1、 CAN/CGSB-4.2 No. 12.2-2012Supersedes CAN/CGSB-4.2 No. 12.2-95Textile test methods Tearing strength Trapezoid methodICS 59.080.01National Standard of CanadaThe CANADIAN GENERAL STANDARDS BOARD (CGSB), under whose auspices this National Standard of Canada has been developed is a government agency wit
2、hin Public Works and Government Services Canada. CGSB is engaged in the production of voluntary standards in a wide range of subject areas through the media of standards committees and the consensus process. The standards committees are composed of representatives of relevant interests including pro
3、ducers, consumers and other users, retailers, governments, educational institutions, technical, professional and trade societies, and research and testing organizations. Any given standard is developed on the consensus of views expressed by such representatives. CGSB has been accredited by the Stand
4、ards Council of Canada as a national standards-development organization. The standards that it develops and offers as National Standards of Canada conform to the criteria and procedures established for this purpose by the Standards Council of Canada. In addition to standards it publishes as national
5、 standards, CGSB produces standards to meet particular needs, in response to requests from a variety of sources in both the public and private sectors. Both CGSB standards and CGSB national standards are developed in conformance with the policies described in the CGSB Policy Manual for the Developme
6、nt and Review of Standards. CGSB standards are subject to review and revision to ensure that they keep abreast of technological progress. Suggestions for their improvement, which are always welcome, should be brought to the notice of the standards committees concerned. Changes to standards are issue
7、d either as separate amendment sheets or in new editions of standards. An up-to-date listing of CGSB standards, including details on latest issues and amendments, and ordering instructions, is found in the CGSB Catalogue, which is published annually and is available without charge upon request. More
8、 information is available about CGSB products and services at our Web site www.tpsgc-pwgsc.gc.ca/ongc-cgsb. Although the intended primary application of this standard is stated in its Scope, it is important to note that it remains the responsibility of the users of the standard to judge its suitabil
9、ity for their particular purpose. The testing and evaluation of a product against this standard may require the use of materials and/or equipment that could be hazardous. This document does not purport to address all the safety aspects associated with its use. Anyone using this standard has the resp
10、onsibility to consult the appropriate authorities and to establish appropriate health and safety practices in conjunction with any applicable regulatory requirements prior to its use. CGSB neither assumes nor accepts any responsibility for any injury or damage that may occur during or as the result
11、of tests, wherever performed. Attention is drawn to the possibility that some of the elements of this Canadian standard may be the subject of patent rights. CGSB shall not be held responsible for identifying any or all such patent rights. Users of this standard are expressly advised that determinati
12、on of the validity of any such patent rights is entirely their own responsibility. Further information on CGSB and its services and standards may be obtained from: The Manager Standards Division Canadian General Standards Board Gatineau, Canada K1A 1G6 The STANDARDS COUNCIL OF CANADA is the coordina
13、ting body of the National Standards System, a coalition of independent, autonomous organizations working towards the further development and improvement of voluntary standardization in the national interest. The principal objects of the SCC are to foster and promote voluntary standardization as a me
14、ans of advancing the national economy, benefiting the health, safety and welfare of the public, assisting and protecting the consumer, facilitating domestic and international trade, and furthering international cooperation in the field of standards. A National Standard of Canada (NSC) is a standard
15、prepared or reviewed by an accredited Standards Development Organization (SDO) and approved by the SCC according to the requirements of CAN-P-2. Approval does not refer to the technical content of the standard; this remains the continuing responsibility of the SDO. A NSC reflects a consensus of a nu
