This style includes the processes by which the aniline colours in the majority of cases are fixed upon cotton goods, and, in addition, the topical application of the artificial alizarine colours; also printing upon woollen, worsted, and silk tissues, as well as upon mixed fabrics, such as delaines, coburgs, etc. The aim of steaming is to get a moist heat, both the temperature and the degree of moisture being carefully regulated, according to the class of the goods, the nature of the colours, etc. In some cases, the pieces after printing are exposed to the air, at common temperatures, for 12 to 24 hours before steaming; whilst in others, they are steamed immediately. Sometimes, the goods are steamed for a time, taken out to air, and steamed again; whilst on other occasions, the steaming is conducted for the necessary time without interruption. The temperature, the pressure, and the degree of moisture, vary greatly, some printers using very dry, and others very moist, steam.
Before the colours are printed on, the calicoes are generally "prepared" by the following process: - The pieces are padded in a solution of stannate of soda, commonly known as " alkaline preparing salts," at 10° Tw., in a machine fitted with wooden rollers. The padding is generally done twice, and in the meantime, the pieces are allowed to remain wet for about 1 hour; next they pass through sours (i.e. dilute sulphuric acid at 1 1/2° to 3° Tw.), then into pure water, and are washed, so that no free sulphuric acid may remain upon them; but the washing must not be so severe as to remove the oxide of tin which has been deposited upon the fibre. The pieces are then drained in the centrifugal machine, carefully dried at a gentle steam-heat, and are ready for printing. For heavy shades, the strength of the solution of stannate may be raised to 24° Tw.; the pieces are left to lie wet for 2 hours, and are then taken through sours at 6° Tw., washed, and drained in the centrifugal. All these operations are repeated once more in the same order, and the goods are then dried. Care must of course be taken to keep the sours up to the same point of acidity.
Without attention to this point, they become rapidly weakened, and the fixation of the tin being thus rendered irregular, the colour subsequently produced will be uneven. Preparation with stannate of soda is useful for calico, and is in general absolutely necessary for worsted stuffs, and mixed goods.
The following are examples of steam colours:
15 lb. gum substitute, 2/8 pint neutral olive oil, 3 gal. bark liquor at 12° Tw., 2 1/4 pints sapan liquor at 8° Tw., 3 qt. red liquor at 16° Tw. Half boil, and add 6 oz. tin crystals, pre-viously dissolved in 2 pints of the red liquor. Mix, and add 3/16 pint oxy-muriate of tin at 120° Tw. Mix well, and strain as fine as possible.
1 gal. logwood liquor at 6° Tw., 1 1/4 lb. starch; boil, and add, whilst still hot, 5 oz. copperas; stir thoroughly, and when the mixture has grown almost cold, add 2 oz. gallipoli oil, and 10 oz. nitrate of iron, well neutralized.
(2) 1 gal. logwood liquor 12° Tw., 1 qt. gall liquor 9° Tw., 1 qt. mordant, 2 lb. flour, 6 oz. starch. For the mordant, mix 1 qt. acetic acid, 1 1/2 qt. acetate of copper, 1 1/2 qt. black liquor 24° Tw., 1 qt. red liquor 20° Tw.
(3) For Calico
Dissolve in water 5 lb. 7 oz. solid French extract of logwood, and allow the liquor to settle. Dissolve separately in water 17 1/4 oz. gum traga-canth. Mix the two solutions, and boil. Boil out 2 lb. 3 oz. gall-nuts in water, and add the decoction to the above, making up to 17 1/2 pints. Let cool, and stir in 2 lb. 3 oz. nitrate of iron at 30 1/2° Tw., and the same weight of black liquor at 26f° Tw. Print, and hang up for 2 days, or preferably for a few hours; steam well, and wash.
(4) For Printing Cotton Yarns
Dissolve in water 5 lb. 7 oz. solid French extract of logwood, and 17 1/4 oz. gum tra-gacanth. Make up the mixed solution to 21 pints, in which dissolve 4 1/2 oz. extract of bark. Let cool, and stir into the mixture 2 lb. 3 oz. black liquor at 30 1/2° Tw., and 17 oz. nitrate of iron at 98° Tw. Print, hang up for 2 days, steam, and wash. If a very blue tone is required, the nitrate of iron is left out.
7 gal. water, 11 lb. starch, 2f lb. sal ammoniac; boil, and add, while hot, 12 lb. yellow prussiate, ground, 6 lb. red prussiate, 6 lb. tartaric acid. When nearly cold, add 1 lb. sulphuric acid at full strength, 2 lb. oxalic acid (previously dissolved in 2 lb. hot water), 6 gal. tin pulp. Tin pulp is prepared as follows: - The strongest double muriate of tin, a saturated solution of the proto-chloride of tin (stannous chloride), is mixed up with as much solution of yellow prussiate as will throw down all the tin as a ferrocyanide. Wash in water by decantation, and drain on a filter till it becomes a stiff paste.
35 fl. oz. red liquor at 20 1/4° Tw., 35 fl. oz. bisulphite of soda at 39 1/2° Tw., 3 1/2 pints strong gum water, 3 1/2 oz. aniline blue (Schlumberger, Brussels). The colour, when ready, is printed at once. The calico may either be printed without any preparation, or it may be padded in a soap-lye containing 1 oz. curd-soap per pint, and dried. After printing, steam for 1 1/2 hour. Wash, take through lukewarm soap-lye, and sour in weak muriatic acid. Wash and dry.
(3) Prussian blue for shawls, etc - Boil up 10 oz. starch to a uniform paste with 7 pints water; stir into it 2 1/2 lb. yellow prussiate, 1 1/2 lb. red prussiate, 7 lb. tin pulp, 4 lb. tartaric acid, 1/4 lb. oxalic acid, 5 1/2 pints water, and 1 oz. sulphuric acid.
Boil 4 lb. catechu in water; let settle, and strain off the clear. The liquor thus obtained is mixed with 1 lb. red liquor at 8 1/4° Tw.; and thickened with 3/4 lb. gum tragacanth.