Pyrotechnic sheet material

A method of manufacturing a pyrotechnic sheet material which comprises vapor depositing a layer of oxidizable metal selected from the group consisting of lithium, sodium, magnesium, beryllium, calcium, strontium, barium, aluminum, titanium, zirconium and alloys thereof on at least a porous portion of a surface layer of oxidizing polymeric film having at least a portion of a surface layer which comprises interconnecting pores and is vapour permeable and having a porosity of 5 to 90% based on total volume of said porous portion occupied by pores, at least part of the oxidizable metal being accommodated within interconnecting pores of the polymeric film, the ratio of the polymeric film and the oxidizable metal at the porous portion being such that the metal and the film are conjointly capable of sustained exothermic reaction on ignition.

A pyrotechnic sheet material comprising a substrate of oxidizing polymeric film having at least a portion of a surface layer which is porous and having a porosity of 5 to 90% based on total volume of polymer film or layer occupied by pores and having a layer of oxidizable material on at least a porous portion of the said porous polymer layer and wherein the pores of the polymeric film are partially filled with sodium azide, the polymeric film and the oxidizable material at the porous portion being conjointly capable of sustained exothermic reaction on ignition.

An inflator for a vehicle occupant safety restraint comprising a pyrotechnic sheet material comprising a substrate of oxidizing polymeric film having at least a portion of a surface layer which is porous and having a porosity of 5 to 90% based on total volume of polymer film or layer occupied by pores and having a layer of oxidizable material on at least a porous portion of the said porous polymer layer the polymeric film and the oxidizable material at the porous portion being conjointly capable of sustained exothermic reaction on ignition.