool lubricants, grease or emulsions are often the preferred option for larger industrial tools such as rock drills operating in underground mines. Blue Chip Lubricants (Pty Ltd have a complete range of lubricants for a broad range of pneumatic tools working in a wide variety of operating conditions. Please mail us at info@bcl.co.za for details.

Grease Oil Separation

Chain Lubrication OilChat#51

Grease Oil Separation

It is almost impossible to imagine life without chains. We are familiar with bicycle chains and forklift trucks that use chains to lift loads. Chains are commonly used in conveyor systems, to transmit power and all of us are acquainted with the irritating sound of chainsaws.  Many chains in use today fail prematurely due to inadequate lubrication. Chain lubrication often consists of applying a heavy oil or grease to the chain. While this may lubricate the sprockets and the outside of the chain, it does little to protect the most vulnerable areas, i.e. the contacting surfaces inside the chain. In dusty environments sand may get trapped in such heavy lubricants to produce a fine grinding paste that will shorten the life of the chain dramatically.

The majority of chains fail from the inside. They lengthen or kink up due to wear and corrosion inside the pin and bushing area. To lubricate them properly, the lubricant needs to be applied to penetrate and protect the inside of the chain and leave a solid film of oil behind. Lubrication is essential between the rollers and bushings, but other important areas to lubricate are the contact surfaces between the pins, the bushings and the link plates, which articulate while the chain is in motion.

To provide effective protection chain lubricants should be formulated to have the following characteristics:

  • Sufficiently low viscosity to reach all internal moving surfaces
  • Enough ‘body’ to maintain the lubricating film under high pressures
  • Effective protection against rust and corrosion
  • Good resistance to throw-off
  • Ability to maintain lubricating qualities under all operating conditions

Chain lubricants are formulated with relatively high viscosity index base oil to penetrate into critical internal surfaces at low temperatures and yet maintain an effective lubricating film at high loads and temperatures. To provide the desired lubricating qualities under all operating conditions, chain lubricants are fortified with antiwear and/or extreme pressure additives, rust and corrosion inhibitors and tackiness agents. Antifoam additives, pour point depressants and solid lubricants may be added to the oil if required by the application. Food grade chain lubricants should be used in food processing plants. Suggested viscosity grades for various ambient temperature ranges are shown in the following table:

TEMPERATURE, C ISO VISCOSITY GRADE
-30 to + 25 32
-20 to +30 46
-15 to +40 68
-5 to + 50 100
0 to +55 150
+5 to +60 220

Equally important is the method of lubricant application. The recommended methods of lubrication for chain drives are indicated in the power rating tables published in ASME B29 Series Standards and in various

manufacturers’ manuals. The methods normally listed are manual, drip, oil bath, slinger disk, brush and oil stream. Regardless of the application method, the lubricant needs to be aimed into the pin and bushing area as shown in the visual on the previous page. To reach all the moving surfaces, the lubricant should be applied to the edges of the link plates on the inside of the chain shortly before the chain engages a sprocket (as illustrated below). As the chain travels around the sprocket, the lubricant is carried by centrifugal force into the clearances between the pins and bushings. Spillage over the link plates supplies lubricant to the interior and the end surfaces of the rollers.

Chain manufacturers often use grease or petroleum jelly as an initial lubricant, but grease should not be used to lubricate chains in service, because they are too thick to penetrate into the internal bearing surfaces. Grease should only be used when fittings for injecting the grease into the chain joints are provided.

To maximize chain life requires attention to detail. Operating conditions (load, environment, temperature, speed, etc.) must always be considered when selecting a chain lubricant. Tailoring the lubricant to the specific operating environment may be required.  At Blue Chip Lubricants we have the people, products and proficiency to keep the chains of industry moving. Simply mail us at info@bcl.co.za  and put us to the test.