Abstract: Described is a process for continuously dyeing high tenacity nylon 6,6 fabrics including the sequential steps of applying to a high tenacity, highly crystalline nylon 6,6 fabric whose fibers have a breaking tenacity in the range of 6.0 to 10 g/denier and an aqueous dyebath containing a tinctorial amount of at least one dye. The dyed fabric is then steamed with superheated steam at atmospheric pressure and at temperatures greater than 100.degree. C., e.g., 100.degree. to 160.degree. C., for a time sufficient to fix the dye to the fabric, usually up to 3 minutes. Following steaming, the dyed fabric is washed to remove any unfixed dye, then dried.

Abstract: Simultaneous dyeing and flame-resistant property improvement of poly(m-phenyleneisophthalamide) fibers using a swelling agent to introduce a dye and a fire retardant into the fiber. The dyed fiber has properties of strength approximating the original undyed fiber, fire retardance greater than the untreated fiber and is conveniently dyed to an unlimited range of colors with high color yield and relatively good lightfastness at a reasonable cost. An aqueous dimethylsulfoxide solution is used as the swelling agent.

Abstract: Aramid fibers, polybenzimidazole fibers or blends of aramid and polybenzimidazole fibers are rendered flame resistant by a flame retardant introduced into the fibers by a polar organic swelling agent such as DMSO. Dyed or undyed fibers so treated exhibit substantially improved flame resistance as compared with untreated fibers.

Abstract: Continuous dyeing of poly(m-phenyleneisophthalamide) fibers using a swelling agent to introduce a dye into the fiber. The dyed fiber has properties of strength and fire retardance approximating the original undyed fiber and is conveniently dyed to an unlimited range of colors with high color yield and relatively good lightfastness at a resonable cost. An aqueous dimethylsulfoxide solution is used as the swelling agent.