The Dyeing of Cotton Fabrics Part 20

_Grey._--Mordant with 1 lb. tannic acid and 1/2 lb. tartar emetic, then dye with 1/2 lb. New Methylene grey B.

_Bluish Rose._--Mordant with 2 lb. tannic acid and 1 lb. tartar emetic, then dye with 1 lb. Rhodamine B.

_Maroon._--Mordant with 4 lb. tannic acid and 2 lb. tartar emetic, and dye with 2 lb. Magenta and 1/2 lb. Auramine.

_Dark Green._--Mordant with 5 lb. tannic acid and 2-1/2 lb. tartar emetic, and dye with 1/2 lb. Methylene blue B B, 1/2 lb. Methyl violet 2 B and 2-1/2 lb. Auramine I I.

_Orange._--Mordant with 3 lb. tannic acid and 2 lb. tartar emetic, and dye with 1 lb. New Phosphine G.

_Lilac Grey._--Mordant with 1 lb. tannic acid and 1-1/2 lb. tartar emetic, and dye with 1/4 lb. Methylene grey B F.

_Gold Brown._--Mordant with 3 lb. tannic acid and 1-1/2 lb. tartar emetic, and dye with 3/4 lb. Thioflavine T and 3/4 lb. Bismarck brown.

_Orange._--Mordant with 2 lb. tannic acid and 1 lb. tartar emetic, and dye with 1 lb. Auramine and 1/4 lb. Safranine.

_Dark Blue._--Mordant with 3 lb. tannic acid and 2 lb. tartar emetic, and dye with 2-1/4 lb. New Methylene blue R and 3/4 lb. Naphtindone B B.

_Olive Green._--Mordant with 5 lb. sumac extract and 2 lb. copperas, and dye with 1 lb. Auramine.

_Russian Green._--Mordant with 5 lb. sumac extract and 2 lb. copperas, and dye with 2 lb. Malachite green.

_Scarlet._--Mordant with 3 lb. tannic acid and 2 lb. tartar emetic, and dye with 1-1/2 lb. Thioflavine T and 1/2 lb. Irisamine G. With these two dye-stuffs it is possible to produce a variety of useful shades from a pure greenish yellow, with Thioflavine T alone, to a bright bluish pink, with the Irisamine alone, through orange, scarlet, etc., with combinations of the two dye-stuffs.

_Dark Grey._--Mordant with 5 lb. sumac extract and 3 lb. copperas, then dye with 1 lb. New Methylene grey G.

_Blue Black._--Mordant with 8 lb. sumac extract and 4 lb. copperas, or better with iron liquor, then dye with 2 lb. Indamine blue N.

_Olive Brown._--Mordant with 5 lb. sumac extract and 3 lb. copperas, and dye with 1-1/2 lb. New Phosphine G.

_Indigo Blue._--Mordant with 1-1/2 lb. tannic acid and 1 lb. tartar emetic; dye with 1/2 lb. New Methylene blue N.

_Sky Blue._--Mordant with 1/2 lb. tannic acid and 3/4 lb. tartar emetic; dye with 1-1/2 oz. New Methylene blue G G.

_Dark Violet._--Mordant with 3 lb. tannic acid and 2 lb. tartar emetic, then dye with 4 lb. Fast neutral violet B.

_Bright Yellow._--Mordant with 2 lb. tannic acid and 1 lb. tartar emetic, and dye with 2 lb. Thioflavine T.

_Primrose Yellow._--Mordant with 1 lb. tannic acid and 1/4 lb. tartar emetic, and dye with 2 oz. Thioflavine T.

_Navy Blue._--Mordant with 5 lb. sumac extract and 3 lb. copperas, then dye with 2 lb. New Methylene blue R.

_Violet._--Mordant with 3 lb. tannic acid and 2 lb. tartar emetic, and dye with 2 lb. New Methylene blue 3 R.

