1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW15564 Long Term Load Loss Set Assessment for Weatherstrips Copyright 2012 General Motors Company All Rights Reserved August 2012 Originating Department: North American Engineering Standards Page 1 of 6 1 Scope Note: Nothing in this standard superced
2、es applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. This test procedure determines the amount of long term load loss set (LLS) of elastomeric seals after they have been compressed to a
3、defined deflection at elevated temperature. 1.2 Foreword. Not applicable. 1.3 Applicability. This standard is applicable to all body and glass weatherstrips. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ISO 18
4、8 2.2 GM Standards/Specifications. GMW14685 3 Resources 3.1 Facilities. Not applicable. 3.2 Equipment. 3.2.1 Compression Fixture. 3.2.2 Mounting Fixtures. 3.2.3 Holding fixture designed for heat aging of seals. 3.2.4 Oven. Heating oven capable of maintaining the required temperatures within the spec
5、ified tolerances (e.g., heat oven to ISO 188 Method B). 3.2.5 Steel Scale. 3.3 Test Vehicle/Test Piece. For Long Term Load Loss testing, three specimens shall be tested. The test specimens shall be 100 1 mm in length, and cut such that the seal is not significantly bent or deformed during cutting. 3
6、.4 Test Time. See Table A1, Appendix A. 3.5 Test Required Information. Not applicable. 3.6 Personnel/Skills. Not applicable. 4 Procedure 4.1 Preparation. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15564 Copy
7、right 2012 General Motors Company All Rights Reserved August 2012 Page 2 of 6 4.1.1 Summary of Test Procedure. The ability of a seal to maintain good sealing force over time is measured by comparing an unstrained, new production seal force to the force remaining after the section has been conditione
8、d (aged) at elevated temperature under constant load and increasing time. Compressibility at a defined deflection (compression load deflection (CLD), GMW14685) is measured on each seal sample. The samples are then compressed to a defined deflection, and aged for a specified period of time at 80 C. A
9、fter each aging period, the compressibility CLD is re-measured. The long term load loss set of an elastomeric seal shall be defined as the amount of CLD lost (expressed as a percentage), after the seal has been aged for a specified period of time at a specified temperature. 4.2 Conditions. 4.2.1 Env
10、ironmental Conditions. The minimum time period between vulcanization and testing of elastomers shall be 72 hours. The test piece shall remain at a temperature of 23 C 5 C for at least 8 hours before testing, and shall be free from strain during this period. 4.2.2 Test Conditions. Deviations from the
11、 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 Assessment of load loss set for body seals shall be made at the minimum and maximum seal gaps, unless otherwise specified.
12、For glass run channels and belt seals, the inner and/or outer lips shall be compressed to the designed nominal positions, unless otherwise specified. 4.3.2 Mount the seals on a flange (or in a suitable holding fixture) representative of the thickness of the mounting section (e.g., header section for
13、 body seals, upper B-pillar for glass seals). The part shall be securely mounted such that it does not rock on the mounting flange. It is recommended to use a fixture that is common for GMW14685 and GMW15564. 4.3.3 Measure and record the initial CLD of each seal section according to GMW14685 2B2, wi
14、th the following exception for pre-flexing the seals. For body seals, measure the initial CLD by pre-flexing the parts to 2 mm beyond the heat aged gap (i.e., if the heat aged gap is 15 mm, the part should be pre-flexed to 13 mm). For glass seals, the parts should be pre-flexed 1 mm beyond the desig
15、ned nominal position unless they come into contact with the support pedestal. If a sealing wing contacts the support pedestal, the position where the wing first contacts the pedestal would be considered the pre-flex position. Parts shall be pre-flexed ten times. 4.3.4 After the CLD measurement, comp
16、ress the seal to the defined deflection (heat aged gap), and place the seal/fixture assembly in an oven at 80 C 3 C for the time period specified in Table A1, Appendix A. 4.3.5 At the end of the aging period, remove the assembly from the oven. Immediately remove the compression feature from the fixt
17、ure. Allow the weatherstrip to cool for 1 0.1 hour. 4.3.6 Re-measure the CLD at the defined heat aged gap according to GMW14685 2B2. 4.3.7 Re-install the compression feature of the fixture. 4.3.8 Repeat 4.3.4 through 4.3.7 for reassessment of CLD for all intervals specified in Table A1, Appendix A.
