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About oil > Terms of Use > Quality indicators > Additives
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A method for improving the quality of lubricating oils by using additives has long been known. In the last century, when we started to apply mineral lubricating oils, attention was drawn to the fact that the lubricating properties of mineral oil drastically improved, when he was a small amount of vegetable or animal oils. Subsequently, mineral oils were added additives of various purposes.
Additive is - a variety of substances complex chemical structure. In their composition depending on the type of additive may be a compound containing oxygen, nitrogen, phosphorus, sulfur, calcium, barium, zinc, aluminum, nickel, cobalt and others.
Currently the engine oil usually contains one or more additives.
Known additives following purposes:
depressor — to reduce the pour point of oils;
In oil may be present in a small amount of solution paraffin. At room temperature, wax - solid. Contained in paraffin oil deteriorates the low temperature properties of oil: with decreasing temperature of the oil wax crystals begin to be released before in the liquid state, and the oil thickens and hardens quickly. Completely remove the wax from the oil difficult. Therefore found another, simpler way to deal with harmful effects on the quality of paraffin oil. Lubricant additives were added depressor which paralyze paraffin harmful effect and thereby reduce the pour point of lubricating oils.
viscosity — to increase viscosity and viscosity index oils;
The advantage of using viscosity index is not only that of the light oil can be obtained highly viscous oil. It appears that the viscosity index improver, increasing viscosity at high temperature, less viscosity change at low temperature and does not change the pour point of oil. Thus, using the viscosity index improver can obtain good winter grade oils, is not curable at low temperatures and sufficiently viscous at high temperatures.
antioxidant — oils to retard oxidation and reduce the risk of sticking piston rings;
To extend the life of the engine and the life of the engine oil, it is necessary first of all to slow down the oxidation of the oil. One effective means to control the oxidation of oils are antioxidant additive. Antioxidant additives are added to oils within 0.5-1%. Compared with butter oil without antioxidant additives containing antioxidant additive can better withstand exposure to high temperature, slowly oxidized, no longer forms acidic products, resinous substances and solid carbonaceous deposits. Antioxidant additives - the most important additives for engine oils.
anticorrosive — to prevent corrosion of bearings;
Oil, oxidized during operation of the engine, forming various kinds of acidic foods, among which there are naphthenic acids. Acid products cause corrosion of metals mainly those which are part of the alloys used for the bearing shells (copper, lead, cadmium and others.). To reduce damage to the bearings from the effects of acidic products within the oil anticorrosion additive is added, typically up to 1%. As an anti-corrosion additive agents containing phosphorus or sulfur. Anti-corrosion additives prevent or inhibit corrosion in two ways.
Firstly, they form the bearing surface a thin solid protective film which protects the metal from contact with the bearing acidic products, just like the paint layer on the metal surface to protect the metal from atmospheric oxygen and thereby protects from corrosion. Secondly, anticorrosive additive reacts with and neutralises acidic products of turning acidic substances in foods, are not capable of acting on the metal.
detergents — to reduce varnish deposits and deposits on engine parts;
Education lacquer on engine parts depends on the detergent properties of the oil. Cleaning properties of pure oils are very small; to improve their Lubricant additives known as detergents. With the engine oil with detergent decreases sharply education varnish on pistons and thereby eliminating the risk of sticking piston rings. Along with these detergents to reduce deposition precipitation on various parts in the crankcase dvigatelya.V used as detergent additive complex chemicals that are soluble in oil. The composition of detergent additives include various metals such as calcium, barium, aluminum, cobalt, zinc, lead, and others. The oil detergency additive does not linger on the surface of the resinous products of metal as soon as they begin to be formed, so immediately washed and entrained oil . Detergent additive added to the oil and helps rinse products with resinous components, of which at accumulating them can form a varnish. The main purpose of detergent additives - to prevent the formation of varnish on the details, but do not remove it. Detergents with parts removed polish not, and the products of oxidation, which is formed from a lacquer. Lubricant is typically added 1-3% of detergents. At higher contents of additives in the oil deteriorating other properties of the oils, especially lubricating properties.
lubricants — to reduce friction losses, to reduce wear and tear and prevent "welding" parts.
Oily additives are added to oils 0.5-2% to reduce friction in engines and machines, to reduce wear and tear, as well as to prevent the "welding" rubbing parts operating at high load.
Oily additive molecules are much more active, the oil molecules, to which is added an additive. Consequently oily additive enhances the strength of the oil film on the metal surface; such a layer can withstand higher load than the oil layer containing no additive. Thus, the oily additive helps prevent dry friction at high load on the details.
As oily additives used a variety of substances, including animal and vegetable fats, stearic and oleic acid esters, various acids, compounds containing sulfur, phosphorus, and so forth.
For hypoid gears operating especially with large specific load on the friction parts, used, for example, additive "sulphidable tar" to ensure the normal operation of these units of friction.
defoamers — to reduce penoobrazova-tion in the engine lubrication system.
The appearance of the foam in the lubrication system brings great harm: firstly, deteriorate lubrication of rubbing parts because of the presence of air bubbles in the oil film; Secondly, there is a loss of oil due to the release; Third, distorted oil level, measured at the probe, -that can cause engine operating with insufficient lubrication.
Foaming depends greatly on the design and arrangement of the oil pump, an oil sump, oil lines and the like. D. Therefore, to reduce foaming, especially changing the design of the system using special lubricants and defoamers. Foaming depends on the quality of the oil.
Water entering the oil also increases foaming. Affect the foaming and viscosity higher than the viscosity of oil, the more difficult to remove it from air bubbles.
The most well known anti-foam additives silicone origin. They are added to the oil in an extremely small amount of about 0.001%.
Foam inhibitors can prevent foaming oil lubrication system. Its effect is to reduce the life span of air bubbles. Antifoaming additive makes foam unstable, easily destroyed, and thus helps to combat foaming.
Some additives simultaneously improve some properties of the oil. Such additives are called multi-functional, comprehensive or universal. The most common multi-functional additives which improve immediately cleaning, anti-corrosion and anti-oxidant properties of oil.
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