Skip to main content
SpringerLink
Log in

Capillary extrusion flow of a fluoropolymer melt

  • Original Research
  • Published:
International Journal of Material Forming Aims and scope Submit manuscript

Abstract

The capillary extrusion-forming flow of a fluoropolymer (FEP) melt was studied both experimentally and numerically. The excess pressure drop due to entry (related to the Bagley correction), the compressibility, and the effect of pressure and temperature on viscosity on the capillary data analysis have been examined. Using a series of capillary dies having different diameters, D, and length-to-diameter L/D ratios, a full rheological characterization has been carried out, and the experimental data have been fitted both with a viscous model (Cross) and a viscoelastic one (the Kaye—Bernstein, Kearsley, Zapas/Papanastasiou, Scriven, Macosko or K-BKZ/PSM model). For the viscous model, the viscosity is a function of both temperature and pressure. For the viscoelastic K-BKZ model, the time-temperature shifting concept has been used for the non-isothermal calculations, while the time-pressure shifting concept has been used to shift the relaxation moduli for the pressure-dependence effect. It was found that the viscous simulations gave good results in the range of apparent shear rates studied. The viscoelastic simulations gave slightly better results in reproducing the experimental data, especially for the entrance pressure losses for L/D = 0. It is concluded that pressure-dependence of the viscosity and viscoelastic effects are small to moderate in flow of the FEP melt, which is a linear polymer.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14

Similar content being viewed by others

References

  1. Imbalzano AE, Kerbow DL (1994) Advances in fluoroplastics. Trends Pol Sci 2:26–30

    Google Scholar 

  2. Ebnesajjad S (2003) Melt Processible Fluoropolymers. Elsevier, New York

    Google Scholar 

  3. Domininghaus H (1993) Plastics for Engineers: Materials, Properties, Applications, Hanser, Munich

  4. Dealy JM, Wissbrun KF (1990) Melt Rheology and its Role in Plastics Processing—Theory and Applications. Van Nostrand Reinhold, New York

    Book  Google Scholar 

  5. Laun HM (2003) Pressure dependent viscosity and dissipative heating in capillary rheometry of polymer melts. Rheol Acta 42:295–308

    Article  Google Scholar 

  6. Laun HM (2004) Capillary rheometry for polymer melts revisited. Rheol Acta 43:509–528

    Article  Google Scholar 

  7. Bagley EB (1957) End corrections in the capillary flow of polyethylene. J Appl Phys 28:193–209

    Article  Google Scholar 

  8. Ansari M, Alabbas A, Mitsoulis E, Hatzikiriakos SG (2010) Entry flow of polyethylene melts in tapered dies. Intern Polym Proc 25:287–296

    Article  Google Scholar 

  9. Horrobin DJ, Nedderman RM (1998) Die entry pressure drops in paste extrusion. Chem Eng Sci 53:3215–3225

    Article  Google Scholar 

  10. Gibson AG (1998) Converging Dies. In: Collyer AA, Gregg DW (eds) Rheological Measurements. Chapman and Hall, London

    Google Scholar 

  11. Ariawan AB, Ebnesajjad S, Hatzikiriakos SG (2002) Paste extrusion of polytetrafluoroethylene (PTFE) fine powder resins. Can J Chem Eng 80:1153–1165

    Article  Google Scholar 

  12. Ochoa I, Hatzikiriakos SG (2005) Paste extrusion of PTFE: viscosity and surface tension effects. Powder Technology 153:108–118

    Article  Google Scholar 

  13. Rosenbaum E, Hatzikiriakos SG, Stewart CW (1995) Flow implications in the processing of teflon® resins. Intern Polym Proc 10:204–212

    Google Scholar 

  14. Rosenbaum E, Hatzikiriakos SG, Stewart CW (1998) Rheological characterization of well defined TFE/HFP copolymers. Rheol Acta 37:279–288

    Article  Google Scholar 

  15. Tordella JP (1963) An unusual mechanism of extrusion of polytetrafluoroethylene at high temperature and pressure. J Appl Polym Sci 7:215–229

    Article  Google Scholar 

  16. Tordella JP (1969) Unstable flow of molten polymers, in rheology. Theory and Application 5:57–92

    Google Scholar 

  17. Rosenbaum EE (1998) Rheology and processability of FEP Teflon resins for wire coating, PhD thesis, University of British Columbia, Vancouver, Canada

  18. Rosenbaum EE, Randa S, Hatzikiriakos SG, Stewart CW (2000) Boron nitride as a processing aid for the extrusion of polyolefins and fluoropolymers. Polym Eng Sci 40:179–190

    Article  Google Scholar 

  19. Hatzikiriakos SG, Dealy JM (1991) Wall slip of molten high density polyethylene I. Sliding plate rheometer studies. J Rheol 35:497–523

    Article  Google Scholar 

  20. Hatzikiriakos SG, Dealy JM (1992) Wall slip of molten high density polyethylene. II. Capillary rheometer studies. J Rheol 36:703–741

