1、June 2007DEUTSCHE NORM English price group 10No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 85.060!,y$“www.din.deDDIN
2、 ISO 1924-3Paper and board Determination of tensile properties Part 3: Constant rate of elongation method (100 mm/min)(ISO 1924-3:2005)English version of DIN ISO 1924-3:2007-06Papier und Pappe Bestimmung von Eigenschaften bei zugfrmiger Belastung Teil 3: Verfahren mit konstanter Dehngeschwindigkeit
3、(100 mm/min) (ISO 1924-3:2005)Englische Fassung DIN ISO 1924-3:2007-06www.beuth.de9860156Document comprises 14 pages 09.07DIN ISO 1924-3:2007-06 2 National foreword This standard has been prepared by Technical Committee ISO/TC 6/SC 2 “Test methods and quality specifications for paper and board” (Sec
4、retariat: SIS, Sweden). The responsible German body involved in its preparation was the Normenausschuss Papier und Pappe (Paper and Board Standards Committee), Technical Committee NA 062-04-26 GA (previously NMP 426/NPa) Physikalisch-technologische Prfverfahren fr Papier und Pappe. The DIN Standards
5、 corresponding to the International Standards referred to in clause 2 of the ISO Standard are as follows: ISO 186 DIN EN ISO 186 ISO 187 DIN EN 20187 ISO 534 DIN EN ISO 534 ISO 536 DIN EN ISO 536 The text of the International Standard ISO 1924-3 “Paper and board Determination of tensile properties P
6、art 3: Constant rate of elongation method (100 mm/min)” was adopted without any modification. National Annex NA (informative) Bibliography DIN EN 20187, Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples DIN
7、 EN ISO 186, Paper and board Sampling to determine average quality DIN EN ISO 534, Paper and board Determination of thickness, density and specific volume DIN EN ISO 536, Paper and board Determination of grammage Contents Page Introduction 1 Scope . 2 Normative references . 3 Terms and definitions.
8、4 Principle. 5 Apparatus 6 Calibration and adjustment of apparatus. 7 Sampling and preparation of test pieces . 7.1 Sampling 7.2 Conditioning 7.3 Preparation of test pieces 8 Procedure 9 Calculation and report 9.1 Tensile strength 9.4 9.5 9.7 9.8 Bibliography . 3 Paper and board Determination of ten
9、sile properties Part 3: Constant rate of elongation method (100 mm/min) DIN ISO 1924-3:2007-06 4555668888889910 1010111112 121212 1213149.2 Tensile index .9.3 Strain at break .Tensile energy absorption .Tensile energy absorption index. 11 Test report . 10 Precision10.1 Repeatability10.2 Reproducibil
10、ityTensile stiffness index .Modulus of elasticity 9.6 Tensile stiffness Introduction This part of ISO 1924 has been developed in order to specify the conditions for determining the tensile properties of paper, including tensile stiffness and tensile stiffness index, using a higher rate of elongation
11、 than specified in ISO 1924-2, which is the most commonly used part where tensile strength, stretch at break, tensile energy absorption and modulus of elasticity are measured. In ISO 1924-2, the tensile properties are measured at a constant rate of elongation of 20 mm/min at a test span of 180 mm. F
12、or the measuring of tensile stiffness in this part of ISO 1924, a higher accuracy in the recording of elongation, compared to ISO 1924-2, is also required. This part of ISO 1924 specifies the fastest of the two methods. In addition to the properties measured in ISO 1924-2, the tensile stiffness is a
13、lso measured. The tensile properties are measured at a constant rate of elongation of 100 mm/min at a test span of 100 mm, and the elongation is recorded with a higher accuracy than the accuracy in ISO 1924-2. This part of ISO 1924 differs from existing standards for testing tensile properties in th
14、at the test span, i.e. the distance between the clamping lines, is 100 mm irrespective of the kind of sample to be tested. The rate of elongation has been increased to 100 mm/min in order to reduce the testing time, thus making it possible to test a greater number of samples within a given time peri
15、od. NOTE The results of tensile tests depend on the rate of elongation applied and the test span. The rate dependence and the effect of test span may vary with paper grade and are different for tensile strength, strain at break, tensile energy absorption and tensile stiffness. In a study within SCAN
16、-test, comparing the results achieved using ISO 1924-2 and this part, the tensile strength increased by 5 % to 15 % when the rate of elongation was increased from 20 mm/min (at a test span length of 180 mm) to 100 mm/min (at a test span length of 100 mm). It is not possible to predict the exact rela
17、tionship between the results for any particular paper whose tensile properties are determined using ISO 1924-2 and this part of ISO 1924. This relationship may only be determined by laboratory experimentation. In this part of ISO 1924, the same terminology and symbols are used as in general literatu
