This standard describes the requirements of flexible expanded materials to be used as air and dust seals or water seals and gaskets in the body area. These materials may also be used as rattle protection, covers for gaps and other suitable applications.

Material Description. Materials meeting the requirements of this specification will be comprised of two (2) classes and several types. 

• Class l: Expanded rubber materials will be used for air, dust and rattle isolators, and will not require a General Motors Material File (MATSPC) approval.

• Class II: Expanded rubber materials must meet the water sealability requirements of this document. All Class II materials will be MATSPC approved.

Materials are divided into several types, depending on the stiffness of the cellular rubber.

Note: Based on the different types of sponge and cellular rubbers, open cells, closed cells, and semi-closed cells, the sealing properties are dependent on the amount of compression so no direct correlation can be given between Compression Deflection values and Class designation.

Materials covered in this specification are resistant to +70 °C continuous and +100 °C excursion. Depending on the base material of the sponge rubber, it can provide better temperature resistance up to +100 °C permanent. This has to be verified on the selected Type and must be specified on the drawing or math data file.

Note: Sponge rubbers made of silicone elastomer (VMQ) are specified in GMW16392 and can be used up to +200 °C continuous.

Certain applications may require the use of an adhesive. If an adhesive (ADH) is required, an ADH suffix shall be added after the basic specification and type number.

Other interior parts will require a low friction coating (CO) to reduce friction between the seal and the substrate. When this coating is required, a CO suffix shall be added after the specification, class and type numbers.

Symbols. Not applicable. 

Typical Applications. Flexible expanded materials, to be used as air and dust seals or water seals and gaskets in the body area and for rattle protection, covers for gaps and other suitable applications.

Remarks. To properly use this specification, the following information must be added to the engineering drawing. 

Specify material, e.g., Acrylonitrile Butadiene Copolymer (NBR), Ethylene Propylene Diene Terpolymer (EPDM). 

Specify density and tolerance. 

Indicate the ADH or CO suffix if an adhesive or low friction coating shall be used. 

Identify application such as interior or exterior. There are specific tests required for each use. 

Specify surface appearance and dimensions using current requirements as agreed upon between engineering and the supplier.