1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW14874 Antiflutter Adhesive/Sealer (Body in White) Performance Requirements Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 1 of 9 1 Scope Note: Nothing in this standard supercedes applicable laws and regulations.
2、 Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Material Description. This standard is intended to cover the performance requirements of antiflutter adhesive candidates that are used to bond metallic automotive substrates. Fo
3、r specific material specifications that meet the classifications described, see 3.4.4. 1.2 Symbols. Not applicable. 1.3 Typical Applications. 1.3.1 Antiflutter. Bonding of inner and outer panels to eliminate metal contacts, act as a vibration dampener and can give the assembly part stiffness. For ex
4、ample, inner and outer panel of hood, tailgate, door, roof bow to roof, fuel filler and wheel arch. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM D638 ASTM D792 ASTM D2240 ISO 4587 ASTM D790 ASTM D1876 AST
5、M E831 2.2 GM Standards/Specifications. 9273089 9985996 GMW3011 GMW15634 9273329 9986265 GMW3025 GMW15635 9273474 9986321 GMW3059 GMW16152 9274178 EDS-M-8506 GMW3154 GMW16700 9274298 EDS-M-8515 GMW3205 L 000 0058 9274773 EDS-M-8597 GMW3286 L 000 0063 94545782 EDS-M-8622 GMW14124 L 000 0131 95999838
6、EDS-M-8634 GMW14706 L 000 0737 9982256 GMW2 GMW14729 L 000 0776 9985745 GMW8 GMW15416 L 000 0780 9985800 GMW11 GMW15477 L 000 0789 9985918 GMW3008 GMW15481 2.3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirements 3.1 Requirements on Test Specime
7、ns. 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-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14874 Copyright 2013 General Motors Company All Rights Reserved Decem
8、ber 2013 Page 2 of 9 3.2 Volumetric Expansion (GMW15481). Volumetric expansion after curing shall be evaluated according to GMW15481. The volumetric expansion range shall be used to determine the approval category per Table 1. Table 1: Volumetric Expansion Volumetric Expansion Code Volumetric Expans
9、ion LE (Low Expansion) vol-%: 25 at Minimum Cure ME (Medium Expansion) vol-%: 25 to 150 at Minimum Cure HE (High Expansion) vol-%: 150 at Minimum Cure 3.3 Substrates. Testing shall be completed with the substrates in Table 2. For oily metal, use one (1) challenging approved lubricant as specified by
10、 the approving material engineer. Degreasing and oiling according to GMW15477. Oil coating weight shall be 3 g/m2 for corrosion protection oils/lubricants and 1.7 g/m2 for drylubes. Table 2: Substrates Substrate Description Note 1 Oily Cold Rolled Steel (CRS) (GMW2) Note 2 Oily Hot Dipped Galvanized
11、 Steel (HDG) (GMW8), 60 g/m2 galvanized coating weight Oily Electrogalvanized Steel (EG) (GMW11), 60 g/m2 galvanized coating weight Other substrates identified and required by the regional material engineering group or the regional material specification Note 1: After application of the sealer, the
12、oily metal panels shall be processed through pretreatment and Electrodeposition or Electrocoat (ELPO) prior to baking and exposure according to 3.6.4. Use any GM approved pretreatment (GMW3011) ELPO (GMW3008) at target film thickness, as specified by the approving material engineer. Note 2: Natural
13、Salt Spray testing according to 3.6.4.2 and Cyclic Corrosion Laboratory Test according to 3.6.4.3 is not required with oily Cold Rolled Steel (CRS). 3.4 Bond Strength, Adhesion, and Corrosion. Antiflutter adhesive candidates shall be evaluated for strength, separation mode and corrosion protection.
