Skip to main content

Effect of a radial flow foregoing a capillary die on the behavior of extruded PDMS: velocity field–distorted strand correlation

Rheologica Acta volume 59, pages 425–434 (2020)Cite this article

Abstract

The present work aimed to investigate the influence of flow geometry on volume instability associated to a linear polydimethylsiloxane (PDMS). To do so, a convergent radial flow was created at the die entrance. The performed particle image velocimetry (PIV) recordings under unstable flow regime, in capillary rheometer, characterized by the new entrance zone, show a new pattern of streamlines above the die and a disappearance of the vortex developed in the corner of the reservoir. Photographs of the extrudate strands obtained at the die exit depict a new morphology of defect which appears with a well-established radial flow. These results led to the correlation agreement between the gross melt fracture and the flow instability at the entrance zone. It also proved the importance of elongational and shear components linked to the upstream flow in the appearance and development of volume distortion.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

USD 39.95

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

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

References

  • Allal A, Lavernhe A, Vergnes B, Marin G (2006) Relationships between molecular structure and sharkskin defect for linear polymers. J Non Newtonian Fluid Mech 134:127–135

    CAS  Article  Google Scholar 

  • Ansari M, Hatzikiriakos SG, Sukhadia AM, Rohlfing DC (2011) Rheology of Ziegler Natta and metallocene high-density polyethylenes: broad molecular weight distribution effects. Rheol Acta 50(1):17–27

    CAS  Article  Google Scholar 

  • Ayadi A, Elgasri S, Mezghani A, Castro M, Elhaouani F (2011) Effect of radial flow in the die entrance region on gross melt fracture of PDMS extrudate. J. Non Newtonian Fluid Mech. 166:661–666

    CAS  Article  Google Scholar 

  • Bagley EB, Schreiber HP (1961) Effect of die entry geometry on polymer melts fracture and extrudate distortion. Trans Soc Rheol 5:341–353

    Article  Google Scholar 

  • Ballenger TF, White JL (1971) The development of the velocity field in polymer melts in a reservoir approaching a capillary die. J Appl Polym Sci 15:1949–1962

    CAS  Article  Google Scholar 

  • Barnes HA (2003) A review of the rheology of filled viscoelastic systems. Rheol Rev 2003:1–36

  • Bergem N (1976) Visualization studies of polymer melt flow anomalies in extrusion. In: Proceedings of the VIIth International Congress on Rheology. Chalmers University of Technology, Gothenburg, pp 50–54

    Google Scholar 

  • Carrot C, Guillet J (2000) Viscoélasticité non linéaire des polymères fondus, Techniques de l’Ingénieur, traité Plastiques et Composites, AM 3630

  • Combeaud C (2004) Study of volume instabilies in extrusion of polypropylene and polystyrene, PHD, University of Mines

  • Den Otter JL (1970) Mechanisms of melt fracture. Plast Polym:155–168

  • Doerpinghaus PJ, Baird DG (2003) Comparison of the melt fracture behavior of metallocene and conventional polyethylenes. Rheol Acta 42(6):544–556

    CAS  Article  Google Scholar 

  • Done DS, Baird DG, Average AE (1983) The influence of porous media on the flow of polymer melts in capillaries. Chem Eng Commun 21:293–309

    CAS  Article  Google Scholar 

  • Elgasri S, Ayadi A, Elhaouani F (2011) Effect of die geometry on helical defect during extrusion of PDMS across a radial flow upstream the contraction. J Non Newtonian Fluid Mech 166:1415–1420

    CAS  Article  Google Scholar 

  • Elkissi N, Piau JM (1996) Stability phenomena during polymer melt extrusion. In: Piau JM, Agassant JF (eds) Rheology for polymer melts processing. Elsevier, Amsterdam

    Google Scholar 

  • Elkissi N, Piau JM, Attane P, Turrel G (1993) Shear rheometry of polydimethysiloxanes. Master curves and testing of Gleissle and Yamamoto relations. Rheol Acta 32:293–310

    CAS  Article  Google Scholar 

  • Elkissi N, Piau JM, Toussaint F (1997) Sharkskin and cracking of polymer melt extrudates. J Non Newtonian Fluid Mech 68(2–3):271–290

    CAS  Article  Google Scholar 

  • Goutille Y, Guillet J (2002) Influence of filters in the die entrance region on gross melt fracture: extrudate and flow visualization. J Non Newtonian Fluid Mech 102:19–36

    CAS  Article  Google Scholar 

  • Goutille Y, Majesté JC, Tassin JF, Guillet J (2003) Molecular structure and gross melt fracture triggering. J Non Newtonian Fluid Mech 111:175–198

    CAS  Article  Google Scholar 

  • Ketata M, Ayadi A, Elkissi N, Bradai C (2017) Effect of rheological and physical properties on mitigation of melt fracture instability during extrusion of polymer melts through a radial flow die. Rheol Acta 56:341–350. https://doi.org/10.1007/s00397-017-0995-2

    CAS  Article  Google Scholar 

  • Koopmans R (2002) Engineering techniques, processed plastics and composites, AM3657

