Differences between Extreme Pressure and Anti - wear Additives
Both extreme pressure additives and anti - wear additives can improve the service life and efficiency of mechanical systems by reducing friction and wear.
What is an Extreme Pressure Additive?
An extreme pressure (EP) additive is a compound used in lubricants such as motor oils. It protects mechanical components from wear and damage under high - pressure and high - load conditions. When the pressure exceeds the normal capacity of the lubricant, these additives form a protective film on the metal surface, preventing components from welding, scoring, or seizing. EP additives are particularly important for gears, bearings, and other heavily - loaded components. Common EP additives include sulfur - phosphorus compounds.
What is an Anti - wear Additive?
An anti - wear (AW) additive is a lubricant additive designed to minimize the wear and tear of moving metal surfaces under normal operating conditions. It functions by forming a thin protective layer that reduces the direct contact between metal parts, decreases friction, and prevents scuffing or abrasion. Unlike EP additives, AW additives are typically used in situations with moderate loads and speeds. Zinc dialkyldithiophosphate (ZDDP) is one of the most commonly used AW additives.
Working Principles and Functions of Extreme Pressure and Anti - wear Additives
Working Principles
Extreme pressure and anti - wear additives reduce friction and wear by forming a protective film on the metal surface. When mechanical components operate under high - load and low - speed conditions, extreme pressure additives can prevent direct contact between metal surfaces under extreme pressure, avoiding sintering or scratching of the metal surface. Anti - wear additives work under normal loads, reducing friction by forming a thin film and protecting the metal surface from wear.
Functions
-Extreme Pressure Function: Extreme pressure additives can handle the pressure under extreme working conditions, prevent the rupture of the lubricating oil film, and protect mechanical components from damage such as welding and scratching.
-Anti - wear Function: Anti - wear additives reduce the direct contact between metal surfaces, lower the wear rate, and extend the service life of mechanical components.
-Friction Reduction: Both types of additives help reduce the coefficient of friction, improve mechanical efficiency, and enhance energy utilization.
-High - temperature Resistance: Extreme pressure additives usually have strong high - temperature stability and can maintain lubrication performance under high - temperature conditions.
-Corrosion Prevention: Some extreme pressure and anti - wear additives also have anti - corrosion effects, preventing metal surfaces from being eroded by moisture or pollutants.
Common Types
-Extreme Pressure Additives: Sulfur - phosphorus compounds, chlorides, sulfides, etc.
-Anti - wear Additives: Zinc sulfide (such as ZDDP), organic friction modifiers, nitrogen - phosphorus compounds, etc.
Application Fields
-Extreme Pressure Additives: Commonly used in high - load and high - temperature equipment such as gears, bearings, compressors, etc.
-Anti - wear Additives: Widely used in lubricating oils such as engine oils and transmission oils, and suitable for mechanical systems with normal loads and high-speed operations.
Performance Optimization
In practical applications, the combination of extreme pressure and anti - wear additives can be adjusted according to different working conditions to optimize the lubrication effect. For example, some lubricating oils may contain both types of additives to ensure continuous protection in variable working environments.
Differences between Extreme Pressure Additives and Anti - wear Additives
In industrial applications, the selection of additives is based on their ability to work synergistically with base oils to perform specific functions under specific working conditions. Essentially, the functions of additives are mainly reflected in three aspects: enhancing the beneficial properties of base oils, suppressing adverse properties, and endowing base oils with entirely new properties. According to different application scenarios, the proportion of additive combinations in the formulated oil volume can usually reach 30%.
Wear and friction control additives are one of the most commonly used types of additives in the industrial field, generally existing in the form of anti - wear (AW) additives and extreme pressure (EP) additives. These additives can provide effective protection for metal surfaces by forming large chemical reactive groups during the processes of mixed - film lubrication and boundary - film lubrication. When the lubrication system is in a full - fluid - film lubrication state, these additives may be in an inactive state.
However, once the micro - asperities on the metal surface start to contact each other, anti - wear and extreme pressure additives will quickly come into play, sacrificing themselves to protect the metal surface. This protective effect will last until the additives are exhausted, after which the metal surface will begin to experience degradation phenomena such as wear and corrosion.
