ISO INTERNATIONAL STANDARD 18908 First edition 2000-05-15 Imaging materials Photographic film - Determination of folding endurance Matériaux pour I'image - Films photographiques - Deétermination de la résistance au pliage Reference number ISO 18908:2000(E) (So @ ISO 2000 ISO 18908:2000(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event ISO2000 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic in the country of the requester. ISO copyright office Case postale 56 . CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 734 10 79 E-mail [email protected] Web www.iso.ch Printed in Switzerland @ ISO 2000 - All rights reserved IS0 18908:2000(E) Contents Page Foreword. iv Introduction 1 Scope 2 Term and definition 3 Principle 4 Apparatus. 5 Sampling.. 6 Conditioning and test conditions... Procedure 3 8 Interpretation of results ... 9 Test report Annex A (informative) Numbering system for related International Standards. Annex B (informative) Description of parts of MIT folding-endurance tester. Bibliography.. on?served ii ISO 18908:2000(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.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas liaison with IsO, also take part in the work. IsO collaborates closely with the International Electrotechnica Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 3. 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 Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. This first edition cancels and replaces ISO 8776:1988, of which it constitutes a minor revision. This International Standard is one of a series of standards dealing with the physical properties and stability of imaging materials. To facilitate identification of these International Standards, they are assigned a number within the block from 18900 - 18999 (see annex A). Annexes A and B of this International Standard are for information only @ISO 2000 - All rights reserved ISO 18908:2000(E) Introduction equipment for which it is intended under the atmospheric conditions likely to be encountered in practice. Photographic film is essentially a laminate of two or more different materials, generally a plastics support and the polymeric binder. The folding endurance of photographic film is affected adversely by both reduced temperature and reduced relative be carried out only in an atmosphere that is accurately controlled with respect to both temperature and relative humidity. The folding endurance of film is very dependent on the sample thickness decreasing with an increase in thickness of eitherthebaseortheemulsion.Forthisreason,thethicknessofthefilmlayershavetobeconsideredwhen comparing the behaviour of different films.The temperaturesand relative humidities to whichthe filmhasbeen subjected between manufacture and testing may also af