DYEING HALF SILK (COTTON-SILK, SATIN) FABRICS.
The direct dyes of the Diamine, Benzo and Congo types have been of late years increasingly used for dyeing satin (silk and cotton), and they have quite displaced the old methods of dyeing this class of fabrics, which consisted in first dyeing the silk with an acid dye and then dyeing the cotton with a basic dye. For details of the method of applying acid dyes to silk reference may be made to Mr. G.H. Hurst's book onSilk Dyeing.
Most of the direct colours are exceedingly well adapted for this purpose, some under certain conditions possess the property of dyeing the cotton a deeper shade than the silk, which is an advantage rather than otherwise.
The dyeing of goods composed of silk and cotton is generally done in winch dye-vats, in some cases also on the jigger.
METHOD OF DYEING.
The direct colours are as a rule dyed in a soap-bath with addition of phosphate of soda, Glauber's salt or common salt and a little soda.
The addition of these salts effects a better exhaustion of the baths; they are therefore principally used for dark and full shades, whilst pale shades are dyed with the addition of soap only or in combination with phosphate of soda. Dark or pale shades may thus be produced at will by selecting theproper additions, but the fact should not be overlooked that the greater exhaustion of the baths not only increases the depth of shade of the cotton but also causes the silk to absorb more dye-stuff. Too large a proportion of salt would cause the dye-stuffs to go on the fibre too quickly and thus make the dyeing liable to turn out uneven.
A large proportion of soap counteracts the effects of the salts, causing the dye-stuff to go on less quickly and tending to leave the silk lighter than the cotton, in some cases even almost white, a property which is valuable in many cases, especially as enabling the silk and cotton to be dyed in different colours to obtain shot effects.
It is thus obvious that a general method applicable in all cases cannot be given; it will vary according to the effect desired, and partly also depend on the material to be dyed.
The following particulars may serve as a guide for the first bath:—
For pale shades each 10 gallons dye-liquor should contain 3¼ to 6½ oz. soap and 4 to 7 drs. soda or 3¼ to 6½ oz. soap, 4 to 5½ drs. soda and 3¼ to 6½ oz. phosphate of soda.
For medium and dark shades each 10 gallons dye-liquor may contain 3¼ to 6½ oz. soap, 4 to 7 drs. soda, 3¼ to 6½ oz. phosphate of soda and 6½ to 13 oz. cryst. Glauber's salt.
For two coloured effects or dyeings, in which the silk is intended to remain as pale as possible or even white, each 10 gallons dye-liquor may contain 4¾ to 8 oz. soap, 4 to 6 drs. soda, 3¼ to 8 oz. phosphate of soda and 4¾ to 9½ oz. cryst. Glauber's salt.
The temperature of the dye-baths is generally 175° to 195° F.; in practical dyeing it is usual to boil up the fully charged dye-bath, shut off the steam, enter the goods and dye for about three-quarters of an hour.
For obtaining level dyeings in pale shades it is advisable not to enter the goods too hot, but to raise the temperaturegradually. Raising the temperature, or dyeing for some time at the boil will deepen the shade of the cotton, but at the same time will have the same effect on the silk which may sometimes be an advantage when dyeing dark shades.
As a complete exhaustion of the baths does not take place, especially when dyeing dark shades, it is advantageous, nay, even imperative, to preserve the baths for further use, they are then replenished with only about three-fourths of the quantities of dye-stuffs used for the first bath, of the soap only about one fourth, of Glauber's salt, soda and phosphate of soda only about one-fifth, of the first quantities are necessary.
The first bath should be prepared with condensed water. If none is at hand ordinary water should be boiled up with soda and soap and the scum removed. Clear soap baths are absolutely necessary for the production of pure shades and clean pieces.
After dyeing, the pieces must be very well rinsed, and the colour raised or brightened with 1 pint of acetic acid in 10 gallons of water.
Many of the Diamine and Titan colours being very fast to acids, but few of them will be affected by this treatment.
In the following tables are given those Diamine, etc., colours especially adapted for the dyeing of goods composed of silk and cotton, divided into three groups according to their relation to silk and cotton:—
1. Dye-stuffs possessing a great affinity to cotton and tinting the silk not at all or only very little. To this class belong Chicago blues, Benzo blues, Diamine fast yellow A, Diamine orange G G, Diamine orange D C, Diamine blue B B, Diamine blue 3 B, Diamine sky blue F F, Diamine brilliant blue G, Diamineral blue E, Diamine black B, Mikado browns, Mikado oranges, Mikado yellows.
