Cotton solvent scouring

Trichloroethylene is an excellent extraction solvent for greases, oils, fats, waxes, and tars and is used by the textile processing industry to scour cotton, wool, and other fabrics (lARC 1979 Kuney 1986 Verschueren 1983). The textile industry also uses trichloroethylene as a solvent in waterless dying and finishing operations (McNeill 1979). As a general solvent or as a component of solvent blends, trichloroethylene is used with adhesives, lubricants, paints, varnishes, paint strippers, pesticides, and cold metal cleaners (Hawley 1981 lARC 1979 McNeill 1979). 

BURCO SCOUR VAR-DF3 is particularly effective for J-Box and Kler bleaching, and for prescouring, of 100% cotton and polyester/cotton blends. It combines the solvents and emulsifiers to penetrate and remove troublesome oils and waxes by holding them in suspension, thus preventing any redeposit on the fabric. 

Anionic/solvent detergent for use in alkaline scouring and bleaching of cotton for removal of oils and waxes. Effective in enzyme desizing. 

Proprietary bleach. Desizes, scours and bleaches simultaneously. Used on cottons, rayons and heavily oiled fabrics such as those containing spandex fiber. Compatible with caustic and does not require solvents in scouring. 

The ICI Markal process is used for desizing and scouring by using suspension of enzyme in trichloroethylene and surfactant solution. The fabric is padded through the solvent formulation, steamed to remove the solvent and to activate the enzyme. A wash-off with water completes the process. The Markal processes are suitable for polyester/cotton, polyester/rayon and other blends as well as for cotton. 

Scouring cotton by extraction with an organic solvent such as trichloroethylene, followed by flash evaporation, is making progress in practical application. Investigation by I.C.I. demonstrated that immersion in trichloroethylene for periods as short as 30 seconds would reduce fat and wax content to about OTS per cent, a figure which is within the tolerance of commercial acceptability. If the cotton is singed it is quenched with steam instead of water so that it enters the solvent extraction unit dry. 

Buschie-Diller, G., Mogahzy, E. Y., Inglesby, M. K., and Zeronian, S. H. (1998). Effect of scouring with enzymes, organic solvents and caustic soda on the properties of hydrogen peroxide bleached cotton yam. Text Res. 

For the tension and pressure measurements, a desized, scoured and bleached 100% cotton interlock knit fabric (205 g/m ) was treated with 50% PEG-1450-11% DMDHEU (Fixapret ECO)-5.1% citric acid-5.1% MgCl2.6H20 to a wet pickup of 110%, then cured for 3 min at 110 °C, washed in warm water to a pH of 8.5 to neutralize acid catalyst, excess water removed, then oven-dried for 7 min at 85 °C. The resultant fabric had a wt. gain of 65% and had shrinkage in one direction (longitudinal) when wet with various polar solvents (28% with water 25% with 1 % aq. NaCl 10% with 95% ethanol and 7% with acetone). Three inches of a 1 x 6 inch strip of the treated fabric was clamped between the jaws of an Instron (Model 4201) having a 10 lb load cell, completely wet with each of the four solvents and tension load/stress measured after initial wetting to a maximum time of 15 min. 

Buschle-DiUer G, El Mogahzy Y, Inglesby M K and Zeronian S H, Effects of scouring enzymes, organic solvents, and caustic soda on the properties of hydrogen jjeroxide bleached cotton yarn . Text. Res. J., 1998, 68(12), 920 9. 

It should be noted that when scouring with solvents, residual moisture in the fiber structure of cotton-based fabrics is common and can react with the solvent to form hydrochloric acid within the fiber. As such, the solvent/acid residue is not able to be completely removed from the fabric. 

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