Built-for-purpose industrial oils play an integral role in operations in a wide range of sectors from metalworking, processing to manufacturing. Oils are applied to enhance the operational performance of industrial equipment and machinery while protecting it against damage. There are many kinds of industrial oils, with classifications based on their natural ingredients and formulation. They are often combined with additives to further improve their properties.
In industrial applications, a wide range of liquid-based lubricants are utilised. While there are specialist oils created to suit specific applications, such as gears, turbines, slide ways and compressors, among others, the main types of general industrial oils fall into three distinctive categories. In this article, we’ll take a close look at these industrial oils, along with some of the additives used to enhanced them.
These industrial oils are produced from natural sources and are not subject to extensive processing. Typical natural oils may be sources from vegetable and animal fat – for example, rapeseed or castor oil.
In term of their attributes, natural oils are known for being unstable products when exposed to thermal or oxidative environments. These oils will oxidise easily when subjected to high temperatures, which causes degradation and their properties become no longer effective. As a result, while natural oils do have their place in industrial lubrication, they are never used to supply oil to machinery onsite.
Unlike natural oils, these lubricants are obtained from petroleum products that are acquired from oil wells, sometimes referred to as “oilers”. Regarding their chemical composition, mineral oils are organic compounds that include both hydrogen and carbon (hydrocarbons).
After the petroleum has been extracted from the oiler, it undergoes a range of fractionation processes. In these processes, fuels, along with oils with different properties like viscosity, are acquired. Products obtained with higher viscosity levels and lubricating properties are utilised as oils and other lubricating agents.
It’s worth noting that mineral oils are especially sensitive to temperature fluctuations and that they typically have a viscosity index of up to 120. The pour point of mineral oils can range between -6℃ and -60℃, but most mineral oils produced have a pour point of -20℃. Furthermore, mineral oils have low flash points and burn easily.
Mineral oils come from natural resources, and as such, they contain several other elements, like nitrogen, phosphor and sulphur, among others. These chemical elements are commonly considered impurities that can contaminate our environment, but also impact lubrication. They can result in deposit and sludge formation, which can occur because of oxidation and other chemical reactions that take place during the lubricating process. As a result, mineral oils must undergo a thorough purification process before they are fit for use. After they are purified, these oils are infused with additives to compensate for any shortcomings. As a rule, mineral oils are often the lubricant most used in industry.
This last type of oil was developed in response to the many disadvantages discovered during mineral oil application. As mentioned, due to being petroleum-based products, they possess impurities that can affect how well they perform, putting limitations on their effectiveness. To answer this issue, synthetic oils were produced using chemical processes to engineer a more advanced option as an alternative to both natural and mineral oils.
As synthetic-based petroleum lubricants, synthetic oils retain some of petroleum’s positive properties. However, unlike mineral oil, synthetic oil has no impurities. This can mitigate or entirely negate any potential deposit formation and, as a result, makes them more stable products. Additionally, they have a far higher VI, making them able to remain stable at a wider range of different operating temperatures. As such, their pour point can range from -18℃ to -74℃ and their temperature range falls between -30℃ and -50℃ generally, with their flow levels at low temperatures greatly improved.
Synthetic oils are also a useful lubrication solution for applications and industries where fire may be a serious hazard. This is because they have an exceptionally higher flash point that reaches the non-flammable level.
While synthetic oils can seem to present a perfect lubricant, they have some key disadvantages in comparison to mineral oils. Firstly, unlike petroleum-based mineral oils, synthetic oils are not suitable as boundary lubricants. Secondly, they are far more expensive to purchase, making them uneconomical for some operations.
Industrial oil additive systems
As mentioned, industrial oils also commonly contain additives. These inclusions are designed to impact the natural properties of the base oil used to improve its performance or give it useful attributes for a specific application. Additives will either enhance or suppress these natural properties to achieve different results.
Additives are typically classified by the attribute they supply. Anti-wear, extreme pressure (EP), antioxidant, and rust and corrosive inhibitors are added for their protective properties. However, pour point depressants, viscosity index modifiers, friction modifiers, ant-foaming agents, dispersants and detergent can also be included to aid performance.