Journal of Materials Science

, Volume 26, Issue 11, pp 2861–2867

The flex fatigue of polyamide and polyester fibres

Part I The influence of temperature and humidity
  • J. W. S. Hearle
  • M. Miraftab

DOI: 10.1007/BF01124814

Cite this article as:
Hearle, J.W.S. & Miraftab, M. J Mater Sci (1991) 26: 2861. doi:10.1007/BF01124814


The flex fatigue of nylon and polyester fibres is measured by pulling them backwards and forwards over a pin in an environmental chamber. The fatigue lives vary over a 20-fold range as temperature and humidity changes. For nylon 6, the plots show a consistent increase to a maximum value and then a decrease as the temperature is increased from 20–120 °C. The peak lifetimes occur at higher temperatures at lower humidities. The results for nylon 6.6 show peaks at intermediate humidities, but little change at low and high humidities. The peak life temperature increases as humidity decreases for nylon 6.6, but is unchanged for polyester. The nylon 6 results follow the same trend as the loss modulus in variation with temperature and humidity, with a high loss correlating with a long life. A possible reason for this and the influence of other complicating factors, are discussed.

Copyright information

© Chapman and Hall Ltd. 1991

Authors and Affiliations

  • J. W. S. Hearle
    • 1
  • M. Miraftab
    • 2
  1. 1.Department of TextilesUMISTManchesterUK
  2. 2.J. J. Thomson Physical LaboratoryUniversity of ReadingReadingUK
  3. 3.School of TextilesBolton Institute of Higher EducationBolton