Testing for abrasive solids in greases.

[Shannow]

Given that some greases, have solid additives and thickeners that are essentially mineral (rock like) in nature, and are in fact often mined for lubricant use. e.g. bentonite clay, MoS2, Graphite.

What test is used to ascertain the presence of abrasive contaminants in a sample of new grease ?

No awards given on Molakule's turf.

 

[IndyIan]

The thumb and index finger test. If you feel any grit, its too big.

 

[Food Scientist]

High Pressure liquid chromatography and mass spectrometry?

 

[kschachn]

I have run ASTM 1404 in the past, is that what you are referring to? However, we had an in-house test for abrasive particles in a type of grease that used a polished plate and an automated screen printer. The screen printer dragged a sample of grease across the plate and it was then cleaned and examined under a microscope.

Originally Posted By: Shannow
Given that some greases, have solid additives and thickeners that are essentially mineral (rock like) in nature, and are in fact often mined for lubricant use. e.g. bentonite clay, MoS2, Graphite.

What test is used to ascertain the presence of abrasive contaminants in a sample of new grease ?

No awards given on Molakule's turf.

 

[CT8]

We are at the mercy of the blenders of the products.

 

[Shannow]

Originally Posted By: kschachn
I have run ASTM 1404 in the past, is that what you are referring to? However, we had an in-house test for abrasive particles in a type of grease that used a polished plate and an automated screen printer. The screen printer dragged a sample of grease across the plate and it was then cleaned and examined under a microscope.


Yep, you got it.

the latter part of your post is a "grind gauge" ??? ... neat eh ?

 

[MolaKule]

Good stuff guys, and no, I don't own this forum, I just contribute to it when I can.

 

[RDMgr]

The device shown in the video is called a Hegman Gauge or fineness of grin gauge. Sometimes the test is called the drawn down test. It isn't a test for abrasives. It is a test to evaluate the size of particles in a material. For example, it will measure particle size of lubricating solids in grease or solids in paint. It is usually used as a QC test and the device is intended for repeated uses. The device is far too expensive to be a test for examining a material for abrasives which would damage the machined surfaces.