A two layer sound deadening material is formed from pumpable material
applied through a pair of extrusion heads mounted on a single mount. A
robot, used in high speed mass production automotive assembly lines,
moves the door panel relative to the stationary extrusion heads to allow
the simultaneous application of the two layers onto the interior side of
the door. The first layer is formed of a thermosetting composition
containing epoxy, rubber and a catalyst and adheres directly to the door
panel. The second layer is formed of a thermosetting composition
containing an epoxy resin, a thermo plastic copolymer and a curative
which will adhere directly to the first layer due to similar chemical
structures. The second layer is positioned such that the edges thereof
are inside of the corresponding edges of the first layer to prevent read
through transmission of noise from the body or door panel.