2. Dye-stuffs producing on cotton and silk the same or nearly the same shade but covering the cotton better than the silk. These are Thioflavine S, Diamine yellow N, Diamine gold, Diamine fast yellow B, Diamine orange B, Diamine grey G, Diamine rose B D, Diamine scarlet S, Diamine scarlet B, Diamine scarlet 3 B, Diamine red 5 B, Diamine fast red F, Diamine Bordeaux B, Diamine Bordeaux S, Diamine violet N, Oxydiamine violet B, Diamine blue R W, Diamine black H W, Diamine steel blue L, Diamine dark blue B, Union black S, Oxydiamine black D, Diaminogene extra, Diaminogene B, Diamine brown M, Diamine brown 3 G, Diamine green B, Diamine green G.
3. Dye-stuffs producing on cotton more or less different shades than on silk. This group comprises Diamine blue C B, Diamine blue B G, Diamine blue B X, Diamine azo blue 2 R, Diamine blue 3 R, Diamine blue black E, Diamine black R O, Oxydiamine black S O O O, Diamine brown V, Diamine brown B, Diamine bronze G. Cotton brown N produces on silk darker shades than on cotton.
Of course this classification cannot be taken as absolutely correct, as by raising or lowering the temperature during the dyeing process or by a larger or smaller addition of soap or Glauber's salt (common salt, phosphate of soda), the dye-stuffs are more or less influenced in one or the other direction. Diamine violet N, for instance, when dyed with an increased addition of soap would dye the cotton somewhat lighter, but at the same time leave the silk perfectly white.
Topping with Basic and Acid Dye-stuffs.—As in very few cases only the desired shade can be obtained in the first instance by bottoming with direct colours, topping generally has to be resorted to. This is best done with basic dyes, in some cases also with acid dye-stuffs in cold or tepid bath with addition of sulphuric acid, hydrochloric or acetic acid. The use of acid dye-stuffs is restricted to cases where the silkalone is to be shaded. In most cases basic dye-stuffs are made use of, which dye silk and cotton the same shade and deepen the shade of the cotton if the latter has a sufficiently good bottom, thus giving the goods a better and fuller appearance.
It is not advisable to employ basic and acid dye-stuffs in the same bath except when the quantities of either class are very small. Should it be necessary to dye with large quantities of both classes, the acid dye-stuffs are first dyed in a tepid acid bath and then the goods are topped with the basic dye-stuffs in a fresh cold bath with the addition of a little hydrochloric or acetic acid.
Of the basic dye-stuffs which are available, the following are the most suitable for topping: New methylene blue N, and other brands; New blue D and other brands; Cresyl blue, Methylindone B and R, Metaphenylene blue, Indazine; the various brands of Brilliant green, Solid green and Malachite green, Capri green, Cresyl violet, Thioflavine T, New phosphine G, Tannin orange R, and the various brands of Bismarck brown; Safranine, Magenta all brands, Tannin heliotrope, all brands of Neutral violet, Methyl violet.
Of the acid dye-stuffs, the following are good for topping or shading the silk: Cyanole extra, Indigo blue N, Indigo blue S G N, and the various brands of Water blue, Soluble blue, Solid blue, and Induline; the various brands of Acid green and Fast acid green; Indian yellow G and R, Naphthol yellow S, Tropæoline O and O O, and the various brands of Milling yellow and Orange; Azo red A, Azo rubine A, Archil substitute N, Azo orseille B B, Brilliant orseille C, and the various brands of Eosine, Erythrosine, Rose bengale, Rhodamine, Brilliant croceine and Brilliant scarlet; the various brands of Formyl violet and Acid violet; Aniline grey B and Nigrosine, soluble in water.
Bright Yellow.—Use 2 lb. Thioflavine S.
Deep Orange Yellow.—This can be dyed by using 2 lb. Diamine yellow N.
Gold Yellow.—Dye with 2 lb. Diamine gold. Some care must be taken with this, especially not to dye too hot or the silk will be dyed deeper than the cotton.
Deep Orange.—Use 2 lb. Diamine orange B.
Bright Rose.—Use 2 lb. Diamine Rose B D. Do not work too high, especially when dyeing light rose shades, as then the silk is apt to take up too much colour.
Scarlet.—Use in the dye-bath 2 lb. Diamine scarlet H S. The heat of the dye-bath should not be allowed to exceed 160° to 170° F., or there is a risk of the shades becoming somewhat duller.
Crimson.—Dye with 2 lb. Diamine fast red F.
Violet.—Use 2 lb. Oxydiamine violet B.
Bright Blue.—A fine shade is dyed with 2 lb. Diamine blue R W.
Dark Green.—Use 2 lb. Diamine black H W. This gives a fine shade of bluish green.
Gold Brown.—Dye with 2 lb. Diamine brown 3 G at a low heat, from 150° to 160° F., otherwise the silk takes up too much colour.
Dark Green.—Dye with 2 lb. Diamine green B.
Deep Rose.—Dye with 2 lb. Diamine red 10 B.
Brilliant Yellow.—Dye with 1½ lb. Mikado golden yellow 8 G; then enter into a cold bath which contains 1½ per cent. Auramine II. This gives a very bright shade of yellow.
