Frequently asked Questions about the Material Data Program LAB
Compound test, common specification of compound, incubation time
Compound test, common specification of compound, marching modulus
Compound test, common specification of compound, 10 set points for state of cure
When has at compound test, edit reaction kinetical data of compound, common specification of compound, a distinct incubation time to be selected?
Answer:
For the compound test (first test) three rheometer curves at three different temperatures (T1, T2, T3) have to be run. The. Incubation time t i is approximately that time at which the rheometer curve rises.
When for the three different temperatures in the order T1 < T2 < T3 incubation time in the order t i1 > t i2 > t i3 is clearly to be seen, then the compound shows a distinct incubation time.
Changes incubation time only little or in the wrong order, then the compound shows no distinct incubation time. The visible incubation time results from heating up the rubber in the rheometer.
In doubt, select yes. After process reaction kinetical data of compound look at these results in the table:
All calculated incubation times have to be positive
The activation energy for incubation time should be larger than 30.
If one or both results do not follow these aims, select no and do process reaction kinetical data of compound again.
When has at compound test, edit reaction kinetical data of compound, common specification of compound, a marching modulus to be selected?
Answer:
Compounds with marching modulus characteristic do not reach maximum torque in a practical short time. To save time at the batch test, the rheometer test is cut before the curve shows a horizontal line.
At compound test, common specification of compound marching modulus has to be selected whenever batch test time is too short to reach maximum torque.
The 10 set points for state of cure should be input according to the estimated maximum torque. If e.g. the batch curve stops always at about 60% of the estimated maximum torque (horizontal line), the 10 set points for state of cure should be selected from 20% to 55%
Which percentage rates have to be input?
Answer:
It depends on cure behaviour of the compound:
For regular compounds, which are run until maximum torque (horizontal line) at batch test, values between 30% und 95% (e.g. 30% / 40% / 50% / 60% / 70% / 75% / 80% / 85% / 90% / 95%) should be selected.
At reverting compounds maximum torque (100%) ist always the 7th point. Batch test time should be 20% or more longer than time for reaching maximum torque. Useful values for the 10 set points for state of cure are e.g. 40% / 50% / 60% / 70% / 80% / 90% / 100% / 99% / 97% / 95%.
Compound with
marching modulus do not reach maximum torque in a practical time.
To reduce batch test time to a practical value, batch test is cut on
the still rising edge of the rheometer curve.
At
compound test, common specification of compound
"marching modulus" has to be selected, whenever batch test
is stopped before reaching maximum torque. When the batch curve is
only run until e.g. 60% of the estimated maximum torque, useful 10
points for state of cure are 20% / 25% / 30% / 35% / 40% / 45% / 48 %
/ 50% / 53% / 55%.