How important are oil additives in effective lubrication.

Whenever oil performance is discussed viscosity is the main focus. Seldom is the importance of additives in oil given center stage.

What are oil additives?

Additives are organic or inorganic compounds dissolved or suspended as solids in oil. They typically make up between 0.1 to 30 percent of the oil volume, depending on the application. Additives have three basic roles:

1. Enhance existing base oil performance with antioxidants, corrosion inhibitors, anti-foam agents and demulsifying agents. 
2. Reduce undesirable base oil properties with pour-point depressants and viscosity index (VI) modifiers. 
3. Enhance base oils with extreme pressure (EP) additives, detergents, metal deactivators and tackiness agents, for specific applications.

What are the most popular oil additives?

Polar Additives
In simple terms, it is anything that water dissolves or dissolves into water. A sponge, a metal surface, dirt, water and wood pulp are all polar. Things that are not polar include wax, Teflon, mineral base stock, a duck’s back and water repellents.

It’s important to note that additives are sacrificial. Once they are gone, they’re gone. If contaminants that additives are attracted to are allowed into the system, the additives will cling to the contaminants and settle to the bottom or will be filtered out and deplete the oil additive package.

Polar Mechanisms
There are a few polar mechanisms such as particle enveloping, water emulsifying and metal wetting that are worthy of discussion.

Particle enveloping means that the additive will cling to the particle surface and envelop it. These additives are metal deactivators, detergents and dispersants. They are used to disperse soot particles and prevent settling and deposits, especially at low to moderate temperatures. You’ll often see this in engines.

How much additive should be used in the base oil?

There is an optimum dosing point: As more additive is blended into the oil, sometimes there isn’t any more benefit gained, and at times the performance actually deteriorates.

In addition, increasing the percentage of a certain additive may improve one property of an oil while at the same time degrade another. When the specified concentrations of additives become unbalanced, overall oil quality can be affected.

How do oil additives work?

Emulsifying agents work by fixing themselves to micro-droplets of moisture. In so doing, the additive is depleted.

Metal wetting is when additives anchor to metal surfaces, which is what they are supposed to do. They attach to the interior of the gear casing, gear teeth, bearings, shafts, etc. Additives that perform this function are rust inhibitors, anti-wear (AW) and EP additives, oiliness agents and corrosion inhibitors.

AW additives work specifically to protect metal surfaces during boundary conditions. They form a ductile, ash-like film at moderate to high contact temperatures . Under boundary conditions, AW film shears instead of surface material.

One common anti-wear additive is zinc dialkyldithiophosphate (ZDDP). It reduces the risk of metal-to-metal contact, which can lead to increased heat, result in oxidation and negatively affect the film strength.

Additive packages can be tailored to suite operating conditions which base oils could never achieve. Hence the importance of using oil additives in effective lubrication. At Habot Synthetic Lubricants our team of professionals can assist you in selecting the best Habot Synthetic oil for your application.