Lubricant Oil Blending – A Science
Lubricant production and science go hand in hand. Through various basic components and advanced blends, products with unique properties are created, for instance when it comes to lubricating at different temperatures. At the same time, modern oils are often closely integrated with the engineering products they lubricate.
This field of science is called tribology, and is the study of lubrication, abrasion and friction. This involves producing the correct lubricating oil for the right technology. Needs vary significantly because of the wide range of products: everything from engine, hydraulic and turbine oils to special products for wind power, forestry agriculture, metalworking and the manufacturing industry. All with their own, more or less, unique blend.
THE BLEND IS CRUCIAL
At the FUCHS’ Lubricants production plant in Nynäshamn outside Stockholm, we work with around 750 products where oils for vehicles and industry are the two largest areas. The work essentially revolves around the art of blending lubricating oils. All raw materials are delivered ready to use to the plant, where they are blended to create the correct oil.
Whatever the application, there are several common denominators for almost all lubricants, namely that the oil should cool, seal, keep clean and protect against rust. Another important aspect is the effect on friction.
The aim of an engine oil is to achieve low friction with adequate lubrication. This affects the blend which gives the oil its specific properties. Technology requirements have also become more advanced over the years and determine how an oil must be formulated.
TOUGHER REQUIREMENTS
An example is in the automotive industry, where emission requirements have increased significantly. And when regulations for vehicle manufacturers and their technologies change, the lubricating oils need to be adapted accordingly. Apart from lower emissions, the regulations also affect lower fuel consumption and extend replacement intervals, so the oil must be able to function longer than before.
Lubricating oils have always been important, but they have become even more important as demands on vehicle and machine manufacturers have increased. You could say that the oil has become an increasingly integrated part of the various equipment that needs lubricating. As tools and machines become more advanced, oil specifications have become increasingly specialised.
THREE MAIN COMPONENTS
Most lubricating oils are based on a few fundamental components. The first is the base oil, which comprises 60–90% of a typical lubricating oil. There are several classes of base oil, both mineral and synthetic oils, and the product achieves its basic performance properties via the right mix.
The base oil affects the end product’s volatility and stability, but also its minimum flow properties, internal friction and how well it protects against corrosion. Synthetic base oil affords broader options, and enables the product to be customised in more ways.
The next ingredient is the viscosity modifier. This influences the oil’s thickness and is designed to reduce its change in viscosity, even when temperatures vary. And they do vary significantly. Some engine oils need to withstand temperatures of between -40 and +350 degrees Celsius, while still retaining their lubricating properties.
And last but not least, various additives are blended into the oil. This is when the oil gains its final properties. Additives function as cleaners and contain antioxidants that affect service life and enable the oil to cope with friction and counteract abrasion more efficiently. In engine oils, the cleaning properties are particularly important. For industrial oils, it is particularly important for the additives to extend the service life of the oil and prevent seizure under high load.
THE RIGHT QUANTITY IN THE RIGHT ORDER
Most of the ingredients mixed into a lubricating oil are liquids. The volume of a blend tends to vary between 1 and 40 cubic metres, and the blending process itself takes between 12 and 48 hours.
For each lubricating oil, there is a recipe which specifies quantities, the order in which the ingredients are added, how long it should take and how high the temperature must be.
A lubricating oil may contain anything from 2 to 22 ingredients. The blending order is important to avoid negative chemical reactions between ingredients. Certain additives must be added when the temperature is high, and others when it is lower.
FINAL QUALITY CONTROL
When the blend is ready, the oil is drained off and packed. The packaging may be anything from 1-litre bottles to 1,000-litre containers. Large volumes of lubricating oil are delivered by tanker directly to the customer’s facility.
Before draining and delivering an oil, samples need to be taken of every product to guarantee that the correct quality. Samples are tested according to various parameters and then stored in archive for at least one year. Quality control is therefore the endpoint in an advanced blending process for vast number of more or less customised lubricating oils.
By Morten Herregarden, FUCHS Lubricants