Industrial lubricants are used in a large variety of equipments and applications.
This deals with all types of products destined for the lubrication of industrial machines, such as hydraulic systems, turbines, compressors, bearings, open and closed gears, machine tool slideway, pneumatic tools and industrial transmissions. In all these categories, the one which has the most volumes is represented by the hydraulic oils. Usually these hydraulic fluids are containing anti-wear additives to minimize wear of the pumps. In general, the inserting of additives in industrial lubricants, except for products with special applications, is not very high (maximum 5%), but that which is fundamental is the balance between the various additives in order to reach some particular performance.
Apart from the chemical/physical requirements on these products, the most important requirement criteria on industrial lubricants have been specified in ISO/DIN standards. In addition, manufacturers or components or machinery have their own specific requirements (EATON VICKERS, DAVID BROWN, DENISON, ALSTHOM, SIEMENS etc.) that prescribe additional tribological laboratory tests (e.g. friction and wear) or tests that simulate practical conditions. Industrial lubricants too are mixtures of carefully matched components, the "base oils" and "additives", which combine to determine behaviour when in use, both in terms of performance and longer life.
Represent the predominant component in the majority of lubricants. The finished product may contain from 70% to 99% base oil.
The quality of base oils is closely linked to the type of crude oil and the process used. The base oils can be of different natures:
Minerals: mix of hydrocarbons obtained from crude by a conventional refinery process or by a standard hydrogenation process. Products of a different viscosity within the distilling process are called "cuts".
The number of "cuts" and relative viscosity properties depend on the manufacturer and type of process. The following oils are normally produced:a very fluid stock (SN 80 ÷ 100 or spindle)a fluid stock (SN 125 ÷ 170 typically 150)a medium stock (SN 350 ÷ 600)a BrightStock (BS 150 ÷ 200)
Non-conventional base oils: Distillates obtained from petroleum stocks by general refining processes and chemical/physical after-treatment (HC method).
Synthetic base oils: all base types obtained by synthetic processes. Obtained by oligomerization and hydrogenation of olefins, they are of higher quality than HC products.
Additives are substances that are added to a lubricant's formulation to achieve defined behaviours in use.
The most important additives are:
to limit deposits
to reduce wear from corrosion and limit mechanical wearAnti-wear additivesAnti-corrosion additives
to modify the physical properties of the base oilPour Point Depressants (P.P.D)Viscosity index enhancersVM friction modifiersAnti-foaming