ISO INTERNATIONAL STANDARD 7822 First edition 1990-09-01 Textile glass reinforced plastics - Determination of void content - Loss on ignition, mechanical disintegration and statistical counting methods Plastiques renforces de verre textile - Détermination de la teneur en vide Methodes par perte au feu, par desintegration mecanique et par comptage statistique Reference number ISO 7822 : 1990 (E) Copyright Intermational Organization for Standardization cense with IS rmitted without license from IHS Not for Resale ISO 7822 : 1990 (E) Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with iSO, also take part in the work. iSO collaborates closely with the International Electrotechnicat Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 7822 was prepared by Technical Committee ISO/TC 61, Plastics. Annex A of this International Standard is for information only. ISO 1990 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Casepostale56·CH-1211Geneve20.Switzerland Printed in Switzerland Not for Resale ISO 7822 : 1990 (E) INTERNATIONAL STANDARD Textile glass reinforced plastics - Determination of void content t - Loss on ignition, mechanical disintegration and statistical counting methods 1 Scope 2 Normative references This International Standard specifies three methods for the Thefollowing standards contain provisions which,through determination of the void content of textile glass reinforced reference in this text, constitute provisions of this International plastics or composites, of which the constituents are of a solid Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to nature. agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions 1.1 Method A - Loss on ignition of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. This method is applicable to composites for which the effects of the loss on ignitionteston the materiais areknown.Most ISo 291:1977,Plastics - Standard atmospheres for condition- matrix resins and textile glass fibre reinforcements fall into this ing and testing. class. ISo 1172:1975, Textile glass reinforced plastics - Determi- The method is not applicable to composites for which the ef- nationoflossonignition. fects of the loss on ignition test on the resin, the reinforcement, andanyfillersare unknown.This mayinciude siliconeresins, Principle which do notburnoff completely,andfillersconsistingof ox- ides,carbonates,etc.,whichmaygainorloseweight.Note that separate weight loss tests onindividual materials will 3.1 MethodA -Lossonignition usually, but not necessarily, give the same result as when all the materials are combined. Determination of the densities of the resin,the reinforcement; filler(s) (if present) and the composite. Determination of the The accuracy of the method is ±2,5 % by volume. resin content and calcutation of a theoretical composite den- sity. ( Comparison with the measured composite density. Th