ISO INTERNATIONAL STANDARD 6721-1 Fourth edition 2019-04 Plastics Determination of dynamic mechanical properties - Part 1: General principles Plastiques - Détermination des propriétés mécaniques dynamiques- Partie 1: Principes généraux Reference number ISO 6721-1:2019(E) ISO @ IS0 2019 IS0 6721-1:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 6721-1:2019(E) Contents Page Foreword ..iv Introduction. .. 1 Scope. ..1 2 Normative references 3 Terms and definitions 4 Principle ..9 5 Test apparatus. .12 5.1 Type. .12 5.2 Mechanical, electronic and recording systems 12 5.3 Temperature-controlled enclosure .12 5.4 Gas supply 12 5.5 Temperature-measurement device .12 5.6 Devices for measuring test specimen dimensions 12 6 Test specimens. .12 6.1 General. .12 6.2 Shape and dimensions. 13 6.3 Preparation .13 7 Number of test specimens ..13 8 Conditioning ..13 9 Procedure. .13 9.1 Test atmosphere .13 9.2 Measurement of specimen cross-section .13 9.3 Mounting the test specimens. 13 9.4 Varying the temperature .13 9.5 Varying the frequency ..14 9.6 Varying the dynamic-strain amplitude. .14 10 Expression of results ..14 11 Precision ..15 12 Test report ..15 Annex A (informative) Resonance curves. ..16 Annex B (informative) Deviations from linear behaviour ..22 Bibliography .23 @ IS0 2019 - All rights reserved iii