Can somebody throw ligh on how there can be air entrapment and hence air bubbles inside a fresh open gear lubricants barrels? Is it because of the filling process or greases physical properties?
These air bubbles causes erratic functions of pumps and lubrcantion systems.
regards.

Arupanjan,
That is a factory/packer facility filling area problem. It not only causes erratic operation in your lubrication systems. It also give you false level readings.

Question: Did you notice a weight diference in this barrels?

its ok by weight but the volume may be effected so how do you eliminate this?
regards

Arup,

This is classic packing and handling problem. I encountered this problem when we supplied hi temp grease to a Sponge Iron Plant, where a grease pump was use to deliver the grease to the sealant area. Due to loose packing the delivery was intermittent leading to failure in application.

My second experience was with "cable filling compound". Jelly filled telephone cables were popular before optic fibre was introduced. Due to an accident barrels were damaged in transit, due to urgency the 'dented barrels' were sent to production lines. Cables manufactured on that date failed in the Type test for water penetration. Indicating intermittent filling of the compound.

Hussam Adeni

One way of solving this problem could be using a follower plate in the grease barrel which goes down as the grease level goes down in the barrel.This is normally used for solving the slumapability problem of some greases.

Vijay

Vijay,

Excellent idea. Could it be possible that hot filling also results in "air pockets."

A good analogy would be the NLGI measurement for greases, which demands "worked penetration" thereby ensuring consistency.

Hussam Adeni

HI ALL!
Well the basic issue for the problem has not been addressed and thus I feel it is partinent to mention what I know about the problem, and its possible solusion!
The air entrapment is due to the psycal activity of filling the oil at high pressure and may be at high temperature also into the barrel. Ususally a good quality oil should have a reasonable Air-Release Value for it so that the entraped air bubbles picked-up during the oils filling / churning operations should get released from the body of the oil and thus very little is left as traped air inside the oil.
However, if this aspect is not addressed during the formulation / QC of the finished product, then to pass the Foaming Characteristics of the oil, defoament is added and that may jeoperdise the Air- Release Value for the oil. Thus there has to be a balence of both the properties to have a good overall quality of the oil, whether it is a Industrial Gear Oil or a Hydraulic Oil!

Tapas,

What you say is valid for fluids or oils. But the reference here, is for Non-Newtonian fluids like Open Gears (Viscosity 1000 Cst plus)or for greases.

Hussam Adeni

Dear Mr Vijay
But the open gear greases are suppose to be slumpable and we have not seen any follower plates.
But would you tell me if a 0 -00 consistency grease can be non slumpable.
How do you handle this problem if there is a dent in the drum?!!!!!!!!!!!

Dear Arupanjan,
You are right.Open gear greases are suppose to be slumpable.But there are some grades which are not slumpable and there is no test for slumpability.So the best way is to have a follower plate.I know of one customer he had a problem of slumpability which was solved by putting a follower plate in the drum which goes down along the level of the the grease.
There could be two greases having the same NLGI Grade(penetration) but different slumpability.
Vijay

But when we have a dent in the drum due to handling and the pump inside the libes like Lincoln system, how do we approach this problem?

quote:

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Originally posted by Arupanjan:
But when we have a dent in the drum due to handling and the pump inside the libes like Lincoln system, how do we approach this problem?

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In this case you are pretty much out of luck. In the future, inspect delivered barrels at the point of delivery and reject ones that are dented.