Lubrication Additives in Oils
http://www.cumminsforum.com/articles/articles/70/1/Lubrication-Additives-in-Oils/Page1.html
Wayne Amsoilman
By Wayne Amsoilman
Published on 04/7/2007
Here is some information regarding Oil Additives for anyone that would like to know.
Lubrication Additives in Oils
Additives
Definition- Materials added to a basestock to change and/or impart new properties, Characteristics or performance which the basestock alone cannot provide.
Antifoam Agents - Help to reduce air bubbles suspended within a lubricant. Silicone is a Common antifoam agent.
Foaming is attributed to mechanical operating conditions producing turbulence in the presence of air. Foaming can also be caused by air leaks. The presence of water and surface active materials such as rust preventatives, detergents, etc. can also cause foaming.
Excessive antifoam agent will also lead to air entrainment (foaming), which causes lubrication Protection problems.
Antiwar Agents - Additives or their reaction products, which form thin, tenacious films on loaded parts to prevent metal-to-metal contact.
Antiwar agents help to reduce friction, wear, scuffing and scoring under boundary lubrication Conditions.
Zinc dithiophosphate and polar molecules such as fatty oils, acids and esters provide antiwar Protection.
Extreme Pressure (EP) Agents - Additives or their reaction products, which form thin, tenacious Films on heavily loaded or shock, loaded parts to prevent metal-to-metal contact.
Sulfur containing additives have excellent EP characteristics. Sulfur compounds form sacrificial materials, so wear occur between the sulfurized films instead of the gear teeth.
Rust and Corrosion Inhibitors - Additives that form protective films on metal surfaces to protect against chemical attack by water and/or other contaminants.
Zinc dithiophosphates (ZDP) are the most common rust and corrosion inhibitors.
Oxidation Inhibitors - Additives that increase a lubricant's oxidation resistance.
Oxidation -Oil heated in the presence of air oxidizes. As a result of this oxidation, viscosity and acid formation increase. Deposits such as varnish and lacquer form on hot metal surfaces and may further oxidize to form sludge and hard carbonaceous materials.
Oxidation increases exponentially as temperature increases. Large amounts of air (oxygen) also increase the oxidation rate. Materials such as metals (copper) and acids act as catalytic agents or oxidation promoters.
Detergents - are added to fuels or lubricants to minimize deposit formation in the hot parts of an engine. The most commonly used detergents in motor oil formulations are metallic (ash) Soaps with reserve basicity to neutralize acids formed during combustion
Detergents are generally used in conjunction with dispersants. ZPD is commonly used as a detergent.
Dispersants (nonmetallic/ashless) - Additives that help keep solid contaminants in suspension within a lubricant to prevent sludge, varnish and other carbon deposits from forming on engine parts and prevent agglomeration into larger, potentially dangerous particles.
Pour Point Depressants - Polymers that inhibit the formation of a wax crystal structure at low temperatures. Crystallized wax prevents oil flow.
Viscosity Index Improves (VII) - Long chain, high molecular weight polymers that function by increasing the relative viscosity of an oil more at high temperatures than at low temperatures.
Viscosity index improvers "coil" at cold temperatures and "uncoil" as temperature increases. Uncoiling makes the molecules larger which increases their viscosity characteristics; therefore, reducing the overall viscosity loss of the fluid.
The long molecules in viscosity index improvers can be subject to shearing in service.
Viscosity Index Improvers - Shear breakdown occurs in two ways.
1.Permanent shear occurs when shear stress ruptures long molecules converting them into lower weight molecules.
2.Temporary shear occurs when long molecules align themselves in the direction of the stress so there is less resistance to flow. When the stress is removed, the molecules return to their random arrangement and the temporary viscosity loss is recovered.
3.Permanent VII shearing can cause ring sticking, increased oil consumption and viscosity loss.
Friction Modifiers - Additives that alter the coefficient of friction.
Organic fatty acid and amides, lard oil, high molecular weight organic phosphorus and phosphoric acid esters are common friction modifiers.
