Are greases with higher extreme temperatures necessarily better?

August 15, 2022

First, drop point ≠ use temperature

In fact, what many people say about the temperature resistance refers to the temperature of the dropping point.

Although dropping point is a very important indicator to measure the high temperature performance of grease, it is by no means the only indicator. Many grease merchants take advantage of the user's point of view that high dropping point means high temperature resistance. In the product introduction, the dropping point is often marked on the outside, and it is written that the dropping point is 380 ° C, 470 ° C, etc., but it can really achieve The temperature may not even be 150 ℃ enough.

The dropping point of many greases exceeds 300 degrees, or even has no dropping point. For example, bentonite grease is not expensive and has no dropping point. You say that it is no problem at 1000 degrees Celsius, but the grease volatilizes faster at around 200 degrees. If it is mineral oil, the Base Oil will be oxidized faster, the grease will become carbon deposits in a short period of time, and the base oil will be evaporated or oxidized. What is the significance of the dropping point?

To determine the maximum service temperature of the grease, in addition to the dropping point, it also depends on its consistency at high temperature, and the antioxidant capacity of the base oil and thickener. Parameters such as colloidal stability at high temperature.

Therefore, a grease with a high dropping point may not be good at high temperature. Of course, a high-temperature grease with a too low dropping point is definitely not good.

Second: Are greases with higher extreme temperatures necessarily better?

For example, let's say there are two kinds of greases (it should be noted: this is not an example we give out of thin air, but two kinds of greases that do exist),

The first grease can be used for a month at 210 degrees, but if it is used in an environment of 250 degrees, it will flow in a mess; it can only be called "temperature resistance of 210 degrees"

The second grease can be used for a week at 210 degrees, and can also be used for several hours or a day at 250 degrees, which can be called "temperature resistance of 250 degrees"

If your ambient temperature is 210 degrees, which one would you choose? More importantly, we also need to consider the comprehensive properties of the grease

●Mechanical stability --- Prevent the grease from thinning and flowing out after high-speed rotation.
●Extreme pressure resistance - ——Better lubrication performance, can be used for heavy-duty bearings.
●Thermal stability ——Avoid the oil and oil from flowing out under heat.
●Oxidation stability.——Avoid rapid oxidation failure of grease under high temperature.
●Water resistance - effective lubrication can be guaranteed even in the presence of water vapor.

Obviously, the so-called higher temperature resistance is not the best choice, it can only be the right product for the right working condition!

Author:

Mr. James

E-mail:

sales@cn-lubricantadditive.com

Phone/WhatsApp:

+86 13783582233