BS-EN-ISO-13935-2-1999.pdf
BRITISH STANDARD BS EN ISO 13935-2:1999 Textiles Seam tensile properties of fabrics and made-up textile articles Part 2: Determination of maximum force to seam rupture using the grab method The European Standard EN ISO 13935-2:1999 has the status of a British Standard ICS 59.080.30 BS EN ISO 13935-2:1999 This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 May 1999 © BSI 03-2000 ISBN 0 580 32511 3 National foreword This British Standard is the English language version of EN ISO 13935-2:1999. It is identical with ISO 13935-2:1999. The UK participation in its preparation was entrusted to Technical Committee TCI/24, Physical testing of textiles, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, pages 2 to 9 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No.DateComments BS EN ISO 13935-2:1999 © BSI 03-2000i Contents Page National forewordInside front cover Foreword2 Text of EN ISO 13935-23 ii blank EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 13935-2 February 1999 ICS 59.080.10 Descriptors: Textiles, textile products, fabrics, sewing, tensile strength, tear strength, tests, pull-out tests, determination, breaking load English version Textiles Seam tensile properties of fabrics and made-up textile articles Part 2: Determination of maximum force to seam rupture using the grab method (ISO 13935-2:1999) Textiles Propriétés de résistance à la traction des coutures détoffes et darticles textiles confectionnés Partie 2: Détermination de la force maximale avant rupture des coutures par la méthode darrachement (Grab test) (ISO 13935-2:1999) Textilien Zugversuche an Nähten in textilen Flächengebilden und Konfektionstextilien Teil 2: Bestimmung der Höchstzugkraft von Nähten mit dem Grab-Zugversuch (ISO 13935-2:1999) This European Standard was approved by CEN on 21 November 1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 13935-2:1999 E EN ISO 13935-2:1999 © BSI 03-2000 2 Foreword The text of EN ISO 13935-2:1999 has been prepared by Technical Committee CEN/TC 248 “Textiles and textile products”, the secretariat of which is held by BSI, in collaboration with Technical Committee ISO/TC 38 “Textiles”. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 1999, and conflicting national standards shall be withdrawn at the latest by August 1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword2 Introduction3 1Scope3 2Normative references3 3Definitions3 4Principle4 5Sampling4 6Apparatus4 7Atmosphere for conditioning and testing4 8Preparation of seams and of test specimens5 9Procedure6 10Calculation and expression of results7 11Test report7 Annex A (informative) Arrangements of jaws for grab test8 Annex B (informative) Bibliography9 Figure 1 Laboratory sample with seams and indication of test specimens5 Figure 2 Test specimen ready for testing6 Figure A.1 Arrangements of jaws for grab test8 EN ISO 13935-2:1999 © BSI 03-20003 Introduction This part of EN ISO 13935 has been prepared in the context of several test methods for determination of certain mechanical properties of textiles using mainly tensile testing machines, e.g. tensile properties, seam tensile properties, tear properties, seam slippage. The procedure for these standards agree where appropriate. The results obtained by one of the methods should not be compared with those obtained by the other methods. See Annex B for informative references. EN ISO 13935 consists of the following parts, under the general title Textiles Seam tensile properties of fabrics and made-up textile articles: Part 1: Determination of maximum force to seam rupture using the strip method; Part 2: Determination of maximum force to seam rupture using the grab method. Annex A and Annex B of this part of EN ISO 13935 are for information only. Where it is intended to compare the seam maximum force values of sewn seams with the fabric maximum force, it is important to use the same type of test, test conditions and test specimens in the tests in this standard and EN ISO 13934-2 (see Annex B). 1 Scope This part of EN ISO 13935 specifies methods for the determination of seam maximum force of sewn seams when the force is applied perpendicularly to the seam. This part of EN ISO 13935 describes the method known as the grab test. NOTEPart 1 of EN ISO 13935 describes the method known as the strip test. For informative references see Annex B. The method is mainly applicable to woven textile fabrics. It may be applicable to fabrics produced by other techniques. It is not normally applicable to woven elastic fabrics, geotextiles, nonwovens, coated fabrics, textile-glass woven fabrics and fabrics made from carbon fibres or polyolefin tape yarns (see Annex B). The sewn fabrics may be obtained from previously sewn articles or may be prepared from fabric samples, as agreed by the parties interested in the results. This method is applicable to straight seams only and not to curved seams. The method is restricted to the use of constant rate of extension (CRE) testing machines. