viscosity index


Also found in: Dictionary, Acronyms, Wikipedia.

viscosity index

[vi′skäs·əd·ē ‚in‚deks]
(chemical engineering)
An arbitrary scale used to show the magnitude of viscosity changes in lubricating oils with changes in temperature. Abbreviated VI.
References in periodicals archive ?
The extent of yield stress, apparent viscosity, firmness, viscosity index and hardness was reduced further as fat and lecithin content increased.
High viscosity index for excellent fill, strength at high temperatures, plus superior fluidity at low temperatures to promote faster draining of any oil that reaches the low-temperature side.
They are tasteless, odorless lubricants with a high viscosity index that contain additives for antiwear protection, oxidation stability and rust protection.
The market for Lubricating Oil Additives is further analyzed in Thousand Metric Tons and US$ Million by the following Functional Segments: Antioxidants, Antiwear Agents, Corrosion Inhibitors, Detergents, Dispersants, Extreme Pressure Additives, Foam Control Agents, Pour Point Depressants, Viscosity Index Improvers, and Other Lube Additives.
Engine oil are mostly differentiated on the basis of their viscosity index (resistance to thinning with increasing temperature), their engine size and volume.
All four suppliers provided their market general GF-5 additive packages, appropriate viscosity index improvers (VIIs) and pour point depressants (PPDs) to support this matrix work.
Bapco's lube base oil plant will produce more than 400,000 metric tonnes per year of Group III very high viscosity index lubricant base oil - the raw material for high-quality finished lubricants.
The joint-venture plant produces Very High Viscosity Index (VHVI) Group III base oils to be used in blending top-tier lubricants and has a production capacity of 400,000 metric tonnes per year, Neste Oil said.
The new plant will utilise feedstock from Bapco's low sulphur diesel plant to manufacture superior sulphur-free high viscosity index grade III lube base oils.
Although monogrades and multigrades have a close kinematic viscosity range, parameters like specific gravity, viscosity index and total base number gives a wide distinction between the two grades of oil [20].
Kresge's elastomer research and technical leadership in collaboration with coworkers has lead to several major innovations in the rubber industry, including EP viscosity index modifiers, polyolefin thermoplastic elastomers and "tailored MWD" EPDM elastomers.