ISO 6721-7:2019

ISO 6721-7:2019

April 2019
International standard Current

Plastics - Determination of dynamic mechanical properties - Part 7: Torsional vibration - Non-resonance method

This document describes a torsional, non-resonance method for determining the components of the shear complex modulus G* of solid polymers in the form of bars or rods at frequencies typically in the range 0,001 Hz to 100 Hz. Higher-frequency measurements can be made, but significant errors in the dynamic properties measured are likely to result (see 10.2.1 and 10.2.2). The method is suitable for measuring dynamic storage moduli ranging from about 10 MPa, which is typical of values obtained for stiff rubbers, to values of about 10 GPa which are representative of fibre-reinforced plastics. Although materials with moduli less than 10 MPa can be studied, more accurate measurements of their dynamic properties can be made using simple shear (see ISO 6721-6) or torsional deformations of thin layers between parallel plates. This method is particularly suited to the measurement of loss factors greater than 0,02 and may therefore be conveniently used to study the variation of dynamic properties with temperature and frequency through most of the glass-rubber relaxation region (see ISO 6721‑1). The availability of data determined over wide ranges of both frequency and temperature enable master plots to be derived, using frequency-temperature shift procedures, which display dynamic properties over an extended frequency range at different temperatures. NOTE Although loss factors below 0,1 can be more accurately determined using the torsion pendulum (see ISO 6721‑2), the method described in this document enables a much wider and continuous frequency range to be covered.

View the extract
Main informations

Collections

International ISO standards

Publication date

April 2019

Number of pages

10 p.

Reference

ISO 6721-7:2019

ICS Codes

83.080.01   Plastics in general

Print number

1
Sumary
Plastics - Determination of dynamic mechanical properties - Part 7: Torsional vibration - Non-resonance method

This document describes a torsional, non-resonance method for determining the components of the shear complex modulus G* of solid polymers in the form of bars or rods at frequencies typically in the range 0,001 Hz to 100 Hz. Higher-frequency measurements can be made, but significant errors in the dynamic properties measured are likely to result (see 10.2.1 and 10.2.2). The method is suitable for measuring dynamic storage moduli ranging from about 10 MPa, which is typical of values obtained for stiff rubbers, to values of about 10 GPa which are representative of fibre-reinforced plastics. Although materials with moduli less than 10 MPa can be studied, more accurate measurements of their dynamic properties can be made using simple shear (see ISO 6721-6) or torsional deformations of thin layers between parallel plates.

This method is particularly suited to the measurement of loss factors greater than 0,02 and may therefore be conveniently used to study the variation of dynamic properties with temperature and frequency through most of the glass-rubber relaxation region (see ISO 6721‑1). The availability of data determined over wide ranges of both frequency and temperature enable master plots to be derived, using frequency-temperature shift procedures, which display dynamic properties over an extended frequency range at different temperatures.

NOTE Although loss factors below 0,1 can be more accurately determined using the torsion pendulum (see ISO 6721‑2), the method described in this document enables a much wider and continuous frequency range to be covered.

Replaced standards (2)
ISO 6721-7:1996
June 1996
International standard Cancelled
Plastics. Determination of dynamic mechanical properties. Part 7 : torsional vibration. Non-resonance method.

ISO 6721-7/A1:2007
February 2007
International standard Cancelled
Amendment 1 to standard ISO 6721-7:1996

ZOOM ON ... the Requirements department
To comply with a standard, you need to quickly understand its issues in order to determine its impact on your activity.

The Requirements department helps you quickly locate within the normative text:
- mandatory clauses to satisfy,
- non-essential but useful clauses to know, such as permissions and recommendations.

The identification of these types of clauses is based on the document “ISO / IEC Directives, Part 2 - Principles and rules of structure and drafting of ISO documents ”as well as on a constantly enriched list of verbal forms.

With Requirements, quickly access the main part of the normative text!

With Requirements, quickly access the main part of the normative text!
What is the Redline format?
The Redline + service - standards comparator allows you to easily and simply identify major changes between the current standard and its last canceled version.

At a glance, you will be able to identify the additions, deletions or modifications to a text, table, figure and formula.
At a glance, you will be able to identify the additions, deletions or modifications to a text, table, figure and formula

The Redlines + service is offered to you on the collection of French standards in force, in French language and in HTML and PDF format.

For an overview of the service, click on View a standard in redline format
Need to identify, monitor and decipher standards?

COBAZ is the simple and effective solution to meet the normative needs related to your activity, in France and abroad.

Available by subscription, CObaz is THE modular solution to compose according to your needs today and tomorrow. Quickly discover CObaz!

Request your free, no-obligation live demo

I discover COBAZ