The Dyeing of Woollen Fabrics Part 8

acetate of ammonia, 5 oz. Acid Blue 4 S, and 1-1/2 oz. t.i.tan Brown R, working at the boil for one hour.

_Silver Grey_.--A very nice shade is dyed with 3 oz. Acid Blue 4 S, 1/4 oz. t.i.tan Red, and 5 oz. acetate of ammonia.

_Silver Grey_.--A shade similar to the last is dyed in a bath containing 10 lb. Glauber's salt, 5 lb. bisulphate of soda, and 3/4 oz. Anthracite Black R. By adding a little Thiocarmine R the (p. 099) shade can be turned bluer in tone, while the addition of a little Milling Yellow O, or t.i.tan Yellow, turns it to the green side.

_Pearl Grey_.--Make the dye-bath with 10 lb. Glauber's salt, 5 lb.

acetic acid, and 3/4 lb. Naphthylamine Black D. This gives fine shades of pearl grey.

_Bluish Grey_.--Mordant the wool by boiling in a bath made with 2 lb.

bichromate of potash, 1 lb. tartar, and 1 lb. sulphuric acid. Dye in a bath containing 2 oz. Diamine Black (or 3/4 oz. Diamond Black and 1-1/2 oz. Alizarine Cyanine R), working at the boil for an hour and a half.

_Grey_.--This can be dyed with 3 oz. Nyanza Black B, and 10 lb.

Glauber's salt, working at the boil.

_Reddish Grey_.--A good full shade is dyed with 1-1/2 oz. Cyanole extra, 1/4 oz. Orange extra, 3/4 oz. Archil Subst.i.tute N, 10 lb.

Glauber's salt and 3 lb. sulphuric acid.

_Slate Grey_.--The dye-bath is made with 3 oz. Cyanole extra, 1/2 oz.

Archil Subst.i.tute N, 3/4 oz. Orange extra, 10 lb. Glauber's salt and 2 lb. sulphuric acid.

_Bright Pearl Grey_.--Prepare a dye-bath with 3/4 oz. Patent Blue, 1/2 oz. Acid Violet N, 3/4 oz. Orange G, 10 lb. Glauber's salt and 2 lb. sulphuric acid.

_Stone Grey on Wool_.--The dye-bath is made with 1/2 oz.

Chromotrop 2 R, 3/4 oz. Cyanole extra, 1-1/2 oz. Fast Acid Blue R, 3/4 oz. Acid Yellow, 20 lb. Glauber's salt, 3 lb. acetic acid. Enter at 80 F., then warm slowly and work to shade, lift, wash and dry.

These recipes will probably be sufficient to show the lines on which greys may be obtained in wool dyeing. It may be added that from the Acid Blacks B, B B, and S, good greys of a violet tone may be obtained, using from 1/2 to 3/4 oz. dye-stuff. The Naphthol Blacks will also be found useful in the same way, while the greys from Anthracene Chrome Blacks and the Alizarine blacks are very good and fast.

#Red Shades on Wool.#--The number of red shades that may be dyed (p. 100) on wool is infinite. They range over every variety of tint of red, from the palest blush-rose to the deepest crimson, and from the most brilliant pink to the dullest grenat shade.

It is quite impossible here to describe the dyeing of every imaginable shade of red, while the great variety of red dye-stuffs, both natural and artificial, adds to the difficulty of dealing in the s.p.a.ce at command with all the various methods and dyes that may be used in the dyeing of reds on wool.

The methods that may be adopted for dyeing red shades on wool are many and various, depending not only on the particular dye-stuff used, but often on the particular shade that is being dyed. One method, which will yield a pale and useful tint with a particular dye-stuff, would fail if a full shade were necessary.

The greater number of red shades are now dyed by means of the artificial dye-stuffs, as these are much easier to dye than are the natural dyes, and they give, on the whole, more even and brilliant shades, while as regards fastness to milling, acids, and light they are fully equal, and in most cases superior, to the natural dyes.

#The Direct Red Dyes.#--Of this group of red dye-stuffs, Benzopurpurine, t.i.tan Scarlet, Diamine Fast Red F, and Benzo Fast Red are types; many of them have been found to be very serviceable in wool dyeing. They may be dyed either from plain baths containing common salt or Glauber's salt, or from baths containing common salt or Glauber's salt and a little acetic acid.