Dark Brown.—Dye a bottom with 2 lb. Mikado brown 3 G O, and then top with 3 lb. Bismarck brown and ½ lb. Capri blue G O N.
Crimson.—Dye with 2 lb. Mikado orange 5 R O and 2 lb. Hessian purple N.
Sage Green.—Dye a bottom with 2 lb. Mikado yellow G, 14 oz. Eboli green T and 3 oz. Mikado brown M, then top ina fresh cold bath with ½ lb. Auramine II and ½ oz. Acridine Orange N 0.
Leaf Green.—Dye a bottom with 3 lb. Mikado golden yellow 8 G and 1 lb. Eboli blue B; then top with 1½ lb. Capri green 2 G in a cold bath.
Deep Brown.—Dye with 2 lb. Mikado orange 3 R O, 3 lb. Hessian grey S and 1 lb. Hessian brown 2 B N; then top with 7 oz. Azine green T 0 and 2¼ lb. Acridine orange N 0.
Dark Cream.—Bottom with 1 oz. Diamine orange G; then top in a fresh warm bath with 1 oz. Orange G G, ½ oz. Indian yellow R, 5 lb. Glauber's salt and 1 lb. acetic acid.
Brilliant Violet.—Give a bottom with 1 lb. Diamine violet N; then top in a fresh warm bath with 4 oz. Methyl violet B and 2 oz. Rhodamine.
Slate.—Bottom in a hot bath with 6 oz. Diamine dark blue B and 1½ oz. Diamine brown M; then top in a fresh bath at 170° F. with 4 oz. Aniline grey B, 1 oz. Cyanole extra, 5 lb. Glauber's salt and 1 lb. acetic acid.
Black Brown.—Give a bottom with 2 lb. Cotton brown A, 1 lb. Diamine gold and 3½ lb. Oxydiamine black S O O O; then top in a fresh bath at 120° F. with 4 oz. New methylene blue N, 1 oz. Safranine and ½ oz. Indian yellow G.
Bright Violet.—Use ½ lb. Oxydiamine violet B and ¾ oz. Diamine dark blue B; top after dyeing with ½ oz. Safranine, ¼ oz. Methylindone B and ¼ oz. Cyanole extra.
Drab.—Dye with 6 oz. Diamine orange G, 1 lb. Diamine bronze G and ¾ lb. Diamine brown M, topping afterwards in a bath of ¼ oz. Aniline grey B and ¼ oz. Bismarck brown F F.
Leaf Green.—Dye with ½ lb. Diamine black H W, and 1 lb. Diamine fast yellow B; top with ¼ oz. Brilliant green, ¼ oz. Indian yellow R, ½ oz. Thioflavine T and ½ oz. Cyanole extra.
Dark Crimson.—Use in the dye-bath 3 lb. Diamine Bordeaux S, ¾ lb. Diamine orange D C and 1½ lb. Diamine brown V, topping with 1 oz. Magenta and ½ oz. Formyl violet S 4 B.
Turquoise Blue.—Use to dye the ground, 6 oz. Diamine sky blue F F and ½ oz. Diamine fast yellow A; top with 1½ oz. Cyanole extra and ¼ oz. Brilliant green.
Dark Grey.—Dye with ½ oz. Diamine grey G, and 1½ oz. Diamine brown M; top with ¼ oz. Orange extra and 1 oz. Cyanole extra.
Brilliant Orange.—Dye with 1 lb. Mikado orange R O, and top with 6 oz. Acridine orange N O and 12 oz. Auramine I I.
Brown.—Dye a bottom colour with 3 lb. Mikado brown M, and top with 2 lb. Bismarck brown and 6 oz. Cresyl fast violet 2 R N.
Deep Crimson.—Dye with 1 lb. Columbia black R and top with 6 oz. Magenta.
Pale Sea Green.—Use in the dye-bath ½ oz. Chrysophenine G, 1½ oz. Chicago blue 6 B and 1½ oz. Alkali blue 6 B.
Bright Crimson.—Dye with 3 lb. Congo Corinth and top with 1 lb. Magenta.
Dark Russian Green.—Dye with 3 lb. Columbia black B; then top with 1 lb. Malachite green.
Gold Drab.—Dye with 5 oz. Columbia black, and top with 5 oz. Chrysoidine R.
Bright Olive Yellow.—Dye with 1½ lb. Diamine gold, 1½ lb. Diamine fast yellow A and ¾ lb. Diamine bronze G; top with ½ lb. Thioflavine T and ¼ lb. Chrysoidine.
Moss Brown.—Dye with 1 oz. Diamine brown M, 6 oz. Diamine fast yellow A, 6 oz. Diamine bronze G, topping with 1 oz. new Methylene blue N and 4 oz. Orange G G.
Dark Sea Green—Dye a bottom with 9 oz. Diamine black B and 4½ oz. Diamine fast yellow B, then top with 2 oz. New methylene blue M and 2 oz. New phosphine G.
