Morton International, Inc.

Morton Thiokol Inc.

Jeremy Ko

Steven H Levis

Harrie Schoots

Peter Modebelu

Matrix-dyed textiles of cellulose acetate, cellulose triacetate, silk, wool, flax, nylon, acrylic, polyethylene terephthalate, cotton, and rayon are stripped of their dyes in a dye stripping system comprising a reducing agent in an aqueous bath produced by the reaction of a bisulfite with about 0.35% or less of a borohydride by weight of the textile. The borohydride may be added to an aqueous bath already containing the bisulfite and the textile or the borohydride and bisulfite may be mixed in an add tank and the mixture added to the aqueous bath. Chelating agents, sequestering agents, fire retardants, and odor scavengers are not needed. Reclaimed textiles having superior receptivity of a new dye are provided.

Textile substrate dye stripping

An improved high yield apparatus for producing sodium hydrosulfite is disclosed wherein sodium borohydride, sulfur dioxide, sodium hydroxide and sodium bisulfite are reacted. Improved results are obtained according to the invention by a novel feed system that requires the introduction of a first reaction mixture comprising sodium borohydride, sodium hydroxide and water (i.e., BOROL) into a process flow stream upstream from, i.e. prior to, the introduction of a second reaction comprising either (1) water and sulfur dioxide (first embodiment) or (2) sodium bisulfite and sulfur dioxide (second embodiment). The best results are realized by combining the just described novel feed arrangement with a system where intimate mixing of both the first reaction mixture and the seocnd reaction mixture and the flow stream. This is achieved by the use of a dual compartmented cylindrical motionless mixer wherein the input means for the first reaction mixture is located at a distance upstream from the first compartment of the mixer that is about the same as the diameter of the mixer and the second reactant mixture input means is similarly located at a distance upstream from the second compartment that is also about the same as the diameter of the mixer. Improved results are also obtained by using the dual compartmented cylindrical mixer above described in conjunction with the known reactant feed systems involving embodiments (1) and (2) above described, i.e. where the reactant inputs are reversed.

Apparatus for producing high yield sodium hydrosulfite

An improved high yield process and apparatus for producing sodium hydrosulfite by reacting sodium borohydride, sulfur dioxide, sodium hydroxide, and sodium bisulfite is provided. The improved result of the invention is obtained by a feed system that requires the introduction of a first mixture comprising sodium borohydride, sodium hydroxide, and water into a flow stream prior to the introduction of a second mixture comprising water and sulfur dioxide. The improved result can be further enhanced by techniques of intimately mixing the first mixture and the flow stream as well as intimate mixing the second mixture and the flow stream.

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Boston, MA, United States of America

Jeremy Ko