16、mber of capable individuals whose collective interests provide, to the greatest practicable extent, a balance of representation of general interests, producers, regulators, users (including consumers), and others with relevant interests, as may be appropriate to the subject in hand. It normally is a
17、 standard, which is capable of making a significant and timely contribution to the national interest. Those who have a need to apply standards are encouraged to use NSCs. These standards are subject to periodic review. Users of NSCs are cautioned to obtain the latest edition from the SDO, which publ
18、ishes the standard. The responsibility for approving standards as National Standards of Canada rests with the: Standards Council of Canada 200-270 Albert Street Ottawa, Ontario K1P 6N7 How to order Publications: by telephone 819-956-0425 or 1-800-665-2472 by fax 819-956-5740 by mail CGSB Sales Centr
19、e Gatineau, Canada K1A 1G6 in person Place du Portage Phase III, 6B1 11 Laurier Street Gatineau, Quebec by email ncr.cgsb-ongctpsgc-pwgsc.gc.ca on the Web www.tpsgc-pwgsc.gc.ca/ongc-cgsb NATIONAL STANDARD OF CANADA CAN/CGSB-4.2 No. 12.2-2012Supersedes CAN/CGSB-4.2 No. 12.2-95 Textile test methods Te
20、aring strength Trapezoid methodNATIONAL STANDARD OF CANADA CAN/CGSB-3.14-2006Prepared by the Approved by the Canadian General Standards Board Standards Council of CanadaPublished November 2012 by the Canadian General Standards Board Gatineau, Canada K1A 1G6 HER MAJESTY THE QUEEN IN RIGHT OF CANADA,
21、as represented by the Minister of Public Works and Government Services, the Minister responsible for the Canadian General Standards Board (2012). No part of this publication may be reproduced in any form without the prior permission of the publisher.CETTE NORME NATIONALE DU CANADA EST DISPONIBLE EN
22、VERSIONSFRANAISE ET ANGLAISE.CAN/CGSB-4.2No. 12.2-2012CANADIAN GENERAL STANDARDS BOARDCommittee on Textile Test Methods and Terminology(Voting membership at date of approval)ChairBauerle, J.1Exova Group Ltd.General Interest CategoryBatcheller, J. University of AlbertaCarrick, D. National Defence/DSS
23、PMDavie, N. ConsultantHickman, P. QualtechLiu, S. University of ManitobaMan, T.M. ConsultantProducer CategoryAdam, C. PGI/Difco Performance Fabrics Inc.Cochran, B. Lincoln Fabrics Ltd.Lawson, L. Marv Holland Apparel Ltd.Leonard, D. Invista (Canada) Co.Templeton, R. DuPont Canada Inc.Regulator Catego
24、ryAndersson, C. Health CanadaUser CategoryBourget, S. National Defence/QETEIzquierdo, V. Textile Technologies CentreLitva (Scalzo), M. Canada Border Services AgencyMacLeod, J. Public Works and Government Services CanadaMorrow-Lamarche, S. Royal Canadian Mounted PoliceSirimanna, A. Sears Canada Inc.T
25、ebbs, C. International Drycleaners CongressSecretary (non-voting)Grabowski, M. Canadian General Standards BoardAcknowledgment is made for the translation of this National Standard of Canada by the Translation Bureau of Public Works and Government Services Canada.1User CGSB 2012 All rights reservedCA
26、N/CGSB-4.2No. 12.2-2012iCGSB 2012 All rights reservedContents1 Scope . 12 Principle . 13 Normative references 14 Apparatus . 25 Test specimens 26 Procedure 27 Calculations . 38 Report 3PageCAN/CGSB-4.2No. 12.2-20121CGSB 2012 All rights reservedTextile test methods Tearing strength Trapezoid methodSc
27、ope1 This method determines the tearing strength of woven and nonwoven fabrics by the trapezoid procedure. Two procedures for the calculation of tearing strength are given, one for woven fabrics and the other for nonwoven fabrics. The two procedures do not usually give the same result.The testing an
28、d evaluation of a product against this method may require the use of materials and/or equipment that could be hazardous. This method does not purport to address all the safety aspects associated with its use. Anyone using this method has the responsibility to consult the appropriate authorities and
29、to establish appropriate health and safety practices in conjunction with any applicable regulatory requirements prior to its use. CGSB neither assumes nor accepts any responsibility for any injury or damage that may occur during or as the result of tests, wherever performed.Principle 2 The force obs
30、erved in the propagation of a tear across the fabric is measured, in which the force is applied parallel to the yarns that are ruptured in the tear.Normative references 3 The following normative documents contain provisions that, through reference in this text, constitute provisions of this method.