Old Gold.—Dye a ground with ½ lb. Diamine gold, 1¼ lb. Diamine fast yellow A, and 6 oz. Diamine bronze G, topping with 8 oz. Thioflavine T, 1 oz. Indian yellow R and 1 oz. Brilliant green.
Cornflower Blue.—Dye the ground with 2½ lb. Diamine azo blue 2 B, 1½ oz. Alkali blue 3 B, ½ lb. Oxydiamine black S O O O, and top with 1 oz. Metaphenylene blue B, 2 oz. New methylene blue R and 1 oz. Indigo blue N.
Slate.—Dye with 7 oz. Diamine dark blue B and 1 oz. Diamine brown M; top with 1 oz. Aniline grey B and 1 oz. Cyanole extra.
Pale Drab.—Dye the ground with 1 oz. Diamine orange G C, ¾ oz. Diamine bronze G and ½ oz. Diamine brown M; top with ¾ oz. New methylene blue N, 1 oz. Bismarck brown and 1 oz. Cyanole extra.
Deep Leaf Green.—Dye a ground colour with 1¼ lb. Diamine bronze G, 1½ lb. Diamine fast yellow A and 1½ lb. Diamine black H W; the topping bath is made with ½ lb. Brilliant green, ½ lb. Chrysoidine and ¼ lb. New methylene blue N.
Maroon.—Dye with 3 lb. Diamine Bordeaux S, ½ lb. Diamine orange D C and ½ lb. Diamine brown V; top with ½ lb. Magenta and ¼ lb. Formyl violet S 4 B.
Heliotrope.—Dye with 1 lb. Heliotrope 2 B.
Lilac Rose.—Dye with 8 lb. Columbia black R and 1 lb. Alkali blue B; after dyeing pass through a weak acetic acid bath, then wash well.
Pea Green.—Dye with 2 lb. Chrysophenine, 1 lb. Chicago blue 6 B and 1 lb. Alkali blue 6 B; pass, after dyeing, through a weak acetic acid bath, then wash well.
Dark Drab.—Dye with ¼ lb. Diamine brown M, 1 lb. Diamine fast yellow A and ¾ lb. Diamine bronze G; top with ½ lb. Orange G G and ½ lb. Cyanole extra.
Deep Rose.—Dye the bottom colour with ½ lb. Diamine rose B D and top with ¼ lb. Rhodamine B and 1 oz. Safranine.
Walnut Brown.—Dye the bottom colour with 1 lb. Oxydiamine black D, 1 lb. Diamine brown M and 1 lb. Oxydiamine violet B; the topping is done with 4 oz. Safranine, 2 oz. New methylene blue N and 2 oz. Chrysoidine.
Dyeing of Plain Black.—Diamine blacks find a very extensive application for dyeing blacks on satin, either dyed direct in one bath, or dyed, diazotised and developed.
Union black S and Oxydiamine black D are particularly suitable for direct blacks, and are used either alone or in a combination with Diamine jet black S S, which produces a better covering of the silk, or with Oxydiamine black S O O O, which deepens the shade of the cotton. According to the shade required Diamine fast yellow A and B, Diamine green B or G, or Alkaline blue may be used for shading.
Dye for about one hour at about 175° to 195° F. in as concentrated a bath as possible, with about 7 to 8 lb. dye per 100 lb. of satin, 8 to 16 oz. Glauber's salt and 5 to 8 oz. soap per 10 gallons dye liquor; keep cool in the bath for some time and rinse.
The raising is either done in a tepid soap bath with the addition of some new methylene blue, or in an acid bath to which Naphthol, blue black, Acid green, etc., is added for shading the silk.
Direct dyed blacks are especially suitable for cheap goods (ribbons, light linings, etc.), for which special fastness to water is not required; also for tram and tussar silk plushes, which are afterwards topped with logwood.
If greater fastness is required, and more especially if it is a case of replacing aniline black, Diaminogene diazotised and developed is a good dye-stuff. It is extensively used for dyeing umbrella cloths and linings. Against aniline black it has the great advantage of not tendering the fibre in the least, and not turning green during storage. Diaminogene B and Diaminogene extra are mostly used for this purpose, the former for jet blacks, the latter for blue-black shades.
Proceed as follows: Enter the boiled off and acidulated goods in a boiling bath as concentrated as possible, chargedwith 16 oz. Glauber's salt per 10 gallons liquor, and 1 lb. acetic acid per 100 lb. dry goods. For jet black add for 100 lb. satin, 6 to 8 lb. Diaminogene, 1 to 2 lb. Naphthylamine black D, ½ to 1 lb. Diamine fast yellow A or Diamine green B; for very deep shades about 1/5 of the quantity of Diaminogene B may be replaced with Diamine jet black S S. For blue black, 6 to 8 lb. Diaminogene B, or 3 to 4 lb. Diaminogene B, and 3 to 4 lb. Diaminogene extra. Dye for three-quarters to one hour at the boil, allow to cool in the bath for about thirty minutes, then rinse, diazotise and develop.
