Closely intermeshing counter-rotating twin screw extruders

CICT is closely intermeshing counter-rotating twin screw extruder (low speed)... 

A COMPOSITE MODEL FOR SOLID CONVEYING, MELTING, PRESSURE, TEMPERATURES AND FILL FACTOR IN A METERED FED CLOSELY INTERMESHING COUNTER-ROTATING TWIN SCREW EXTRUDER.491... 

A typical screw geometry of a closely intermeshing counter-rotating (CICT) twin screw extruder is shown in Fig. 10.27. 

The industrial use of twin-screw extruders for this purpose revolves extensively, but not exclusively, around intermeshing co-rotating variants. Closely intermeshing counter-rotating designs are widely used for profile extrusion of UP VC dry-blends since they permit close temperature control and exhibit a high conveying efficiency due to the positive displacement of material where the screws intermesh [150]. 

K. J. Gadzenveld and L. P. B. M. Janssen, Scale-up of Counter-rotating Closely Intermeshing Twin Screw Extruders without and with Reactions, Polym. Eng. Sci., 30, 1529-1536 (1990). 

In this case study, a urethane prepolymer based on polyalkylene etherglycol and an aliphatic diisocyanate group (methylene-bis, 4-cyclohexyl isocyanate), Adiprene LW-520, reacted with 1,4-butane diol in a counter-rotating closely intermeshing twin screw extruder with dibutyltin dilaurate as a catalyst (5). 

Thanks to their residence time distributions, co-rotating, closely intermeshing twin-screw extruders have assumed a dominant market position. Other machines, such as single-screw and counter-rotating extruders are used only for special tasks. Fig. 4.7 [35]. 

Counterrotating intermeshing twin-screw extmd-ers have the narrowest residence time distribution followed closely by co rotating intermeshing twin-screw extmders. Counter rotating nonintermeshing twin-screw extruders have the broadest residence time distribution. 

Figure 6.8 Leakage gaps in a counter-rotating, closely intermeshing twin-screw extruder (from [4]).

Counter-Rotating Closely Intermeshing Twin-Screw Extruder... 

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