In-line measurement of residence time distribution in twin-screw extruder using non-destructive ultrasound

  • Lee, Sang-Myung (Applied Rheology Center, Dept. of Chemical Engineering, Sogang University) ;
  • Park, Jong-Cheol (Applied Rheology Center, Dept. of Chemical Engineering, Sogang University) ;
  • Lee, Sang-Mook (Applied Rheology Center, Dept. of Chemical Engineering, Sogang University) ;
  • Ahn, Young-Joon (Applied Rheology Center, Dept. of Chemical Engineering, Sogang University) ;
  • Lee, Jae-Wook (Applied Rheology Center, Dept. of Chemical Engineering, Sogang University)
  • Published : 2005.06.01

Abstract

In this study, we performed RTD measurement at the die exit of co-rotating twin-screw extruder using a non-destructive ultrasonic device. The ultrasonic device was attached at slit die and was composed of a steel buffer rod and 10 MHz longitudinal piezoelectric ultrasonic transducer. This in-line ultrasonic monitoring method is based on the ultrasonic response of $CaCO_3$ filled in polymer. The RTD is evaluated by variation of ultrasonic attenuation with time caused by change of the tracer concentration during extrusion. The ultrasonic tracer, pellet type of compounded $CaCO_3$ in polymer was used in this study. The effects of tracer concentration on RTD and flow patterns were studied. Evaluation for the residence functions at different screw speeds, feeding rates and screw configurations were also carried out.

Keywords

References

  1. Ainsworth, P., S. Ibanoglu and G. D. Hayes, 1997, Influence of process variables on residence time distribution and flow patterns of tarhana in a twin-screw extruder, J. of Food Eng. 32, 101-108 https://doi.org/10.1016/S0260-8774(97)00001-0
  2. Bur, A. J. and F. M. Galland, 1991, Fluorescence monitoring of twin screw extrusion, Polym. Eng. Sci. 31, 1365-1371 https://doi.org/10.1002/pen.760311902
  3. Cassagnau, P., C. Mijangos and A. Michel, 1991, An ultraviolet method for the determination of the residence time distribution in a twin screw extruder, Polym. Eng. Sci. 31, 772-778 https://doi.org/10.1002/pen.760311103
  4. Cassagnau, P., T. Nietsch and A. Michel, 1999, Bulk and dispersed phase polymerization of urethane in twin screw extruders, Intern. Polym. Proc. 14, 144-151 https://doi.org/10.3139/217.1531
  5. Chen, T., W. I. Patterson, and J. M. Dealy, 1995, On-line measurement of residence time distribution in a twin-screw extruder, Intern. Polym. Proc. 5, 3-9
  6. Chen, T. F., K. T. Nguyen, S. L. Wen and C. K. jen, 1999, Temperature measurement of polymer extrusion by ultrasonic techniques, Meas. Sci. Tech. 10, 139-145 https://doi.org/10.1088/0957-0233/10/3/007
  7. Choudury, G. S. and A. Gautam, 1998, On-line measurement of residence time distribution in a food extruder, J. of Food Sci. 63, 529-534 https://doi.org/10.1111/j.1365-2621.1998.tb15779.x
  8. Curry, J., A. Kiani and A. Dreiblatt, 1991, Feed variance limitations for co-rotating intermeshing twin screw extruder, Intern. Polym. Proc. 6, 148-155 https://doi.org/10.3139/217.910148
  9. Dankwerts, P. V., 1953, Continuous flow systems. Distribution of residence times, Chem. Eng. Sci. 2, 1-13 https://doi.org/10.1016/0009-2509(53)80001-1
  10. Franca, D. R., C. K. Jen, K. T. Nguyen and R. Gendron, 2000, Ultrasonic in-line monitoring of polymer extrusion, Polym. Eng. Sci. 40, 82-94 https://doi.org/10.1002/pen.11141
  11. Gao, J., G. C. Walsh, D. Bigio, R. M. Brider and M. D. Wetzel, 1999, Residence-time distribution model for twin-screw extruders, AIChE J. 45, 2541-2549 https://doi.org/10.1002/aic.690451210
  12. Gassner, G. E., D. Bigio, C. Marks, F. Magnus and C. Kiehl, 1999, A new approach to analyzing residence time and mixing in a co-rotating twin screw extruder, Polym. Eng. Sci. 39, 286- 298 https://doi.org/10.1002/pen.11415
  13. Gendron, R., L. E. Daigneault, J. Tatibouet and M. M. Dumoulin, 1996, Residence time distribution in extruders determined by in-line ultrasonic measurements, Adv. in Polym. Tech. 15, 111- 125
  14. Hu, G. H., I. Kadri and C. Picot, 1999, On-line measurement of the residence time distribution in screw extruders, Polym. Eng. Sci. 39, 930-939 https://doi.org/10.1002/pen.11482
  15. Melo T. A. and S. V. Canevarolo, 2002, An optical device to measure in-line residence time distribution curves during extrusion, Polym. Eng. Sci. 42, 170-181 https://doi.org/10.1002/pen.10938
  16. Nietsch, T., Ph. Cassagnau and A. Michel, 1997, Melt temperatures and residence times in an extruder by infrared spectroscopy, Intern. Polym. Proc. 12, 307-315 https://doi.org/10.3139/217.970307
  17. Puaux, J. P., G. Bozga and A. Ainser, 2000, Residence time distribution in a corotating twin-screw extruder, Chem. Eng. Sci. 55, 1641-1651 https://doi.org/10.1016/S0009-2509(99)00430-3
  18. Sun, Z., C. K. Jen, C. K. Shih and D. A. Denelsbeck, 2003, Application of ultrasound in the determination of fundamental extrusion performance: Residence time distribution measurement, Polym. Eng. Sci. 43, 102-111 https://doi.org/10.1002/pen.10009
  19. Thompson, M., J. P. Puaux, A. N. Hrymak and A. E. Hamielec, 1995, Modeling the residence time distribution of a non-intermeshing twin screw extruder, Intern. Polym. Proc. 10, 111-119 https://doi.org/10.3139/217.950111
  20. Todd, D. B., 1975, Residence time distribution in twin screw extruder, Polym. Eng. Sci. 15, 437-443 https://doi.org/10.1002/pen.760150607
  21. Unlu, E. and J. F. Feller, 2001, Geometric mean vs. Arithmetic mean in extrusion residence time studies, Polym. Eng. Sci. 41, 743-751 https://doi.org/10.1002/pen.10770
  22. Youssef, M. H., 2001, Temperature dependence of the degree of compatibility in SBR.NBR blends by ultrasonic attenuation measurements: influence of unsaturated polyester additive, Polymer, 42, 10055-10062 https://doi.org/10.1016/S0032-3861(01)00554-7