Phenylene diamine (93 per cent.) serves for developing jet blacks mixed with resorcine for greenish shades. Beta-naphthol is used for blue blacks (1 lb. 5 oz. per 100 lb. of dry material, dissolved in its own weight of soda lye, 75° Tw.). The three developers may also be mixed with each other in any proportions.
After developing soap hot with addition of new methylene blue, by choosing a reddish or a bluish brand of new methylene, blue and black may be shaded at will in the soap bath; finally rinse and raise with acetic acid.
If properly carried out this process will give a black almost equal to aniline black; but having, as already mentioned, the advantage of not impairing the strength of the fibre, and not turning green during storage.
As the dye-baths for blacks are charged with a proportionately high percentage of dye-stuff for the first bath, and will not exhaust completely, it is advisable to preserve them for further use.
For subsequent lots only two-thirds to three-fourths of the quantities of dye-stuffs used for the first baths are required, which fact has to be taken into consideration when calculating the cost of dyeing.
Dyeing Shot Effects on Satin.—Not all direct colours are equally well adapted for the production of shot effects;those enumerated in Group I. are most suitable for the purpose, and should be dyed with a larger quantity of soap than is usual for solid shades, in order to leave the silk as little tinted as possible. Dye-stuffs of the other groups may be used if the dyeing is conducted with proper care,i.e., keeping the baths more alkaline and lowering the temperature. The goods are dyed with the addition for the two coloured effects previously mentioned, then they are well rinsed, and afterwards the silk is dyed with the suitable acid dye-stuffs, with addition of sulphuric acid at a temperature of about 150° F. Care should be taken not to use too much acid, and to keep the temperature of the bath sufficiently low, as otherwise the acid may cause some of the dye-stuff to go off the cotton and tint the silk. It is best to work at a temperature of about 150° F., with addition of about 3 oz. concentrated sulphuric acid per 10 gallons dye-liquor.
For shading the silk all acid dye-stuffs can be used which have been mentioned in the foregoing tables.
If in shot effects the cotton is to be dyed bright and full shades, this is best achieved by dyeing with direct colours first, and then topping with basic colours as follows:—
Bottom the cotton first with the suitable direct colours, then dye the silk and then treat the pieces for about two hours in a cold tannin bath (about 8 oz. tannin per 10 gallons of water), then rinse once and pass through a tartar emetic bath (about 3 oz. per 10 gallons), rinse thoroughly and dye the cotton to shade with basic colours in a cold bath to which some acetic acid has been added.
Should the silk become a little dull after this process, this may be remedied by a slight soaping. After dyeing rinse well and raise with acetic acid.
Shot Effects with Black Cotton Warp.—Effects much in favour are designs composed of black cotton and light orcoloured silk. The most suitable black dye for this purpose is Diamine black B H, diazotised and developed.
Dye in as concentrated a bath as possible at about 160° F. with about 6 lb. Diamine black B H, 1 lb. Diamine sky blue, pat., per 100 lb. of dry goods, ½ lb. Diamine orange D C, pat., with an addition of 6½ oz. soap, 4 to 5 dr. soda per 10 gallons liquor, 16 oz. Glauber's salt. After dyeing rinse well in a bath containing 6 dr. soda and 3 oz. soap per 10 gallons water, diazotised in a fresh bath with 4 lb. nitrite of soda and 12 lb. hydrochloric acid (per 100 lb. of dry goods), rinse thoroughly and develop with 3 to 16 oz. phenylene diamine (93 per cent.), with addition of 1 to 2 lb. soda. These two operations should follow each other as quickly as possible, also care has to be taken that the diazotised goods are not exposed to direct sunlight or heat, which causes unlevel dyeings. The silk is then cleaned as far as possible by hot soaping, and dyed at about 120° to 140° F., with acid dye-stuffs and the addition of sulphuric acid. After dyeing rinse as usual and brighten.
Yellow and Violet,—Dye the cotton with 2 lb. Diamine fast yellow A, the silk with 1 lb. Cyanole extra, and 1 lb. Forinyl violet S 4 B.
Black and Blue.—Dye the cotton with 5 lb. Diamine black B H, 1 lb. Diamine sky blue, and ¼ lb. Diamine orange D C. After dyeing, diazotise and develop with phenylene diamine as described above. Then dye the silk with ½ lb. Pure soluble blue and 1 lb. Cyanole extra.
Black and Crimson.—Dye the black as in the previous recipe, then dye the silk with 2 lb. Brilliant croceine 3 B and ½ lb. Rhodamine S.
Blue and Gold.—Dye the cotton with 2 lb. Diamine sky blue and the silk with 1 lb. Fast yellow S.
