Patent ID: 7736696

Claim:
A continuous, closed loop process for rendering fibers flame retardant, comprising the steps of: processing separate successive batches of fibers to be rendered flame retardant, by repeatedly performing the steps of placing a batch of fibers in a stock or package dye machine together with a flame retardant composition; permitting said flame retardant composition to impregnate or otherwise penetrate through a cross-section of individual fibers of said batch of fibers; removing said batch of fibers from said stock dye machine; centrifuging said batch of fibers removed from said stock or package dye machine and recovering a portion of said flame retardant composition removed from said batch of fibers by centrifugation; drying said batch of fibers to produce flame retardant treated fibers; and adding additional flame retardant composition to said stock or package dye machine before each repeat of said processing steps, at least some of the time using said at least a part of said portion of said flame retardant composition recovered during said centrifuging step.