Well the limited reply is that grease is a lubricant added to a thickening agent to sort a semi-solid lubricating solution and that’s an all right answer but truly… grease is sooo significantly more!
Human beings have been lubricating (greasing) items for millennia. The earliest greases ended up simply animal and vegetable fats. And guess what! These types of greases are nevertheless employed for certain items.
These days though when an individual asks about lubricating grease they are typically referring to a item utilised to lubricate shut bearing methods or other shut or difficult to lubricate units this sort of as pivot factors on steering equipment or large equipment.
The base oil or lubricant part of grease is most generally both petroleum or synthetic oil of different viscosities despite the fact that there are other much less properly know base lubricants utilized in grease, mostly for industrial purposes this kind of as silicones and flouroether’s
The base oil of grease is typically the first thought when choosing grease for a specific software. The items to be regarded when picking grease are, functioning speed, the temperature assortment that the equipment operates and total load.
Now on to thickening brokers, the things that can make a base oil “appear” like grease. By far the most widespread thickening agent is lithium soap, the term “soap” indicating a metallic salt of a fatty acid. This metallic salt forms an emulsion with the base oil, indicating they are blended with each other but not chemically mixed.
Aside from lithium, there are a lot of different thickening agents that let grease to be customized for 1000’s of different purposes. These contain other metallic soaps these kinds of as calcium, sodium and, aluminum.
These in flip can be mixed with complexing brokers to form lithium complex, calcium intricate or aluminum sophisticated greases. Complexing brokers add stability and overall performance boosts like increasing the substantial and reduced temperature efficiency of the grease or make it a lot more h2o resistant.
Some non-metallic cleaning soap thickening brokers are various polymers, polyurea’s, natural clay’s, silica and carbon black
Now on to the additive package. When grease is made different additive are mixed in to make the grease operate effectively underneath different circumstances.
Maritime grease made for a salt water environment for case in point will include strong rust and corrosion inhibitors. Grease utilized in high temperature applications will usually incorporate oxidation inhibitors to keep the grease from degrading underneath the outcomes of warmth. Grease’s intended for excessive force circumstances will usually incorporate some form of solid lubricant such as molybdenum or graphite. The solids sort a sacrificial layer below severe force and substantial loads that help avert steel to metallic contact and the attendant wear that leads to.
Grease that is designed to be utilised on open up gears or unsealed hinge details will often include a takifying agent to trigger it to cling to the metallic surface area and not be slung off in the circumstance of open up gears or squeezed out so conveniently in the circumstance of hinge factors on gear that have higher masses this sort of as the hinge points on the arm of a backhoe.
Truly, correctly formulated grease’s will usually have a mix of these additives. Oxidation inhibitors, rust and corrosion inhibitors, anti-put on elements like zinc or extreme force additives like molybdenum to make the completed solution a effectively rounded 1 that performs its perform nicely.
A great illustration of effectively rounded grease designed for a distinct professional use is Amsoil’s new synthetic polymeric off road grease which combines an more than-based mostly calcium-sulfonate intricate thickener and proprietary artificial polymeric engineering to offer extraordinary overall performance in hefty obligation off-road purposes this kind of as earth transferring, mining and design equipment.
Greased components on this type of heavy products are subjected to high masses accompanied by effect and shock loading. The heavy substantial influence hundreds common to off-highway tools forces all of that load (strain) on to spots where the tools pivots, relying on the grease to avoid steel-to-steel make contact with.