Dark Blue and Green.—Dye the cotton with 1½ lb. Diamine black B H, 1½ lb. Diamine sky blue and ½ lb. Diamine azoblue 2 R; the silk with 2 lb. Naphthol yellow S and 1 lb. New methylene blue G G.
Violet and Yellow.—Dye the cotton with 2 oz. Diamine violet N and the silk with 1 lb. Fast yellow S.
Orange and Violet.—Dye the cotton with 2 lb. Diamine orange D C and the silk with 1 lb. Formyl violet S 4 B.
Dark Blue and Olive.—Dye the cotton with 1½ lb. Diamineral blue R and ½ lb. Diamine azo blue 2 R, and the silk with 1 lb. Naphthol yellow B and 1 lb. Orange G G.
Green and Pink.—Dye the cotton with 1½ lb. Diamine fast yellow A and ¼ lb. Diamine sky blue, and the silk with 1 lb. Erythrosine B.
Brown and Blue.—Dye the cotton with 3 lb. Mikado brown 2 B, and the silk with ½ lb. Pure blue.
It is quite possible to produce two coloured effects containing blue in one bath by using Alkali blue as a constituent with a direct dye which works only on to the cotton, the alkali blue going on to the silk, as, for example, in the following recipes:—
Orange and Blue.—The dye-bath is made with 3 lb. Mikado orange 5 R O and 1¼ lb. Alkali blue 6 B. After the dyeing the goods are rinsed, then passed through a bath of 1½ lb. sulphuric acid in 10 gallons water, washed well and dried.
Olive and Blue.—The dye-bath is made with 1½ lb. Diamine fast yellow A, 2½ lb. Diamine orange DC, ¼ lb. Diamine sky blue, and 1 lb. Alkali blue 6 B, After dyeing rinse, then acidulate as above and wash well.
OPERATIONS FOLLOWING DYEING.
WASHING, SOAPING, DRYING.
After loose cotton or wool, or cotton and woollen yarns, or piece goods of every description have been dyed, before they can be sent out for sale they have to pass through various operations of a purifying character. There are some operations through which cloths pass that have as their object the imparting of a certain appearance and texture to them, generally known as finishing processes; of these it is not intended here to speak, but only of those which precede these, but follow on the dyeing operations.
These processes are usually of a very simple character, and common to most colours which are dyed, and here will be noticed the appliances and manipulation necessary in the carrying out of these operations.
Squeezing or Wringing.—It is advisable when the goods are taken out of the dye-bath to squeeze or wring them according to circumstances, in order to press out all surplus dye-liquor, which can be returned to the dye-bath if needful to be used again. This is an economical proceeding in many cases, especially in working with many of the old tannin materials like sumac, divi-divi, myrobolams, and the modern direct dyes which in the dyeing operations are not completely extracted out of the bath, or in other words, the dye-bath is not exhausted of colouring matter, and, therefore, it canbe used again for another lot of goods, simply by adding fresh material to make up for that absorbed by the first lot of goods.
Loose wool and loose cotton are somewhat difficult to deal with by squeezing or wringing, but the material may be passed through a pair of squeezing rollers, such as are shown in Fig. 31, which will be more fully dealt with later on. The machine shown is made by Messrs Read Holliday & Sons.
FIG. 31.--Squeezing Rollers.FIG. 31.—Squeezing Rollers.
Yarns in Hanks.—In the hank-dyeing process the hanks are wrung by placing one end of the hank on a wringinghorse placed over the dye-tub, a dye stick on the other end of the hank giving two or three sharp pulls to straighten out the yarn, and then twisting the stick round, the twisting of the yarns puts some pressure on the fibres, thoroughly and uniformly squeezing out the surplus liquor from the yarn.
Hank-wringing Machines.—Several forms of hank-wringing machines have been devised. One machine consists of a pair of discs fitted on an axle; these discs carry strong hooks on which the hanks are placed. The operator places a hank on a pair of the hooks. The discs revolve and carry round the hank, during the revolution the hank is twisted and the surplus liquor wrung out, when the revolution of the discs carries the hank to the spot where it entered the machine the hooks fly back to their original position, the hank unwinds, it is then removed and a new hank put in its place, and so the machine works on, hanks being put on and off as required. The capacity of such a machine is great, and the efficiency of its working good.
Mr. S. Spencer of Whitefield makes a hank-wringing machine which consists of a pair of hooks placed over a vat. One of the hooks is fixed, the other is made to rotate. A hank hung between the hooks is naturally twisted, and all the surplus liquor wrung out. The liquor falling into the vat.
Roller Squeezing Machines for Yarn.—Hanks may be passed through a pair of indiarubber squeezing rollers, which may be so arranged that they can be fixed as required on the dye-bath. Such a pair of rollers is a familiar article, and quite common and in general use in dye houses.
Piece Goods.—These are generally passed open through a pair of squeezing rollers which are often attached to the dye-vat in which the pieces are dyed.
