A fire-retarded cellulose fiber material composed of phosphoric acid and ammonium sulfate as fire-retardant chemical components, absorbed, adsorbed and/or adhered on the cellulose fibers, and optional non-fire retardant additives, and methods of producing the fire-retarded cellulose fiber material are disclosed.

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.

The invention relates to a fire retardant paper comprising reinforcing fibre, a fire retardant material and a binder system, wherein the binder system comprises a first organic binder and a second organic binder, wherein the first organic binder has a lower glass transition temperature than the second organic binder.

Methods for making fire retardant material including fire retardant cellulosic insulation are described. The methods include arrangements for partitioning fibers derived from fiber feedstocks and adding at least a portion of fibers of one or more feedstocks and a fire retardancy chemical compound to a mixer prior to fiber drying. The fibers may be disentangled and/or partitioned prior to mixing with the fire retardancy chemical compound. The fibers may be partially dewatered prior to the drying or other steps of the methods. The feedstock may include old newsprint (ONP), old corrugated containers (OCC), and/or other cellulose-based materials. The method further includes retaining the fibers feedstock and the chemical compound together for enough time to ensure adherence and impregnation of enough of the chemical to and in the fibers after the drying process. Fibers may be partitioned and disentangled prior to, during, and/or after treatment with the fire retardancy compound. The fire retardant cellulose insulation may be a standalone product or may be a component of a finished insulation end product.