1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW16878 Sprayable Polyurethane for Sound Barriers and Decouplers Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 1 of 3 1 Scope This specification details the requirements of a two-component (2K) sprayable polyuret
2、hane sound barrier material that can be used for front of dash applications or other applications where a barrier material or decoupler assembly is required. 1.1 Material Description. Two-component meter-mixed polyurethane (PU) materials which can be applied at varying thicknesses across an area. Ex
3、pandable polyurethane material may then be applied via injection in order to fabricate a decoupler. Materials must be homogenous and free of voids for maximum acoustic performance. 1.2 Symbols. Not applicable. 1.3 Typical Applications. Any noise and vibration application where a variable thickness b
4、arrier or sound decoupler is required. 1.4 Remarks. Not applicable. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM D412 FMVSS 302 ISO 34-1 ISO 868 2.2 GM Standards/Specifications. GMW3059 GMW3221 GMW3259 GM
5、W16534 GMW3154 GMW3232 GMW4217 GMW16853 GMW3205 GMW3235 GMW15635 2.3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirements 3.1 Requirements on Test Specimens. All materials tested to this specification shall be conditioned for 24 h according to G
6、MW3221, Code A. 3.1.1 Specific Gravity. Refer to Table 1 for specific gravity range of the cured PU materials. Table 1: Specific Gravity Range Sprayed Dense 55 5.0 kg/m Sprayed Expanded 1500 50 kg/m 3.1.2 Tensile Strength (ASTM D412). Tensile strength of cured dense PU material shall be 1350 kPa whe
7、n tested per ASTM D412, Method A, Die C. 3.1.3 Elongation (ASTM D412). Elongation of cured dense PU material shall be 45% when tested per ASTM D412, Method A, Die C. 3.1.4 Tear Strength (ISO 34-1 Method B, Procedure A). This method requires an angle test piece without a nick. Data for both initial t
8、ear and tear propagation shall be required. 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 GMW16878 Copyright 2013 General Motors Company A
9、ll Rights Reserved February 2013 Page 2 of 3 3.1.5 Hardness (ISO 868). Hardness of dense PU shall be 85 5 Shore A. 3.1.6 Dimensional Stability (GMW4217). Use dry method, 1.5% maximum change. 3.1.7 Low Temperature Flexibility (GMW3154). Polyurethane material shall not break, crack or deteriorate in a
10、ny fashion after the mandrel test. 3.1.8 Odor (GMW3205). Rating of six (6) minimum. Refer to GMW16853. 3.1.9 Flammability (GMW3232). Must comply with FMVSS 302. Test to GMW3232. 3.1.10 Mildew (GMW3259). There shall be no visible growth or odor of mildew. 3.1.11 Fogging. Refer to GMW16853. Test accor
11、ding to GMW3235, Method A, Code T1: 90% minimum reflectance; or Method B, Y1, T1, P1, 2.0 mg maximum. 3.1.12 Emissions. Refer to GMW16853. Test according to GMW16534. A report on Volatile Organic Compound (VOC) and Semi-volatile Organic Compound (SVOC) emissions shall be submitted. 3.1.13 Carbonyl E
12、missions. Refer to GMW16853. Test according to GMW15635. Carbonyl emissions shall be as follows: Formaldehyde: 8 mg/kg Acetaldehyde: 8 mg/kg Acrolein: 8 mg/kg Sum of C2 thru C6 Carbonyls: 20 mg/kg 3.2 Other Requirements. 3.2.1 Parts made from sprayable PU must be flexible enough for aid of installat
13、ion but be stiff enough to lean and not fold over onto itself. 4 Manufacturing Process Not applicable. 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event of confli
14、ct between the English and domestic language, the English language shall take precedence. 5.3 Inspection and Rejection. Samples of components or materials released to a GM material specification shall be tested for conformity with the requirements of this material specification and approved by the r
15、esponsible Engineering department prior to commencement of delivery of bulk supplies. A new approval must be received for any changes, e.g., properties, manufacturing process, location of manufacture, etc. If not otherwise agreed, all testing and documentation normally required for initial release m
16、ust be completed. It is the responsibility of the supplier to inform the customer in a timely manner, without solicitation, and to include documentation of all modifications of materials and/or processes and to apply for a new release. If not otherwise agreed, all release tests shall be repeated and
17、 documented by the supplier prior to commencement of delivery of non-conforming bulk supplies. In individual cases, a shorter test can be agreed to between the responsible Engineering department and the supplier. 5.4 Material Safety Data Sheets/Safety Data Sheets (MSDS/SDS). For new product submissi
18、ons, or when a change in chemical composition of an existing product has occurred, a complete copy of the Material Safety Data Sheet/Safety Data Sheet must be submitted in compliance with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) requirements or other country-s
19、pecific MSDS/SDS requirements. In addition, product MSDS/SDS submissions must be in compliance with specific country General Motors TMC003 Material Safety Data Sheet/Safety Data Sheet guidance documents where available. 5.5 All materials supplied to this standard must comply with the requirements of
20、 GMW3059, Restricted and Reportable Substances for Parts. 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 GMW16878 Copyright 2013 General Mo
21、tors Company All Rights Reserved February 2013 Page 3 of 3 6 Approved Sources Materials supplied to this specification must be approved by General Motors. A list of approved materials can be found in MATSPC. This GM Material File is provided to third parties to reduce redundant testing of materials.
22、 If approved material already listed is used, the part supplier can use GM Material File reference for Production Part Approval Process (PPAP) material approval. If the decision is made to use a not yet approved material, contact GM Materials Engineering for details on the approval process. The mate
23、rial approval process must be completed prior to PPAP start date of the part supplied to General Motors. 7 Notes 7.1 Glossary. MATSPC: Global repository of GM approved materials for corresponding GM Engineering Standards. 7.2 Acronyms, Abbreviations, and Symbols. 2K Two-component ASTM ASTM Internati
24、onal GHS Globally Harmonized System of Classification and Labeling of Chemicals GSSLT Global Subsystem Leadership Team ISO International Organization for Standardization MSDS Material Safety Data Sheet PU Polyurethane SDS Safety Data Sheet SVOC Semi-volatile Organic Compound VOC Volatile Organic Com
25、pound 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: Material per GMW16878 9 Release and Revisions This standard was originated in October 2012. It was first approved by the Trim Materials/Textiles/Leather/Foam Global Subsystem Leadership Team (GSSL
26、T) in January 2013. It was first published in January 2013. Issue Publication Date Description (Organization) 1 JAN 2013 Initial publication. 2 FEB 2013 Corrected referenced GMWs in 3.1.11, 3.1.12 and 3.1.13. (Trim Materials/Textiles/Leather/Foam GSSLT) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