14、Samples testing shall be done in sample “sets”. Five (5) samples shall constitute a “set”. 3.4.1 Lap Shear (ISO 4587). All antiflutter adhesive candidates shall be evaluated using the lap shear configuration. Lap shear testing shall be done to establish tensile shear strength and separation mode of
15、the adhesive. Lap shear shall be tested according to ISO 4587. Evaluation according to 3.6. The only acceptable separation mode of the adhesive shall be “cohesive” within the adhesive layer. “Adhesive” separation of the adhesive layer to a test substrate shall be deemed unacceptable. In any case, th
16、e minimum required lap shear strength shall be maintained, both initially, and after environmental exposure. Test specimen sizes according to ISO 4587 with a bond gap of 1.0 mm 0.1 mm. In deviation to this norm, other individual sample sizes, e.g., 20 mm 100 mm, with a bond flat of 20 mm 20 mm, are
17、acceptable. Lap shears shall be tensile tested (pulled) at a rate of 100 mm/minute. The lap shear range shall be used to determine the approval category according to Table 3. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or ne
18、tworking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14874 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 3 of 9 Table 3: Lap Shear Lap Shear Code Lap Shear Strength in Megapascals (MPa) LS (Low Strength) 1.5 3.4.2 Classification of Stre
19、ngths and Expansion Performance. Antiflutter adhesive/sealer (body in white) systems shall be classified as described in Table 4. Table: 4: Classifications LE-HS (Low Expansion-High Strength) Exhibiting expansion degree up to 25% (according to GMW15481) and lap shear strengths 1.5 MPa (according to
20、ISO 4587) LE-MS (Low Expansion-Medium Strength) Exhibiting expansion degree up to 25% (according to GMW15481) and lap shear strengths 0.2 MPa but 25% but 1.5 MPa (according to ISO 4587) ME-MS (Medium Expansion-Medium Strength) Exhibiting expansion degree 25% but 0.2 MPa but 25% but 150% (according t
21、o GMW15481) and lap shear strengths 0.2 MPa but 150% (according to GMW15481) and lap shear strengths 0.2 MPa (according to ISO 4587) 3.4.3 Adhesion (GMW14706) and Corrosion. All antiflutter adhesive candidates shall be evaluated using the “Adhesion” and “Corrosion” configuration. Adhesion shall be t
22、ested according to GMW14706 to establish separation mode. Test piece preparation according to GMW15477 (panel configuration: constrained). Evaluation according to 3.6. The evaluation criteria are summarized in Table 5. 3.4.3.1 T-Peel (ASTM D1876). If the results of the adhesion testing according to
23、GMW14706 are not definitive, T-Peel Testing according to ASTM D1876 will be required. Individual sample pieces shall measure 30 mm 200 mm, with a bond flat of 30 mm 100 mm. The bond gap shall be 2.0 mm 0.1 mm T-Peels shall be tested (pulled) at a rate of 50 mm/minute. Copyright General Motors Compan
24、y Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14874 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 4 of 9 Table 5: Adhesion Evaluation C
25、riteria Substrate 3.6.1 Initial Test 3.6.2 Cold Test 3.6.3 Hot Test 3.6.4 Corrosion Tests 3.6.4.1 Humidity Test 3.6.4.2 NSS Test 3.6.4.3 Cyclic Corrosion Lab Test Oily CRS Not Required Oily HDG 100% Cohesive Separation 90% Cohesive Separation Oily EG No Corrosion Under Sealer No Corrosion Under Seal
26、er Other Oily Substrates, e.g, Aluminum 3.4.4 Material Specifications. Table 6 contains identification of the material specifications that meet the respective performance classifications. Table 6: Material Identification GMW GMNA GME GMSA GM Holden GMK PATAC GMW14874-LE-HS 9985800 L 000 0780/9274298
27、 L 000 0780/ 9274298 9985800 EDS-M-8634 9985800 GMW14874-LE-MS - L 000 0063/9274773 L 000 0776/9273329 (primary sealer function, also as antiflutter applicable) - - EDS-M-8506 EDS-M-8515 EDS-M-8597 - GMW14874-ME-HS - L 000 0789/9273474 - - - - GMW14874-ME-MS 9985996 L 000 0058/9274178 - 9985996 EDS-
28、M-8622/ 94545782 9985996 GMW14874-ME-LS 9985745 - - 9985745 EDS-M-8622/ 95999838 9985745 GMW14874-HE-MS 9982256 - - - - 9982256 GMW14874-HE-LS 9985918 L 000 0737/9273089 - 9985918 9985918 9985918 3.5 Bead Structure. 3.5.1 Structure. The structure and appearance of a cured bead of the adhesive observ
29、ed, and noted, to ensure that there is a homogeneous bead structure when a 6.0 mm bead of adhesive is subjected to either the minimum bake or overbake schedule. See 4.1 and Table 9. 3.6 Test Environments for Lap Shear Adhesive Strength, Adhesion and Corrosion. Evaluate for strength retention, separa
30、tion mode and corrosion. For following tests, evaluate all substrates according to 3.3 and all bakes according to 4.1 and Table 9. For performance requirements of the tests in 3.6.1 through 3.9, see 3.4. 3.6.1 Initial Test. Testing shall be completed after adhesive cure, without any aging, but no so
31、oner than 16 h after completion of the cure schedule. 3.6.2 Cold Test. Testing shall be completed after a 24 h minimum aging at -40 C. Actual test temperature shall be recorded and reported as part of the test. Copyright General Motors Company Provided by IHS under license with General Motors Compan
