1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW16702 Pumpable Adhesive for Anti-flutter Applications Acceptance Criteria and Repair Procedures Copyright 2012 General Motors Company All Rights Reserved February 2012 Originating Department: North American Engineering Standards Page 1 of 5
2、1 Scope Note: Nothing in this standard supercedes 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 standard provides the acceptance criteria and repair procedures for pumpable adhe
3、sive(s) for anti-flutter applications in automotive products for which GM is responsible for establishing or approving product design. 1.2 Applicability. This standard applies to any application where an adhesive intended for use in the body shop is used for bonding exterior automotive body panels f
4、or anti-flutter. The criteria established in this standard become mandatory when referenced in product release information or an approved Product Quality Standard (PQS) document. Deviations from any adhesive criteria provided in this standard must be identified in product release information or an a
5、pproved PQS document. 1.3 Usage. Structural bonds are considered satisfactory when they meet the performance requirements, defined in the material specifications. Service loads on structures containing adhesive in a vehicle are varied in both type and magnitude and cannot be addressed by this standa
6、rd. Therefore, while the adhesive quality criteria of this standard are consistent with service loading requirements, they have been established specifically for use in process and product monitoring. Any attempted application of this document to other uses, such as post-crash quality assessment, ma
7、y lead to an erroneous result or conclusion. Discrepant adhesive applications may still contribute to the integrity of the assembly by retaining a portion of their engineering properties. 1.4 Clarification. For clarification of this standard or editorial comments, email the GM Weld Council at: . Pro
8、posed changes to this standard must be presented to the Global Weld Council. To suggest a change to this standard, reference the “Procedure for Weld Standard Changes” on the Weld Councils web page. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 E
9、xternal Standards/Specifications. None 2.2 GM Standards/Specifications. GMW15563 2.3 Additional References. GMS Operating Guidelines and Global Launch Manual, Section B4 Procedure for Weld Standard Changes 3 Requirements 3.1 General Acceptance Criteria. 3.1.1 Correct Material. The anti-flutter adhes
10、ive applied shall be the material specified in the design release documentation and/or the Process Data Sheet for Sealer Application (see Appendix A, Figure A1). The product is non-conforming if incorrect material is being applied. Copyright General Motors Company Provided by IHS under license with
11、General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16702 Copyright 2012 General Motors Company All Rights Reserved February 2012 Page 2 of 5 3.1.2 Substrate Condition. Cleaning of the faying surfaces is not r
12、equired unless visibly contaminated by dirt, dust, corrosion, or other foreign matter. Preparation of the faying surfaces is not required unless specified in the material specifications. 3.2 Visual Acceptance Criteria. 3.2.1 Location. The bead or gum drop position on the flange is properly located w
13、hen installed within 6 mm from the location indicated in the design release documentation and/or the Process Data Sheet. Beads or gum drops not properly located require the process to be adjusted to eliminate the condition. Bead position across the flange may be adjusted to achieve wet out and to mi
14、nimize or eliminate excess material squeezed out of the joint. Missing or mislocated beads cause the product to be non-conforming. 3.2.2 Wet Out. Wet out is defined as the “footprint” of adhesive surface area on each of the flanges in a joint that the adhesive covers. It is required that both flange
15、 surfaces exhibit evidence of adhesive contact (flattening of the dispensed bead) after separation. Actual transfer of adhesive during this separation may, or may not occur. On flange surfaces that do not exhibit some evidence of adhesive “footprint” on both flanges, the process is to be adjusted to
16、 eliminate the condition. 3.2.3 Wet Out Width. The wet out width is to be a minimum 1 times to a maximum of 2 times the average gap between surfaces to be joined. It is to be measured on the bead application flange surface at the narrowest place. If the wet out width is less than 1 times or more tha
