2.2. Processing of rubber–clay nanocomposites
Compound mixing was carried out in two stages, in the firststage uncured rubber was mixed with essential additives and themixing was carried out in laboratory size 1.5-l Banbury mixer(Farrel, UK). Banbury temperature control is maintained by manualcontrolled Temperature Control Unit (TCU). Master-batch (uncuredrubber and additives) was mixed at 60 rpm screw speed for6 min and the batches were dumped at 145 8C. After adequatematuration of the master-batches (28 h) it was mixed with the curatives and nanoclay at different dosages. The mixing was done at 40 rpm for 4 min and the batches were dumped at 100–110 8C.
After final mixing and 24 h maturation is done and then after
moulding is started. The compounds are sheeted out at the
required thickness using laboratory mill. Mouldings were done in a
22 in. 24 in. steam heated automatic press at 140 8C at a pressure
of 10 MPa for 40 min. The moulded pieces were cooled in water
and conditioned at 23 2 8C and 50% relative humidity for 24 h
before testing. Also, two-roll mixer is also adopted for rubber with
3 wt.% nanoclay composites.
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