Intermeshing mixer

Results of a Fingerprint Analysis of a Masterbatch and Remill Mixing Process of a Styrene-Butadiene Rubber-Carbon Black (SBR-CB) Compound on a CK320E Intermeshing Mixer with PES3 Rotors (Harburg Freudenberger)... 

Pomini reported that their VIC technology combines the fair raw material intake behavior of the tangential mixer with the excellent dispersion and cooling behavior of an intermeshing mixer. 

The VIC mixer is an intermeshing mixer in which the distance between the two rotors can be varied during mixing. Power input can be controlled better, it is said." During masterbatch mixing the interclearance section between the two rotors can be maximal. After material intake and incorporation, the interclearance section can be reduced by reducing the distance between the two rotor axes, which leads to better dispersion performance. 

Internal mixers with a much different mixing chamber design were proposed by Cooke [C17] of Francis Shaw and Company and by Lasch and Stromer [L3] of Werner and Pfleiderer. These internal mixers possess intermeshing counterrotating rotors (Fig. 1.9). In these internal mixers, both rotors must move at the same angular velocity. The Francis Shaw mixer, the Intermix, was marketed first and received considerable attention. In time, the intermeshing mixers dominated the mechanical rubber goods industries in Europe and Japan. 

Fig.1 Rotor geometries of the tangential mixer Werner Pfleiderer GK-2 and the intermeshing mixer Francis Shaw K1 Mark 4 Intermix.

The main cause of this significantly higher energy consumption is the well-established higher heat transfer to the cooling fluid taking place in the intermeshing mixer, as indicated by the fact that the temperature of the batch... 

In Fig. 11, the carbon black dispersion is plotted versus time for polymer D in the two mixers the intermeshing mixer is somewhat faster, but not a great deal similarly for polymer E (see Fig. 12). Translated to the... 

However, the fact that the traces of carbon black dispersion versus temperature are the same in both mixers irrespective of the upswing of carbon black dispersion for polymer E in the intermeshing mixer at 30°C lower than in the tangential mixer must then be explained on the basis of geometrical considerations of the mixers. To compare the fundamentally different geometries of the two mixers is difficult for the two mixers, the following clearances were measured ... 

Note that the difference in shape of the discharged lump occurs because of the way that the batch breaks at the door edges as the door opens. With an intermeshing mixer on which the door is more closely profiled to the shape of the rotors, the batch is wound out from between the rotors in the form of the gap between them, hence the rough sheet form of the dumped batch. With a tangential machine, a significant proportion of the batch is between the door and the rotors, hence a large lump is dumped followed by material which is carried round and often stretched out by the rotor. 

INTERMESHING MIXERS VARIABLE CLEARANCE VERSUS FIXED CLEARANCE Regalia R Moriconi M Techint-Pomini... 

An overview of the mixing machinery cmrently available for the manufacture of silica compounds and the requirements for the design of an internal mixer for the production of these compotmds is presented. A comparison is made of different mixers and the replacement of a 270-litre tangential mixer with a250-litre intermeshing mixer to make use of the advantages of mtermeshing irrtemal rrrixers is demonstrated. 12 refs. (International Tyre Exhibition Conference, Akron, USA, Sept. 12-14, 2000). 

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