LUBRICATING
GREASE
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Table of Contents
Overview Properties
Types and
Applications FAQ’s about
Grease
01
❑ What is Lubricating Grease?
❑ Lubricating Grease Anatomy
❑ Method of Production for Grease
Overview
❑ The American Society for Testing and Materials
(ASTM) defines lubricating grease as: "A solid to
semifluid product of dispersion of a thickening agent
in liquid lubricant. Other ingredients imparting special
properties may be included" (ASTM D 288, Standard
Definitions of Terms Relating to Petroleum).
❑ Greases are applied to mechanisms that can be
lubricated only infrequently and where lubricating oil
would not stay in position.
What is
Lubricating Grease?
Lubricating Grease Anatomy
❑ Grease consists for 70 – 95% of base oils,
therefore the properties of a grease depend a lot
on the selected base oil to formulate the grease.
Although mineral oils are far the most common
used, synthetic oils are generally superior to
mineral oils providing better oxidation stability,
higher viscosity index and lower friction
coefficient. Synthetic fluids are also used for
extreme temperatures.
Base Oils
❑ The thickener may be any material that, in
combination with the base oil, will produce the
solid to semi-fluid structure. Simply put, a grease
thickener in combination with the base oil acts
much the same way as a sponge holding water.
❑ The nature of the thickener is essential for the
final product. Properties such as dropping point,
mechanical stability, water resistance, lubricity,
re-lubrication intervals, running temperatures
and sealing properties can all be attributed to the
thickener system.
Thickeners
Thickeners
Grease
Thickeners
Soap
Straight Li, Al, Ca,
Na
Mixed Li, Al, Ca,
Na
Complex Li, Al, Ca,
Na, CAS
Non Soap
Inorganic
Clay
(Bentonite)
Silica
Organic
Polyurea
PTFE
❑ As in lubricating oil additives, grease additives and modifiers
impart special properties or modify existing ones. Additives
and modifiers commonly used in lubricating greases are
oxidation or rust inhibitors, polymers, extreme pressure (EP)
additives, anti-wear agents, lubricity or friction-reducing
agents.
❑ In addition to these additives, boundary (thin-film condition)
lubricants such as molybdenum disulfide (moly) or graphite
may be suspended in the grease to reduce friction and wear
without adverse chemical reactions to the metal surfaces
during heavy loading and slow speeds.
Additives
Additives
How is grease made?
Methods of
Production
Open Kettle Process
❑ Open kettle manufacturing is
probably the simplest, although
not the most efficient, way to