Suspended solids (Teflon, PTFE, graphite, and moly) sometimes are also used as friction modifiers.
Wayne
amsoilman
Definition- Materials added to a basestock to change and/or impart new properties, Characteristics or performance which the basestock alone cannot provide.
Antifoam Agents - Help to reduce air bubbles suspended within a lubricant. Silicone is a Common antifoam agent.
Foaming is attributed to mechanical operating conditions producing turbulence in the presence of air. Foaming can also be caused by air leaks. The presence of water and surface active materials such as rust preventatives, detergents, etc. can also cause foaming.
Excessive antifoam agent will also lead to air entrainment (foaming), which causes lubrication Protection problems.
Antiwar Agents - Additives or their reaction products, which form thin, tenacious films on loaded parts to prevent metal-to-metal contact.
Antiwar agents help to reduce friction, wear, scuffing and scoring under boundary lubrication Conditions.
Zinc dithiophosphate and polar molecules such as fatty oils, acids and esters provide antiwar Protection.
Extreme Pressure (EP) Agents - Additives or their reaction products, which form thin, tenacious Films on heavily loaded or shock, loaded parts to prevent metal-to-metal contact.
Sulfur containing additives have excellent EP characteristics. Sulfur compounds form sacrificial materials, so wear occur between the sulfurized films instead of the gear teeth.
Rust and Corrosion Inhibitors - Additives that form protective films on metal surfaces to protect against chemical attack by water and/or other contaminants.
Zinc dithiophosphates (ZDP) are the most common rust and corrosion inhibitors.
Oxidation Inhibitors - Additives that increase a lubricant's oxidation resistance.
Oxidation -Oil heated in the presence of air oxidizes. As a result of this oxidation, viscosity and acid formation increase. Deposits such as varnish and lacquer form on hot metal surfaces and may further oxidize to form sludge and hard carbonaceous materials.
Oxidation increases exponentially as temperature increases. Large amounts of air (oxygen) also increase the oxidation rate. Materials such as metals (copper) and acids act as catalytic agents or oxidation promoters.
Detergents - are added to fuels or lubricants to minimize deposit formation in the hot parts of an engine. The most commonly used detergents in motor oil formulations are metallic (ash) Soaps with reserve basicity to neutralize acids formed during combustion
Detergents are generally used in conjunction with dispersants. ZPD is commonly used as a detergent.
Dispersants (nonmetallic/ashless) - Additives that help keep solid contaminants in suspension within a lubricant to prevent sludge, varnish and other carbon deposits from forming on engine parts and prevent agglomeration into larger, potentially dangerous particles.
Pour Point Depressants - Polymers that inhibit the formation of a wax crystal structure at low temperatures. Crystallized wax prevents oil flow.
Viscosity Index Improves (VII) - Long chain, high molecular weight polymers that function by increasing the relative viscosity of an oil more at high temperatures than at low temperatures.
Viscosity index improvers "coil" at cold temperatures and "uncoil" as temperature increases. Uncoiling makes the molecules larger which increases their viscosity characteristics; therefore, reducing the overall viscosity loss of the fluid.
The long molecules in viscosity index improvers can be subject to shearing in service.
Viscosity Index Improvers - Shear breakdown occurs in two ways.
1.Permanent shear occurs when shear stress ruptures long molecules converting them into lower weight molecules.
2.Temporary shear occurs when long molecules align themselves in the direction of the stress so there is less resistance to flow. When the stress is removed, the molecules return to their random arrangement and the temporary viscosity loss is recovered.
3.Permanent VII shearing can cause ring sticking, increased oil consumption and viscosity loss.
Friction Modifiers - Additives that alter the coefficient of friction.
Organic fatty acid and amides, lard oil, high molecular weight organic phosphorus and phosphoric acid esters are common friction modifiers.
Suspended solids (Teflon, PTFE, graphite, and moly) sometimes are also used as friction modifiers.
Wayne
amsoilman