ISO INTERNATIONAL STANDARD 4604 Second edition 2011-11-15 Reinforcement fabrics Determination of conventional flexural stiffness Fixed-angle flexometer method Tissus de renforcement Determination de la rigidite conventionnelle enflexion-Methodeduflexometrea anglefixe Reference number ISO 4604:2011(E) ISO ISO2011 ISO 4604:2011(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2. The main task of technical committees is to prepare International Standards. 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 document may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 4604 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13, Composites and reinforcementfibres This second edition cancels and replaces the first edition (isO 4604:1978), of which it constitutes a minor revision. The main changes are as follows: the scope has been broadened to cover all reinforcement fabrics (not just textile glass fabrics) and the title of the standard modified in consequence; thenormativereferencesclausehasbeenupdated @ ISO 2011 - All rights reserved ii INTERNATIONAL STANDARD ISO4604:2011(E) Reinforcement fabrics Determination of conventional flexural stiffness Fixed-angle flexometer method 1 Scope This International Standard specifies a method of determining the conventional flexural stiffness of reinforcement have a marked tendency to curl or twist or fray. 2Normative references The following referenced documents are indispensable for the application of this document. For dated (including any amendments) applies. Iso 291, Plastics Standard atmospheres for conditioning and testing IsO 3374, Reinforcement products - Mats and fabrics - Determination of mass per unit area 3 Principle the platform. The strip is moved in the direction of its length so that an increasing portion overhangs and bends down under its own weight. When the tip of the specimen has reached a plane passing through the edge of the The conventional flexural stiffness is calculated from the overhanging length of the test specimen and the mass per unit area of the fabric. NOTE This determination of the conventional flexural stiffness is based on a report published in Shirley Institute Memoirs, 9 (1930), p. 81, and Journal of the Textile Institute, 21 (1930), T380. 4 Apparatus 4.1 Fixed-angle flexometer, the essential features of which are shown in Figure 1. On the horizontal platform P rests a slide S, graduated on its upper surface in millimetres The under-surface of S is covered with a layer of high-friction antistatic material such as sheet rubber, and the slide and the platform P. The width of the slide S shall be 25 mm and the length at least 300 mm, and its mass shall be 10 g ± 2 g per centimetre of length. When the front edge of the slide coincides with the front edge of P, the zero of the scale on S coincides with a datum line D on the instrument. Two sighting lines, L1 and L2, passing through the upper forward edge of P and inclined at an angle of 41,5° below the horizontal, are inscribed on the transparent side-pieces of the instrument. The range of the instrument is governed by its size. It shall allow the determination of the overhanging length of the specimen. @ ISO 2011 - All rights reserved 1