Banbury intermixer

Sangari and co-workers [18, 19] have used a two-litre Banbury intermixer and a combination of accelerators with a peptiser to devulcanise both standard SBR compounds (unfilled and filled) and ground tyre tread. The devulcanisation recipes that were used in the study are shown in Table 5.3. 

Processing variables can affect to a very great extent the results obtained on the rubber product or test piece and, in fact, a great number of physical tests are carried out in order to detect the result of these variables, for example state of cure and dispersion. In a great many cases, tests are made on the factory prepared mix or the final product as it is received but, where the experiment involves the laboratory preparation of compounds and their moulding, it is sensible to have standard procedures to help reduce as far a possible sources of variability. Such procedures are provided by ISO 2393 which covers both mills and internal mixers of the Banbury or Intermix type, and also procedures for compression moulding. 

Other major machines in use in the rubber industry are the Shaw intermix and the Baker-Perkins shear-mix. Both the Banbury-type and the intermix mixers have passed through modifications and refinements at different points in time. Mechanical feeding and direct oil injection in measured doses into the mixing chamber through a separate oil injection port are notable features of modern internal mixers. Higher rotor speeds and, in the Banbury type, the higher ram pressures, are used for speedy output. 

In Banbury-type mixers, the rotors run at different speeds, while in intermix mixers the rotor speeds are equal but the kneading action between the thicker portion of one rotor and the thinner portion of the other produces a frictional effect. 

Figure 3, Rotor designs (A) Banbury two-wing design (B) four-wing design (C) Shaw Intermix three-wing design (D) Werner Pfleiderer four-wing design.

Fig. 5. Examples of rotor designs A, Banbury two-wing B, Banbury four-wing C, Shaw Intermix three-wing D, Werner and Pfieiderer four-wing. The pumping action of the wings is indicated by arrows.

RubberTech China 98. Conference proceedings.. Shanghai, China, 24th-26th Match, 1998, paper 28. 012 BANBURY MIXER AND INTERMIX FOR MIXING TECHNICAL RUBBER GOODS Melotto M A... 

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