Mordant for Calico-Printing.

Scientific American 10, 3.3.1860

A patent has been iecured by Mr. Walter Crum, an eminent color chemist Thornliebank, Scotland, for a very novel mordant for fixing [colors?] in printed and other muslin goods. He mixes gluten with caustic potash or soda, or with the bilicate [] potash or soda, and prints this on the fabric or impregnates it with such a solution; then the fabric is afterwards submitted to the joint action of heat and moisture before the coloring matter is applied. The process is described in Newton's London Journal of Arts, and we would direct the attention of our calico-printers to it (especially those engaged on the finer styles), as it is one of the most peculiar and original chemical discoveries which has been made for many years. He first takes the gluten of wheat, which is produced by the well-known process of kneading flour with water and washing away the starch, then allowing the gluten to remain in a suitable vessel until it has lost its tenacious character and has acquired, in some measure, the quality of common mucilage. The period at which this change takes place varies with the different kinds of flour and the temperature at which the gluten is kept. It is usually sufficiently fluid after five or six days, when kept at summer heat, and between that period and eight or ten days thereafter it is in the best condition to be used for the purposes of this invention. Then proceed to purify this mucilage by rendering the gluten which it contains again insoluble and coherent, and for that purpose mix it with a solution of carbonate of soda sufficient to saturate the acid which has been funned in it; the point of saturation being indicated by testpaper in the usual way. For 10 lbs. of gluten in this condition, there is usually required 18 oz. of solution of carbonate of soda of the specific gravity of 1.50. The gluten, in becoming again soluble, gradually separates from the soda solution and partially resumes its tenacious and coherent state, and the whole being shaken on a cloth the solution passes away, along with sonic portions of starch not previously separated. Asauming the above quantities to have been used, the gluten remaining is then to he kneaded or washed with 3 lbs, of cold water, and shaken on a cloth as before end this washing operation is to be performed three times. Ten pounds, by weight, of the purified gluten is to be mixed with 14 oz. of solution of caustic soda of the specific gravity of 1.080. The gluten immediately dissolves and forms a mucilage which is to be diluted with water to tho required thickness, as is understood by calicoprinters. For cylinder printing, add seven plaids of water. When the fiber or fabric of cotton or linen has been printed or otherwise impregnated with the compound just described, rind dried, it is subjected to the action of steam (or of heated air, more or less moist), then rinsed in water. Dyeing in is preparation of orchil, in the manner well known, or in picric acid, or dinitroplicnylie acid, or in the coloring matter obtained from coal tar or from aniline; or the same coloring matters may be applied by printing them upon a fiber or fabric, previously prepared with the glutinous mordant fixed by steam, and, subsequently, again subjecting the printed fabric to steam.