US Patent 10245804 Fire retarded aramid fiber-based honeycomb

An alternate resin-coated paper material for use in making honeycomb. The alternate resin-coated paper material is made from a paper that contains from 30 to 50 weight percent aramid fibers and from 50 to 70 weight percent of non-aramid fibers. A fire retarded phenolic resin is incorporated into the paper to make it self-extinguishing in less than 10 seconds with a self-extinguishing burn length of less than 12 inches when exposed to a 12-second vertical flame in accordance with the vertical burn test requirements set forth in 14 C.F.R. Part 25.583. The fire retarded phenolic resin includes a phenol formaldehyde resin and a phosphorous-containing fire retardant.