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. EN 20139, Textiles Standard atmospheres for conditioning and testing. (ISO 139:1973) EN 10002-2, Metallic materials Tensile testing Part 2: Verification of the force measuring system of the tensile testing machines. EN 30012-1, Quality assurance requirements for measuring equipment Part 1: Metrological confirmation system for measuring equipment. (ISO 10012-1:1992) 3 Definitions For the purposes of this part of EN ISO 13935 the following definitions apply: 3.1 constant-rate-of-extension (CRE) testing machine tensile-testing machine provided with one clamp which is stationary and another clamp which moves with a constant speed throughout the test, the entire testing system being virtually free from deflection (EN ISO 13934-1) 3.2 grab test tensile test in which only the centre part of the test specimen is gripped in the jaws of the testing machine (EN ISO 13934-2) 3.3 maximum force at seam rupture maximum force recorded when a test specimen with a seam perpendicular to the direction of extension is taken to seam rupture during a tensile test under the specified conditions (EN ISO 13935-1) 3.4 gauge length distance between the two effective clamping points of a testing device (EN ISO 13934-1) NOTEThe effective clamping points (or lines) of jaws can be checked by clamping a test specimen under defined pretension with carbon copy paper to produce a gripping pattern on the test specimen and/or the jaw faces (EN ISO 13934-1). EN ISO 13935-2:1999 4 © BSI 03-2000 4 Principle A fabric test specimen having a seam in the middle is gripped in its centre part by jaws of specified dimensions and is extended perpendicularly to the seam at a constant rate until the seam ruptures. The maximum force to seam rupture is recorded. 5 Sampling Select samples either in accordance with the procedure laid down in the material specification for the fabric, or as agreed between the interested parties. If preparation of seams prior to testing is required, avoid test specimens from folded or creased areas, selvedges and areas not representative of the fabric. For seams obtained from previously sewn articles ensure that the test specimens contain seams in straight line only and are representative for the relevant seam type of the textile article. Record any details in the test report. 6 Apparatus 6.1 CRE machine. Metrological confirmation system of the tensile-testing machine shall be in accordance with EN 30012-1. The constant-rate-of-extension (CRE) machine shall have the general characteristics given in 6.1.1 to 6.1.6: 6.1.1 The tensile-testing machine shall be provided with means for indicating or recording the force applied to the test specimen in stretching it to rupture. Under conditions of use, the accuracy of the apparatus shall be class 1 of EN 10002-2. The error of the indicated or recorded maximum force at any point in the range in which the machine is used shall not exceed ± 1 %. 6.1.2 If a class 2 tensile testing machine according to EN 10002-2 is to be used, this shall be stated in the test report. 6.1.3 If recording of force is obtained by means of data acquisition boards and software, the frequency of data collection shall be at least eight per second. 6.1.4 The machine shall be capable of constant rate of extension of 50 mm/min, with an accuracy of ± 10 %. 6.1.5 The machine shall be capable of setting the gauge length to 100 mm, to within ± 1 mm. 6.1.6 The clamping device of the machine shall be positioned with the central point of the two jaws in the line of applied force, the front edges shall be at right angles to the line of applied force and their clamping faces shall be in the same plane. The jaws shall be capable of holding the test specimen without allowing it to slip and designed so that they do not cut or otherwise weaken the test specimen. The faces of the jaws shall be smooth and flat, except that when, even with packing, the test specimen cannot be held satisfactorily with flat-faced jaws, engraved or corrugated jaws can be used to prevent slippage. Other auxiliary materials for use with either smooth or corrugated jaws to improve specimen gripping include paper, leather, plastics or rubber. For the grab test the dimensional clamping area of the fabric shall be (25 mm ± 1 mm) × (25 mm ± 1 mm). This area can be achieved by either the method given in a) or b) and illustrated in Annex A. a) One clamp (25 mm) × (40 mm min., preferably 50 mm), positioned with the wider direction of the clamp perpendicular to the line of application of the force; a second clamp of the same dimensions positioned perpendicular to the first so that the wider direction of the clamp is parallel to the direction of application of the force. b) One clamp (25 mm) × (40 mm min., preferably 50 mm), positioned with the wider direction of the clamp perpendicular to the line of application of the force; a second clamp (25 mm) × (25 mm). 6.2 Equipment for sewing defined seams. 6.3 Equipment for cutting test specimens. 7 Atmosphere for conditioning and testing The atmospheres for preconditioning, conditioning and testing shall be as specified in EN 20139. NOTEIt is recommended that samples be conditioned for at least 24 h in the relaxed state. EN ISO 13935-2:1999 © BSI 03-20005 8 Preparation of seams and of test specimens 8.1 Preparation of seams, if required, before testing. Where the seams are to be prepared for testing, the interested parties shall agree on the conditions of sewing, including type of sewing threads, type of needle, type of seam, seam allowance and number of stitches per unit length. The sewing machine shall be adjusted to give the correct conditions, using a spare piece of the fabric for testing. Cut a sample of the fabric 250 mm by at least 700 mm. Fold the sample in half with the fold parallel to the longer dimension, make the agreed seam in this direction, and cut to give the agreed seam allowance. Seams may be sewn for testing parallel to the warp or weft direction, or both, as agreed between the interested parties. 8.2 Dimensions From each laboratory sample with seams cut a set of at least five test specimens of width 100 mm, as shown in Figure 1. When using seams prepared as described in 8.1, do not cut samples within 100 mm of either end of the prepared seam (see Figure 1). 8.3 Preparation of test specimens O
