초록 ▼

Particulate cellulose insulation material is rendered fire retardant by a wet process requiring considerably less fire retardant composition than normally employed in the usual dry processes or in wet processes proposed heretofore, and yielding a product with significantly enhanced insulating proper

Particulate cellulose insulation material is rendered fire retardant by a wet process requiring considerably less fire retardant composition than normally employed in the usual dry processes or in wet processes proposed heretofore, and yielding a product with significantly enhanced insulating properties. Impregnation of a cellulosic insulating material, such as waste paper in finely divided form, with an aqueous solution of a non-hygroscopic fire retardant composition, such as boric acid, a borate, or the composition of U.S. Pat. No. 3,983,040, is carried out under conditions whereby a minimum amount of water is first utilized for the purpose of dissolving the fire retardant composition and to serve as a carrier in distributing it throughout the cellulosic insulating material. For example, only from about 14 to 45% by weight of add-on water is utilized in the presence of from about 5 to 10% by weight of the fire retardant composition and preferably in the presence of a surfactant. The so-treated insulation material is then maintained in a hot and humid atmosphere, as in a closed conditioning bin, for a prolonged period of time prior to drying.

대표청구항 ▼

Wet process apparatus for rendering cellulosic insulation particles fire retardant by the use of a non-hygroscopic boric acid or borate composition, comprising a grinder for producing cellulosic insulation particles from cellulosic material such as waste paper; spray means for water or an aqueous so

Wet process apparatus for rendering cellulosic insulation particles fire retardant by the use of a non-hygroscopic boric acid or borate composition, comprising a grinder for producing cellulosic insulation particles from cellulosic material such as waste paper; spray means for water or an aqueous solution, said spray means being located in the path of discharge of material from said grinder; conduit means for receiving cellulosic insulation particles wetted by said spray means; means for flowing a hot moist vapor through said conduit means as a carrier for the wetted insulation particles; a closed conditioning bin into the top of which said conduit means discharges; discharge means at the bottom of said conditioning bin; second conduit means into which said discharge means discharges conditioned insulation material from said conditioning bin; means for introducing hot drying air into said second conduit means for carrying said conditioned insulation material through said second conduit means; and means for collecting dried conditioned insulation material from said second conduit means.