There are two different types of internal mixers used in the industry at large. The first type is more commonly known as a “Banbury®” type intensive mixer and the second type is known as a “Kneader”. The primary difference between the two types of mixers is rotor, throat, chamber and floating weight design. The former also discharges the batch through a bottom door where as the kneader tilts to discharge the batch.
Conventional; kneaders have 2 tangential non-intermeshing rotors as well as pneumatic operated floating weights. With the conventional kneader design the temperature in a batch can not be sufficiently controlled to achieve 1 pass mixing. With conventional kneaders the batch temperature after the primary kneading stage is high because of poor temperature transfer from the mixing contact surfaces to the batch. Therefore the batch has to be either cooled down or transferred to another kneader for the final kneading stage. This additional step is cost prohibitive as well as time consuming.