Patent GB-380208-A (GB)
Title: Improvements in or relating to methods for applying designs to yarns, bands or fabrics by the aid of dyeing means
IPC: G03C1/76
Filed: 1931-07-21
Abstract: <PICT:0380208/IV/1> <PICT:0380208/IV/2> <PICT:0380208/IV/3> Designs are applied to yarns, bands or fabrics of non-animal origin in a continuous operation comprising uniform application of a metal compound capable of conversion photochemically into a compound in which the valency of the metal is different, exposure to artificial light in accordance with the desired pattern, washing, if necessary, conversion of either the converted or the non-converted metal compound into a compound incapable of being washed out, and finally washing and drying.  Specified textile materials used are linen, cotton and regenerated cellulose (e.g. viscose) silk.  The light may be derived from carbon arc lamps, mercury discharge tubes, or gas-filled electric incandescent lamps with tungsten filaments and envelopes of quartz glass or glass transparent to ultraviolet light. Variations of tone in the printed parts are obtainable by varying the intensity of the light.  The following examples are specified: (1) A linen fabric 1, Fig. 1, is continuously pulled by rollers 2, 3 through a solution of potassium bichromate in a vessel 4 and passes between rollers 6, 7 which squeeze out the excess liquid.  A heated roller 8 bearing against the roller 6 may be provided to dry the fabric, which then passes around rollers 9, 10 and over a rotary cylindrical stencil 11 enclosing one or more lamps 12, thence by way of rollers 13 .. 17 through water in a vessel 18, by way of rollers 21 .. 25 through a solution of a mordant dyestuff, such as sodium alizarin sulphonate, in a vessel 26, by way of rollers 28 .. 31 through water in a vessel 32, and thence to a drying device.  The water preferably flows in countercurrent through the vessels 18, 32. Alternatively the solution in the vessel 4 may contain both the bichromate and the sodium alizarin sulphonate, the vessels 26, 32 being then dispensed with.  As a further alternative the solution in the vessel 4 may contain the bichromate and a compound of a metal, e.g. copper or manganese, yielding an insoluble compound with chromate but not with bichromate, the vessels 26, 32 being dispensed with.  (2) A cotton fabric is passed through a solution of a ferric salt, exposed to light as shown in Fig. 1, passed through a solution of potassium ferricyanide, washed, passed through an alkaline lye, washed again, passed either through a bath of mordant dyestuff, e.g. a hot suspension of purpurin or through a tannin solution, and finally washed.  (3) An artificial silk, e.g. viscose, fabric is passed through a solution of potassium ferricyanide, exposed in parts to light as shown in Fig. 1, passed through a solution of ferric chloride, washed, passed through an alkaline lye and further developed as in (2); alternatively a ferric salt, e.g. ferric ammonium citrate, and potassium ferricyanide may be applied together before the exposure to light.  (4) A linen fabric is passed through ferric chloride solution, exposed in parts to light and passed through a solution of sodium alizarin sulphonate; the non-exposed parts are more deeply coloured.  (5) A fabric of viscose silk is passed through an ammonium bichromate solution, dried, exposed in parts to light, washed, passed through a solution of a mordant dyestuff which colours only the exposed parts, washed and then passed through a solution of a dyestuff which colours only the non-exposed parts; the order of the dyebaths may in this case be reversed.  In a modification, Fig. 2, of the stencilling apparatus the fabric 42 is moved step by step past a stationary stencil 35 provided with lamps 36, 37. Fig. 3 shows an arrangement for use in printing yarns, &c. The yarns, bands or threads 43 pass continuously across a case 44 containing lamps 45, 46 which are simultaneously illuminated intermittently or are subjected to gradual increases and decreases of luminous intensity.