31、The referenced documents may be obtained from the source noted below.An undated reference is to the latest edition or revision of the reference or document in question, unless otherwise specified by the authority applying this method. A dated reference is to the specified revision or edition of the
32、reference or document in question. However, parties to agreements based on this method are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below.3.1 Canadian General Standards Board CAN/CGSB-4.2 Textile Test Methods:No. 1 Precision
33、and Accuracy of MeasurementsNo. 2 Conditioning Textile Materials for Testing.3.1.1 Source The above may be obtained from the Canadian General Standards Board, Sales Centre, Gatineau, Canada K1A 1G6. Telephone 819-956-0425 or 1-800-665-2472. Fax 819-956-5740. E-mail ncr.cgsb-ongctpsgc-pwgsc.gc.ca. We
34、b site www.tpsgc-pwgsc.gc.ca/ongc-cgsb.2CAN/CGSB-4.2No. 12.2-2012CGSB 2012 All rights reservedApparatus 4 4.1 Constant-rate-of-extension (CRE) machine: a testing machine in which one end of the specimen is held by a virtually stationary clamp and the other end of the specimen is gripped in a clamp t
35、hat is driven at a constant speed. A suitable system is provided for detecting and recording the force applied.4.2 Constant-rate-of-traverse (CRT) machine: a testing machine in which one end of the specimen is held by a clamp driven at a constant speed while the other end is gripped in a clamp attac
36、hed to a weighing mechanism of a type that permits movement of the attached clamp, e.g. as in pendulum machines. The specimen is therefore not extended at a constant rate (see Note). A suitable system is provided for recording the force applied.NOTE Significant errors due to inertia are frequently e
37、ncountered in testing machines in which the moving parts of the weighing mechanisms are massive (e.g. CRT machines), especially if such machines are used on materials with low extensibilities or are operated at high speeds. Caution should therefore be exercised in testing anything other than convent
38、ional materials and in testing specimens that break near the lower end of the force range of such machines.4.3 Both types of machines shall have a suitable capacity (see 6.2) and operate with the driven clamp moving at a speed of 300 10 mm/min (see Note)NOTE Due to presence of inertia factors in the
39、 pendulum-type testing machine, the values for tearing strength of a given fabric determined by this method on pendulum and inertialess types of machines will usually differ. The difference is usually small and varies with the fabric under test. Values from the two types of machines cannot be correl
40、ated by any numerical factor valid for fabrics in general.4.4 Both gripping surfaces of the clamps shall measure 25 x 75 mm or more, with the longer dimension perpendicular to the direction of the application of the force. The distance between the clamps at the start of the test shall not be more th
41、an 25 mm. The ratchet pawls of the CRT (pendulum) type machine shall be rendered inoperative during the test.Test specimens5 5.1 Specimens shall be cut 75 mm wide and 150 mm long. Two sets of at least five specimens each (see 5.2) shall be tested, one set for warp or machine direction tearing streng
42、th, having the longer dimension parallel to the warp yarns, the other set for weft or cross direction tearing strength, having the longer dimension parallel to the weft yarns (see 6.2). No two warp-tearing specimens shall contain the same warp yarns nor shall any two weft-tearing specimens contain t
43、he same weft yarns. An isosceles trapezoid with a length of 75 mm and bases of 25 mm and 100 mm in width is marked on each specimen, preferably with the aid of a template (Figure 1). A cut 5 to 10 mm in length is then made at the centre of, and perpendicular to, the 25 mm trapezoid edge.5.2 If the p
44、recision with which the tearing strength to be measured is specified, refer to CAN/CGSB-4.2 No. 1 for procedures to determine the required number of test specimens. If the precision is unknown, then the number of specimens indicated in 5.1 shall be taken.Procedure 6 6.1 Condition the specimens in ac
45、cordance with CAN/CGSB-4.2 No. 2. Clamp each specimen in the testing machine with the longer edges of the jaw faces accurately aligned with the non-parallel sides of the trapezoid (Figure 2). Start the machine and record the force reached during the tearing of the specimen.6.2 If the tearing strengt
46、h of a single specimen is less than 10% of the capacity of the testing machine, then use composite specimens to obtain a tearing force of at least 10% of the capacity of the machine. In such cases, no fewer than five composite specimens shall be tested. Composite specimens shall consist of two or mo
47、re individual specimens, superimposed and clamped together in the machine, to be torn simultaneously. The individual specimens included in each composite specimen shall be fastened together at the corners to assist in aligning them correctly in the clamps of the testing machine.CAN/CGSB-4.2No. 12.2-
48、20123CGSB 2012 All rights reservedCalculations7 7.1 For woven fabrics, the autographic record obtained will normally consist of a succession of peak force values corresponding to the rupturing of successive yarns or groups of yarns during tearing. Disregard the initial peak force because it is frequ
49、ently greater than subsequent peak forces and therefore shall not be included in the calculation of the average tearing strength. Immediately after the first peak, record the maximum force for each of the five successive 5 mm intervals of tearing in the specimens. Calculate the tearing strength of each single or composite specimen by averaging the five maximum force values obtained from the record.7.2 For nonwoven fabrics, note the maximum force recorded for each specimen (single or composite).7.3 For each direction of the fabric, calculate th