Alkaline or soap baths do not work well as a rule, and must be avoided in wool dyeing. Generally the dye-bath is exhausted of colour, and full shades are easily obtained, while these reds are in general remarkable for the evenness and uniformity of tint which can be (p. 101) produced. The reds so dyed are, on the whole, fairly fast to soaping, and can be used for dyeing goods that have to be milled, while their resistance to light and air is fairly good. Benzopurpurine and Diamine Red are more or less affected by acids, but the t.i.tan Red and some of the more modern reds, Diamine Brilliant Scarlet, Benzo Fast Scarlets, are all fast to acids. The fastness to washing and light of some of them, Benzo Fast Red, Diamine Fast Red F, t.i.tan Red, is much increased by adding, after the wool has been dyed, 3 per cent. of fluoride of chromium to the dye-bath, and working a little longer.

The dyeing with these colours is done at the boil, and the goods may be entered direct into the boiling bath without fear of uneven shades being produced. This bath may be kept as a standing one, simply adding as each lot is dyed the necessary quant.i.ty of dye-stuff, a little fresh water to bring the bath up to its original volume, and a corresponding quant.i.ty of the salt originally added. The wool can then be entered and dyed.

In place of using salt or Glauber's salt, acetate of ammonia is an excellent a.s.sistant for this cla.s.s of dyes.

The following are some recipes for dyeing various shades of red on wool with this cla.s.s of dyes.

_Scarlet_.--The dye-bath is made with 3 lb. t.i.tan Scarlet C B, and 10 lb. acetate of ammonia. This gives a good bright shade of scarlet, which is fast to acids and soaping, although not fast to light.

_Scarlet_.--Dye in a bath made with 3 lb. Diamine Scarlet B and 10 lb.

Glauber's salt. This yields a light shade, not so fast to acids as the last, but equally fast to soaping and light.

_Scarlet_.--Make the dye-bath with 3 lb. Benzopurpurine 4 B, and 10 lb. Glauber's salt. This also gives a good shade of Scarlet fast to soaping. It is turned dark blue by acids, and is not fast to (p. 102) light. It is very largely used on underwear goods, but is not so satisfactory for this as the t.i.tan Scarlet C B, or Benzo Fast Scarlet B S.

_Scarlet_.--The dye-bath may be made with 3 lb. Brilliant Congo G, 10 lb. Glauber's salt and 2 lb. acetate of ammonia. This gives a satisfactory shade of scarlet.

_Bright Scarlet_.--The dye-bath prepared with 2 lb. Geranine G, 5 lb.

sulphate of soda, 5 lb. acetate of ammonia. Work at the boil for one hour, then wash and dry.

_Dark Crimson_.--Prepare a dye-bath with 1-1/2 lb. Chrysophenine, 1-1/2 lb. Hessian Violet, 25 lb. salt. Heat to 150 F., enter the goods, heat to boil and dye boiling for one hour, take out, rinse and wash.

_Scarlet_.--A brilliant shade of scarlet can be dyed in a bath of 3 lb. Benzo Fast Red, 1 lb. Chrysophenine, 10 lb. Glauber's salt and 2 lb. acetic acid.

_Fast Red_.--Dye the wool in a bath boiling, containing 1 lb. Diamine Fast Red F, 10 lb. Glauber's salt, and 2 lb. acetic acid, until the bath is exhausted, then add 3 lb. fluoride of Chrome and work half an hour longer at the boil.

_Bordeaux_.--Dye with 3 lb. Diamine Bordeaux, and 10 lb. Glauber's salt.

_Pink_.--Dye with 2 lb. Diamine Rose B D, 10 lb. Glauber's salt and 1 lb. acetic acid.

The basic red dyes are not very numerous, and comprise Magenta, Saffranine, Acridine Reds, Acridine Scarlets, Rhoduline Reds, Rhodamine and Neutral Beds. For successful dyeing they require a perfectly neutral bath. This bath should contain 10 per cent. of Glauber's salt, and is started cold and not too strong; when all the material has been entered the steam may be turned on and the temperature slowly raised, the material being turned over and over.

The operation is continued only until the bath has been exhausted of colour, when it is stopped, and the wool taken out, and washed (p. 103) and dried. The liquor in the dye-baths may be allowed to cool down, and then it may be used for making the dye-bath for a second lot of goods, or it may be run away. It is best not to add the dye to the bath all at once, but in several portions as the work proceeds. The affinity of the wool for the basic dyes is usually so strong that if all were added to the dye-bath at the start, then the first portion of the goods entered might take up all, or nearly all, the colour, leaving but little for the last portion; the consequence being that the goods are dyed of an uneven colour, deeper in some parts than others. This defect is remedied by adding the dye in portions, entering the goods rather quickly, working cold, or by adding a little acetic acid and plenty of Glauber's salt. Notwithstanding all these precautions it is quite possible for the shades to come up somewhat uneven. These remarks are applicable not only to the basic reds but to the whole range of basic dyes, hence this cla.s.s of dye-stuffs is but little used in the dyeing of wool.

