This specification identifies all types of sound absorbing and/or sound dissipative materials used in vehicles.

Material Description. Products qualified to this specification shall be identified by their general composition and areas in a vehicle where they will yield their best acoustical performance.

Symbols. Not applicable.

Applicability. All materials qualified to this specification shall be listed by type and recommended areas of the vehicles to be used.

Classification.

Type 1: Textile Fibers (Non-wovens). These type materials will contain a blend of fibrous materials that may be bound together by needling or bonding. Type 1 materials are recommended for usage in the vehicle interiors or other areas where exposure to moisture and exterior exposure is very limited. For example, these materials can be used for under carpet applications. These materials can also withstand higher heat applications and can be used in the engine compartment.

Type 2: Fiberglass. One hundred percent (100%) fiberglass, phenolic cured materials for underhood use only and not for interior applications.

Type 2 materials are recommended for exterior or underhood locations where performance and exposure to chemicals will have an insignificant effect on performance. All fiberglass constructions shall have cut edges compressed around the entire circumference, and the components shall not have any extractable constituents being offensive, detrimental to health, or causing malfunctions during assembly or vehicle operation.

Type 3: 100% Polypropylene Fibers. This material will be composed of 100% fibrous polypropylene. Type 3 materials are recommended for areas where exposure to moisture will have an insignificant effect on performance. Not recommended for front of dash applications.

Type 4: One Hundred Percent (100%) Polyester Fibers. These materials will be composed of 100% polyethylene terephthalate (PET) fibers.

Type 4 materials are recommended for areas where exposure to moisture will have an insignificant effect on performance.

Type 5: Fiber Blends. Type 5 materials are recommended for areas where exposure to moisture will have an insignificant effect on performance. Not recommended for engine-side front of dash applications.

Type 6: Blends of Fiberglass. These materials are blends of fiberglass with other natural and/or synthetic fibers. Not to be used for interior applications.

Type 7: Other Fibers. These materials may contain oxidized polyacrylonitrile fibers or other fibers or fiber blends which meet acoustic and/or thermal requirements for specific applications.

Remarks. Materials intended to be used in substrate applications must also meet the assembly performance requirements per GMW14444 as assembled.