18、5 Data 5.1 Calculations. Not applicable. 5.2 Interpretation of Results. Not applicable. 5.3 Test Documentation. The following information shall be reported. 5.3.1 Part information including part name, program name/vehicle program name, specimen number, production or development batch number. 5.3.2 L
19、ocation, date, and time of test. 5.3.3 Conditioning of the test specimen, if any. 5.3.4 Test conditions temperature, test speed, etc. 5.3.5 Deflection used for the compressed aging. 5.3.6 Report CLD in Newtons and Percent load loss set at each heat aged gap and aging period. 5.3.7 Any deviations to
20、the test method. Data shall be submitted using the format outlined in Appendix A, Figures A1 through A3. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15564 Copyright 2012 General Motors Company All Rights Rese
21、rved August 2012 Page 3 of 6 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
22、practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. CLD Compression Load Deflection LLS Load Loss Set 8 Coding System This standard shall be referenced in other documents, drawings, etc., as
23、 follows: Test to GMW15564 9 Release and Revisions This standard was originated in February 2007. It was first approved by the Global Elastomers Team in April 2007. It was first published in June 2007. Issue Publication Date Description (Organization) 1 JUN 2007 Initial publication. 2 AUG 2012 2012
24、Refresh; corrected pre-flex deflections and temperature tolerances. (Global Elastomers GSSLT Team) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15564 Copyright 2012 General Motors Company All Rights Reserved A
25、ugust 2012 Page 4 of 6 Appendix A Table A1: Aging Schedule CLD Measurement Number Cumulative Time in Oven at 80 C Sequential Exposure (for clarification purposes) 1 0 hours Initial CLD measurement (pre-aged CLD) 2 24 hours 24 hours of exposure 3 48 hours Additional 24 hours of exposure 4 72 hours Ad
26、ditional 24 hours of exposure 5 168 hours Additional 96 hours of exposure 6 240 hours Additional 72 hours of exposure 7 360 hours Additional 120 hours of exposure Figure A1: Long Term Load Loss Set Data Reporting Se al G ap ( m m ) Pr e- f lex G ap ( m m ) 0 Ho u r 24 Ho u r s 48 Ho u r s 72 Ho u r
27、s 16 8 Ho u r s 24 0 Ho u r s 36 0 Ho u r sM ax im u m * ( M ax - 2) M in im u m * * ( M in - 2) No t e: * M ax im u m se al gap w ill h av e min im u m com p r es sion* * M in im u m se al gap w ill h av e maximu m com p r es sion* * * Se al G ap = h ea t age gap* * * * Hig h lig h t ed C ells ar e
28、 f o r Dat a Inp u tCalculat io n o f L o ad Lo ss Pe r ce n tage; ( Pr e- aged C L D at Spec if ied G ap) ( Post a g ed C L D at Spec if ied G ap ) / ( Pr e- aged C L D at Spec if ied G ap ) x 1 00 %Bo d y Se al: CL D at Se al G ap ( N) , L o ad L o ss ( % )S ea l G ap ( mm ) P r e-f lex G ap ( mm
29、) 0 Hou r 24 Ho u r s 48 Ho u r s 72 Ho u r s 16 8 Hou r s 24 0 Hou r s 36 0 Hou r sNo min al No t e: * S ea l G ap = heat age gap* * High ligh t ed Cells ar e fo r Data Inp u tCalc u latio n of Lo ad Lo ss P er ce n tage ; ( Pre - aged CL D at Speci f ied G ap ) ( P o st aged CL D at Speci fied G a
30、p ) / ( Pre - aged CL D at Speci f ied G ap ) x 100 %G las s S ea l: CL D at Se al G ap ( N) , Lo ad L o ss ( % )Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15564 Copyright 2012 General Motors Company All Rig
31、hts Reserved August 2012 Page 5 of 6 Figure A2: Representative LLS Plot for Body Seal Pl o tte d L o a d L o s s Se t D a ta 8 0 C B o d y Se a l01234567891011121314151617181920212223240 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360T i m e ( H o u r s )CLD(N/100mm)G M X X X X X
32、 X m m G a p R e q u i r e m e n tN o t e : M i n i m u m C L D o f 2 N / 1 0 0 m m i s b a s e d o n M i n i m u m S e a l i n g C r i t e r i a o f 7 0 0 0 P a a n d 3 m m C o n t a c t W i d t hM i m i m u m S e a l C L D R e q u i r e d f o r S e a l i n gProvided by IHSNot for ResaleNo reproduc
33、tion or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15564 Copyright 2012 General Motors Company All Rights Reserved August 2012 Page 6 of 6 Figure A3: Representative LLS Plot for Glass Seal Pl o tted L o ad L o ss Set D ata 80 CGl ass Seal01234567891011121
34、314151617181920212223240 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360T i me (H o u r s)CLD(N/100mm)Nom i na l Requ i r em en tM inim um S e a l CLD Re quire d for S e a li ngNOT E : M i n i m u m CL D o f 2 N/1 0 0 M M i s b a s e d o n M i n i m u m S e a l i n g Crit e r i a o f 7 0 0 0 P a a n d 3 M M C o n ta c t W i d th Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
