1、WORLDWIDEENGINEERINGSTANDARDSTest Procedure GMW3390Procedure for Determining the Flexibilityof Automotive Upholstery Materials Copyright 2012 General Motors Company All Rights ReservedDecember 2012 Originating Department: North American Engineering Standards Page 1 of 41 ScopeNote: Nothing in this s
2、tandard supercedes 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 procedure uses a 45 degree cantilever testing apparatus to determine flexibility ofautomotive upholstery materials
3、based on bending length. It is not recommended that this test be performedon laminated materials whose laminates have been removed.1.2 Foreword. Not applicable.1.3 Applicability. Automotive upholstery materials.2 ReferencesNote: Only the latest approved standards are applicable unless otherwise spec
4、ified.2.1 External Standards/Specifications.None2.2 GM Standards/Specifications.GMW32213 Resources3.1 Facilities. Not applicable.3.2 Equipment.3.2.1 A 45 degree Cantilever Bending Tester.3.2.1.1 Horizontal platform with a minimum area of 35 mm x 200 mm, and having a smooth, low-friction, flatsurface
5、 such as polished metal, plastic or smooth varnished wood.3.2.1.2 Weighted hold-down plate not less than 25 mm x 200 mm and with sufficient mass to insure the testspecimen moves with the hold-down plate. Hold-down plate may have a rubber like surface on the side thatwill contact the test specimen to
6、 eliminate slippage.3.2.1.3 Scale (in millimeters) and reference point to measure the length of the overhang.3.2.2 Apparatus for conditioning to the appropriate requirements as described in GMW3221, Code A, unlessotherwise specified in the relevant materials specification.3.2.3 Cutting die or shears
7、 for preparation of the test specimens.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 Procedure4.1 Preparation.4.1.1 Cut three test specimens from each direction: machine direction (MD) an
8、d cross machine direction(CMD) or for leather, parallel to the backbone and perpendicular to the backbone. Cut test specimens to a sizeCopyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from
9、IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3390 Copyright 2012 General Motors Company All Rights ReservedDecember 2012 Page 2 of 4of 25 mm 1 mm x 200 mm 1 mm with the long direction considered the direction of the material (MD orCMD).4.1.2 Unless otherwise specified in the relevant material speci
10、fication, conditioning shall be performedaccording to GMW3221, Code A.4.2 Conditions.4.2.1 Environmental Conditions. Not applicable.4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Suchrequirements shall be specified on component drawings, test ce
11、rtificates, reports, etc.4.3 Instructions. Using a hold-down plate, the specimen is moved slowly along the horizontal surface until itdrapes to the 45 degree incline of the cantilever testing apparatus.When the test specimen contacts the 45 degree incline, movement is stopped and bending length isme
12、asured.4.3.1 Set the Cantilever Bending Tester (See Figure 1) on a stable surface making sure that the horizontalplatform is level.Figure 1: 45 Degree Cantilever Bending Tester4.3.2 Place the test specimen, appearance side up alongside the metric scale, on the horizontal platform withthe length of t
13、he specimen parallel to the length of the platform. Align one end of the test specimen at thescales 0-point and the other end with the beginning of the 45 degree downward slope.4.3.3 Place the hold-down plate directly over the test specimen being careful not to change its initial position.4.3.4 Slow
14、ly slide the hold-down plate and the test specimen over the sloped side of the tester.Note: It is important that the hold-down plate remain directly over the test specimen and move as one duringthe course of the test.4.3.5 Continue to slide the test specimen until the leading edge first touches the
15、sloped surface or bends45 degrees.4.3.6 Read and record the overhang length from the metric scale by the end position of the test specimen andhold-down plate on the horizontal platform.4.3.7 If required in the material specification, repeat 4.3.2 through 4.3.6 with the appearance side down usingthe
16、same test specimen.5 Data5.1 Calculations.5.1.1 Bending Length. Calculate the bending length as the average of the overhang length of the three testspecimens for each individual direction, (MD and CMD) in millimeters, appearance side up.If required by material specification, calculate the bending le
17、ngth as the average of the overhang length of thethree test specimens for each individual direction (MD and CMD) in millimeters, appearance side down.5.2 Interpretation of Results. Report the average bending length in millimeters (appearance side up) formachine direction. Also, separately report the
18、 average bending length (appearance side up) in the crossmachine direction or parallel to the backbone and perpendicular to the backbone.Note: There may be a maximum of four averages reported. See 5.1.1.5.2.1 Report the average bending lengths for each individual direction (MD and CMD).Copyright Gen
19、eral 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 GMW3390 Copyright 2012 General Motors Company All Rights ReservedDecember 2012 Page 3 of 45.3 Test Docume
20、ntation. Report data as required per the material specification using the appropriate lab datasheet.6 SafetyThis standard may involve hazardous materials, operations, and equipment. This standard does not propose toaddress all the safety problems associated with its use. It is the responsibility of
21、the user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations priorto use.7 Notes7.1 Glossary.Bending Length: A measure of stiffness of a material based on how the material bends in one plane underthe force of gravity.Flexibil
22、ity: A term relating to the haptic feel of the material, referring to the ease of bending and ranging frompliable to stiff.7.2 Acronyms, Abbreviations, and Symbols.CMD Cross Machine DirectionMD Machine Direction8 Coding SystemThis standard shall be referenced in other documents, drawings, etc., as f
23、ollows:Test to GMW33909 Release and RevisionsThis standard was originated in October 1999. It was first approved in April 2000. It was first published inDecember 2000.Issue Publication Date Description (Organization)1 DEC 2000 Initial publication.2 MAY 2007 Editorial changes associated with Global T
24、extile Development Group Conference(Global Textile Development Group).Section 1 Editorial change.Section 3.1.1 Added the equipment option to use a smooth varnished wood.Section 5.1 Editorial changes.Section 5.2.1 Changed the correct size of the specimens for testing and addeddirection.Section 5.3.Su
25、bsection renumbered and deleted section 5.3.1.Section 5.3.3 Renumbered as 5.3.2 and editorial changes.Section 5.3.4 Speed not applicable for the test.Section 5.3.7 Editorial changes.Section 6.1.1 Editorial change, deleted the note section and deleted section6.1.2 and section 6.2 and the following su
26、bsection.Section 7.1 Editorial changes.7.4 Was deleted and replaced as Section 7.3.Appendix A was deleted and moved to Section 9.1 Glossary and renumbered.Flexural rigidity definition was deleted.Section 9 Coding system became Section 10.Section 10 Release and Revision became Section 11.Copyright Ge
27、neral 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 GMW3390 Copyright 2012 General Motors Company All Rights ReservedDecember 2012 Page 4 of 4Issue Publicat
28、ion Date Description (Organization)3 DEC 2012 Five year refresh of standard. Converted from a Test Method into a TestProcedure template. Origination month corrected from original publication.(Global Textiles and Trim Materials Subsystem Leadership Team)Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
