Difference Between Oil and Grease

Thekey differencebetween oil and grease is thatoil has a comparatively low level ofviscosity, whereas grease has a very high initial viscosity.

Oil and grease are two types of high viscous substances; these two compounds differ from each other according to the viscosity level. We can easily distinguish oil from a grease depending on the level of viscosity.

CONTENTS

1.Overview and Key Difference
2.What is Oil
3.What is Grease
4.Side by Side Comparison – Oil vs Grease in Tabular Form
5.概括

What is Oil?

Oil is a non-polar substance that is a viscous liquid at normal temperatures. It is bothhydrophobicandlipophilic. Generally, an oil contains a high content of carbon and hydrogen, which can make the oil flammable and surface active. Mostly, oils are unsaturated lipids that occur in the liquid state at room temperature.

The origin of an oil can be an animal, vegetable, or petrochemical source. Some oils are volatile whereas others are nonvolatile. We can use oils for food production, as fuel, for medical purposes, for lubrication, and the manufacture of paints, plastics, etc.

There are two major types of oils as organic oils and mineral oils. Organic oils can be obtained from a large diversity of plants, animals and other organisms. This oil extraction is done through natural metabolic processes. Organic oils can contain components other than lipids, including proteins, waxes and alkaloids. When considering the second type of oils, mineral oils, these oils include crude oil or petroleum and its refined components (collectively these oils are called petrochemicals), etc.

When considering the lubrication property of oils, they are non-polar and do not easily adhere to other substances. Therefore, oils are important as lubricants for various engineering purposes. Moreover, mineral oils are common as machine lubricants than biological oils.

What is Grease?

Grease is a semisolid substance which is useful mainly as a lubricant and is formed as a dispersion of thickening agents in a liquid lubricant. Generally, grease contains a soap emulsified with mineral or vegetable oil. As a common feature of grease, we can observe that it has a very high viscosity. Upon the application of a shear force, the viscosity of grease drops to give an effect of an oil-lubricated bearing that has approximately the same viscosity as the base oil that is used in the grease. We can call this change in the viscosity as shear thinning.

通常，真正的油脂含有与增稠剂（例如肥皂）混合的油和另一种液体润滑剂，形成固体或半固体。油脂被认为是伪塑料的流体，这意味着液体的粘度会降低剪切下的粘液。此外，随着时间的流逝，剪切力的减少使油脂触变。但是，有些油脂在工作时变得更加粘稠。通常，使用油脂枪在表面上施加油脂。

What is the Difference Between Oil and Grease?

油和油脂是两种高粘性物质，两种化合物根据粘度水平彼此不同。油和油脂之间的关键区别在于，油具有相对较低的粘度，而油脂的初始粘度很高。

Below is a summary of the difference between oil and grease in tabular form.

摘要 - 油与油脂

油和油脂是两种高粘性物质，两种化合物根据粘度水平彼此不同。油和油脂之间的关键区别在于，油具有相对较低的粘度，而油脂的初始粘度很高。

Reference:

1. “Grease (Lubricant).”Wikipedia, Wikimedia Foundation, 6 Jan. 2021,Available here.

Image Courtesy:

1. “3326715” (CC0) viaPixabay

2. “Wheel Bearing Grease” By Surv1v4l1st – Own work(CC BY-SA 4.0)viaCommons Wikimedia