Abstract
We present a semi-numerical modeling approach to analyzing the role of surface renewal during bubble-free devolatilization in vented single-screw extruders. To demonstrate the significance of surface renewal in the mass transport of volatiles, we derived approximate analytical solutions for the two-dimensional circulatory flow in a partially filled screw channel, placing special emphasis on the melt pool that forms in front of the active flight. By applying the resulting velocity field to the governing conservation equation for the volatile concentration in the polymeric phase, the convective influence of the polymer flow on mass transport is taken into account. The resulting convection-diffusion equation, which is solved numerically using the finite-volume method, provides both qualitative and quantitative insights into how volatile depletion in the melt pool is related to the flow field developed. Thus, we clearly demonstrate that surface renewal improves mass transport efficiency considerably, even at very low screw speeds.
| Original language | English |
|---|---|
| Pages (from-to) | 387-393 |
| Number of pages | 6 |
| Journal | International Polymer Processing |
| Volume | 32 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Jul 2017 |
Fields of science
- 205 Materials Engineering
- 205011 Polymer engineering
- 102009 Computer simulation
- 104018 Polymer chemistry
- 205012 Polymer processing
- 104019 Polymer sciences
JKU Focus areas
- Nano-, Bio- and Polymer-Systems: From Structure to Function
- Engineering and Natural Sciences (in general)