The rubber sample was added to a
Brabender internal mixer (70 g capacity) at 60 °C and 60 rpm.
The sample was allowed to mix alone for a short period of time (1
min) followed by the addition of the silica filler. The ram of the
mixer was left up for 2 min in order to allow the silica to enter
the mixer. After the ram was lowered, the compound was mixed for an
additional minute (4 min total) and a sweep was performed. The compound
was mixed for 5 min total. The compound was then processed on a 4
× 6″ mill operating at 30 °C and 18 rpm with a thin
nip. Any loose silica from the mixer was added, and 6 three-quarter
cuts and 6 endwise passes were performed. RPA was run exactly 1 h
after mixing.
Brabender internal mixer (70 g capacity) at 60 °C and 60 rpm.
The sample was allowed to mix alone for a short period of time (1
min) followed by the addition of the silica filler. The ram of the
mixer was left up for 2 min in order to allow the silica to enter
the mixer. After the ram was lowered, the compound was mixed for an
additional minute (4 min total) and a sweep was performed. The compound
was mixed for 5 min total. The compound was then processed on a 4
× 6″ mill operating at 30 °C and 18 rpm with a thin
nip. Any loose silica from the mixer was added, and 6 three-quarter
cuts and 6 endwise passes were performed. RPA was run exactly 1 h
after mixing.
