Textile substrate dye stripping
AssigneeMorton International, Inc.
InventorsPeter Modebelu, Harrie Schoots, Jeremy Ko
Life of this patent
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Abstract
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.
Claims1
A method for stripping dye from textiles selected from the group consisting of cellulose acetate, triacetate, and rayon/acetate blends comprising the steps of:
- (a) preparing a bath comprising a reducing agent produced by the reaction of a bisulfite having the formula MHSO3, with from about 0.09% to about 0.3% by weight of said textile, of ZBH4, wherein Z is sodium or potassium, wherein M is sodium, potassium or ammonium, and wherein the bath is prepared using 8-12 moles of MHSO3 per mole of ZBH4;
- further provided that said reaction occurs at a pH of from about 5 to about 8;
- (b) adding said textiles to said bath, wherein said bath is at a temperature of 180°-230° F. and the pH is 4.0-7.4.
Dependencies are inferred from the claim text.