Journal of Materials Science

, Volume 43, Issue 15, pp 5211–5221 | Cite as

The development of voidage and capillary size within extruded plastic films

  • D. I. Medina
  • B. Hallmark
  • T. D. Lord
  • M. R. MackleyEmail author


This paper describes how both capillary diameter and voidage can be manipulated by downstream mechanical processing of plastic microcapillary films (MCFs). MCFs are a novel thermoplastic extrudate that have been manufactured by the entrainment of gas within nozzles positioned in an extrusion die; the film resembles a plastic tape but contains an array of equally spaced parallel microcapillaries that run along its entire length. The low-voidage MCFs manufactured from linear low density polyethylene were made by melt drawing the polymer to produce an essentially isotropic MCF. This MCF could then be subsequently mechanically drawn to form small diameter MCFs. By altering process conditions an anisotropic high voidage MCF was produced. This MCF was brittle when drawn in the capillary direction but showed unusual mechanical transverse drawing. The paper presents experiment details for the manufacture of the different MCF structures together with mechanical properties and X-ray orientation data. From this, qualitative explanations for the mechanisms to achieve the different structures are given.


Draw Ratio LLDPE Hydraulic Diameter Molten Polymer Capillary Size 



Financial support from EPSRC (Polymer Process Innovation) and CONACyT are gratefully acknowledged.


  1. 1.
    Hallmark B, Mackley MR, Gadala-Maria F (2005) Adv Eng Mater 7(6):545. doi: CrossRefGoogle Scholar
  2. 2.
    Briston JH, Katan LL (1974) Plastics films. The Plastics Institute, LondonGoogle Scholar
  3. 3.
    Han CD (1976) Rheology in polymer processing. Academic Press Inc., New YorkGoogle Scholar
  4. 4.
    Zatloukal M, Vlcek J (2006) J Non-Newt Fluid Mech 133(1):63. doi: CrossRefGoogle Scholar
  5. 5.
    Dees JR, Spruiell JE (1974) J Appl Polym Sci 18(4):1053. doi: CrossRefGoogle Scholar
  6. 6.
    White J, Cakmak M (1986) Adv Polym Technol 6(3):295. doi: CrossRefGoogle Scholar
  7. 7.
    Syang-Peng R (2001) J Appl Polym Sci 82(12):2896. doi: CrossRefGoogle Scholar
  8. 8.
    Mills NJ, Zhu HX (1999) J Mech Phys Solids 47(3):669. doi: CrossRefGoogle Scholar
  9. 9.
    Zhu HX, Mills NJ, Knott JF (1997) J Mech Phys Solids 45(11–12):1875. doi: CrossRefGoogle Scholar
  10. 10.
    Hallmark B, Gadala-Maria F, Mackley MR (2005) J Non-Newt Fluid Mech 128(2–3):83. doi: CrossRefGoogle Scholar
  11. 11.
    Hornung CH, Mackley MR, Baxendale IR, Ley SV (2007) Org Process Res Dev 11(3):399. doi: CrossRefGoogle Scholar
  12. 12.
    Hornung CH, Hallmark B, Hesketh RP, Mackley MR (2006) J Micromech Microeng 16(2):434. doi: CrossRefGoogle Scholar
  13. 13.
    Jiang PX, Fan MH, Si GS, Ren ZP (2001) Int J Heat Mass Transfer 44(5):1039. doi: CrossRefGoogle Scholar
  14. 14.
    Ward IM (1983) Mechanical properties of solid polymers. Wiley, BristolGoogle Scholar
  15. 15.
    Lamberti G, Titomanlio G, Brucato V (2001) Chem Eng Sci 56(20):5749. doi: CrossRefGoogle Scholar
  16. 16.
    Bashir Z, Keller A (1989) Colloid Polym Sci 267(2):116. doi: CrossRefGoogle Scholar
  17. 17.
    Ward IM (1962) Proc Phys Soc 80:1176. doi: CrossRefGoogle Scholar
  18. 18.
    Vincent PI (1960) Polymer (Guildf) 1:7. doi: CrossRefGoogle Scholar
  19. 19.
    Robertson RE (1964) General Electric Co. Report No. 64-RL-358OCGoogle Scholar
  20. 20.
    Zhang XM, Elkoun S, Ajji A, Huneault MA (2004) Polymer (Guildf) 45(1):217. doi: CrossRefGoogle Scholar
  21. 21.
    Hallmark B, Medina DI, Mackley MR (2007) In: Proceedings of PPS-23 polymer processing society. Salvador, BrazilGoogle Scholar
  22. 22.
    Hammersley AP, Svensson SO, Thompson A, Graafsma H, Kvick A, Moy JP (1995) Rev Sci Instrum 66(3):2729. doi: CrossRefGoogle Scholar
  23. 23.
    Bunn CW (1939) Trans Faraday Soc 35:482. doi: CrossRefGoogle Scholar
  24. 24.
    Schrauwen BAG, Von Breemen LCA, Spoelstra AB, Govaert LE, Peters GWM, Meijer HEH (2004) Macromolecules 37(23):8618. doi: k CrossRefGoogle Scholar
  25. 25.
    Hermans PH (1946) Contributions to the physics of cellulose fiber. Elsevier, AmsterdamGoogle Scholar
  26. 26.
    Liang RF, Mackley MR (2001) J Rheol 45(1):211. doi: CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • D. I. Medina
    • 1
  • B. Hallmark
    • 1
  • T. D. Lord
    • 1
  • M. R. Mackley
    • 1
    Email author
  1. 1.Department of Chemical EngineeringUniversity of CambridgeCambridgeUK

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