Selecting synthetic lubes
Be aware of differences to mineral lubes.
Synthetic lubricants are gaining traction as an alternative to mineral oils for machine lubrication because they’re perceived to be better, but be aware of the differences in the chemistries, the price and what you hope trying to achieve by using them.
Dean Belovari, the regional sales manager for Canada at Klüber Lubrication North America LP in Ancaster, Ont., presented selection criteria at the Hamilton Section of the Society of Tribologists and Lubrication Engineers (STLE) technical meeting.
He suggests four imperatives for selecting lubricants: define the tribological system; know what you want to achieve; match the performance range; and work with the lubricant suppliers.
Here are some highlights from the session:
- The cost of synthetics is generally four times that of mineral oils so decide which type best satisfies the basic requirements of a machine lubricant – minimizing friction, improving heat dissipation, binding wear particles and protecting against corrosion. Aging characteristics must also be considered.
- The major inherent properties of synthetic lubes are low pour point, high flash point, thermal stability and oxidation stability. They also have a longer service life than comparable mineral oils. Watch for compatibility. Don’t mix mineral and synthetic oils, and check out compatibility with thickeners.
- Points to consider when selecting a lubricant are the range of operating temperatures, machine speeds, extreme pressure applications, fretting, and maintenance and relubrication intervals. Also consider specific load requirements, the type of motion (sliding or rolling) and the environmental conditions in which the lubricant must operate – moisture, vacuum, dust, vapours and chemicals.
- Special requirements exist for sintered bearings, selected seal materials and special applications, such as biodegradability in the food and beverage industries, pharmaceutical industry and kosher production lines.
- Equipment design types to evaluate include geometry and material.
So which is better, mineral or synthetic? In general, synthetic lubricants perform beyond the limits of mineral oils, operate with a higher efficiency, allow for specific formulations, and offer a greater range of selection.
This article appears in the Nov./Dec. 2013 issue of PLANT West.