    Article  Google Scholar 

  21. Tanner RI (2000) Engineering Rheology, 2nd edn. Oxford University Press, Oxford

    Google Scholar 

  22. Mitsoulis E, Hatzikiriakos SG (2009) Steady flow simulations of compressible PTFE paste extrusion under severe wall slip. J Non-Newtonian Fluid Mech 157:26–33

    Article  Google Scholar 

  23. Sedlacek T, Zatloukal M, Filip P, Boltizar A, Saha P (2004) On the effect of pressure on the shear and elongational viscosities of polymer melts. Polym Eng Sci 44:1328–1337

    Article  Google Scholar 

  24. Carreras ES, El Kissi N, Piau J-M, Toussaint F, Nigen S (2006) Pressure effects on viscosity and flow stability of polyethylene melts during extrusion. Rheol Acta 45:209–222

    Article  Google Scholar 

  25. Papanastasiou AC, Scriven LE, Macosko CW (1983) An integral constitutive equation for mixed flows: viscoelastic characterization. J Rheol 27:387–410

    Article  Google Scholar 

  26. Luo X-L, Tanner RI (1988) Finite element simulation of long and short circular die extrusion experiments using integral models. Int J Num Meth Eng 25:9–22

    Article  MATH  Google Scholar 

  27. Kajiwara T, Barakos G, Mitsoulis E (1995) Rheological characterization of polymer solutions and melts with an integral constitutive equation. Int J Polymer Analysis & Characterization 1:201–215

    Article  Google Scholar 

  28. Luo X-L, Mitsoulis E (1990) A numerical study of the effect of elongational viscosity on vortex growth in contraction flows of polyethylene melts. J Rheol 34:309–342

    Article  Google Scholar 

  29. Luo X-L, Tanner RI (1987) A pseudo-time integral method for non-isothermal viscoelastic flows and its application to extrusion simulation. Rheol Acta 26:499–507

    Article  MATH  Google Scholar 

  30. Alaie SM, Papanastasiou TC (1993) Modeling of non-isothermal film blowing with integral constitutive equations. Intern Polym Proc 8:51–65

    Google Scholar 

  31. Beaulne M, Mitsoulis E (2007) Effect of viscoelasticity in the film-blowing process. J Appl Polym Sci 105:2098–2112

    Article  Google Scholar 

  32. Barakos G, Mitsoulis E (1996) Non-isothermal viscoelastic simulations of extrusion through dies and prediction of the bending phenomenon. j non-Newtonian Fluid Mech 62:55–79

    Article  Google Scholar 

  33. Peters GWM, Baaijens FPT (1997) Modelling of non-isothermal viscoelastic flows. J Non-Newtonian Fluid Mech 68:205–224

    Article  Google Scholar 

  34. Van Krevelen DW (1990) Properties of Polymers, 3rd edn. Elsevier, New York

    Google Scholar 

  35. Ebnesajjad S (2000) Fluoroplastics: Vol. 2, Melt Processing Fluoroplastics. William Andrew Inc, New York

    Google Scholar 

  36. Hatzikiriakos SG, Dealy JM (1994) Start-up pressure transients in a capillary rheometer. Polym Eng Sci 34:493–499

    Article  Google Scholar 

  37. Winter HH (1977) Viscous dissipation in shear flows of molten polymers. Adv Heat Transfer 13:205–267

    Article  Google Scholar 

  38. Mitsoulis E, Wagner R, Heng FL (1988) Numerical simulation of wire-coating low-density polyethylene: theory and experiments. Polym Eng Sci 28:291–310

    Article  Google Scholar 

  39. Bird RB, Armstrong RC, Hassager O (1987) Dynamics of polymeric liquids, vol. 1: Fluid mechanics, 2nd Ed. Wiley, New York

    Google Scholar 

  40. Hannachi A, Mitsoulis E (1993) Sheet coextrusion of polymer solutions and melts: comparison between simulation and experiments. Adv Polym Technol 12:217–231

    Article  Google Scholar 

  41. Luo X-L, Mitsoulis E (1990) An efficient algorithm for strain history tracking in finite element computations of non-Newtonian fluids with integral constitutive equations. Int J Num Meth Fluids 11:1015–1031

    Article  MATH  Google Scholar 

  42. Meissner J (1975) Basic parameters, melt rheology, processing and end-use properties of three similar low density polyethylene samples. Pure Appl Chem 42:551–612

    Article  Google Scholar 

Download references

Acknowledgements

Financial assistance from the Natural Sciences and Engineering Research Council (NSERC) of Canada and the programme “PEBE 2009-2011” for basic research from NTUA are gratefully acknowledged.

Author information

Authors and Affiliations

  1. School of Mining Engineering and Metallurgy, National Technical University of Athens, Zografou, 157 80, Athens, Greece

    Evan Mitsoulis

  2. Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada

    Savvas G. Hatzikiriakos

Authors
  1. Evan Mitsoulis
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Savvas G. Hatzikiriakos
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Evan Mitsoulis.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Mitsoulis, E., Hatzikiriakos, S.G. Capillary extrusion flow of a fluoropolymer melt. Int J Mater Form 6, 29–40 (2013). https://doi.org/10.1007/s12289-011-1062-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12289-011-1062-7

Keywords

Search

Navigation