Specification of Twin Screw

Figure 1: Co-rotating intermeshing twin screw extruder screw set

Process control parameters include screw speed (rpm), feed rate, barrel/die temperatures, and vacuum level. Typical

readouts include melt pressure, melt temperature, motor amperage, and in-line optical sensors. Depending on how the TSE

 is configured and operated, residence times can be as short as 5 seconds, as long as 10 minutes, and are typically in the 20

second to 2 minute range.

Starve feeding refers to the extruder being fed at a rate less than the forwarding efficiency of the screws. The independence

of feed rate from screws rpm facilitates control of surface area generation, residence time, and mixing (to eliminate gradients);

 and is what makes the TSE an effective tool for stripping volatiles from polymer melts.