SBIR Phase I: Optimization of Screw Geometry and Processing Conditions using Three-Dimensional Simulation of Melting and Melt Flow in Twin-Screw Extruders

This Small Business Innovation Research (SBIR) Phase I project will develop software for three-dimensional simulation of the two-phase flow in a twin-screw extruder. Currently available analytical tools for design of twin-screw extruders are based upon simplified one-dimensional or two-dimensional analysis. However, the two-phase flow in twin-screw extruders is complex; and predictions from these simplified analyses cannot reliably predict the velocity, pressure and temperature distribution. The proposed software for three-dimensional simulation of the two-phase flow will incorporate a proprietary constitute theory that takes into account both the shear viscosity and the elongational viscosity of the polymer. Since the flow in intermeshing region of a twin-screw extruder is highly elongation dominated, the predictions from the proposed software will be more accurate than those from currently available tools that ignore the effect of elongational viscosity. The proposed technology will enhance the understanding of polymer flow in twin-screw extruders and will lead to developing innovative screw profiles. The use of this software will also enable various companies including plastic material suppliers, twin-screw extruder manufacturers and plastic compounders to cut costs.