Polímeros: Ciência e Tecnologia
Polímeros: Ciência e Tecnologia
Scientific & Technical Article

Influence of flow pattern development at die entrance and inside annular die on extrudate swell behavior of NR compound

Intawong, Naret; Udomsom, Sittichai; Sugtakchan, Konnatee; Sitticharoen, Watcharin

Downloads: 0
Views: 374


This research studies influence of the flow pattern at annular die entrance through the inside of annular die flow channel of capillary rheometer on the swell behavior of NR compound. The annular die used in this research was specifically designed to create the specific pattern of Vortex Flow at Die Entrance (VFE) of NR compound. Results of the study showed that the thickness swell ratio was higher than diameter swell ratio by an average of 20% at every die gap size. It was also found that the VFE flow pattern had direct significant influence on the swell behavior of NR compound while extrudating through annular die. Results from the study of the flow pattern could be used to explain why the thickness swell ratio is higher than the diameter swell ratio in every test condition.


capillary rheometer, annular die, diameter swell ratio, thickness swell ratio, NR compound.


1. Cogswell, F. N. (1981). Polymer melt rheology. London: George Godwin.

2. Garcia-Rejon, A., & Dealy, J. M. (1982). Swell of extrudate from an annular die. Polymer Engineering and Science, 22(3), 158-165. http://dx.doi.org/10.1002/pen.760220305.

3. Wagner, A. H., & Kalyon, D. M. (1996). Parison formation and inflation behavior of polyamide-6 during extrusion blow molding. Polymer Engineering and Science, 36(14), 1897-1906. http://dx.doi.org/10.1002/pen.10586.

4. Song, H. J., White, J. L., Min, K., Nakajima, N., & Weissert, F. C. (1988). Rheological properties, extrudate swell, and die entry extrusion flow marker experiments for rubber-carbon black compounds. Advances in Polymer Technology, 8(4), 431-449. http://dx.doi.org/10.1002/adv.1988.060080407.

5. Wood, A. K., Read, A. G., & Lovegrove, J. G. A. (1989). The effects of rheometer design in the measurement of the flow properties of polymer melts. Plastics and Rubber Processing and Applications, 12(1), 15-20.

6. Eggen, S., & Hinrichsen, E. (1996). Swell and distortions of high-density polyethylene extruded through capillary dies. Polymer Engineering and Science, 36(3), 410-424. http://dx.doi.org/10.1002/pen.10428.

7. Sombatsompop, N., & Dangtungee, R. (2001). Effect of die design on flow visualization and die swell of NR in a capillary rheometer. Journal of Materials Science Letters, 20(15), 1405-1408. http://dx.doi.org/10.1023/A:1011695527853.

8. Sombatsompop, N., & Dangtungee, R. (2001). Flow visualization and extrudate swell of natural rubber in a capillary rheometer: effect of die/barrel system. Journal of Applied Polymer Science, 82(10), 2525-2533. http://dx.doi.org/10.1002/app.2103.

9. Intawong, N-T., Wiratket, A., & Meechue, P. (2014). Flow visualization & extrudate swell behavior of natural rubber compound in annular die capillary rheometer. Polímeros: Ciência e Tecnologia, 24(4), 434-440. http://dx.doi.org/10.1590/0104-1428.1696.

10. Intawong, N.-T., Darajang, A., Udomsom, S., Yoochooshai, T., & Kantala, C. (2014). An annular rotating-die technique in extrusion process: effect of mandrel rotating speed on entrance pressure drop and flow properties of molten HDPE. International Journal of Plastics Technology, 18(2), 241-251. http://dx.doi.org/10.1007/s12588-014-9080-1.

11. Intawong, N.-T., Wongchaleo, C., & Sombatsompop, N. (2008). Rheological properties, flow visualization and extrudate swell of NR compound by rotating-die rheometer. Polymer Engineering and Science, 48(6), 1191-1198. http://dx.doi.org/10.1002/pen.21074.

12. Winter, H. H., & Fritz, H. G. (1986). Design of dies for the extrusion of sheets and annular parisons: the distribution problem. Polymer Engineering and Science, 26(8), 543-553. http://dx.doi.org/10.1002/pen.760260805.

13. Koopmans, R. J. (1992). Extrudate swell of high density polyethylene. Part III: extrusion blow molding die geometry effects. Polymer Engineering and Science, 32(23), 1755-1764. http://dx.doi.org/10.1002/pen.760322304.

14. Intawong, N.-T., Kantala, C., Lotaisong, W., & Sombatsompop, N. (2011). A die rotating system for moderations of extrusion load and pressure drop profiles for molten PP and wood/polypropylene composites in extrusion processes. Journal of Applied Polymer Science, 120(2), 1006-1016. http://dx.doi.org/10.1002/app.33209.

15. Diraddo, R. W., & Garcia-Rejon, A. (1992). Noncontact measurement of parison thickness profiles affected by swell and sag in continuous extrusion blow molding. Polymer Engineering and Science, 32(19), 1401-1410. http://dx.doi.org/10.1002/pen.760321902.

16. Intawong, N.-T., Darajang, A., Udomsom, T., Yoochooshai, S., & Kantala, C. (2014). An annular rotating-die technique in extrusion process: effect of mandrel rotating speed on extrudate swell behavior of HDPE parison. International Polymer Processing, 29(5), 607-615. http://dx.doi.org/10.3139/217.2930.

17. Mu, Y., Zhao, G., Wu, X., & Zhang, C. (2010). An optimization strategy for die design in the low-density polyethylene annular extrusion process based on FES/BPNN/NSGA-II. International Journal of Advanced Manufacturing Technology, 50(5-8), 517-532. http://dx.doi.org/10.1007/s00170-010-2556-z.
588371c97f8c9d0a0c8b4a6f polimeros Articles
Links & Downloads

Polímeros: Ciência e Tecnologia

Share this page
Page Sections