A thermoplastic blanket includes multiple layers of thermoplastic
material. The first such layer has a first surface zone, a second,
optional surface zone and a first base zone between the first and second
surface zones. The second layer of thermoplastic material includes a
third surface zone, a fourth optional surface zone and a second base zone
between the third and fourth surface zones. At least one surface zone of
each layer is densified to a density of between about 1.5 to about 30.0
pcf while each base zone has a density of between about 0.5 to about 10.0
pcf.