Internal mixer for unvulcanised rubber with shearing disc feed rolls - has integral construction for improved cutting, premixing, optionally with additives, and energy redn.

摘要

Internal mixer for mixing or compounding unvulcanised rubber with structurally-integral arrangement of intermeshing nip rolls (shearing discs), at least one of which is serrated, feeding directly to the feed hopper. Bales of raw rubber are fed on a horizontal conveyor to the nip rolls which shear them into strips to fall by gravity into the mixer. The rolls are at an angle to each other of 0-90 deg., pref. 30-45 deg., to the vertical, and are pref. of different mean dia.. ADVANTAGE - The nip roll assembly is integral with the mixer, promoting gravity feeding and conserving the heat produced by the cutting energy, so reducing the energy consumption in the main mixer. Unequal nip roll diameters are claimed to improve feeding of the bale through increased contact surface between rolls. Additives, esp. carbon black, may optionally be fed directly and simultaneously to the nip rolls, giving considerable pre-mixing before the main compounding unit. As a consequence of pre-heating by cutting and pre-mixing, the same cpd. quality can be achieved with smaller rating of main drive. The integral construction avoids intermediate storage of the cut rubber. (0/1)