_Crimson_.--Make the dye-bath with 2 lb. Magenta, and 15 lb. Glauber's salt, working as described above. This gives a fine crimson shade which, however, is not fast to soaping or to light. The quant.i.ty of dye-stuff given above should not be exceeded or the shades may come up bronzy, this may be avoided if a trace of acetic acid is added to the dye-bath.

_Crimson_.--Dye with 2-1/2 lb. of Saffranine and 15 lb. Glauber's salt. This dyes a fine Crimson shade.

_Deep Red_.--Use 3 lb. Rhoduline Red and 10 lb. Glauber's salt.

_Scarlet_.--The dye-bath is made with 1 lb. Saffranine Prima, 1 lb.

Auramine, and 10 lb. Glauber's salt. The goods are entered into the dye-bath at about 120 F., and well worked about, then the temperature is raised slowly. When the dye-bath is exhausted the goods are lifted, washed and dried. There are no pure basic scarlets, and the above and similar combinations of a basic red and a basic yellow are the (p. 104) only ways in which a scarlet can be dyed on wool with basic coal-tar colours.

The basic colours are, in general, the hydrochlorides of some colour base, and in the process of dyeing the acid const.i.tuent of the wool fibre unites with the colour base, while the hydrochloric acid which is liberated pa.s.ses into the dye-bath.

The acid reds are a very large group of red dyes, of somewhat varied chemical composition, which all have the property of dyeing from baths containing Glauber's salt and sulphuric acid or acetic acid, the usual proportions being 10 per cent. of the former, and 2 to 5 per cent. of the acid. Some are best dyed from a bath containing bisulphate of soda. The dyeing should be started cold, or at a lukewarm heat, then steam should be turned on and the temperature raised to the boil, at which it is maintained for an hour; this boiling serving to more intimately fix the dye-stuff on the woollen fibre.

The Eosine reds, of which Eosine in its various brands, Rose Bengale, Phloxine, Saffrosine and Erythrosine, are examples, are best dyed upon wool from a bath containing Glauber's salt and a little acetic acid.

They do not require a very acid bath, hence the reason of using acetic acid. The method of dyeing is that given above as for basic reds, namely, enter into cold, or at most lukewarm bath, and raise the heat slowly, continuing the work until the shade required has been obtained. It is a good plan to start work in a neutral bath, and then when the material has become thoroughly impregnated with the dye-liquor to add the acetic acid. The shades obtained from these Eosine reds are remarkable for their brilliance, but unfortunately their fastness to light, washing, etc., is but slight, although it may be increased by treating the dyed wool in a bath of alum or acetate of lead.

Some of the acid reds, _e.g._, Acid Magenta, Acid Violet, belong (p. 105) to the group of sulphonated basic dyes. The vast majority belong to the group of azo dyes, which can be employed to dye from palest pinks to the deepest crimson reds. Some dye very brilliant shades, others only yield dull reds. Some dye shades remarkable for their fastness to all agencies, soap, acids, alkalies, light and air; others dye shades which may be fast to soap, but loose to acids and light. Generally even shades are readily obtained on any kind of woollen fabric. It is practically impossible to name all the acid reds that are known and that may be used, but a fairly representative series of recipes will be given.

_Ponceau_.--Wet out, then prepare a bath with 2 lb. Ponceau R, 10 lb.

Glauber's salt, 2 lb. sulphuric acid. Enter the wool in the cold, bring to a boil and work to shade, wash and dry.

_Crushed Strawberry_.--Prepare a bath containing 10 lb. Glauber's salt, 4 oz. Scarlet R S, 9 oz. Indigo extract, 2 oz. Orange Y, 4 oz.

sulphuric acid. Enter wool at 160 F., give four turns, raise temperature slowly to a boil, and turn to shade, lift and wash.

_Scarlet_.--Prepare a dye-bath with 2 lb. Azo cochineal, 10 lb.

Glauber's salt, 4 lb. sulphuric acid. Work at the boil until the full shade is obtained, then lift, wash and dry.

_Terra Cotta Red_.--The dye-bath is made from 2-1/2 lb. Fast Acid Magenta B, 2-1/2 lb. Fast Yellow F Y, 10 lb. Glauber's salt, 2 lb.

sulphuric acid. Work at the boil to shade.