Introduction

In the world of industry, where gears grind, engines roar, and pistons churn relentlessly, there exists an often-overlooked facilitator: Lubricants. These unassuming fluids, made from human ingenuity, serve as the lifeblood of machinery,  ensuring the seamless operation of our modern mechanical marvels. From the towering cranes of construction sites to the sleek engines of supersonic jets, lubricants play a significant role.  They reduce friction, dissipate heat, and prolong the lifespan of the equipment they serve. The earliest known use of lubricants dates back to the Mesopotamian civilization.  Chariot wheels, hubs, and other moving parts were lubricated with animal fats and plant oils. In this article, we will discuss details of widely used lubricants including Industrial lubricants and Automotive lubricants.


Classification

A very broad classification would be mineral lubricants derived from crude oil through a refining process, Synthetic lubricants that are chemically engineered to get a precise molecular structure and properties, and bio-lubricants obtained from resources such as animal fats, vegetable oils, etc. A crucial parameter that applies to all lubricants is viscosity, referring to thickness or flow resistance. Grades of viscosity like SAE ( Society of Automotive Engineers) or ISO ( International Standards Organization) are utilized to define them. Some popular grades are SAE 10W - 30, SAE 10W -40, ISO VG32 , ISO VG46, etc. Another classification method would be application-wise, which could be more relevant. Below you will find succinct descriptions for a portion of these:

Automotive lubricants - Forms the bulk of usage. Derived mainly from refining crude oil, they lubricate and protect engines and other moving parts of vehicles. They assist in cooling and cleaning internal components.

Industrial lubricants - Essential for the smooth operation of machinery in various manufacturing and industrial processes. They reduce friction between moving parts and prevent wear and tear under harsh operating conditions of high temperatures and heavy mechanical loads.

Marine lubricants -  Utilized in equipment on ships,  large boats, and offshore platforms. They are formulated to withstand environments like high humidity, saltwater exposure, and heavy loads.

Aviation lubricants -  Engineered to withstand the extreme conditions of altitude, temperature, and speed. Used in aircraft engines and hydraulic equipment like landing gears. These lubricants undergo rigorous testing and certification by Aviation authorities.

Specialty lubricants - Formulated with advanced additives and base oils, they meet very specific requirements. Examples include food-grade lubricants used in beverage and food processing equipment, and pharmaceutical-grade used in pharmaceutical processing machinery.

Manufacturing process

The typical manufacturing process consists of blending base oils with additives,  a complex procedure. The first step is selecting base oils,  which could be mineral oils derived from crude or synthetic oil produced through chemical synthesis or a combination of both. Parameters like viscosity, temperature, and application etc determine the selection. Next, the base oils are blended with  Lubricant additives, like viscosity index enhancers, anti-wear agents to reduce friction and wear, antioxidants to prevent oxidation, etc. The entire mixture is then mixed to achieve a uniform distribution of the base oils and additives. Quality checks are conducted at various stages to meet the requirements of Lubricant Properties like viscosity, chemical composition, and the performance characteristics of the blend. Thereafter the finished product is packaged into bottles, drums, or bulk tankers as required and shipped to customers.

Oil Lubrication Systems
 
Typical Oil Lubrication System - Courtesy : SKF
1. Pump with Motors  2. Oil Filters  3. Heat Exchanger  4. Bearings of various Machinery. 5. Electrical Control Panel .  6  Oil Tank


Most of us are familiar with the use of lubricants in automobiles. However, there is a lot of it used in industry. A typical example is illustrated in the figure above. Here,  a centralized lubrication system is used to supply the oil to various bearings of machinery. It not only supplies the lubrication but also takes away the heat that is generated. Two motor-driven pumps ( 1 running and one standby) draw oil from the tank. It is then pumped through oil filters to remove dirt and tiny metal particles. The hot oil is subsequently cooled through a water-to-oil heat exchanger.  Cooled and filtered oil is then taken through a main pipe and fed to distributors, which in turn supply it to individual bearings. The hot oil is collected and then returned to the tank. An electrical control panel facilitates the operation of the motors and also displays important parameters like oil pressure and flow, and signals like filter chocked, low pressure,  low flow, high temperature, etc, conveying this information to a centralized digital control system.

Lubricants Market
 
The figure above illustrates the distribution of lubricants market consumption sector-wise in India for the year 2020. The Indian economy is projected to grow at a CAGR of 6.9%. It is expected the quantity of lubricants will also grow to meet this demand, although proportions are likely to remain the same. However, some decrease in the automobile sector is anticipated in the long run as EVs ( Electric vehicles) become more prevalent.

Conclusion

From the chariots of Mesopotamia to the sleek spacecraft of the 21st Century, lubricants have stood testament to human ingenuity and perseverance. They have adapted and evolved to meet the ever-growing demands of technology and industry. Yet amidst the ceaseless march of progress, one thing remains constant:  the vital role of lubricants in ensuring the smooth functioning of our mechanical world.