GB/T Translated English of Chinese Standard: GB/T NATIONAL STANDARD OF

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1 Translated English of Chinese Standard: GB/T GB NATIONAL STANDARD OF THE PEOPLE S REPUBLIC OF CHINA ICS W 04 GB/T Replacing GB/T Textiles - Tear properties of fabrics - Part 3: Determination of tear force of trapezoid-shaped test specimens (ISO :1997, Textiles - Test methods for nonwovens - Part 4: Determination of tear resistance, MOD) 纺织品织物撕破性能第 3 部分 : 梯形试样撕破强力的测定 GB/T How to BUY & immediately GET a full-copy of this standard? Search --> Add to Cart --> Checkout (3-steps); 3. No action is required - Full-copy of this standard will be automatically & immediately delivered to your address in 0~60 minutes. 4. Support: Sales@ChineseStandard.net. Wayne, Sales manager Issued on: March 19, 2009 Implemented on: January 1, 2010 Issued by: General Administration of Quality Supervision, Inspection and Quarantine of the People s Republic of China; Standardization Administration of the People s Republic of China. Page 1 of 9

2 Table of Contents Foreword Scope Normative references Terms and definitions Principle Apparatus Sampling Preparation and conditioning of test pieces Procedure Expression of results Test report... 8 Page 2 of 9

3 Foreword GB/T 3917 Textiles - Tear properties of fabrics is divided into the following 5 parts: Part 1: Determination of tear force using ballistic pendulum method (Elmendorf); Part 2: Determination of tear force of trouser-shaped test specimens (Single tear method); Part 3: Determination of tear force of trapezoid-shaped test specimens; Part 4: Determination of tear force of tongue-shaped test specimens (Double tear test); Part 5: Determination of tear force of wing-shaped test specimens (Single tear method). This is Part 3 of GB/T This Part uses the re-drafting method to modify ISO :1997 Textiles - Test methods for nonwovens - Part 4: Determination of tear resistance (English version). The differences between this Part and ISO :1997 are as follows: DELETE the Foreword and Introduction in the International Standard; MODIFY the standard name and scope; USE our national standards to substitute the corresponding international standards in the normative references, DELETE a reference standard; ADD Chapter 3 Terms and definitions, and the subsequent chapter numbers are postponed; and MODIFY the provisions in Chapter 5 Sampling method of the original International Standard. This Part substitutes GB/T Textiles - Tear properties of fabrics - Part 3: Determination of tear force of trapezoid-shaped test specimens. The major differences between this Part and GB/T are as follows: ADD Chapter 3 Terms and definitions, and the subsequent chapter numbers are postponed; Page 3 of 9

4 Textiles - Tear properties of fabrics - Part 3: Determination of tear force of trapezoid-shaped test specimens 1 Scope This Part of GB/T 3917 specifies a method for the determination of tear force of fabrics by the trapezoid method. This Part is applicable to various kinds of woven fabrics and nonwovens. 2 Normative references The provisions in the following documents become the provisions of this Part through reference in this Part of GB/T For dated references, the subsequent amendments (excluding corrections) or revisions do not apply to this Part. However, parties who reach an agreement based on this Part are encouraged to study if the latest editions of these documents are applicable. For undated references, the latest editions apply to this Part. GB/T 6529 Textiles - Standard atmospheres for conditioning and testing (GB/T , ISO 139:2005, MOD) 3 Terms and definitions The following terms and definitions are applicable to this Part of GB/T Constant-rate-of-extension (CRE) testing machine It refers to a tensile tester with one clamp being fixed while the other in uniform motion throughout the test. 3.2 Gauge length It refers to the distance between the two effective clamping lines on the test device. Note: The effective clamping line of the chuck can be measured by simultaneously clamping the specimen and the carbon paper to which the pre-tension is applied. 3.3 Tear force Page 5 of 9

5 6529). 8.2 At the start of the test, SET the clamps (25 ± 1) mm apart and STRETCH the machine at a speed of 100 mm/min. SELECT suitable load range so that the tear force falls between 10% and 90% of the full scale. 8.3 SECURE the test piece. CLAMP along the non-parallel sides of the trapezoid with the cut half-way between the clamps. HOLD the short edge taut and LET the long edge lie in folds. 8.4 START the apparatus, if appropriate, and RECORD the tear force, in newtons (N), on the autographic recorder. If the test piece does not tear at the cut, no result shall be registered. Note: The tear force will not usually be a single value but will generally appear as a series of peaks. 9 Expression of results Automatically DETERMINE the average value of the series of significant peaks (SEE note) represented on the autographic recorder for each individual test piece in both the machine (longitudinal) and cross-machine (transverse) directions. In the event that there is only one significant peak on the recorder, this value shall be taken as the test result for the specimen. DETERMINE the mean value of the results for the five test pieces in both the machine (longitudinal) and cross-machine (transverse) directions. RETAIN two significant digits. DETERMINE the coefficient of variation. Accurate to 0.1%. Note 1: The displacement of the clamps is measured with the starting distance between the clamps at 25mm until the test piece breaks completely. However, the results are only valid up to the displacement of the clamps reaching 64mm. Beyond this value, the tear force is reduced by the proximity of the border of the test piece. For this reason, the significant peaks are those corresponding to the displacement of the clamps below the limit of 64mm. Note 2: Where an electronic recording machine is used, it is possible to obtain a mean tear force for each test piece, which is then averaged to give the final results. For the same reason as expressed in Note 1, the mean value shall be calculated between the following two limits: the displacement of the clamps corresponding to the first force peak; the displacement of the clamps equal to 64mm. 10 Test report The test report shall include the following information: Page 8 of 9