  • Legrand F, Piau JM (1998) Spatially resolved stress birefringence and flow visualization in the flow instabilities of a polydimethylsyloxane extruded through a slit die. J Non-Newtonian Fluid Mech 77:123–150

    CAS  Article  Google Scholar 

  • Meh M (1997) Private communication

  • Miller E, Rothstein JP (2004) Control of sharkskin instability in the extrusion of polymer melts using induced temperature gradients. Rheol Acta 44(2):160–173

    CAS  Article  Google Scholar 

  • Miller E, Lee SJ, Rothstein JP (2006) The effect of temperature gradients on the sharkskin surface instability in polymer extrusion through a slit die. Rheol Acta 45(6):943–950

    CAS  Article  Google Scholar 

  • Muller R, Vergnes B (1996) Validity of the stress optical law and application of birefringence to polymer complex flows. In: Piau JM, Agassant JF (eds) Rheology for Polymer Processing. Elsevier 5:257–284

  • Oyanagi Y (1973) A study of irregular flow behavior of high density polyethylene. Appl Polymer Symp 20:123–136

    Google Scholar 

  • Piau JM, ElKissi N, Tremblay B (1988) Low Reynolds number flow visualization of linear and branched silicones upstream of orifice dies. J Non-Newtonian Fluid Mech 30:197–232

    CAS  Article  Google Scholar 

  • Piau JM, ElKissi N, Tremblay B (1990) Influence of upstream instabilities and wall slip on melt fracture and sharkskin phenomena during silicones extrusion through orifice dies. J Non-Newtonian Fluid Mech 34:145–180

    CAS  Article  Google Scholar 

  • Piau JM, Nigen S, ElKissi N (2000) Effect of die entrance filtering on mitigation of upstream instability during extrusion of polymer melts. J Non-Newtonian Fluid Mech 91:37–57

    CAS  Article  Google Scholar 

  • Rothstein JR, McKinley GH (2001) The axisymmetric contraction expansion: the role of extensional rheology on vortex growth dynamics and the enhanced pressure drop. J Non Newtonian Fluid Mech 98:33–63

    CAS  Article  Google Scholar 

  • Sentmanat M, Hatzikiriakos SG (2004) Mechanism of gross melt fracture elimination in the extrusion of polyethylenes in the presence of boron nitride. Rheol Acta 43:624–633. https://doi.org/10.1007/s00379-004-0359-6

    CAS  Article  Google Scholar 

  • Tordella JP (1969) In: Eirich FR (ed) Unstable flow of molten polymers in rheology, vol V. Academic Press, New York

    Google Scholar 

  • Wang SQ, Drda PA (1996) Superfluid-like stick-slip transition in capillary flow of linear polyethylene: 1. General features. Macromolecules 29:4115–4119

    CAS  Article  Google Scholar 

  • Wang S, Drda PA (1997) Stick-slip transition in capillary flow of linear polyethylene: 3. Surface conditions. Rheol Acta 36:128–134. https://doi.org/10.1007/BF00366818

    CAS  Article  Google Scholar 

  • Wassner E, Schmidt M, Münstedt H (1999) Entry flow of a low-density polyethylene melt into a slit die: an experimental study by laser-Doppler velocimetry. J Rheol 43(6):1339–1353

    CAS  Article  Google Scholar 

  • Weill A (1980) About the origin of sharkskin. Rheol Acta 19(5):623–632

    CAS  Article  Google Scholar 

  • White JL (1973) Critique on flow patterns in polymer fluids at the entrance of a die and instabilities leading to extrudate distortion. Appl Polym Symp 20:155–174

    Google Scholar 

  • Yang X, Wang SQ, Halasa A, Ishida H (1998) Fast flow behavior of highly entangled monodisperse polymers. 1. Interfacial stick-slip transition of polybutadiene melts. Rheol Acta 37:415–423

    CAS  Article  Google Scholar 

  • Zhu X, Yang W, Wang S (2013) Exploring shear yielding and strain localization at the die entry during extrusion of entangled melts. J Rheol 57(1):349–364. https://doi.org/10.1122/1.4769898

    CAS  Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. National Engineering School of Sfax, LASEM, University of Sfax, 3038, Sfax, Tunisia

    Manel Ketata, Chedly Bradai & Mohamed Salah Abid

  2. National Engineering School of Sfax, CFDTP, University of Sfax, 3038, Sfax, Tunisia

    Abdehak Ayadi

Authors
  1. Manel Ketata
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Abdehak Ayadi
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Chedly Bradai
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Mohamed Salah Abid
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Manel Ketata.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Ketata, M., Ayadi, A., Bradai, C. et al. Effect of a radial flow foregoing a capillary die on the behavior of extruded PDMS: velocity field–distorted strand correlation. Rheol Acta 59, 425–434 (2020). https://doi.org/10.1007/s00397-020-01207-7

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00397-020-01207-7

Keywords

  • PDMS
  • Radial flow
  • PIV
  • Gross melt fracture
  • Elongational and shear component