17、n 2 times the average gap between surfaces at the narrowest place, then the bead is to be adjusted to eliminate the condition. 3.2.4 Voids, Skips or Interruptions. Adhesive voids, skips or interruptions are discontinuities and cannot be counted in the effective bond line length. 3.3 Measurable Accep
18、tance Criteria. 3.3.1 Effective Bond Line Length (Le). Adhesive bond lines that have an effective length greater than or equal to the minimum required length (as described in Table 1) are acceptable provided that the maximum allowable discontinuity value listed in Table 1 is not exceeded. Adhesive b
19、ond lines that do not have an effective bond line length greater than or equal to the minimum required length (as described in Table 1) are non-conforming and the process is to be adjusted to eliminate the 3.4 Disposition/Repair Procedure. Table 1: Bond Line Length Requirements Note 1 Specified Bond
20、 Length (mm) Lw Maximum Allowable Length (mm) for any Single Discontinuity (post wet out) Length Tolerance (mm) Lt Minimum Required Length (mm) Lr 150 30 Note 1: Effective Bond Length is defined as Le = La Ld. Where: Le = Effective Bond Length La = Actual Bond Length Ld = Combined discontinuity leng
21、ths Note 2: A single discontinuity may not exceed 30 mm for any bead. 3.4 Disposition/Repair Procedure. 3.4.1 Disposition. All known and suspect product with non-conforming anti-flutter adhesive applications must be repaired. Refer to Appendix B, Table B1 to determine when an anti-flutter adhesive a
22、pplication is non-conforming. When required, sealer applications shall be repaired according to the procedures specifically authorized by the appropriate Product Engineer. 3.4.2 Repair Procedure. Beads or gum drops that are non-conforming with this standard can be repaired with suitable methods, e.g
23、., placement of a new bead or gum drop of adhesive conforming to this standard. 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 GMW16702 Cop
24、yright 2012 General Motors Company All Rights Reserved February 2012 Page 3 of 5 4 Manufacturing Process 4.1 Process Control. The welding source is responsible for establishing practices and test methods to assure that the criteria of this standard are met and are consistent with the GM Joining and
25、Dispense Process Control Procedure, GMW15563. 4.2 Adhesive Cure Control. The painting source is responsible for establishing practices and test methods to assure that the cure and/or post-cure cycle criteria are met and are consistent with the applicable material specifications. 5 Notes 5.1 Glossary
26、. Bond Line: Intermediate layer of adhesive used to connect substrates of similar or different materials. Faying Surfaces: Pre-bonded pair of close-fitting surfaces that are to be connected. Product Quality Standard (PQS): Measurable requirements for product characteristics which, when satisfied, en
27、sure the product meets internal and external customer requirements. (Refer to GMS Operating Guidelines and Global Launch Manual, Section B4.) 5.2 Acronyms, Abbreviations, and Symbols. BFO Bill of Material Family Owner BOM Bill of Material MPD Master Process Document PQS Product Quality Standard 6 Co
28、ding System This standard shall be referenced in other documents, drawings, etc., as follows: GMW16702 7 Release and Revisions This standard was originated in September 2011. It was first approved by the Global Weld Council in February 2012. It was first published in February 2012. Issue Publication
29、 Date Description (Organization) 1 FEB 2012 Initial publication. 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 GMW16702 Copyright 2012 Gen
30、eral Motors Company All Rights Reserved February 2012 Page 4 of 5 Appendix A Figure A1: Process Data Sheet for Anti-flutter Adhesive Bead Application Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted withou
31、t license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16702 Copyright 2012 General Motors Company All Rights Reserved February 2012 Page 5 of 5 Appendix B Table B1: Determining When an Anti-flutter Adhesive Application Is Discrepant Attribute Criteria Does Non-conformance Make the Bond Discre
32、pant? Corrective Action(s) Required Disposition Wrong Material Refer to Section 3.1 Yes Replace with Correct Material and Purge System Refer to Section 3.4 Shelf Life exceeded Refer to Section 3.1 No Replace Expired Material and Purge Dispense System N/A Contaminated Substrate Refer to Section 3.1 N
33、o Clean Substrate N/A Missing Bead Refer to Section 3.2 Yes Adjust Process Refer to Section 3.4 Mislocated Bead Refer to Section 3.2 Yes Adjust Process Refer to Section 3.4 Wet Out Refer to Section 3.2 No Adjust Process N/A Bond Line Length Refer to Section 3.3 Yes Adjust Process Refer to Section 3.4 N/A = Not Applicable Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
