Engine oil and oil in general can be made from several materials. The following is some types of mineral oil materials are one of medium-heavy crude petroleum fractions, with a specific gravity of 0.86-0.89 at 30 ° c. Mineral oil is crude oil which is mined from the soil may be paraffin or asphaltic oil. Each has a weakness to the influence of temperature. Paraffinic oil tends to be solid at low temperatures, whereas asphaltic tend to evaporate at high temperatures. Process distillation is very influential on the quality of base stock produced. Based on quality, base stock is divided into 6 different categories, call it category 1 to with category 6. Most brands of engine oil on the market in made from base stock category 2. Mineral base oil is still the main oil base used currently in the market, mineral base oil is processed from crude c rude oil at a refinery based on the boiling point. Asar (base oil) o il) manufacture of engine oil and oil. Type of base oil is divided into two namely mineral base oil and synthetic oil.
then the second type of base oil is synthetic oil where synthetic oil is base oil that may be derived from further processed mineral oil, vegetable oils (vegetable oils), or it may also be the synthesis of the poly alva olfim group. And synthetic oil comes from a chemical reaction (synthesis) of certain chemical compounds that produce one type of chemical compound with the expected device. Synthetic oil made from a mixture of a wide range of light hydrocarbon molecules and heavy molecules. It's not it's hard for a chemist to do it. They can design mixes (compound) hydrocarbon molecules so as to produce oil with the appropriate quality specific needs. This mixing process will determine the final quality of the resulting base stock.
Examples of synthetic base stocks are esters, pao (polyalphaolephins) and hydrocracked. In addition, there are also silicones and pag's (polyalcholineglycols), which are not used in automotive world
excess synthetic oil compared with mineral oil is its ability to survive at high temperature range, not easy to react with oxygen, not volatile and more durable. And recently also developed base oil from the latest sumer that comes from plants and animals but this type of base oil still has some disadvantages such as oxidation resistance or he at resistance is still low so it is not too good to use on base oil and have high pour point and viscosity which is limited or can be said to be watery.
Before all additives are added and mixed, mix ed, the base oil is the base all the lubricants that are later grouped in the direction where the oil is used. The american petroleum institute (api) has 5 base oil designations. The first three
groups are derived from crude oil (mineral oil); group iv base oils are fully synthetic; group v is for all other base oils not included in groups i through iv
These oils can be further classified into these categories, depending on composition: paraffinic, naphthenic, aromatic.
When it comes to choosing a base oil, it’s important to make sure it’s appropriate for your application; before you select a lubricant, make sure it can handle the temperature range and operating conditions for which it will be used. Since proper lubrication is integral to properly maintain your equipment, make sure you adhere to the specifications provided by the manufacturer\
Base oils are described by four physical ph ysical properties that dictate how they will perform in service:
Pour point. The lowest temperature at which a sample of oil can be poured determines the pour
point. Viscosity. An oil’s resistance to flow defines the viscosity. Honey, for example, is more viscous
than water. Viscosity index (vi ). As an oil’s temperature changes, so does its viscosity, v iscosity, defining its vi. A highhigh-
vi oil, for example, changes viscosity less with temperature than a low-vi oil. The multigrade engine oils specified by vehicle makers require high-vi base oils as a starting place in the formulation process. High-vi base oils have lower volatility and are designed to operate at low as well as high temperatures Purity. Constituents of many lubricants such as sulfur, nitrogen and polycyclic aromatic
compounds must be held within strict limits
Properties
Viscosity The viscosity of an oil is important for its cooling and lubricity properties. The lower the
viscosity, the better the cooling. An increase in temperature reduces the viscosity. The rate of change in viscosity with temperature can be expressed in terms of viscosity index (vi). A small reduction in viscosity coupled with a large temperature changes indicates a high viscosity index. Paraffinic oils have a higher vi than naphthenic oils. A high vi is required in certain applications. Automotive lubricants is one example where lubrication is needed at both high and low temperatures. However, for cooling applications, such as metal working or quenching, a low vi is better because of the lower viscosity (better heat transfer) at operating temperatures. Viscosity (kinematic) is measured according to astm d 445. Flash point
The flash point of an oil is specified for safety reasons, but also because it indicates how volatile the oil is. Light parts of the oil determine the flash point which is extremely sensitive to contaminants from lighter oils, such as gas oil or gasoline. The flash point is reached when the oil releases enough gases to make the gas mixture above the oil ignitable in the presence of an open flame. The pm (pensky marten) closed cup method (astm d 93) gives the best repeatability. Another method is the coc (cleveland open cup) astm d 92, which, generally, gives 5- 10°c higher flash point values. This method is often used in the usa and elsewhere for formulated products.
