ISO INTERNATIONAL STANDARD 4591 Second edition 1992-12-01 Plastics Film and sheeting Determination of average thickness of a sample, and average thickness and yield of a roll, by gravimetric techniques (gravimetric thickness) Plastiques - Film et feuille -- Determination de I'épaisseur moyenne d'un échantillon, et de I'épaisseur moyenne d'un rouleau, ainsi que de sa surfaceparunitedemasse,parmesuresgravimetriquesfepaisseur gravimetrique) Reference number ISO 4591:1992(E) No reproductic Not for Res ISO 4591:1992(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 and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are Standard requires approval by at least 75 % of the member bodies casting a vote ISO/TC 61,Plastics,Sub-CommitteeSC11,Products. This second edition cancels and replaces the first edition (1s04591:1979),whichhasbeentechnicallyrevised 1SO1992 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 per- mission in writing from the publisher. International Organizationfor Standardization Case Postale 56 . CH-1211 Geneve 20 · Switzerland Printed in Switzerland ii No reproduction or networking permited without license from IHS Not for Resale INTERNATIONAL STANDARD ISO 4591:1992(E) Plastics -- Film and sheeting Determination of average thickness of a sample, and average thickness and yield of a roll, by gravimetric techniques (gravimetric thickness) Scope 3 Determination of gravimetric thickness of a sample This International Standard specifies 3.1Principle a method for the determination of the gravimetric thickness of a sample of plastics film or sheeting The gravimetric thickness of a sample is calculated (see clause 3); from measurements of its mass, area and density. a method for the determination of the average gravimetric thickness and, if required, the yield 3.2 Apparatus (area per unit mass) of a roll of plastics film or sheeting (see clause 4). 3.2.1 Knife-edged punch, square or circular, having an area of 100 cm²± 0,5 cm², or These methods are applicable to all plastics films and sheeting, and have special value when mechanical 3.2.2 Square template, having scanning is not sufficiently precise, particularly for an area of measuring the thickness of embossed sheeting. 100cm²±0.5cm². 3.2.3 Balance, accurate to 0,000 1 g. 3.3Specimens 2 Normative references Specimens of area 100 cm? ± 0,5 cm? shall be cut at positions approximately equally spaced across the The following standards contain provisions which, width of the sample in each of two bands approxi- through reference in this text, constitute provisions mately 1 m apart in the longitudinal direction. of this International Standard. At the time of publica- The minimum number of specimens taken from each tion, the editions indicated were valid. All standards band across the film or sheeting shall be dependent are subject to revision, and parties to agreements on the width of the sample as follows: based on this International Standard are encouraged to investigate thepossibilityof applyingthe most re- widths smaller than or equal to 1 000 mm 3 cent editions of ' the standards indicated below. Members of IEC and ISO maintain registers of cur- widths greater than 1 000 mm and up to rently valid International Standards. 1500mm 5 widths greater than 1 500 mm 10 Is0 1183:1987, Plastics --- Methods for determining the density