1、BRITISH STANDARDBS EN ISO 9073-18:2008Textiles Test methods for nonwovens Part 18: Determination of breaking strength and elongation of nonwoven materials using the grab tensile testICS 59.080.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g3
2、8g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 9073-18:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2008 BSI 2008ISBN 978 0 580 56797 1National forewordThis British Stan
3、dard is the UK implementation of EN ISO 9073-18:2008. It is identical to ISO 9073-18:2007.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 secretar
4、y.This publication does not 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/corrigenda issued since publicationDate CommentsEUROPEAN STANDARDNO
5、RME EUROPENNEEUROPISCHE NORMEN ISO 9073-18May 2008ICS 59.080.30English VersionTextiles - Test methods for nonwovens - Part 18: Determinationof breaking strength and elongation of nonwoven materials usingthe grab tensile test (ISO 9073-18:2007)Textiles - Mthodes dessai pour nontisss - Partie 18:Dterm
6、ination de la rsistance la rupture et delallongement de matriaux nontisss par lessai de traction larrachement (ISO 9073-18:2007)Textilien - Prfverfahren fr Vliesstoffe - Teil 18:Bestimmung der Hchstzugkraft und derHchstzugkraftdehnung von Vliesstoffen mit dem Grab-Zugversuch (ISO 9073-18:2007)This E
7、uropean Standard was approved by CEN on 12 April 2008.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 co
8、ncerning such nationalstandards may be obtained on application to the CEN Management Centre 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 ow
9、n language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania
10、, Luxembourg, Malta, Netherlands, Norway, 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 2008 CEN All
11、rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 9073-18:2008: EForeword The text of ISO 9073-18:2007 has been prepared by Technical Committee ISO/TC 38 “Textiles” of the International Organization for Standardization (ISO) and has been t
12、aken over as EN ISO 9073-18:2008 by Technical Committee CEN/TC 248 “Textiles and textile products” the secretariat of which is held by BSI. 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 November
13、 2008, and conflicting national standards shall be withdrawn at the latest by November 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent r
14、ights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
15、Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 9073-18:2007 has been approved by CEN as a EN ISO 9073-18:2008 without any modification. BS EN ISO 90
16、73-18:2008iiiiiContents Page 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 2 5 Material and reagents. 2 6 Apparatus 2 7 Procedure 3 8 Calculation. 4 9 Test report . 4 Annex A (informative) Possible reasons for low precision of grab tensile test 6 BS EN ISO 9073-18:20
17、08blank1Textiles Test methods for nonwovens Part 18: Determination of breaking strength and elongation of nonwoven materials using the grab tensile test 1 Scope This part of ISO 9073 specifies a grab tensile test procedure for determining the breaking strength and elongation of most nonwoven materia
18、ls. It includes instructions for the testing of wet specimens. This grab tensile test procedure is applicable for most nonwovens, but is not recommended for nonwovens which have a high percentage of stretch. 2 Normative references The following referenced documents are indispensable for the applicat
19、ion 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. ISO 139, Textiles Standard atmospheres for conditioning and testing ISO 186, Paper and board Sampling to determine ave
20、rage quality ISO 10012:2003, Measurement management systems Requirements for measurement processes and measuring equipment 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 grab test tensile test in which only the centre part of the test specim
21、en is gripped in the jaws of the testing machine NOTE Normally, the grab tensile strength is determined using a 100 mm wide strip of material. This tensile load is applied at the midpoint of the 100 mm specimen. This is done using 25 mm wide jaw faces that are used to clamp the specimen at each end.
22、 3.2 elongation deformation in the direction of load caused by a tensile force NOTE Elongation is generally expressed as a percentage, as a ratio of the length of the stretched material to the length of the unstretched material. Elongation may be determined by the degree of stretch under a specific
23、load, or the point where the stretched material breaks. BS EN ISO 9073-18:20082 3.3 breaking force maximum force applied to a material when it is carried to rupture NOTE Materials that are brittle usually rupture at the maximum force. Materials that are ductile usually experience a maximum force bef
24、ore rupturing. 3.4 tensile strength strength of a material when subjected to either pulling or compressive stress NOTE It measures the stress a material can bear without breaking or tearing. 4 Principle Using a tensile testing machine, mount a 100 mm wide specimen centrally with 25 mm clamps at each
25、 end of the specimen. The tensile testing machine applies force until the specimen breaks. Values for the breaking force and the elongation of the test specimen are obtained from tensile test instruments by recording charts, or a computer interface. This test is performed to simulate the stress a me
26、dical doctor would place on the elbow of his surgical gown or other similar pressure points. This stress on the elbow of the surgical gown is not replicated by a strip tensile test because, in the grab tensile test, the adjacent material is providing added strength. The grab test procedure is applic
27、able to the determination of the operative strength of the nonwoven material. There is no straightforward relationship between grab tests and strip tests. 5 Material and reagents 5.1 Distilled water, for wet testing. 5.2 Non-ionic wetting agent, for wet testing. 5.3 Container, for wetting the specim
28、ens. 6 Apparatus 6.1 Tensile testing machine, with a constant rate of extension and designed for operation at a speed of (300 10) mm/min. Metrological confirmation of the testing apparatus shall be in compliance with Clause 7 and Figure 2 and Annex A of ISO 10012:2003. This instrument should be able
