1、WORLDWIDEENGINEERINGSTANDARDSTest Procedure GMW14695Determining the Cohesive Strength of Felts and Similar Materials Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Originating Department: North American Engineering Standards Page 1 of 41 ScopeNote: Nothing in this standard sup
2、ercedes applicable laws and regulations.Note: In the event of conflict between the English and domestic language, the English language shall takeprecedence.1.1 Purpose. This standard shall be used to determine the cohesive strength of felts and similar materialscomprised of animal, vegetable or synt
3、hetic fibers, either singly or in combination, the fibers being physicallyinterlocked by the inherent felting properties of the based materials or assisted by synthetic bonding.The cohesive strength as determined by this test procedure shall be defined as the force required to separatethe fibers of
4、the test material across its thickness over a standard area of 100 cm2.1.2 Foreword. Not applicable.1.3 Applicability. Not applicable.2 ReferencesNote: Only the latest approved standards are applicable unless otherwise specified.2.1 External Standards/Specifications.None2.2 GM Standards/Specificatio
5、ns.GMW3010 GMW32213 Resources3.1 Facilities. Not applicable.3.2 Equipment.3.2.1 Apparatus for conditioning to the appropriate requirements as described in GMW3221, Code B unlessotherwise specified in the relevant material specification.3.2.2 Cutting dies or shears for preparation of the test pieces.
6、3.2.3 Mechanical convection oven capable of maintaining the required temperature from the materialspecification to a tolerance of 3 C.3.2.4 Test fixture (see Figure 1).3.2.5 Synthetic adhesive (neoprene base).3.2.6 Tensile test machine in accordance with GMW3010, capable of traversing at a speed of2
7、5 mm 2 mm/minute and equipped with a force-extension recorder.3.3 Test Vehicle/Test Piece. From the available material square test pieces of 100 mm 25 mm, sides shallbe taken from various areas of the material but not closer than 100 mm to an edge. For initial sample approval,arbitration purposes an
8、d for routine quality control, at least three test pieces shall be tested.3.4 Test Time. Not applicable.3.5 Test Required Information. Not applicable.3.6 Personnel/Skills. Not applicable.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reprod
9、uction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14695 Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Page 2 of 44 Procedure4.1 Preparation. For initial sample approval and arbitration purposes, conditioning shall be carried out
10、according to GMW3221, Code B. Routine quality control tests shall be carried out on test pieces in the as-received condition (i.e., no special pre-conditioning).4.2 Conditions.4.2.1 Environmental Conditions. See Table 1 for ageing temperatures.Table 1: Ageing TemperaturesCoding Temperature in CA +70
11、 3B +80 3C +90 3D +100 3E +120 3F As specially defined4.2.1.1 Ageing Time. The ageing time for all temperatures shall be 120 h 2 h, followed by 2 h cooling to23 C 5 C.4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Suchrequirements shall be speci
12、fied on component drawings, test certificates, reports, etc.4.3 Instructions.4.3.1 Duplicate tests shall be performed, one immediately after conditioning or in the as-received condition; theother after ageing of the test piece at the temperature specified in the appropriate material specification. F
13、orroutine quality control, the test after ageing may be omitted.4.3.2 Preparation of Test. The test piece shall be adhered, using the adhesive, between the plates of the testfixture as shown in Figure 1, and allowed to stand for 2 h at a temperature of 23 C 5 C.4.3.3 The test piece/fixture assembly
14、shall be pulled in the tensile testing machine in the direction of the arrowsindicated in Figure 1, and the force required to cause rupture of the test piece recorded autographically. Thejaw separation rate shall be 25 mm 2 mm/minute.Copyright General Motors Company Provided by IHS under license wit
15、h General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14695 Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Page 3 of 4A - Test piece with both plates adheredFigure 1: Test Fixture5 Data5
16、1 Calculations. The cohesive strength shall be denoted as the maximum force recorded on the force-extension diagram, expressed as N/100 cm2.5.2 Interpretation of Results. With reference to this test procedure, the cohesive strength shall be expressedas N/100 cm2 rounded to the nearest 0.5 N/100 cm2
17、 (each individual value or in the case of several test pieces,the rounded arithmetic average) for both before and after ageing.5.3 Test Documentation. The test results should be documented and reported in the Test Report.6 SafetyThis standard may involve hazardous materials, operations, and equipmen
18、t. This standard does not propose toaddress all the safety problems associated with its use. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations priorto use.7 Notes7.1 Glossary. Not applic
19、able.7.2 Acronyms, Abbreviations, and Symbols. Not applicable.8 Coding SystemThis standard shall be referenced in other documents, drawings, etc., as follows:Test to GMW14695Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or net
20、working permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14695 Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Page 4 of 49 Release and RevisionsThis standard was originated in October 2005. It was first approved by the Textiles GSSLT in November 200
21、6.It was first published in August 2007.Issue Publication Date Description (Organization)1 AUG 2007 Initial publication.2 OCT 2012 Five year refresh of standard. (Textiles & Trim Material Global SubsystemLeadership Team)Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
