PARAFIL® types F and G stand the test of time

November 2010

34 years ago Linear Composites Ltd erected an external test rig and suspended PARAFIL® type F 3 tonne (NBL) ropes under constant loads of 1200kg (40% NBL). From this point until present we have periodically measured the creep strain of the ropes in conjunction with the Industrial Fibre department at DuPont®.

Over the period of this test the creep strain characteristics of PARAFIL® type F and G ropes surpassed all expectations. The measured creep over the duration of the test is 0.23%, this works out at a strain rate of 0.035% per decade. Assuming that the PARAFIL® ropes continue to creep at the same rate we have calculated that the ropes will not fail for another 992 years.

Long term creep tests in their nature are inconvenient, spanning decades! In the rope industry it is standard to model creep behaviour on the results of accelerated age testing. Long term creep models give a reasonable understanding of creep strain behaviour but are only an approximation and are no substitute for actual test data. Our test results prove the long term performance of PARAFIL®, giving design engineer’s confidence when selecting PARAFIL®ropes for projects with a long design life.

It is our understanding that this is the world’s longest continual rope test.



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Linear Composites Limited
Vale Mills, Oakworth, Keighley, West Yorkshire, BD22 0EB, UK
Tel: +44 (0)1535 643363 Fax: +44 (0)1535 646889