Consider blending polypropylene (80%) and EDPM (20%) in the melting zone of the screw channel of a single screw extruder with a speed of 120 rpm and a flow rate Q of 3 times 10^-6 m^3/s at 190 degree C. Calculate the viscosity ratio needed for the breakup of the droplets under the following conditions: Screw speed = 120 rpm L/D s 5 Flight clearance = 0.2 mm Right width = 4 mm Screw diameter = 25 mm Initial radius of EPDM particles = 1 mu m PP/EDPM interfacial tension @ 190 degree C = 3 times 10^-3 N/m PP viscosity = 400 Pa-s Solution The answer of following question is as follows.. The maximum viscosity ratio for the given problem is 8:5.