Skip to main content
SpringerLink
Log in

Enhanced melt strength and stretching of linear low-density polyethylene extruded under strong slip conditions

  • Original Paper
  • Published:
Rheologica Acta Aims and scope Submit manuscript

Abstract

The influence of extrusion under strong slip conditions on the extensional properties of linear low-density polyethylene was studied in this work. The material was extruded at two different temperatures under strong slip and no slip conditions, and was subsequently subjected to uniaxial elongational flow by means of a Rheotens device. Strong slip was evident through the elimination of sharkskin distortions and the stick-slip instability, as well as by the electrification of the extrudates. The extrudate swell was smaller in the presence of slip when comparing with no slip conditions at constant apparent shear rate, but it was found to be a unique function of the shear stress if comparison was performed at constant stress. The draw ratio and melt strength of the filaments obtained under slip conditions were larger compared to those without slip. In addition, draw resonance was postponed to higher draw ratios during the extrusion with strong slip at constant apparent shear rate. It is suggested that slip of the polymer at the die wall decreases the shear stress in the bulk, and therefore, restricts the disentanglement and orientation of macromolecules during flow, which subsequently produces the increase in draw ratio and melt strength during stretching.

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. 4a,b
Fig. 5
Fig. 6
Fig. 7
Fig. 8a,b
Fig. 9a,b
Fig. 10a,b
Fig. 11
Fig. 12

Similar content being viewed by others

References

  • Bernnat A, Wagner MH (1999) Effect of wall slip on Rheotens master curves for linear PE melts. Int Polym Proc XIV:336–341

    Google Scholar 

  • Bernnat A, Wagner MH, Chai CK (2000) Assessment of LDPE melt strength by use of Rheotens mastercurves. Int Polym Proc XV:268–272

    Google Scholar 

  • Denn MM (2001) Extrusion instabilities and wall slip. Ann Rev Fluid Mech 33:265–297

    Article  Google Scholar 

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

    CAS  Google Scholar 

  • Ghanta VG, Riise BL, Denn MM (1999) Disappearance of extrusion instabilities in brass capillary dies. J Rheol 43:435–442

    Article  CAS  Google Scholar 

  • Goutille Y, Guillet J (2002) Disentanglement of polymer melts flowing through porous medium before entering a capillary die. J Rheol 46:1307–1323

    Article  CAS  Google Scholar 

  • Graessley WW, Glasscok SD, Crawley RL (1970) Die swell in molten polymers. J Rheol 14:519–544

    Article  CAS  Google Scholar 

  • Hatzikiriakos SG, Dealy JM (1993) Effects of interfacial conditions on wall slip and sharkskin melt fracture of HDPE. Int Polym Proc 8:36–44

    CAS  Google Scholar 

  • Hatzikiriakos SG, Hong P, Ho W, Stewart CW (1995) The effect of Teflon coatings in polyethylene capillary extrusion. J Appl Polym Sci 55:595–603

    Article  CAS  Google Scholar 

  • Hyun JC (1999) Draw resonance in polymer processing: a short chronology and a new approach. Korea-Austr Rheol J 11:279–285

  • Jay P, Piau JM, El Kissi N, Cizeron J (1998) The reduction of viscous extrusion stresses and extrudate swell computation using slippery surfaces. J Non-Newtonian Fluid Mech 79:599–617

    Google Scholar 

  • Kharchenko SB, McGuiggan PM, Migler KB (2003) Flow induced coating of fluoropolymer additives: development of frustrated total internal reflection imaging. J Rheol 47:1523–1545

    Article  CAS  Google Scholar 

  • Liang RF, Mackley MR (2001) Gas assisted extrusion of molten polyethylene. J Rheol 45:211–226

    Article  CAS  Google Scholar 

  • Migler KB, Lavallée C, Dillon MP, Woods SS, Gettinger CL (2001) Visualizing the elimination of sharkskin through fluoropolymer additives: coating and polymer-polymer slippage. J Rheol 45:565