18、re concerning physics and mechanics of materials. 4 DIN ISO 1924-3:2007-06 1 Scope This part of ISO 1924 specifies a method for measuring the tensile strength, strain at break, tensile energy absorption and tensile stiffness, using a testing machine operating with a constant rate of elongation (100
19、mm/min). This part of ISO 1924 also specifies equations for calculating the tensile index, the tensile energy absorption index, the tensile stiffness index and the modulus of elasticity. When tensile stiffness is to be determined, a greater accuracy is required in the elongation measurement than whe
20、n the other tensile properties are to be determined. If the elongation is determined with the lower accuracy, the tensile stiffness value obtained is not in accordance with this part of ISO 1924. This part of ISO 1924 is applicable to all papers and boards, including papers of high extensibility, su
21、ch as creped papers and extensible sack papers, but with the exception of low-density papers such as tissue papers and tissue products for which ISO 12625-42is recommended. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated ref
22、erences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 186, Paper and board Sampling to determine average quality ISO 187, Paper, board and pulps Standard atmosphere for conditioning and testing and proce
23、dure for monitoring the atmosphere and conditioning of samples ISO 534, Paper and board Determination of thickness, density and specific volume ISO 536, Paper and board Determination of grammage 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1
24、 tensile strength maximum tensile force per unit width that paper and board will withstand before breaking under the conditions defined in this standard test method 3.2 tensile index tensile strength divided by the grammage 5 DIN ISO 1924-3:2007-06 3.3 elongation increase in length of a test piece 3
25、.4 strain ratio of the elongation of a test piece to the initial test length NOTE The initial test length of the test piece is the same as the initial span between the clamping lines. 3.5 strain at break strain at the maximum tensile force 3.6 tensile energy absorption amount of energy per unit surf
26、ace area (test length width) of a test piece when it is strained to the maximum tensile force 3.7 tensile energy absorption index tensile energy absorption divided by the grammage 3.8 tensile stiffness maximum slope of the curve obtained when tensile force per unit width is plotted versus strain 3.9
27、 tensile stiffness index tensile stiffness divided by the grammage 3.10 modulus of elasticity tensile stiffness divided by the thickness 4 Principle A test piece of given dimensions is strained to break at a constant rate of elongation using a testing machine that automatically records both the tens
28、ile force and the elongation. From the recorded data, the tensile strength, the strain at break, the tensile energy absorption and the tensile stiffness are calculated. 5 Apparatus 5.1 Tensile testing machine, including means of determining the force (i.e. a load-cell), the elongation and the area b
29、etween the force-elongation curve and the elongation axis. The testing machine is designed to strain a test piece at a constant rate of elongation of 100 mm/min 10 mm/min, and to record both the tensile force and the elongation. NOTE 1 The true elongation rate is less than the rate of movement of th
30、e moving clamp due to the deflection of the load-cell and the testing machine. This rate difference has, however, normally a negligible effect on the strength values. The testing machine shall have two clamps for holding the test piece. Each clamp shall be designed to grip the test piece firmly, but
31、 without damage, along a straight line across the full width of the test piece (the clamping line), and have a means of adjusting the clamping force. 6 DIN ISO 1924-3:2007-06 NOTE 2 The clamping line is the contact zone resulting from gripping the test piece between a cylindrical and a flat surface
32、or between two cylindrical surfaces whose axes are parallel. For certain grades of paper, “line contact” clamps may not be appropriate and it may be necessary to replace them with another type of gripping surface. Other types of clamps may be used, provided no slippage of, or damage to, the test pie
33、ce occurs during the test. When the test piece is clamped, the clamping lines shall be parallel to each other within an angle of 1, see Figure 1. During the test, the angle between the clamping lines shall not change by more than 0,5 in the plane of the test piece. The centre-line of the test piece
34、shall be perpendicular to the clamping lines within an angle of 1. If there is any suspicion that the test piece slips, a test with different clamping forces shall be carried out. If the clamping force influences the strain at break, this means that the test piece may be slipping in the clamp. If th