Read Holliday's Squeezing Machine.—In Fig. 31 is shown a squeezing machine very largely employed for squeezingall kinds of piece goods and cotton warps after dyeing or washing. It consists of a pair of heavy rollers on which, by means of the screws shown at the top, a very considerable pressure can be brought to bear. The piece is run through the eye shown on the left, by which it is made into a rope form, then over the guiding rollers and between the squeezing rollers, and into waggons for conveyance to other machines. This machine is effective.
Another plan on which roller, or rather in this case disc, squeezing machines is made, is to make the bottom roller with a square groove in the centre, into this fits a disc, the cloth passing between them. The top disc can by suitable screws be made to press upon the cloth in the groove, and thus squeeze the water out of it.
Washing.—One of the most important operations following that of dyeing is the washing with water to free the goods, whether cotton or woollen, from all traces of loose dye, acids, mordanting materials, etc., which it is not desirable should be left in, as they might interfere with the subsequent finishing operations. For this purpose a plentiful supply of good clean water is required; this should be as soft as possible, free from any suspended matter which might settle upon the dyed goods, and stain or speck them.
Washing may be done by hand, as it frequently was in olden days, by simply immersing the dyed fabrics in a tub of water, shaking, then wringing out, again placing in fresh water to finish off. Or if the dye-works were on the banks of a running stream of clean water the dyed goods were simply hung in the stream to be washed in a very effectual manner.
In these days it is best to resort to washing machines adapted to deal with the various kinds of fibrous materials and fabrics in which they can be subjected to a current of water.
FIG. 32.--Yarn-washing Machine.FIG. 32.—Yarn-washing Machine.
Loose Wool and Cotton.—If this has been dyed by hand then the washing may also be done in the same way by hand in a plain vat. If the dyeing has been done on a machine, then the washing can be done on the same machine.
Yarns.—Yarn in the cop form is best washed in the machine in which it is dyed.
Yarns in Hanks.—A very common form of washing machine is shown in Fig. 32. As will be seen it consists of a wooden vat, over which are arranged a series of revolving reels on which the hanks are hung. The hanks are kept in motion through the water, and so every part of the yarn is thoroughly washed. Guides keep the hanks of yarn separate and prevent any entanglement one with another. A pipe delivers constantly a current of clean water, while another pipe carries away the used water. Motion is given to the reels in this case by a donkey engine attached to the machine, but it may also be driven by a belt from the main driving shaft of the works. This machine is very effective.
FIG. 33.--Dye-house Washing Machine.FIG. 33.—Dye-house Washing Machine.
Piece Goods.—Piece goods are mostly washed in machines,of which two broad types may be recognised; first, those where the pieces are dealt with in the form of ropes in a twisted form, and, second, those where the pieces are washed open. There are some machines in which the cloths may be treated either in the open or rope form as may be thought most desirable.
FIG. 34.--Cloth-washing Machine.FIG. 34.—Cloth-washing Machine.
Fig. 33 represents a fairly well-known machine, made by Messrs. Mather & Platt, in which the pieces are treated in a rope-like form. It consists of a trough in which a constant current of water is maintained. At one end of this trough is a square beating roller, at the other a wooden lattice roller. Above the square beater, and out of the trough, are a pair of rollers whose purpose is to draw the cloth through the machine and also partly to act as squeezing rollers. As will be seen the cloth is threaded in rope form spirally round the rollers, passing in at one end and out at the other, pegs in a guide rail serving to keep the various portions separate. The square beater in its revolutions has a beating action on the cloth tending to more effectual washing. The lattice roller is simply a guide roller.
Fig. 34 shows a washing machine very largely used in the wool-dyeing trade. The principal portion of this machine is of wood.
The internal parts consist of a large wooden bowl, or oftener, as in the machine under notice, of a pair of wooden bowls which are pressed together by springs with some small degree of force. Between these bowls the cloth is placed, more or less loosely twisted up in a rope form, and the machines are made to take four, six or eight pieces, or lengths of pieces, at one time, the ends of the pieces being stitched together. A pipe running along the front of the machine conveys a constant current of clean water which is caused to impinge in the form of jets on the pieces of cloth as they run through the machine, while an overflow carries away the used water. The goods are run in this machine until they are considered to be sufficiently washed, which may take half to one and a half hours.
In Fig. 35 is shown a machine designed to wash pieces in the broad or open state. The machine contains a large number of guide rollers, built more or less open, round whichthe pieces are guided—the ends of the pieces being stitched together. Pipes carrying water are so arranged that jets of clean water impinge on and thoroughly wash the cloth as it passes through—the construction of the guide rollers facilitating the efficient washing of the goods.
FIG. 35.--Cloth-washing Machine.FIG. 35.—Cloth-washing Machine.