29、 to be calibrated and supplied with a fact sheet indicating that it meets the specified requirements of ISO 10012:2003. This calibration should be maintained in accordance with the manufacturers specifications. 6.2 Clamps and jaw faces, capable of holding the test piece securely without damaging or
30、altering the results of the nonwoven. The faces shall be parallel and have matching centres with respect to one another in the same clamp, and to the corresponding jaw face of the other clamp. Each clamp shall have a front (or top) jaw face measuring (25 1) mm perpendicular to the direction of the a
31、pplication of force, and not less than 25 mm parallel to the direction of the application of force. The back, or bottom, jaw face of each clamp should be at least as large as its mate, but using a larger face for the second jaw reduces the problem of front and back jaw-face misalignment. NOTE If sli
32、ppage occurs while the specimen is being tested, the parallel direction width can be changed from 25 mm to 50 mm. BS EN ISO 9073-18:200837 Procedure 7.1 Bring the specimens from the prevailing atmosphere to moisture equilibrium for testing in the standard atmosphere as specified in ISO 139. Specimen
33、s to be tested in wet conditions shall be immersed in water at room temperature until thoroughly wetted. To thoroughly wet a specimen, it may be necessary to add no more than 0,05 % of a non-ionic wetting agent to the water. A test of any specimen shall be completed within 2 min after its removal fr
34、om the water. 7.2 Set the distance between the clamps (gauge length) at (75 1) mm. 7.3 Set the testing machine for an extension rate of (300 10) mm/min unless otherwise specified. 7.4 Select the force range of the testing machine for the break to occur between 10 % and 90 % of full-scale force. Cali
35、brate or verify the testing machine for this range. 7.5 Sample in accordance with ISO 186 and, unless otherwise specified, use 5 as the minimum specimen size. 7.6 Handle the test specimens carefully at the edges, to avoid changing the natural state of the test area of the nonwoven material. 7.7 From
36、 each sample, prepare five specimens in the machine direction and five specimens in the cross-direction for each testing condition (dry and wet if needed). 7.8 Cut each specimen (100 1) mm wide by at least 150 mm long with the long dimension parallel to the direction of testing and force application
37、. The length of the specimen depends on the type of clamps being used. The specimen should be long enough to extend through the clamps by at least 10 mm at each end. 7.9 Mount the specimen in the top and bottom clamps (jaws) so that the front 25 mm clamps are centred across the width of the specimen
38、. Carefully mount the specimen so that all the slack in the material is removed, but care should be taken so that pretension is not applied to the specimen. Placing of the specimen into the upper and lower jaws of the tensile machine can be a large source of error in performing this method. The elon
39、gation measurement is taken from the point where the force curve leaves the zero line. Mounting the specimens carefully and methodically into the jaws can reduce some of the technician error. 7.10 Trace a mark across the specimen at the front inner edge of each jaw, to check for specimen slippage. W
40、hen slippage occurs, the mark will move away from the jaw edge and the results of this specimen should be discarded. 7.11 Engage the machine to “run” and break the specimen. 7.12 Read the breaking force, and elongation if required, from the mechanism provided for such a purpose. Record the machine-d
41、irection and cross-direction results separately. For most testing machines, data will be obtained using an interface with a computer. If a specimen slips in the jaws, or breaks at the edge of or in the jaws, or if for any reason the result falls markedly below the average for the set of specimens, d
42、iscard the result and take another specimen. Continue this until the required number of acceptable breaks has been obtained. The decision to discard a break should be based on observation of the specimen during the test, and upon the inherent variability of the material. In the absence of other crit
43、eria for rejecting a jaw break, any break occurring within 5 mm of the jaws which results in a value below 50 % of the average of all the other breaks should be discarded. No other break should be discarded, unless it is known to be faulty. 7.13 If a material manifests any slippage in the jaws, or i
44、f more than 25 % of the specimens break at a point within 5 mm of the edge of the jaw, one of the modifications listed below may be tried. If any of these modifications are used, state the method of modification in the test report. BS EN ISO 9073-18:20084 The jaws may need to have rubber pads applie
45、d to each jaw surface. The surface of the jaws may be serrated or notched to better hold the material. The surface of the jaws may have a sharp edge that could be causing these breaks. It is sometimes difficult to determine the precise reason for certain specimens to break near the edge of the jaws.
46、 If such a break is caused by damage to the specimen by the jaws, then the results should be discarded. If, however, the break is due merely to randomly distributed weak places, it is a legitimate result. In some cases, it may also be caused by a concentration of stress in the area adjacent to the j
47、aws, because the jaws prevent the specimen from contracting in width as the force is applied. In such cases, a break near the edge of the jaw is inevitable and should be accepted as a characteristic of the particular material and the test method. 8 Calculation 8.1 Breaking force Calculate the averag
48、e of the breaking force observed for all acceptable specimens. That is, the maximum force exerted on the specimen as read directly from the testing machine. 8.2 Measurement of apparent elongation at break (unless some other force is specified): Measure the apparent elongation of acceptable specimens
49、 at the breaking force. Measure the increase in length from the start of the force-extension curve to a point corresponding with the breaking force, or other specified force. Calculate the apparent elongation as the percentage increase in length based on the gauge length. 8.3 Wet specimens If tests were performed on wet specimens, the results should be calculated in the same way as for dry specimens (i.e. the average of the breaking force and the average apparent elongation at the breaking force). 9 Test report The test report shall inc
