Lubricating Oil
is a liquid product that has the function of lubricating parts of engines and machinery. It consists of 2 important parts:
1. Base Oils
2. Additives
Base Oils
There are 3 types of base oils in use: vegetable or animal oils, mineral oils, and synthetic oils. However, mineral oil is mostly used because it is of good quality and cheap. Other types of oils are used only in applications that require certain special properties.
1. Vegetable or Animal Oil In the past, it was used in many applications. However, because vegetable and animal oils tend to have low chemical stability and deteriorate easily during use, they must go through a quality improvement process, which increases the price. Therefore, it is no longer popular. Vegetable oils that can be used include castor oil, palm oil, and animal oils that used to be used include lard and fish oil. Currently, there is very little use of vegetable or animal oil as base oil.
2. Mineral Oils This is the most commonly used base oil because in addition to being good quality, it is also cheap. Mineral oil is obtained by taking the part at the bottom of the atmospheric distillation column and distilling it under a vacuum. Separate the clear and thick lubricant oils. The remaining residue is used to produce asphalt. The type and amount of mineral oil that can be separated depends on the type of crude oil that is refined. Some crude oils are not suitable for producing mineral oil. Mineral oils obtained from vacuum distillation are usually not of good quality to be used to produce lubricant oils. They must go through various processes to remove the desired substances in order to have good chemical and thermal stability. Mineral oils used to make lubricant oils are divided according to the viscosity index, which can be divided into high, medium and low viscosity indexes. Mineral oils with high viscosity indexes are obtained from the distillation of paraffinic crude oils. Mineral oils with medium and low viscosity indexes are obtained from naphthenic oils. 3. Synthetic Oils are oils that are synthesized by chemical processes. The starting material used is usually petroleum. There are many types of synthetic oils that are quite expensive. Currently, they are used as base lubricants only in special jobs that require high viscosity indexes, low pour points and low evaporation. The most commonly used synthetic oils are: Polyalphaolefins (PAO), Estes (Diester and Complex Ester), Polyglycols, Silicone, Halogenated Hydrocarbon and Polypheny Ethers
Additives
Today’s machinery and engines are designed to be smaller, faster and with higher loads. Lubricants in such machinery and engines are subject to high temperature, stress and load conditions. Pure base oils are often not of good quality enough to perform all their functions with reasonable service life. Therefore, additives must be added in the right amount to enhance the chemical and physical properties of the base oil to be suitable for the required work. There are many types and types of additives, but the most commonly used are:
– Antioxidants
– Anti-wear agents
– Rust inhibitors
– Anti-foaming agents
– Extreme pressure agents
– Viscosity index improvers
– Detergents / dispersants
– Alkalinity enhancers
Lubricants are usually produced for specific uses, such as engine oil, gear oil, hydraulic oil, etc. In order to produce a particular type of lubricant, the function that the lubricant must perform must be considered. and the various conditions that the lubricant will encounter while lubricating. Then select the base lubricant and the type/amount of additives that are appropriate for the required job. Then there is a test for actual use and an evaluation to ensure that the lubricant is of good quality as required. Therefore, each type of lubricant uses a different type of base oil and amount of additives.
