Patent ID: 6158427
Filing Date: 2000-12-12
Classification: A61F,B32B,D06M,D06N

Abstract:
A thermal cell comprising:a) a bottom sheet formed to have a pocket, said bottom sheet being impermeable to oxygen;b) a plurality of particles placed in said pocket, said plurality of particles reacting exothermally when exposed to oxygen; andc) a top sheet sealed to said bottom sheet at a flange of said pocket to enclose said plurality of particles such that said particles cannot exit said pocket, said top sheet having a porous substrate, said substrate being coated with a pattern of spots made of hot melt adhesive, said hot melt adesive uniformly covering greater than about 95%of a surface of said porous substrate such that said top sheet has a diffusive oxygen permeability at 0.21 atmosphere diffusive driving force ranging from about 0.5.times.10.sup.5 cm.sup.3 /100 square inches/day to about 2.times.10.sup.5 cm.sup.3 /100 square inches/day.