Soaping.—- Sometimes yarns or cloths have to be passed through a soap bath after being dyed in order to brighten up the colours or develop them in some way. In the case of yarns this can be done on the reel washing machine such as is shown in Fig. 32. In the case of piece goods, a continuous machine, in which the washing, soaping, etc., can be carried on simultaneously, is often employed. Such a machine is shown in Fig. 36. It consists of a number of compartments fitted with guide rollers so that the cloth passes up and down several times through the liquors in thecompartments. Between one compartment and another is placed a pair of squeezing rollers. The cloth is threaded in a continuous manner, well shown in the drawing, through the machine. In one compartment it is treated with water, in another soap liquor, in another water, and so on; and these machines may be made with two, three or more compartments as may be necessary for the particular work in hand. As seen in the drawing, the cloth passes in at one end and out at the other finished. It is usually arranged that a continuous current of the various liquors used flows through the various compartments, thus ensuring the most perfect treatment of the cloths.
FIG. 36.--Washing and Soaping Vats.FIG. 36.—Washing and Soaping Vats.
Steaming.—Sometimes it becomes necessary to subject dyed goods to a process of steaming, as, for instance, with steam aniline blacks, khaki shades, alizarine reds, etc., for the purpose of more fully developing and fixing the dye upon the fibre. In the case of yarns, this operation is carried out in the steaming cottage, one form of which is shown in Fig. 37. It consists of a horizontal cylindrical iron vessel like a steam boiler, one end is entirely closed, while the other is made to open and be closed tightly and hermetically. The cottage is fitted with the necessary steam inlet and outlet pipes, drain pipes for condensed water, pressure gauges. The yarn to be steamed is hung on rods placed on a skeleton frame waggon on wheels which can be run in and out of the steaming cottage as is required. The drawing shows well the various important parts of the machine. In the case of piece goods these also can be hung from rods in folds on such a waggon, but it is much more customary to employ a continuous steaming chamber, very similar to
FIG. 37.--Steaming Cottage.FIG. 37.—Steaming Cottage.
the ageing and oxidising machine shown in Fig. 38, and also used in the dyeing of aniline black.
Drying.—Following on the washing comes the final operation of the dyeing process, that of drying the dyed and washed goods. Textile fabrics of all kinds after they have passed through dye-baths, washing machines, etc., contain a large amount of water, often exceeding in weight that of the fibre itself, and to take the goods direct from the preceding operations to the drying plant means that a considerable amount of fuel must be expended to drive
FIG. 38.--Steaming and Ageing Chamber.FIG. 38.—Steaming and Ageing Chamber.
off this large amount of water. It is therefore very desirable that the goods be freed from as much of this water as possible before they are sent into any drying chambers, and this may be done in three ways, by wringing, squeezing and hydro-extracting. The first two methods have already been described (p. 239, etc.) and need not again be alluded to; the last needs some account.
FIG. 39.--Hydro-extractor.FIG. 39.—Hydro-extractor.
Hydro-extractors are a most efficient means for extracting water out of textile fabrics. They are made in a variety of forms by several makers. Essentially they consist of a cylindrical vessel, or basket, as it is called, with perforated sides so constructed that it can be revolved at a high speed. This vessel is enclosed in an outer cage. The goods are placed in the basket, as it is termed, and then this is caused to revolve at high speed, when centrifugal action comes into play, and the water contained in the goods finds its way to the outside of the basket through the perforations,and so away from the goods. Hydro-extractors are made in a variety of sizes and forms—in some the driving gear is above, in others below the basket; in some the driving is done by belt-gearing, in others a steam engine is directly connected with the basket. Figs. 39 and 40 show two forms which are much in use in the textile industry. They are very efficient, and extract water from textile goods more completely than any other means, as will be obvious from a study of the table below.
FIG. 40.--Hydro-extractor.FIG. 40.—Hydro-extractor.
The relative efficiency of the three systems of extracting the moisture out of textile fabrics has been investigated by Grothe, who gives in hisAppretur der Gewebe, published in 1882, the following table showing the percentage amount of water removed in fifteen minutes:—
Yarns. Wool. Silk. Cotton. Linen.Wringing 44.5 45.4 45.3 50.3 Squeezing 60.0 71.4 60.0 73.6 Hydro-extracting 83.5 77.0 81.2 82.8
Pieces. Wringing 33.4 44.5 44.5 54.6 Squeezing 64.0 69.7 72.2 83.0 Hydro-extracting 77.8 75.5 82.3 86.0
In the practical working of hydro-extractors it is of the utmost importance that the goods be carefully and regularly laid in the basket—not too much in one part and too little in another. Any unevenness in this respect at the speed at which they are driven lays such a strain on the bearings as to seriously endanger the safety of the machine.
After being wrung, squeezed or hydro-extracted the goods are ready to be dried. In the case of yarns, this may be done in rooms heated by steam pipes placed on the floor, the hanks being hung on rods suspended from racks arranged for the purpose.