Residence time distribution of polymer melts in the linearly tapered coat-hanger die

This article analyzes the average residence time distribution of polymer melt across the die width in a common linearly tapered coat-hanger die, which excells the T die but is a little inferior to the curvilinearly tapered coat-hanger die in residence time uniformity according to the approximated calculation of ten used. From another point of view, a linearly tapered coat-hanger die may be designed so that a desired ratio of the residence time through the die far end to that along the die center line may be imposed as one of the design constraints.