35、e strain at break is independent of the clamping force, then no slipping in the clamps occurs. The applied tensile force shall be parallel to the test piece centre-line, in the direction of the test piece, within an angle of 1. The distance between the clamping lines (the test span) shall be 100 mm
36、0,5 mm. The apparatus shall have means of recording the elongation and the force as follows: Property Elongation Force Tensile strength to an accuracy of 1,0 % of the true force Strain at break to an accuracy of 0,1 mm Tensile energy absorption to an accuracy of 0,1 mm to an accuracy of 1,0 % of the
37、 true force Tensile stiffness to an accuracy of 0,01 mm, in the range 0 to 1 mm to an accuracy of 1,0 % of the true force The elongation shall be calculated from the change in distance between the clamps, or by the use of an extensometer. Clamping lines parallel to each other within an angle of 1 Ce
38、ntre-line of test piece perpendicular to clamping line within an angle of 1 Tensile force parallel to the test piece centre-line within an angle of 1 Figure 1 Clamping line and test piece relationship NOTE 3 If the elongation is calculated from the movement of the moving clamp, the deflection of the
39、 load-cell and of the testing machine must be taken into consideration and adjusted for. 5.2 Device for cutting test pieces to the dimensions required (see 7.3). 7 DIN ISO 1924-3:2007-06 6 Calibration and adjustment of apparatus The apparatus shall be calibrated according to the instructions given b
40、y the manufacturer. Ensure that the criteria stated in the Table in 5.1 are fulfilled. Position the clamps so that the test span is 100 mm 0,5 mm. Check the test span by measuring the two impressions produced by the clamps when strips of, for example, thin aluminium foil are clamped. Adjust the rate
41、 of separation of the clamps to 100 mm/min 10 mm/min. Adjust the clamping force so that there is neither slipping of, nor damage to, the test piece. 7 Sampling and preparation of test pieces 7.1 Sampling If the tests are being made to evaluate a lot, the sample shall be selected in accordance with I
42、SO 186. If the tests are made on another type of sample, make sure that the test pieces are representative of the sample received. 7.2 Conditioning Condition the specimens of paper and board as specified in ISO 187. Keep them in the conditioning atmosphere throughout the test. This test, like other
43、mechanical tests, is very sensitive to changes in the moisture content of the test piece. Handle the test pieces carefully, and avoid touching with a bare hand the part of the test piece to be placed between the clamps. Keep the test pieces away from moisture, heat and other influences that may chan
44、ge their moisture content. 7.3 Preparation of test pieces If the tensile index, tensile stiffness index or tensile energy absorption index is required, determine the grammage of the specimens as described in ISO 536. If the modulus of elasticity is required, determine the thickness as described in I
45、SO 534. From specimens of undamaged paper and board, cut test pieces with a width of 15,0 mm 0,1 mm and long enough to be clamped in the clamps. Avoid touching with a bare hand the part of the test piece to be placed between the clamps, avoiding watermarks, folds and wrinkles. Ensure that the test p
46、ieces are representative of the sample to be tested. The long edges of the test pieces shall be straight, parallel to within 0,1 mm over the total clamping length, cleanly cut and undamaged. Cut a sufficient number of test pieces to enable at least 10 tests to be made in each direction of interest (
47、machine direction, cross direction). NOTE Several test pieces can be cut simultaneously, provided that the test pieces obtained fulfil the requirements specified above and that the test pieces obtained give the same result as test pieces cut one at a time. A test width of 25,0 mm 0,1 mm or 50,0 mm 0
48、,1 mm is also permitted, but this shall be reported. 8 Procedure Ensure that the testing machine is calibrated as described in Clause 6. Place the test piece in the clamps without straining it and so that any observable slack is eliminated. Avoid touching the test area between the clamps with the fi
49、ngers. Align and tightly clamp the test piece and perform the test. Test at least 10 test pieces in each direction of interest (machine direction, cross direction). Reject all readings for test pieces that break within 2 mm of the clamping lines. 8 DIN ISO 1924-3:2007-06 NOTE If more than 20 % of the test pieces break within 2 mm of the clamping lines, inspect the apparatus for conformity with the specifications and take the appropriate remedial measures. Accept the results if the apparatus conforms to the specifications i
