ISO 6721-9 is the ninth part of the ISO 6721 multi-series on dynamic mechanical properties of plastic. ISO 6721-9 describes a pulse propagation method for determining the storage component of the complex tensile modulus E' of polymers at discrete frequencies typically in the range of 3 kHz to 10 kHz. The method is suitable for measuring materials with storage moduli in the range 0,01 GPa to 200 GPa and with loss factors below 0,1 at around 10 kHz. With materials having a higher loss, significant errors in velocity measurement are introduced through the decay of amplitude.
Note 1: The method allows measurements to be made on thin films or fine fibers and long specimens, typically tapes of 300 mm × 5 mm × 0,1 mm or fibers of 300 mm × 0,1 mm (diameter).
Note 2: This method may not be suitable for cellular plastics, composite plastics, and multilayer products.
ISO 6721-9 on tensile vibration of plastic is useful for:
ISO 6721-9 describes the terms and definitions, principles, test devices, test specimens, test procedure.
ISO 6721-9 provides guidance on calculation and expression of results (that involves symbols, calculation of the longitudinal wave velocity, calculation of the tensile storage modulus, significant figures).
As a user of ISO 6721-9, you can be ensured of methods of measuring dynamic mechanical properties of plastic. With obedience and compliance to ISO 6721-9, you can determine the accurate value of tensile vibration from the dynamic mechanical properties of plastic to improve the quality. ISO 6721-9 provides you with comprehensive information useful throughout the process of measurement.
BS ISO 6721-9:2019 supersedes BS ISO 6721‑9:1997 which has been withdrawn.
BS ISO 6721-9:2019 includes some technical changes with respect to BS ISO 6721‑9:1997. These include:
ISO 6721-9