_Dark Blue._--Mordant with 5 lb. sumac extract and 3 lb copperas, and dye with 2 lb. New Methylene blue N X.

_Blue Black._--Mordant with 8 lb. sumac extract and iron liquor, then dye with 3 lb. Metaphenylene blue B.

_Emerald Tint._--Mordant the cotton in the usual way with 1 lb. tannic acid and 1 lb. tartar emetic; dye to shade at 180 F. in a bath containing 14 oz. Auramine G, 2 oz. Brilliant green, then lift, wash and dry.

_Orange._--Mordant with 3 lb. tannic acid and 2 lb. tartar emetic, then dye with 4 lb. Tannin orange R.

_Scarlet._--Mordant with 3 lb. tannic acid and 2 lb. tartar emetic, and dye with 2 lb. Tannin orange R and 1 lb. Safranine S.

_Dark Scarlet._--Mordant with 3 lb. tannic acid and 2 lb. tartar emetic, and dye with 1/2 lb. Tannin orange R and 2 lb. Safranine S.

The Ja.n.u.s colours are a series of dyes of a basic nature which can be applied somewhat differently to the ordinary basic dyes, although the ordinary method can be followed. With these Ja.n.u.s dyes a two-bath process is followed. A dye-bath is prepared containing the dye-stuff, sulphuric acid and common salt, and this is used at the boil from half to three-quarters of an hour, and the goods are allowed to remain in another three-quarters of an hour while the bath cools down. Next the dyed goods are run in a fixing bath of sulphuric acid, tannic acid and tartar emetic, this is used at the boil from half to one hour, after which the dyed goods are taken out and washed. If necessary the goods may be now topped with basic colours in order to produce any desired shade. The following recipes will show how the Ja.n.u.s dyes may be used:--

_Blue._--Dye with 9 oz. sulphuric acid, 8 oz. Ja.n.u.s blue G, and 5 lb.

common salt; fix with 3/4 lb. sulphuric acid, 8 oz. tannic acid and 4 oz. tartar emetic.

_Turquoise Blue._--Dye with 9 oz. sulphuric acid, 1 lb. Ja.n.u.s green B and 10 lb. salt, fixing with 3/4 lb. sulphuric acid, 1 lb. tannin and 1/2 lb. tartar emetic.

_Dark Blue._--Dye with 9 oz. sulphuric acid, 2-1/2 lb. Ja.n.u.s blue R and 15 lb. common salt; fix with 3/4 lb. sulphuric acid, 2-1/2 lb. tannic acid and 1-1/4 lb. tartar emetic.

_Buff._--Dye with 9 oz. sulphuric acid, 2 oz. Ja.n.u.s yellow R and 3 lb.

salt; fix with 3/4 lb. sulphuric acid, 3 oz. tannic acid and 3 lb.

tartar emetic.

_Crimson._--Dye with 9 oz. sulphuric acid, 2-1/2 lb. Ja.n.u.s red B and 15 lb. salt, fixing with 3/4 lb. sulphuric acid, 2-1/2 lb. tannic acid and 1-1/4 lb. tartar emetic.

_Red Violet._--Dye with 9 oz. sulphuric acid, 1 lb. Ja.n.u.s claret red B and 10 lb. salt; fix with 12 oz. sulphuric acid, 1 lb. tannic acid and 1/2 lb. tartar emetic.

_Orange._--Dye with 9 oz. sulphuric acid, 1 lb. Ja.n.u.s yellow R and 10 lb. salt; fix with 12 oz. sulphuric acid, 1 lb. tannic acid and 1/2 lb.

tartar emetic.

_Dark Violet._--Dye with 9 oz. sulphuric acid, 2 lb. Ja.n.u.s grey B and 15 lb. salt; fix with 12 oz. sulphuric acid, 2-1/2 lb. tannic acid and 1-1/4 lb. tartar emetic.

