1、 WORLDWIDE ENGINEERING STANDARDS General Specification GMW14171 Heavy Layer Sound Barriers and Decoupler Assemblies Copyright 2011 General Motors Company All Rights Reserved September 2011 Originating Department: North American Engineering Standards Page 1 of 3 1 Introduction Note: 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 take precedence. 1.1 Scope. This specification identifies all types of heavy layer or sound barrier materials and their usage with sound absorbing
3、or dissipative materials for noise decoupling assemblies. 1.2 Mission/Theme. Products qualified to this specification shall be identified in two parts. The first part shall identify heavy layer sound barriers by class according to density ranges. These heavy layer materials will be further identifie
4、d, in 1.4.1, 1.4.2 and 1.4.3, as decoupler assemblies and/or dashmats when used in conjunction with sound absorbing materials identified in GMW14194 and GMW14196. 1.3 Classification. 1.3.1 All heavy layer sound materials qualified to this specification shall be listed by class. 1.3.1.1 Class 1 (2.5
5、0.50 kg/m). 1.3.1.2 Class 2 (3.5 0.50 kg/m). 1.3.1.3 Class 3 (4.5 0.50 kg/m). 1.3.1.4 Class 4 (5.5 0.50 kg/m). 1.3.1.5 Class 5 (Barrier materials less than 2.0 kg/m or greater than 6.0 kg/m). 1.3.1.5.1 Mass per unit area for Class 5 barrier materials must be specified in math file and on print. 1.3.
6、2 All decoupler assemblies shall be identified by the proper class of heavy layer and the specific type of sound absorbing material as identified in GMW14194 or GMW14196. 1.4 Decoupler Identifications. 1.4.1 Fibrous Noise Decoupler Combinations. Material is designated by “A”; Type refers to only tho
7、se fibrous materials outlined in GMW14194. (See Table 1). Example designation: GMW14171 Class 2 Type A4. 1.4.2 Polyurethane Foam Noise Decoupler Combinations. “Material” is designated by “B”; Type refers to only those materials referenced in GMW14196. (See Table 1). Example designation: GMW14171 Cla
8、ss 5 Type B6. 1.4.3 Micro Perforated Film Decoupler Combinations. Material is designated by “C”. Type refers to only those materials referenced in GMW16347. (See Table 1). Example designation: GMW16347 Class 1 with GMW14171 Class 1 Type A2. Table 1: Material Code Combinations Class Material Material
9、 Type 1 2 3 4 5 A B C 1 2 3 4 5 6 Note 1 Note 1: Material Type six (6) is only for Type B materials. 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 S
10、TANDARDS GMW14171 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 2 of 3 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. FMVSS 302 ISO 868 ISO 34-1 2.2 GM Standards/Specifications. G
11、MW3059 GMW3221 GMW3259 GMW14196 GMW3154 GMW3232 GMW4217 GMW16347 GMW3205 GMW3235 GMW14194 3 Requirements 3.1 All materials tested to this specification shall be conditioned for 24 h according to GMW3221 Code A. 3.1.1 Tear Strength (ISO 34-1 Method B, Procedure a). This method requires an angle test
12、piece without a nick. Data for both initial tear and tear propagation shall be required. 3.1.2 Hardness (ISO 868). Hardness shall be 80 5 Shore A. 3.1.3 Dimensional Stability (GMW4217). Use dry method. 1.5% maximum change. 3.1.4 Low Temperature Flexibility (GMW3154). The backing shall not break crac
13、k or deteriorate in any fashion after the mandrel test. 3.1.5 Odor (GMW3205). Report both wet and dry results. Rating of six (6) minimum. 3.1.6 Flammability (GMW3232). Must comply to FMVSS 302. Test to GMW3232. Note: If the material is a composite or is to be used in a composite, the composite must
14、meet this requirement. 3.1.7 Mildew (GMW3259). Required only if natural fibers are present in the construction. There shall be no visible growth or odor of mildew. 3.1.8 Fogging (GMW3235). Method A, Code T1 90% minimum reflectance or Method B, Y1, T1, P1, -2.0 mg maximum. 3.2 Performance Requirement
15、s. Some products may be highly sound absorbing but not meet chemical resistant requirements for underhood applications. 4 Validation 4.1 General. Not applicable. 4.2 Validation Cross Reference Index. Not applicable. 4.3 Supporting Paragraphs. Not applicable. 5 Provisions for Shipping Not applicable.
16、 6 Notes 6.1 Glossary. Not applicable. 6.2 Acronyms, Abbreviations, and Symbols. Not applicable. 7 Additional Paragraphs 7.1 All parts or systems supplied to this standard must comply with the requirements of GMW3059, Restricted and Reportable Substances for Parts. Copyright General Motors Company P
17、rovided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14171 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 3 of 3 8 Coding System This standard sh
18、all be referenced in other documents, drawings, etc., as follows: GMW14171 Class X, Type YZ Where: X refers to sound barrier material referred to in paragraph 1.3. Y refers to the sound absorption materials referred to in 1.4.1, 1.4.2 and 1.4.3. Z refers to type of sound absorption materials referre
19、d to in 1.4.1, 1.4.2 and 1.4.3. 9 Release and Revisions This standard was originated in June 2005. It was first approved by the Global Acoustics Committee in February 2006. It was first published in February 2006. Issue Publication Date Description (Organization) 1 FEB 2006 Initial publication. 2 SEP 2011 Five year refresh. (Interiors) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
