Lubezine Volume 8 * NOVEMBER 2013 - JANUARY 2014 | Page 25

Homogenizing the grease breaks down the solid
particles or fibers, disperses the resultant small particles
in the liquid by breaking up lumps and eliminates
graininess, producing a smooth product.
NLGI GRADE CONE PENETRATION*, mm-1 CONSISTENCY
OOO

445-475

SEMI-FLUID

OO 400-430

SEMI-FLUID

O 355-385

VERY SOFT

1 310-340

SOFT

2 265-295

MEDIUM SOFT

3 220-250

MEDIUM

4 175-205

STIFF

5 130-160

VERY STIFF

6 85-115

BLOCK GREASE

produce a uniform crystal and gel structure
that will not change as the grease is used.
Homogenizing the grease breaks down the
solid particles or fibers, disperses the resultant
small particles in the liquid by breaking up
lumps and eliminates graininess, producing
a smooth product.
The process can reduce the penetration
value of some types of grease by stiffening
it, while it can also improve the texture and
appearance. This process is carried out at
slightly lower temperatures than saponification of about °C , after which the grease is
further cooled and packaged.
Please note that there are many methods
that can be followed depending on the type of
grease and the equipment available.

Calcium, Lithium, Titanium, Sodium, Aluminium , Clay, Polyurea and others.
The other major classification type
involves the use of consistency as depicted
by the NLGI (National Lubricant Greasing
Institute) as below:

Lithium Grease Manufacturing
Process
Lithium-based grease is generally manufactured using two methods: Batch or Continuous process. Batch process is usually
preferable due to the numerous benefits it
has over the continuous process.
The basic elemental ingredients for a
lithium based grease production are Base
Oils: different grades for different applications; thickener: depending upon application
different type of soap or non soap thickener
will be used; additives: depending on application many different additives can be used,
such as anti oxidation, anti wear, EP and solid
additives.

Continuous Manufacturing Process:

Batch Manufacturing Process:
The ingredients in this process are metered or
weighed in bulk into the processing reactor,
where the process of saponification occurs.
Saponification is the process of forming soap
by splitting a fat with an alkali. The fat, alkali
and some base oil are added to the reactor.
The reactor is then heated up to about 150oC
to 250oC and mixing occurs. During this
process, the fat is converted to soap which is
dispersed throughout the mixture. The process can be done in closed pressure kettles or
open kettles.
The next process is dehydration, where
water is removed from the mixture before
going to the next step of milling and homog-

enization.
The homogenization or milling process
is vital as it works on the structure of the
grease, giving it a uniform crystal and gellike structure that remains intact when in
use. This is very important because it will

November 2013-January 2014 | LUBEZINE MAGAZINE

The fat, alkali and some base oil are added to
the reactor for saponification to take place.
The reactor mainly is tubular in structure.
The temperature is maintained up to 180°F.
In the tubular section, the flow velocity produces h