There might be a thermal gradient in the larger sample so you will need to adjust for that.

Dear Salih Abbas Habeeb: you must take into account that rubber samples for rheometric tests are thin (approximmately 1 mm thick), but rubber molded parts have different thickness so thermal gradient must be taken into account as Peter Farrington stated previously. For example, thickness of rubber samples for tensile tests is 2 or 3 mm then thermal gradient is very similar to rubber samples for rheometric tests. However, if you want to obtain rubber samples for compression test with a thickness of 12 mm, higher thermal gradients are achieved across the sample; in my work I found that 12 mm-thick samples for compression tests must be molded during 2.3 times the tc90 if a state of cure of 90% is desired. The same rule (2.3 times) must be applied to TC100 if you want achieve approximmately 100% of state of cure. For other thickness, you can estimate the optimum curing time by cutting the samples and measuring the hardness at the center and the surface of the moulded part, varying the curing time at the press and repeating the procedure until the desired hardness or the desired state of cure is achieved. If you need more detailed information, please do not hesitate in send me a message.

As the previous comments said, you have to consider the temperature gradient in your material.

In my opinion a factor concerning the Tc90 is not applicable in general as Tc90 is highly influenced by the curing system but thermal conduction is not that much influenced by different curing systems. Therefore i would suggest as a first approximation to measure the core temperature of the sample and add Tc90 to the time which is required to reach the curing temperature in the core.

Two parameters must be considered for production of rubber goods by compression molding base on obtained results from rheometer:

1. The temperature of rheometer: If the temperature of rheometer and compression molding is not the same, for every 10 degree rise in temperature, the curing time decreases by half. For example, if the curing time is 10 min at 150˚C, it would be approximately, 5 min at 160˚C.

2. The thickness of rubber goods: It is necessary to consider the maximum thickness of samples that must be cured by compression molding and consider the thickness of sample vulcanized by rheometer. The curing time obtained by the rheometer is based on the thickness of test sample.

The temperature at compression molding of press must be dependent on curing the temperature at rheometer but the TC90 at rheometer dependent on the thickness of sample .

Diego Giraldo is there any mathematical model to calculate this time margin for actual cure time for rubber curing. As you have stated it 2.3 for your process. Is there any mean to calculate it for specific rubber curing process like compression, injection molding autoclave curing, internal pressure cure, hot water cure etc.

How to calculate this time for a specific process and validate it?