1、BRITISH STANDARDBS EN 14704-2:2007Determination of the elasticity of fabrics Part 2: Multiaxial testsThe European Standard EN 14704-2:2007 has the status of a British StandardICS 59.080.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51
2、g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14704-2:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2007 BSI 2007ISBN 978 0 580 53449 2National forewordThis British Standard was pu
3、blished by BSI. It is the UK implementation of EN 14704-2:2007.The UK participation in its preparation was entrusted to Technical Committee TCI/24, Physical testing of textiles.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not
4、 purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORME
5、N 14704-2February 2007ICS 59.080.30English VersionDetermination of the elasticity of fabrics - Part 2: Multiaxial testsDtermination de llasticit des toffes - Partie 2: EssaismultiaxiauxBestimmung der Elastizitt von textilen Flchengebilden -Teil 2: Multiaxiale PrfungenThis European Standard was appro
6、ved by CEN on 7 January 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalsta
7、ndards 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 translationunder the responsibility of a CEN member into its own language and notified to
8、the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norwa
9、y, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and
10、by any means reservedworldwide for CEN national Members.Ref. No. EN 14704-2:2007: EEN 14704-2:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Principle5 5 Sampling.5 6 Atmosphere for conditioning and testing .5 7 Preparation of test specimens .5 8 M
11、ethod A Dynamic test 6 9 Method B Static test .8 Annex A (informative) Example of a typical cycling graph.12 Annex B (informative) Procedure for sampling13 Annex C (informative) Example of a pattern for cutting test specimens from a laboratory sample 14 Annex D (informative) Method A - Dynamic test
12、equipment.15 Annex E (informative) Method B - Static test equipment 18 EN 14704-2:2007 (E) 3 Foreword This document (EN 14704-2:2007) has been prepared by Technical Committee CEN/TC 248 “Textiles and textile products”, the secretariat of which is held by BSI. This European Standard shall be given th
13、e status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2007, and conflicting national standards shall be withdrawn at the latest by August 2007. The reasons for the development of this European Standard are because of technical advancem
14、ents in yarn and fabric structures and properties, which increase product range and developments. EN 14704 Determination of the elasticity of fabrics consists of the following parts: Part 1: Strip tests Part 2: Multiaxial tests Part 3: Narrow fabrics According to the CEN/CENELEC Internal Regulations
15、, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
16、Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14704-2:2007 (E) 4 1 Scope This European Standard specifies the methods of test, which can be used to measure elasticity and related properties of fabrics, when they undergo a deformation of their surfac
17、e, excluding narrow fabrics. Two methods are specified, one a dynamic method (method A) and the other a static method (method B). The results obtained cannot be compared. The choice of method should be agreed between parties and indicated in the test report. 2 Normative references The following refe
18、renced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 14704-1, Determination of the elasticity of fabrics Part 1: Stri
19、p tests EN ISO 139, Textiles Standard atmospheres for conditioning and testing (ISO 139:2005) EN ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system (ISO 7500-1:2004) E
20、N ISO 10012, Measurement management systems Requirements for measurement processes and measuring equipment (ISO 10012:2003) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 narrow fabric woven or knitted construction intended for use as a trim
21、, binding, edging, strapping or harness, and designed to be used in its full width 3.2 elasticity property of a material by virtue of which it tends to recover its original size and shape immediately after the removal of the force causing deformation 3.3 constant-rate-of-extension (CRE) testing mach
22、ine 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 3.4 bagging residual deformation, expressed in millimetres, between the original state and
23、 the state of the surface when it has undergone a multidirectional force, which by repetition creates a “bag” 3.5 maximum deformation maximum deformation, expressed in millimetres, developed when a specified force is applied to the surface of the test specimen compared to the original state of a tes
24、t specimen EN 14704-2:2007 (E) 5 3.6 residual deformation deformation, expressed in millimetres, after the removal of the hemispherical probe and an agreed recovery time 3.7 maximum force force recorded in newtons at the position when a test specimen is taken to a fixed distension 3.8 modulus force
25、measured at a given distension on either the load or unload curves 3.9 cycle process whereby a fabric is taken from the original position to a fixed load or fixed distension and returned to the original position 3.10 force decay due to time loss of force measured over time when a test specimen is st
26、retched to a specified distension or force and held at this position for a given time period NOTE The decay in force is expressed as a percentage of the original force recorded at the specified position. See Annex A. 4 Principle A fabric test specimen of specified dimensions is distended at a consta
27、nt rate to either a specified force or distension for an agreed number of cycles, and its elasticity determined by measuring certain characteristics. 5 Sampling Fabric samples shall be selected in accordance with the product specification. In the absence of a product specification for the fabric, th
28、e sampling method given in Annex B may be used. 6 Atmosphere for conditioning and testing The atmospheres for preconditioning, conditioning and testing shall be as specified in EN ISO 139. The fabric samples shall be conditioned for a minimum of 20 h in a tension free state. The prepared specimens s