Although anti - wear additives and extreme pressure additives are usually classified as friction and wear control additives, there are significant differences between them.
Anti - wear additives are mainly used to prevent wear and metal surface loss during the processes of mixed - film lubrication and boundary - film lubrication. This type of additive is usually triggered by an increase in the temperature of the contact surface or an increase in load. Its mechanism of action is to form a dense protective film on the metal surface, thereby minimizing wear to the greatest extent. During this process, the additive chemically reacts with the metal surface to form a protective film with anti - wear, anti - corrosion, and anti - oxidation properties. The chemical composition of anti - wear additives is usually based on zinc and phosphorus compounds, and the common form is zinc dialkyldithiophosphate (ZDDP). This type of additive is widely used in hydraulic oils, engine oils, gear oils, automatic transmission oils, and some greases.
Extreme pressure additives are usually more powerful and more chemically corrosive than anti - wear additives. They are mainly used to adsorb surface - active materials to cope with high - load and high - pressure working conditions. This type of additive is usually activated by high loads, and some extreme pressure additives are also temperature - independent. Temperature - related extreme pressure additives usually contain elements such as boron, chlorine, phosphorus, and sulfur, while temperature - independent extreme pressure additives mainly belong to the high - base sulfonate category. In addition, some solid - suspended film materials, such as graphite and molybdenum disulfide, can also be used as extreme pressure additives. The most common form of this type of additive is sulfur - phosphorus compounds, which are mainly used in gear oils except for worm gears.
In summary, although both anti - wear additives and extreme pressure additives belong to friction and wear control additives, there are significant differences in their activation methods and the applicable working conditions. In practical applications, it is necessary to reasonably select and use these two types of additives according to specific working conditions and lubrication requirements to ensure the normal operation and long - term service life of mechanical equipment.
The Price of EP/AW additives
The price of EP/AW additives depending on factors such as brand, specification, composition, and sales channels. If you are interested in EP/AW additives, please feel free to contact us.
Supplier of EP/AW additives
UNPChemicals is a professional supplier of high-quality and effective EP/AW additives. We offer several remarkable products, namely Amine-neutralized hexyl phosphate PSAIL 3490,Amine-neutralized mixed phosphate Esters PSAIL 2280,Phosphorothioate acrylate derivatives PSAIL 3530,etc.
Amine-neutralized hexyl phosphate PSAIL 3490 is a specialized mixture of amine phosphate salts known for its multifunctional ashless additive characteristics. As an ashless additive, PSAIL 3490 does not produce ash as combustion by-products, reducing engine deposits and harmful emissions. PSAIL 3490 is a multifunctional additive, providing a range of benefits in a single product, making it highly versatile and cost-effective.
Amine-neutralized mixed phosphate esters PSAIL 2280 is a multifunctional ashless additive structured as a phosphate ester amine salt with excellent load carrying capacity, anti-wear and corrosion protection properties. As a multifunctional additive, PSAIL 2280 reduces the amount of anti-emulsifier and rust inhibitor and has good tribological properties, especially at higher temperatures, forming thicker boundary lubricant films. In addition, PSAIL2280 is widely used in metalworking fluid formulations in conjunction with sulfur carriers because of its good anti-wear properties.
Phosphorothioate Acrylate Derivatives PSAIL 3530 is an ashless EP/AW additive with dialkyl dithiophosphate structure, especially suitable for industrial lubricating oils with FZG test requirements, such as industrial gear oil, anti-wear hydraulic oil containing ZDDP, lubricating grease and metal processing oil.
Professional Lubricant Additive Manufacturer
UNPChemicals, aka Luoyang Pacific United Petrochemical Co., Ltd., focuses on the application and development of special lubricating grease additives such as MODTC, MODTP, molybdenum amide, thiadiazole metal deactivators, and phosphate esters. With nearly 30 products in seven series, including extreme pressure anti-wear additives and special grease additives, it is a global manufacturer of special lubricating grease additives and a national high-tech enterprise with great influence and leading role in the industry. If you are looking for Lubricant Additive or technical information, feel free to contact UNPChemicals.