1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14146 Stitch Tear Out Resistance Copyright 2012 General Motors Company All Rights Reserved August 2012 Originating Department: North American Engineering Standards Page 1 of 5 1 Scope Note: Nothing in this standard supercedes applicable laws and reg
2、ulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. The object of this test is to determine the resistance to which threads or fibers of felts, leather, and other trim materials have to being “torn” out. There a
3、re two test procedures: Procedure A: Stitch Tear Out (using a needle). Procedure B: Stitch Point Tear Out (using a flat mandrel). Note: Procedure A shall be used for all materials except leather. Use procedure B for leather. 1.2 Foreword. This test procedure measures the stitch tear out resistance a
4、s defined as the maximum force attained when a penetrator (needle or flat mandrel), acting perpendicular to the thread direction, is pulled through a test piece at a specified speed. 1.3 Applicability. This standard applies to textile materials including fabric and leather. 2 References Note: Only t
5、he latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. GMW3221 2.3 Additional References. 3 Resources 3.1 Facilities. Not applicable. 3.2 Equipment. 3.2.1 Test Machine. Use a Constant Rate of Extension (C
6、RE) tensile test machine and a test speed of 100 mm 10 mm/minute. 3.2.2 Clamping Device. The support brackets of the clamping device shall be adjustable to accommodate the thickness of the test specimen. See Appendix A for information to order the clamping devices for Procedures A and B. 3.2.2.1 Pro
7、cedure A. A special clamping device, according to Figure 1, is required for holding the steel needle. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING
8、STANDARDS GMW14146 Copyright 2012 General Motors Company All Rights Reserved August 2012 Page 2 of 5 Figure 1: Clamping Device for Procedure A (all dimensions are in millimeters) 3.2.2.2 Procedure B. A special clamping device, according to Figure 2, is required for holding the stitch point penetrato
9、r. Figure 2: Clamping Device for Procedure B 3.2.3 Stitch Penetrator. See Appendix A for information to order the penetrators for Procedures A and B. 3.2.3.1 Procedure A. The stitch penetrator for Procedure A is a needle. The needle shall be 1 mm in diameter and have a conical tip (see Figure 3). Th
10、e length of the needle is dependent on the clamping device. The typical length is about 38 mm. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDAR
11、DS GMW14146 Copyright 2012 General Motors Company All Rights Reserved August 2012 Page 3 of 5 Figure 3: Needle 3.2.3.2 Procedure B. The stitch penetrator for Procedure B is a flat mandrel of 10 mm width and 1 mm thickness having round edges with a radius of 0.5 mm (see Figure 4). The length of the m
12、andrel is 30 mm minimum, but dependent on the clamping device. Figure 4: Flat Mandrel (all dimensions are in millimeters) 3.2.4 Cutting dies and shears for preparation of test pieces. 3.2.5 Procedure B Only. Suitable punch cutter for preparation of a long hole according to Figure 5. Figure 5: Specim
13、en Prepared with a Long Hole (all dimensions are in millimeters) 3.3 Test Vehicle/Test Piece. Not applicable 3.4 Test Time. Not applicable. 3.5 Test Required Information. Not applicable. 3.6 Personnel/Skills. Not applicable. 4 Procedure 4.1 Preparation. From available material, test pieces of 100 mm
14、 by 20 mm shall be taken in warp and filling, wale and course, or longitudinal and transverse direction (longitudinal direction = machine direction). If the machine direction cannot be determined, specimens shall be taken from the material in two directions perpendicular to one another. For initial
15、sample approval and arbitration purposes, test at least three specimens taken from each direction, and for routine quality control, at least one specimen shall be tested. 4.2 Conditions. 4.2.1 Environmental Conditions. All test specimens shall be conditioned to GMW3221, Code A. 4.2.2 Test Conditions
16、. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.3 Instructions. 4.3.1 The test shall be performed after conditioning for a minimum of 24 h to the requirements of GMW3221, C
17、ode A. 4.3.2 Procedure A and B. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14146 Copyright 2012 General Motors Company All Rights Re
18、served August 2012 Page 4 of 5 4.3.2.1 Procedure A. The specimens shall be punctured with the steel needle at the center of the shortest edge at a distance of 5 mm from the edge and as vertically as possible. Holes of bores should not be previously made. 4.3.2.2. Procedure B. The punch cutter referr
19、ed to in 3.2.5 shall be used to cut the long hole (see Figure 5) into the specimens at the center of the shortest edge at a distance of 5 mm from the edge and as vertically as possible. Afterwards, the penetrator is pushed through the hole. 4.3.3 The specimen with the penetrator (needle or flat mand
20、rel) shall then be placed in the support bracket and the spacing of the support brackets relative to the specimen thickness shall be adjusted such that no pressure is exerted on the specimen. The other end of the specimen shall be clamped in the lower clamping device. 4.3.4 The specimen shall then b
21、e pulled at a speed of 100 mm 10 mm/minute. The maximum force occurring during the tearing-out of the penetrator (needle or flat mandrel) shall be measured. 5 Data 5.1 Calculations. 5.1.1 The stitch tear-out resistance shall be recorded as the measured individual value (quality control) or as the ar
22、ithmetical mean value (initial approval or arbitration) in newtons rounded to the nearest 0.5 N. 5.1.2 The direction from which the test piece was taken shall also be noted. 5.1.3 Report the averaged measurements individually for each direction (machine direction or cross machine direction). For lea
23、ther, report the averages for each direction as “parallel to the backbone” and “perpendicular to the backbone”. 5.2 Interpretation of Results. Not applicable. 5.3 Test Documentation. Report the average of the required number of data points to the nearest 0.5 N on the appropriate commodity data sheet
24、. 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the
25、 applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. CRE Constant Rate of Extension 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: Test to GMW14146 9 Release and Revis
26、ions This standard was originated in May 2005. It was first approved by the Global Textile Development Group in May 2005. It was first published in September 2005. Issue Publication Date Description (Organization) 1 SEP 2005 Initial publication. 2 AUG 2007 Addition of Procedure B for leather. (Globa
27、l Textile Team) 3 AUG 2012 Five year refresh of standard. Converted from a Test Method to a Test Procedure. (Textiles Global Subsystem Leadership Team) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted with
28、out license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14146 Copyright 2012 General Motors Company All Rights Reserved August 2012 Page 5 of 5 Appendix A For Information Only: Clamping devices for this test method can be ordered from Zwick () under the following order numbers: Procedure A Cl
29、amping device plus needle: Order Item 8281.00.00. Procedure B Clamping device plus penetrator: Order Item 8282.00.00. For Procedure A Testing: The needle Prym Mild Steel Pins, nickel-plated, No. 109, O21 205/, may also be used. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
