Lubricant

Oil helps things move.

It stops parts from rubbing. This keeps them from getting too hot. It also keeps food from sticking in a pan.

People have used oil for a long time. Long ago, people used olive oil. They even used fat from animals. Today, we use oil in many machines. It helps them work well. It can also stop rust. This keeps metal parts safe.

A lubricant is a substance that helps surfaces move easily. When two parts touch, they rub together. This rubbing is called friction. Friction can make things very hot. A lubricant helps by reducing that friction. This keeps parts cool and helps machines work well.

People have used lubricants for thousands of years. In ancient times, people used olive oil or animal fats. Later, people used oil to slide heavy stones. Today, most lubricants are made from petroleum. Petroleum is a type of oil found deep in the ground. Most lubricants are 90% base oil. The rest is made of additives. Additives are special parts that help the oil do more. Some additives stop rust. Others keep the oil from turning into foam. Some help the oil stay thick even when it is hot.

Lubricants are not always liquids. Some are solids, like graphite. These are called dry lubricants. They can work in very high heat. Some lubricants are also used in cooking. They stop food from sticking to pans.

A lubricant is a substance that helps surfaces move smoothly. When two surfaces touch and move, they create friction. This friction can make parts get very hot. Lubricants help by reducing this friction. This process is called lubricity.

By reducing friction, lubricants help machines work better. They can also move heat away or carry tiny particles. Some lubricants even help move forces from one place to another.

Most lubricants work by creating a layer between surfaces. A typical lubricant is made of 90% base oil. This base oil is often a petroleum fraction called mineral oil. The other 10% is made of additives. Additives are special ingredients that give the oil new jobs. Some additives stop rust by absorbing acids. Others prevent the oil from turning into foam. Some even keep the oil thick when it gets hot.

Humans have used lubricants for thousands of years. People used calcium soaps on chariot axles in 1400 BC. During the time of the pyramids, builders used oil on wood to slide stones. In the Roman era, people used animal fats and olive oil. The Industrial Revolution made the need for lubricants grow much faster. In the early 1900s, people started using petroleum instead of natural oils. The Vacuum Oil Company helped by using vacuum distillation to purify oils.

There are many different kinds of lubricants used today. Most are liquids, but some are solids called dry lubricants. Dry lubricants like graphite can work in heat up to 350 °C. Some lubricants are also greases. A grease is a mix of 80% oil and some thickener. This thickener acts like a sponge to hold the oil in place. In 1999, the world used about 37,300,000 tons of lubricants. Most of these were used for cars and big machines.

You can find lubricants in many parts of your life. They are used in cooking to keep food from sticking to pans. Doctors use them during medical exams or ultrasound tests. Some are even used for artificial joints in the human body.

You might also see them used for sexual activities. Whether it is a tiny engine or a large ship, lubricants help everything run smoothly.

A lubricant is a substance used to reduce friction between surfaces in contact. Friction is the resistance that occurs when two objects move against each other. By reducing this resistance, a lubricant also lowers the heat generated by movement. This ability to reduce friction is known as lubricity. Beyond friction, lubricants can transmit forces, transport foreign particles, or help heat and cool surfaces. They ensure that mechanisms function with greater efficiency and longevity.

Most liquid lubricants follow a specific formulation to achieve their goals. They typically consist of 90% base oil and less than 10% additives. The base oil provides the primary body of the lubricant. This can be mineral oil, which comes from petroleum fractions. It can also be vegetable oils or synthetic liquids like silicones and esters. Additives are then mixed in to provide specific performance characteristics. These chemical ingredients help the oil resist aging, contamination, or corrosion.

Modern automotive lubricants are complex chemical mixtures. They can contain as many as ten different types of additives, making up 20% of the total volume. For example, pour point depressants prevent the crystallization of waxes at low temperatures. Viscosity index improvers, such as polyacrylates, help the oil maintain its thickness when it gets hot. To prevent damage, antioxidants suppress the oxidative degradation of hydrocarbon molecules. Other additives, like detergents, keep engine components clean by preventing deposits from forming on hot surfaces. Some additives even form protective "tribofilms" on metal parts to suppress wear.

Lubricants exist in several distinct physical states. Liquid lubricants dominate the global market, but solid lubricants are also vital. Dry lubricants include powders like graphite, molybdenum disulphide, and tungsten disulphide. These solids can operate at temperatures up to 350 °C, which is higher than many liquid oils. Another common form is grease, which is a semi-solid substance. A grease is made by blending a thickening agent into a liquid lubricant. This thickener, often a metal soap, creates a sponge-like structure that holds oil droplets in place. This structure allows the grease to provide both lubrication and corrosion protection.

Humans have utilized lubrication for thousands of years. Evidence shows calcium soaps were used on chariot axles as early as 1400 BC. During the era of the pyramids, builders used oil-impregnated lumber to slide heavy stones. In the Roman era, people relied on animal fats and olive or rapeseed oils. The Industrial Revolution accelerated the need for advanced lubrication as metal machinery became common. In the early 1900s, the industry shifted from natural oils to petroleum-based materials. A major breakthrough occurred when the Vacuum Oil Company developed vacuum distillation. This technology allowed for the purification of non-volatile substances used in modern lubricants.

There are many specialized categories of base oils, especially within the petroleum industry. The American Petroleum Institute (API) classifies these into groups. Group I oils are manufactured through solvent extraction and catalytic dewaxing. Group II oils are produced via hydrocracking and have superior anti-oxidation properties. Group III oils are made through special processes like isohydromerization and have very high viscosity indices. There are also synthetic groups, such as Group IV polyalphaolefins (PAO). These synthetic options allow engineers to tailor lubricants for very specific environmental conditions.

In recent years, biolubricants have become an area of significant scientific interest. These are derived from renewable sources like vegetable oils and animal fats. Examples include canola, castor, palm, and sunflower oils. Researchers at Australia's CSIRO have studied safflower oil for use in engines. They found it could offer lower emissions than petroleum-based options for agricultural equipment. In the United States, scientists at Montana State University have also tested safflower oil in large diesel engines. These advancements suggest that renewable oils could eventually become a "game-changer" for the industry.

Today, the scale of lubricant use is massive. In 1999, an estimated 37,300,000 tons of lubricants were consumed worldwide. While automotive applications dominate this consumption, industrial, marine, and metalworking sectors are also major users. Lubricants are essential in many unexpected places. They are used in cooking to prevent food from sticking to pans. In medicine, they are used for ultrasound examinations and for artificial joints in the human body.

They are also used to facilitate sexual intercourse. From massive industrial engines to tiny medical tools, lubrication is a fundamental part of modern technology.