The Twin-Screw Extruder Simulator (TXS™) is a personal computer software package for process simulation and analysis of plastics compounding operations in corotating, intermeshing, modular twin-screw extruders. TXS allows you to obtain quick approximate answers to many processing problems that arise in the compounding plant and the process development laboratory. TXS simulates all the steps in the process: solids conveying, melting, mixing, melt conveying, pressurization, and die flow. The simulations are performed in realistic settings, with multiple feed and vent ports. TXS can simulate complex processing operations, such as the extrusion compounding of filled compounds, reinforced materials, elastomer-plastomer blends, color concentrates, etc. TXS may be used for specific process applications wherever corotating twin-screw extruder are employed: in the farmaceutical and cosmetics industries, in food processing, etc.