Without ts2 on the Rheo test 2

[orion1]

Dear All,

After mixing some rubber batches with isoprene elastomere formulation there missing ts2 on the Rheo testing?
After remmiling there are ts2 but ts1 is much lower.
What is the main cause that Ts2 is missing?


Thanks in advance,
Orion1

 

[tom1953]

I'm not clear on what you mean.
Are you saying that the rheometer is not showing you a ts2 value (but the cure curve looks normal)? or, are you saying that the compound's rheometer test doesn't show a two-point rise, indicating very little cure activity?

If it's the former, it sounds like a mechanical problem with the rheometer. If it's the latter, it sounds like a compound problem. If you can post your rheometer curve and the formula, that might clarify the problem.
tom

 

[orion1]

Rheometer is not showing a ts2 value on some mixed batches , but on some mixed batches there are Ts2?!


Orion 1

 

[orion1]

Generally,

Could one please explain what is the meaning of ts2 and ts1?

Regards,

 

[tom1953]

ts1 and ts2 indicate the time it takes for the torque of the rheometer to increase 1 and 2 units above the minimum value. It's an indication of the scorch time of the compound, and the time the rubber can flow before significant curing starts. The attached file is from "Rubber Technology" 2nd edition, a fairly old book, but it shows rheometer curves and several points on the curve pointed out (e.g., ts2 and tc90).

The rheometer shown is an old one, but older ones and newer ones should be able to give you the values of ts1 and ts2 or you could determine the values by examining the cure curve.



Tom Jablonowski, TSE Industries, Inc.
www.tse-industries.com

 

[RubberDog]

Hello, sorry I saw the question only now. In what equipment (brand and model) you are testing? Are you manually calculating the Ts1 and Ts2 or the software is giving this?
In the Alpha (previously Monsanto) ODR and MDR, when equiped with a colection system, it will always have the data points, but maybe your system is not configurate to show it. For instance, in our company, we normally use Ts1, but our sister plants in France uses the Ts2... when we want to compare some compounds, it is just matter of using the data existent...

If you have any question regarding rheometer in rubber, please let me know we I'll be glad to help.
Daniel.