Mastication and mill processability

Reprinted with permission from N. Tokita and J. L White, Journal of Applied Polymer Science, 1968, 12, 7, 1589. Copyright 1968, John Wiley Sons, Inc. 

All in all the handling of rubber is very difficult. The operator tries to avoid Region III behaviour as much as possible. In Region IV there is no problem in the incorporation of the filler but the dispersion is not effective, because the stress transmitted from the machine to the filler agglomerate is not high enough to break it. The tack of the rubber also makes handling difficult. 

Sometimes rubber and additives are charged together into the internal mixer without masticating the rubber. This is done with relatively soft rubber or with the aid of a process oil . During mastication, NR chains break, resulting in a substantial decrease of 

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