| 摘要 |
A self-extinguishing blanket comprises an insulating layer of glass fiber strands which include air spaces within the layer. Each surface of the layer has a bi-directional strand reinforced plastic film which extends continuously along the surface for keeping moisture out of the layer. Each plastic film is attached to the associated surface of the insulation layer by non-contiguous, longitudinally and laterally spaced apart areas of a thermoplastic adhesive. The adhesive areas provide attachment between the strand reinforcement and the layer of glass fiber strands. Each area of adhesive attachment provides sufficient retention to prevent shifting of the film during the sewing together of peripheral edge portions of the sandwiched plastic films and inner insulation layer as required to produce a selected, peripheral configuration of a blanket package. Each area of adhesive attachment is however small enough to permit ready detachment of the strand reinforcement and associated film from the layer of glass fiber strands upon exposure to the heat of a flame. Each plastic film has a composition and embodies a stress condition which enables a portion of the plastic film, when subjected to a direct flame or to the heat developed by an adjacent flame, to soften, to pull apart, and to shrink and curl back and to continue to curl back sufficiently far so as to prevent heating of that portion of the plastic film to the ignition temperature. This blanket construction leaves only the non-flammable layer of glass fiber strands exposed to the heat of the flame, and the shrinking and curl back of the plastic film prevent both ignition of the plastic film and propagation of the flame through the plastic film. |
