Burlington Industries, Inc.

James K Davis

Barbara J Cates

Ernest J Russell

Tanya E FitzGerald

Tina V Lorenzo

Robert S Craycroft

Robert W Connelly

The flame-resistant properties of aramid fibers are improved using a swelling agent to introduce a flame retardant into the fiber. The treated fiber has properties of strength approximating the untreated fiber, flame resistance greater than the untreated fiber and is conveniently dyed to an unlimited range of colors with high color yield. An aqueous dimethylsulfoxide solution is used as the swelling agent.

Aramid fibers with improved flame resistance

Textiles, especially polyester, nylon and high-tenacity nylon, are continuously dyed in an organic medium containing a high-boiling, nonionic solvent admixed with one or more lower-boiling organic solvents and at least one dyestuff dissolved in the solvent media. The lower-boiling solvent acts as a carrier to entrain the dye and allows the dye to enter the fiber evenly. The non-aqueous dyestuff medium allows the process to be conducted above the boiling point of water which facilitates dye penetration into the fiber and, in turn, shortens the dyeing process. Atmospheric pressure may be used, thus avoiding the constraints of a batch-type operation of pressurized dyeing procedures, as is conventionally used in this art. Fabric may be dyed in open width under restraint at elevated temperatures thereby achieving uniform coloring of the fabric without shade variations from end-to-end or 'tailing'. Dyeing the fabric at elevated temperatures with dimensional control allows the fabric to be heatset simultaneously with the dyeing.

Method for dyeing in high-boiling nonionic solvents

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.

Process for simultaneously dyeing and improving the flame-resistant

Dyes are removed from waterless dye compositions by mixing the dyeing composition, composed of one or more dyes in a high-boiling, nonionic liquid, with an extraction solvent that is immiscible with the high-boiling liquid, yet solubilizes the dye. The dye laden extraction solvent is separated as a separate phase from the high-boiling, nonionic liquid medium.

Method of stripping dyes from high-boiling non-ionic media

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.

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Greensboro, NC, United States of America

James K Davis