_Chocolate Brown._--Dye with 9 oz. sulphuric acid, 3-1/2 lb. Ja.n.u.s brown B and 15 lb. salt, fixing with 2 oz. sulphuric acid, 2-1/2 lb. tannic acid and 1 lb. tartar emetic.

(6) DYEING ON METALLIC MORDANTS.

There are a number of dye-stuffs or colouring matters like alizarine, logwood, fustic, barwood, cutch, resorcine green, etc., which have no affinity for the cotton fibre, and of themselves will not dye it. They have the property of combining with metallic oxides such as those of iron, chromium, aluminium, tin, lead, calcium, etc., to form coloured bodies which are more or less insoluble in water. These coloured bodies are called "colour lakes," and the metallic compounds used in connection with their production "mordants," hence often the dye-stuffs applied by this method are termed "mordant dyes". In the case of the natural dye-stuffs--logwood, fustic, Persian berries, Brazil wood, camwood, cochineal, quercitron, cutch, etc.--which belong to this group of "mordant dyes," the whole of the material does not enter into the operation, but only a certain const.i.tuent contained therein, which is commonly soluble in boiling water, and extracted out by boiling. This const.i.tuent is called the "colouring principle" of the dye-stuff or wood, and naturally varies with each. It is not intended here to deal in detail with these colouring principles. The methods of applying and the colours which can be got from these dyes varies very much. Roughly, the modes of application fall under three heads: (1) the particular metallic mordant is first fixed on the fibre by any suitable method, and then the fibre is dyed; (2) the dye-stuff is first applied to the fibre, and then the colour is fixed and developed by treatment with the mordant; and (3) the dye-stuff and the mordant are applied at the same time. This last method is not much used. In the following sections many examples of these methods will be given.

The dyes fixed with metallic mordant vary in their composition and properties. There is first the group of eosine dyes, which are acid derivatives of a colour-base, and, in virtue of being so, will combine with the metallic oxides. The colour of these colour lakes is quite independent of what oxide is used, depending only on that of the particular eosine dye employed. Then there are some members of the azo dyes, particularly the croceine scarlets, which can also be dyed on the cotton by the aid of tin, lead or alum mordants. Here, again, the mordant has no influence on the colour, but only fixes it on the cotton.

The most important cla.s.s of dye-stuffs which are dyed on to cotton with a metallic mordant is that to which the term "mordant dyes" is now given. This includes such dyes as logwood, fustic, madder, alizarine, and all the dyes derived from anthracene. Many of these are not really dyes, that is, they will not of themselves produce or develop a colour on to any fibre when used alone; it is only when they combine with the mordant oxide which is used, and then the colour varies with the mordant. Thus, for instance, logwood with iron produces a bluish black; with chrome, a blue; with alumina, a reddish blue. Alizarine with iron produces a dark violet; with alumina, a scarlet; with chrome, a red; with tin, a bright scarlet. Fustic gives with tin and alumina, bright yellows; with chrome, a dark yellow; with iron, an olive, and so on with other members of this group, of which more will be said later on.

_Dyeing with Eosines._

At one time a fairly large quant.i.ty of cotton was dyed with the eosines, owing to the brightness of the shades given by them; but the introduction of such direct dyes as the Erikas, Ceranines, etc., has thrown the eosines out of use.

The method adopted for the production of eosine pinks and scarlets on cotton involves three operations: (1) impregnating the cloth with sodium stannate; (2) fixing oxide of tin by a bath of weak sulphuric acid; and (3) dyeing with the eosine.

=(1) Preparing with Sodium Stannate.=--A bath of 8 Tw. is prepared, and the cotton is allowed to steep in this bath until it becomes thoroughly impregnated, after which it is taken out and wrung.

=(2) Fixing the Tin Oxide.=--A bath of sulphuric acid of 2 to 4 Tw. is prepared, and the cotton is sent through it, after which it is washed well with water, when it is ready for dyeing.