29、hall be conditioned in a tension free state for a further 4 h after preparation, to minimise the effects of handling during preparation. 7 Preparation of test specimens From each laboratory sample prepare a minimum of five test specimens. For Method A, no test specimens shall be cut from within 150
30、mm of either edge of the laboratory sample. No test specimen taken from the sample shall contain the same ends and picks or wales and courses. NOTE An example of a suitable pattern for cutting test specimens from the laboratory sample is given in Annex C. Avoid selecting test specimens from folded o
31、r creased areas, selvedges and areas not representative of the fabric. EN 14704-2:2007 (E) 6 8 Method A Dynamic test 8.1 Apparatus 8.1.1 CRE testing machine Metrological confirmation system of the tensile testing machine shall be in accordance with EN ISO 10012. The constant-rate-of-extension testin
32、g machine shall conform to the following. a) The tensile testing machine shall be provided with the means for indicating or recording the force and deformation values when cycling between the original position and either a fixed load or fixed deformation. Under conditions of use, the accuracy of the
33、 apparatus shall be at least class 1 of EN ISO 7500-1. 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 % and the error of the indicated or recorded jaw separation shall not exceed 1 mm. b) If recording of force or elongat
34、ion is obtained by means of data acquisition boards and software, the frequency of data collection shall be at least eight per second. c) The machine shall be capable of constant rates of distension including 20 mm/min to 500 mm/min with an accuracy of 10 %. d) The machine shall be capable of variab
35、le gauge length settings including 0 to 100 mm, to an accuracy of 1 mm. e) The clamping ring and probe shall be positioned with the centre in line with the applied force. The machine shall be calibrated with the clamp and probe in position. The clamping ring shall be capable of holding the test spec
36、imen without allowing it to slip and designed so that it does not cut or otherwise weaken the test specimen (see Annex D). 8.1.2 Equipment for cutting circular test specimens to the required dimensions. 8.1.3 Calibrated metal rule graduated in millimetres. 8.2 Test specimen preparation Each test spe
37、cimen shall be cut (145 2) mm in diameter (see Annex C). 8.3 Procedure for loading test specimen in clamping ring (see Figures D.1 and D.2) 8.3.1 Position the clamping ring (2) onto loading base (7), place the test specimen face down into the ring, the face of the fabric will be visible to the opera
38、tor during the test. Next locate holding ring (4) onto the specimen and finally locking ring (5) and screw down on the specimen. 8.3.2 Set the distension rate of the specimen at 100 mm/min for woven and non-woven fabrics and 500 mm/min for knitted. 8.3.3 Fix a suitable load cell to the moving crossh
39、ead of the testing machine and then connect the probe. 8.3.4 Set the required cycling limits to cycle between the original position and 10 N (knitted and non-woven) or 50 N (woven) or 100 N (upholstery). Other loading limits can be used as agreed between parties. 8.3.5 Invert the loaded clamping rin
40、g with specimen in place onto the base unit (6) which has been attached onto the base of the testing machine (see Figure D.2). EN 14704-2:2007 (E) 7 8.3.6 Position the probe to give a distance of between 2 mm and 5 mm between the fabric surface and the bottom of the probe. 8.3.7 Engage the device fo
41、r recording the force and deformation measurements required. Put the crosshead in motion and cycle the test specimen between the original position and the required maximum force for 5 cycles. During the first cycle determine the deformation at a force of 0,2 N. For the determination of force decay,
42、due to time, on the final cycle set the CRE testing machine to hold at the maximum force for a 60 s period. If it is required to determine the un-recovered deformation, wait for 60 s after completion of the fifth cycle. Take the crosshead down for a further sixth cycle and record the deformation aft
43、er cycling and recovery at a force of 0,2 N. NOTE Many of the parameters measured can be determined by manual analysis of graphs and by software data collection procedures. It is recommended that assessment of the individual software is carried out to establish accuracy of the data collected. 8.4 Re
44、cording 8.4.1 Record the maximum deformation in millimetres at the maximum force during the fifth cycle, from the curves or data generated in the test, as agreed between the relevant parties. 8.4.2 Record the modulus at any deformation point along the load or unload curves as agreed between relevant
45、 parties. 8.5 Expressions and calculations of test results The following values shall, where applicable, be calculated from the data recorded during the test. Maximum deformation, S, expressed in millimetres S = E - L where E is the deformation (mm) at maximum force on the fifth cycle; L is the orig
46、inal deformation at 0,2 N (mm). Force decay due to time, A, expressed as a percentage. A 100=VWVwhere V is the maximum force from the final cycle; W is the maximum force on the final cycle, after a specified holding period. EN 14704-2:2007 (E) 8 Un-recovered deformation (bagging), C, expressed in mm
47、 C = Q - P where Q is the deformation at 0,2 N in millimetres after a specified recovery period at the original position; P is the original deformation take during the first cycle at 0,2 N. 8.6 Test report The test report shall include the following information: a) reference to this European Standar
48、d, i.e. EN 14704-2 and date of test; b) identification of test sample and sampling procedure, if required; c) force used to record the deformation before and after cycling; d) rate of extension used in millimetres per minute; e) state or condition of test specimens (original, washed, aged); f) numbe
49、r of test specimens particularly if less than 5; g) diameter of test ring and probe; h) any deviation from this procedure; i) maximum cycling force; j) arithmetic mean of maximum deformation in millimetres which ever is required and for which cycle; k) arithmetic mean of modulus, the deformation point in millimetres and cycle, when required; l) arithmetic mean of force decay due to time and relevant cycles, when required; m) arithmetic mean of un-recovered deformation, when required; n) if required, the coefficient of variation for the relevant