    Article  CAS  Google Scholar 

  • Mooney M (1931) Explicit formulas for slip and fluidity. J Rheol 2:210–222

    CAS  Google Scholar 

  • Pérez-González J (2001) Exploration of the slip phenomenon in the capillary flow of linear low-density polyethylene via electrical measurements. J Rheol 45:845–853

    Article  Google Scholar 

  • Pérez-González J, Denn MM (2001) Flow enhancement in the continuous extrusion of linear low-density polyethylene. Ind Eng Chem Res 40:4309–4316

    Article  CAS  Google Scholar 

  • Pérez-González J, de Vargas L (2002) Quantification of the slip phenomenon and the effect of shear thinning in the capillary flow of linear polyethylenes. Polym Eng Sci 42:1231–1237

    Article  Google Scholar 

  • Pérez-González J, de Vargas L, Pavlínek V, Hausnerová B, Sáha P (2000) Temperature dependent instabilities in the capillary flow of a metallocene linear low density polyethylene melt. J Rheol 44:441–451

    Article  Google Scholar 

  • Pérez-Trejo L, Pérez-González J, de Vargas L, Moreno E (2004) Triboelectrification of molten linear low-density polyethylene under continuous extrusion. Wear 257:329–337

    Article  Google Scholar 

  • Piau JM, El Kissi N (1994) Measurement and modelling of friction in polymer melts during macroscopic slip at the wall. J Non-Newtonian Fluid Mech 54:121–142

    Google Scholar 

  • Piau JM, El Kissi N, Toussaint F, Mezghani A (1995) Distortions of polymer melt extrudates and their elimination using slippery surfaces. Rheol Acta 34:40–57

    CAS  Google Scholar 

  • Piau JM, Nigen S, El Kissi 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

    Google Scholar 

  • Ramamurthy AV (1986) Wall slip in viscous fluids and influence of materials of construction. J Rheol 30:337–357

    Article  CAS  Google Scholar 

  • Reiner M (1931) Slippage in a non-Newtonian liquid. J Rheol 2:338–349

    Google Scholar 

  • Robens G, Winter HH (1974) Kapillaryrheometrie: Abschätzen und Verkleinern des Dissipationseinflusses. Kunststofftechnik 13:61–64

    Google Scholar 

  • Rosenbaum EE, Hatizikiriakos SG (1997) Wall slip in the capillary flow of molten polymers subject to viscous heating. AIChE J 43:598–608

    Article  CAS  Google Scholar 

  • Schallamach A (1963) A theory of dynamic rubber friction. Wear 6:375–382

    Article  Google Scholar 

  • Wagner MH, Bernat A, Shulze V (1998) The rheology of the Rheotens test. J Rheol 42:917–928

    Article  CAS  Google Scholar 

  • Wang SQ (1999) Molecular transitions and dynamics at polymer/wall interfaces: origins of flow instabilities and wall slip. Adv Polym Sci 138:239

    Google Scholar 

Download references

Acknowledgements

This research was supported by CGPI-IPN (20010565, 2003-0555) and CONACYT (34971-U). T. J. G-M has CONACYT and PIFI-IPN scholarships. J. P-G and L. de V. are COFFA-EDI fellows. We wish to acknowledge the reviewers for very useful comments.

Author information

Author notes

  1. Teresita de Jesús Guadarrama-Medina

    Present address: Metalurgia y Materiales, Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, México D. F., México

Authors and Affiliations

  1. Laboratorio de Reología, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Apdo. Postal 118-209, C. P. 07051, México D. F., México

    Teresita de Jesús Guadarrama-Medina, José Pérez-González & Lourdes de Vargas

Authors
  1. Teresita de Jesús Guadarrama-Medina
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. José Pérez-González
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Lourdes de Vargas
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to José Pérez-González.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Guadarrama-Medina, T.d.J., Pérez-González, J. & de Vargas, L. Enhanced melt strength and stretching of linear low-density polyethylene extruded under strong slip conditions. Rheol Acta 44, 278–286 (2005). https://doi.org/10.1007/s00397-004-0409-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00397-004-0409-0

Keywords

Search

Navigation