32、yNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14874 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 5 of 9 3.6.3 Hot Test. Testing shall be completed after 120 h aging at +80 C. Two (2) sample se
33、ts are required. One (1) sample set shall be tested at the test temperature and the other set shall be tested at +23 C after a 24 h minimum ”recovery” from environment. 3.6.4 Corrosion Tests. 3.6.4.1 Humidity Test (GMW14729). Testing shall be completed after 240 h of exposure to high humidity. Testi
34、ng shall be done after a 24 h minimum “recovery” from environment. 3.6.4.2 Neutral Salt Spray (NSS) Exposure (GMW3286). Testing shall be completed after 480 h of exposure to NSS. Testing shall be done after a 24 h minimum “recovery” from environment. 3.6.4.3 Cyclic Corrosion Laboratory Test (GMW1412
35、4, Cycle U, or V, 10 Cycles). Testing shall be started after a 24 h minimum “recovery” from environmental cycling. 3.6.5 Water Test. Testing shall be completed after 168 h water storage (adhesive area is completely dipped in deionized water) at +55 C. Testing shall be done after a 24 h minimum “reco
36、very” from environment. 3.7 Compatibility with Cavity Wax. When coated with a GMW15416 approved cavity wax, the sealer shall not show any loss of adhesion, collapse or other negative effects from contact with the wax. Testing shall include a “100% Solids Content” cavity wax technology, a “Solventbor
37、ne” cavity wax technology, and a non-waxed control panel, as specified by the approving material engineer. 3.7.1 Cavity Wax Compatibility Test Procedure. Prepare panel according to GMW15477 using one (1) substrate (Oily HDG) and the most challenging regional oil as specified by the approving materia
38、l engineer. Panel configuration shall be unconstrained. Bake sealer at Minimum and Maximum bake according to 4.1. Cavity Wax Application: Brush 5 g to 20 g of cavity wax (dry film thickness approximately 50 m) on to the cured sealer, being sure to apply wax to the sealer-to-substrate interface. If r
39、equired for the cavity wax technology (e.g., 100% Solids Content Cavity Wax according to L 000 0131/9986265). Bake the test panel at the cavity wax Target bake as defined by the material specification or the approving material engineer. Age panel 48 h at + 23 C 5 C prior to environmental exposure. E
40、xpose panel to humidity per GMW14729, Option A or B, 96 h. Condition the panel for 1 h minimum at +23 C 5 C prior to evaluating. Evaluate the test piece compared to the non-waxed control. 3.8 Hardness Test Shore A (ASTM D2240). Hardness after curing according to 4.1 shall be evaluated according to A
41、STM D2240 and is defined in Table 7. Table 7: Shore A LE- HS (Low Expansion-High Strength) See Local Material Specification - Table 6 LE- MS (Low Expansion-Medium Strength) See Local Material Specification - Table 6 ME-HS (Medium Expansion-High Strength) See Local Material Specification - Table 6 3.
42、9 Hardness Test Shore 00 (ASTM D2240). Hardness after curing according to 4.1 shall be evaluated per ASTM D2240 and is defined in Table 8. Table 8: Shore 00 ME-MS (Medium Expansion-Medium Strength) See Local Material Specification Table 6 ME-LS (Medium Expansion-Low Strength) See Local Material Spec
43、ification Table 6 HE-MS (High Expansion-Medium Strength) See Local Material Specification Table 6 HELS (High Expansion-Low Strength 1. See Local Material Specification Table 6 Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or n
44、etworking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14874 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 6 of 9 3.10 Cold Mandrel-bend-test based on GMW3154; bead diameter: 6 mm to 8 mm, test temperature: 30 C 3 C. No chipping off. 3.1
45、1 Water Absorption (GMW16152, 24 h Immersion). Material cured at the Minimum and Maximum bakes according to 4.1 shall exhibit a water absorption of 1% after 24 h immersion. 3.12 Engineering Material Properties. In order to support the initiative to provide “Bulk Material Properties” to facilitate Co
46、mputer Aided Engineering (CAE) and Finite Element Modeling (FEM) activities, the following minimum data shall be supplied prior to material approval. Cured Material Density. ASTM D792 Youngs Modulus. ASTM D638 Flex Modulus. ASTM D790 Poissons Ratio. ASTM D638 Coefficient of Linear Thermal Expansion
47、(CLTE). ASTM E831 3.13 Passenger Compartment Emissions. Currently, no requirement defined, but measuring results shall be communicated. For following determinations in 3.13.1 through 3.13.3, the test samples shall be baked at minimum cure schedule according to 4.1 and Table 9. 3.13.1 Volatile and Se
48、mi-Volatile Organic Compounds from Interior Materials (GMW15634). Volatile and Semi-Volatile Organic Compounds shall be determined according to GMW15634. The determined values are for information and control if the adhesive contains substances which are not allowed according to GMW3059. 3.13.2 Aldeh
49、yde and Ketone Emission from Interior Materials (GMW15635). Aldehyde and Ketone Emissions shall be determined according to GMW15635. The limiting values are: Formaldehyde: 10 g/g Acetaldehyde: 10 g/g Amount of all aldehyde: 20 g/g maximum 3.13.3 Odor (GMW3205 - 4 - B). Note: Odor Testing shall be performed after completion of the tests according to
