Abstract
We propose a new control scheme to maintain a constant strain rate of the
mid-filament diameter in a filament stretching rheometer for polymer melts.
The scheme is cast as a velocity algorithm and consists of a feed-back and
a feed-forward contribution. The performance of the controller is demonstrated
on a commercial low density polyethylene. Several strain rates and
experimental conditions are tested to demonstrate the necessity of the control
parameters and the limits of both the control scheme and the experimental
apparatus. When the control parameters are properly tuned, the algorithm
ensures that the applied strain stays within 2% of the set point and measurements
can be made up to Hencky strains of 6.5.
mid-filament diameter in a filament stretching rheometer for polymer melts.
The scheme is cast as a velocity algorithm and consists of a feed-back and
a feed-forward contribution. The performance of the controller is demonstrated
on a commercial low density polyethylene. Several strain rates and
experimental conditions are tested to demonstrate the necessity of the control
parameters and the limits of both the control scheme and the experimental
apparatus. When the control parameters are properly tuned, the algorithm
ensures that the applied strain stays within 2% of the set point and measurements
can be made up to Hencky strains of 6.5.
| Original language | English |
|---|---|
| Journal | Journal of Non-Newtonian Fluid Mechanics |
| Volume | 194 |
| Pages (from-to) | 14-22 |
| ISSN | 0377-0257 |
| DOIs | |
| Publication status | Published - 2013 |
Keywords
- Filament stretching rheometer
- Extensional rheometry
- Feed-back and feed-forward control
- Low-density polyethylene