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Journal of Polymer Research

, Volume 14, Issue 3, pp 181–189 | Cite as

An alternative approach to the evaluation of the slow crack growth resistance of polyethylene resins used for water pipe extrusion

  • Fabiano Moreno Peres
  • Cláudio Geraldo SchönEmail author
Article

Abstract

High-density polyethylene (HDPE) pipes have been largely employed in water and gas distribution systems. In spite of offering significative advantages over other materials, HDPE pipes suffer from premature failures due to creep fracture. The current industrial criterium for design and sizing of HDPE pipes is discussed. The concept of ‘regression curve,’ i.e. of a time-to-failure criterium based in long-term-hydrostatic strength (LTHS) tests, is criticised and concluded to be unsatisfactory for this purpose. An alternative approach is suggested, which is based on shorter-term tests. This is illustrated by testing five HDPE resins designed for pipe extrusion and comparing with their standard ‘regression curves’. The obtained results are consistent with the ‘regression curve’-based analysis, justifying the use of the alternative approach in the industry.

Key words

HDPE pipes slow crack growth water distribution systems regression curve ramp test 

Abbreviations

LTHS

Long-term hydrostatic strength

MRS

Minimum required strength

LCL

Lowest confidence level

SCG

Slow crack growth

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References

  1. 1.
    Janson L-E (2003) Plastic pipes for water supply and sewage disposal. In: VBB/SWCO International, Stockholm, SwedenGoogle Scholar
  2. 2.
    Mills MJ (1993) Plastics: microstructure and engineering applications, 2nd edn. E. Arnold, London, UKGoogle Scholar
  3. 3.
    Fayolle B, Verdu J (2005) Polym Eng Sci 45:424CrossRefGoogle Scholar
  4. 4.
    Hamouda HB, Simoes-Betbeder M, Grillon F et al (2001) Polymer 42:5425CrossRefGoogle Scholar
  5. 5.
    Gere JM, Timoshenko SP (1991) Mechanics of materials, Chap 6. Chapman & Hall, London, UK, p 411Google Scholar
  6. 6.
    ISO 9080 (2003) Plastic-piping and ducting systems – determination of the long-term hydrostatic strength of thermoplastic materials in pipe form by extrapolation. StandardGoogle Scholar
  7. 7.
    ISO 12162 (1995) Thermoplastic materials for pipes and fittings for pressure applications – classification and designation – overall service (design) coefficient. StandardGoogle Scholar
  8. 8.
    Krishnaswamy RK (2005) Polymer 46:11664CrossRefGoogle Scholar
  9. 9.
    Zhou W, Chen D, Shulkin Y, Chudnowsky A, Livraj N, Sehanobish K, Wu S (2001) Plastic failure – analysis and prevention. Failure mechanisms, Chap 6. William Andrew Publishing, Norwich/Plastic Design Library, New York, p 25Google Scholar
  10. 10.
    Chudnowsky A, Shulkin Y (1999) Int J Fract 97:83CrossRefGoogle Scholar
  11. 11.
    Williams FR, Jordan ME, Dannenberg EM (1995) J Appl Polym Sci 9:861CrossRefGoogle Scholar
  12. 12.
    Flores A, Cagiao ME, Ezquera TA et al (2001) J Appl Polym Sci 79:90CrossRefGoogle Scholar
  13. 13.
    Chodak I, Krupa I (1999) J Mater Sci Lett 18:1457CrossRefGoogle Scholar
  14. 14.
    Krishnaswamy RK, Lamborn MJ (2005) Adv Polym Technol 24(3):226CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  • Fabiano Moreno Peres
    • 1
  • Cláudio Geraldo Schön
    • 1
    Email author
  1. 1.Department of Metallurgical and Materials EngineeringEscola Politécnica da Universidade de São PauloSão PauloBrazil

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