1、WORLDWIDEENGINEERINGSTANDARDSTest Procedure GMW14358Procedures of Test for Cellular and Related MaterialsDetermination of Resistance to Heat Aging Copyright 2012 General Motors Company All Rights ReservedDecember 2012 Originating Department: North American Engineering Standards Page 1 of 21 ScopeNot
2、e: Nothing in this standard supercedesapplicable laws and regulations.Note: In the event of conflict between the Englishand domestic language, the English language shalltake precedence.1.1 Purpose. The object of this test method is todetermine the resistance of cellular and relatedmaterials to heat
3、aging. Deterioration of thematerial is observed by measurements of physicalproperties prior to and after heat aging.1.2 Foreword. Not applicable.1.3 Applicability. Cellular materials.2 ReferencesNote: Only the latest approved standards areapplicable unless otherwise specified.2.1 External Standards/
4、Specifications.ISO 1856 ISO 3386-12.2 GM Standards/Specifications.None2.3 Additional References.None3 Resources3.1 Facilities. Not applicable.3.2 Equipment.3.2.1 Heating oven with forced circulation, capableof maintaining the required temperature within 1 C.For rubber-based materials, the rate of ai
5、r changesin the oven shall be 3 to 10 changes per hour. Theair shall be pre-heated.It should be possible to store the test pieces in theoven to ensure full exposure to the hot air.3.2.2 Test equipment for the performance of theappropriate physical property tests.3.3 Test Vehicle/Test Piece. Test pie
6、ces shallcomply with the appropriate requirements for thetest procedure to which physical property testsshall be performed (e.g., tensile strength,compression set, etc.)3.4 Test Time. Not applicable.3.5 Test Required Information. Not applicable.3.6 Personnel/Skills. Not applicable.4 Procedure4.1 Pre
7、paration. Not applicable.4.2 Conditions.4.2.1 Environmental Conditions. Not applicable.4.2.2 Test Conditions. Deviations from therequirements of this standard shall have beenagreed upon. Such requirements shall be specifiedon component drawings, test certificates, reports,etc.4.3 Instructions.4.3.1
8、Test Temperature. See Table 1.Table 1: Test TemperatureCodingTestTemperatureTypical MaterialsTestedA Specially DefinedB +70 C Polyethylene andNatural Rubber LatexC +100 CSynthetic Lattices andPolyvinyl Chloride(PVC)D +140 C PolyurethanesCopyright General Motors Company Provided by IHS under license
9、with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14358 Copyright 2012 General Motors Company All Rights ReservedDecember 2012 Page 2 of 24.3.2 Test Period. See Table 2.Table 2: Test PeriodCoding Test P
10、eriod in Hours 5%1 Specially Defined2 163 224 725 1686 2404.3.3 Procedure.4.3.3.1 The initial property A0 (i.e., tensile strength)is to be determined on the required number of testpieces.4.3.3.2 The remaining test pieces shall be stored inthe heating oven and exposed for the required timeat the requ
11、ired temperature (see Table 1 andTable 2).4.3.3.3 After the appropriate test period (seeTable 2), the test pieces shall be removed and theappropriate physical properties after heat aging(A1) determined according to the appropriate testprocedure. Where such test procedure requiresconditioning at +70
12、3 C, this may be omitted.Note: Only materials of similar chemicalcomposition shall be tested at the same time in thesame oven.5 Data5.1 Calculations.The percentage change in property after heataging shall be calculated as follows:100A A-A=Change001 u in percent (%)Where:A0 = Value (arithmetic averag
13、e) of propertyprior to heat aging (units dependent on test)A1 = Value (individual values and arithmeticaverage) of property after heat aging (unitsdependent on test)Note: Except values for compression, loaddeflection to ISO 3386-1 since test prior to andafter heat aging shall be performed on the sam
14、etest piece.5.2 Interpretation of Results. Not applicable.5.3 Test Documentation.5.3.1 For compression, set tests to ISO 1856-Aafter heat aging. Results shall be recorded only asindividual and arithmetic average values and,deviating from Paragraph 5.1, not as percentagechange.5.3.2 Only results on t
15、est pieces of the samedimension can be compared to each other.5.3.3 Testing results as described in Section 5shall be presented in a test report to the involvedGM Engineer.6 SafetyThis standard may involve hazardous materials,operations, and equipment. This standard does notpropose to address all th
16、e safety problemsassociated with its use. It is the responsibility of theuser of this standard to establish appropriate safetyand health practices and determine theapplicability of regulatory limitations prior to use.7 Notes7.1 Glossary. Not applicable.7.2 Acronyms, Abbreviations, and Symbols.GSSLT
17、Global Subsystem Leadership TeamPVC Polyvinyl Chloride8 Coding SystemThis standard shall be referenced in otherdocuments, drawings, etc., as follows:Test to GMW14358 B 3Where:B = Test temperature according to Table 13 = Test duration according to Table 29 Release and RevisionsThis standard was origi
18、nated in September 2005. Itwas first approved by the Global Foam Team inDecember 2006. It was first published in February2007.Issue PublicationDate Description (Organization)1 FEB 2007 Initial publication.2 DEC 2012 Five-year refresh to updatetemplate and references. (TrimMaterials/Textiles/Leather/FoamGSSLT)Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
