This paper presents the numerical modeling of heat and mass transfer processes that govern the extrusion of polymeric fluids such as plastics and food materials. Such materials are non-Newtonian and also have strong property variations with temperature and composition. Numerical schemes are developed for both single- and twin-screw extruders. The latter are largely treated as a combination of a translation zone, which is similar to the channel in a single-screw extruder, and a mixing region. The basic approach is outlined and typical numerical results are presented. Of particular interest are the resulting velocity and temperature distributions, pressure developed, temperature rise and the residence time in the extruder. These are computed for a few typical materials. The effect of the presence of additional components, such as moisture in food materials, is also investigated. Chemical reactions may arise in reactive polymers and in biopolymers. A simple numerical approach to model such processes is outlined. Finally, the flow through a die due to the pressure generated in the extruder is considered and linked with the flow in the screw channel. The paper brings out important basic aspects that govern the thermal transport in this manufacturing process and presents the important considerations in the numerical simulation.
|Original language||English (US)|
|Number of pages||26|
|Journal||Journal of Materials Processing and Manufacturing Science|
|State||Published - Jul 1 1994|
All Science Journal Classification (ASJC) codes
- Materials Science(all)