Di. Bigio et al., PRESSURE-RELATED DRIVING FORCES IN THE FULLY FILLED NONINTERMESHING TWIN-SCREW EXTRUDER, Advances in polymer technology, 12(4), 1993, pp. 353-360
Research in understanding the mechanisms behind driving forces in the
fully filled nonintermeshing twin screw extruder concentrated on exper
imental analysis of the relation between stagger, screw speed, and cro
ss-channel flow due to measured pressure differential in the nip regio
n. A new measure of the pressure driving force was also sought out, to
correlate new data to previous findings from visual studies. The firs
t part of the study was to obtain the values for the dynamic pressure
on both sides of the nip region. Further refinements to the equipment
used in previous studies allowed closer placement of the transducers i
n the nip region. After the data were stored, analysis started by dete
rmining the DELTAp values from the trace of the pressure differential.
By plotting these values, we obtain a highly repeatable curve confirm
ing that the greatest pressure flow occurs at small staggers. A simple
2-D model for pressure flow in the nip region was used to estimate th
e effect of the cross-channel pressure differential. Values for the cr
oss-channel pressure flow were calculated and compared with the drag f
low and found to be significant. (C) 1993 John Wiley & Sons, Inc.