A-A-52169 Insulation; Sound, Vibration, And ThermalThis CID covers the physical, chemical, and performance characteristics of the composite material used to make insulating pads for use on the High Mobility Multipurpose Wheeled Vehicle HMMWV series of vehicles and for other similar applications. The insulating pads are used as a thermal, sound, and vibration barrier. The insulating pad is made of five layers of material consisting of the following components: a deep twist outer vinyl wear surface with a cloth reinforcement backing; a sound barrier layer; a closed cell acoustical and thermal foam insulation layer; a high temperature needle mat thermal blanket layer; and a fiberglass cloth reinforced vinyl and mylar backing see figure 1.

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A-A-52169B

2.2.5 Fiberglass reinforced vinyl and mylar. The backing component shall be made of a fiberglass cloth reinforced vinyl and mylar material and shall conform to table V.

TABLE III. Closed cell foam component.

Characteristic

Requirement

Color Thickness Temperature limits Tensile strength Density

Thermal conductivity

Black.

6.35 mm.

-46 to 121°C

2.82 kg/sq.cm.

48 to 80 kg/cu m

0.04 watts/m. C.

TABLE IV. HTNM component.

Characteristic

Requirement

Color Thickness Temperature limits Mass

Thermal conductivity Sound absorption Chemical resistance

White.

1.27 0.32 cm.

-46 to +650 C.

1.83 0.18 kg/sq. m.

K factor: 0.40 at 150 C.

Noise reduction coefficient (NRC): 0.50. Excellent for acids, oils, and alkalis.

TABLE V. Fiberglass cloth reinforced vinyl and mylar component.

Characteristic

Requirement

Color

Thickness

Temperature limits

Black or Green 383, color no. 34094 per

FED-STD-595.

12.7 micrometer mylar and 76.2 micrometer vinyl.

-46 to +177 C

2.3 Composite requirements. The composite requirements for the insulating pad shall conform to table VI. The insulating pad composite shall be made by encapsulating the insulating materials

(see 2.2.2, 2.2.3, and 2.2.4) with the wear surface (see 2.2.1) and the backing (see 2.2.5) materials. The wear surface and backing shall then be bonded together using a plastisol heat seal to form a waterproof joint around the periphery of the insulating pad (see figure 1).

NOTE: Refer to the AED for the design, configuration, and finish dimensions of the part made from this composite material (see 5.2).