Principles and Practice of Fur Dressing and Fur Dyeing Part 13

Water 1 liter

Copper mordant.

Copper sulphate 2 gms.

(Acetic acid 50% 2 gms.) Water 1 liter

Iron mordant.

Ferrous sulphate 2 gms.

(Acetic acid 50% 2 gms.) Water 1 liter

or,

Iron pyrolignite 30% 10 gms.

Water 1 liter

Chrome-copper mordant.

Bichromate of soda 2 gms.

Copper sulphate 0.25 gms.

Cream of tartar 1.0 gms.

Water 1 liter

Copper-iron mordant.

Copper sulphate 2 gms.

Ferrous sulphate 2 gms.

(Acetic acid 50% 2 gms.) Water 1 liter

The killed skins are immersed in the mordanting solution, and allowed to remain the required length of time. They are then thoroughly rinsed to remove any excess of the mordant, and are hydro-extracted. Under no circ.u.mstances should mordanted skins be permitted to dry, for they would be unfit for use again.

The dyebath is next prepared by dissolving the necessary quant.i.ty of the dye, varying from 0.1 gm. to 10 gms. per liter. Then if the solution must be neutralized, the ammonia is added and the temperature of the bath is brought to 3035 C. by the addition of cold water. This temperature is maintained throughout the dyeing operation. To the solution is added the oxidizing agent. Ordinary commercial peroxide of hydrogen containing 3% by weight is the usual oxidizer, although perborates have been suggested.

1520 parts of peroxide of hydrogen for every part of dye are added, and the dye solution brought to the proper dilution. As soon as the dyebath is ready, the skins are entered, and worked for a short time to effect even penetration. They are then left in the dyebath for 212 hours or longer according to the depth of shade. After being satisfactorily dyed, the furs are rinsed thoroughly, hydro-extracted and dried and finished. Where the dye is to be applied by the brush to the tips of the hair, stronger dye solutions are used, the brushed skins being placed hair together and let lie for about 6 hours in order to permit the color to develop, after which the furs are dried and drum-cleaned.

Some shades, particularly black, have a tendency to rub off slightly. In order to overcome this, the dyed furs, after rinsing, are treated with a cold solution of 1/2 part of copper sulphate per 1000 parts of water, for 34 hours, then without rinsing, hydro-extracted and dried. Furs which have been tipped are brushed with a 12% solution of copper sulphate and dried. Care must be taken in this after-treatment, for the use of too strong a solution of copper sulphate, or too prolonged action of such a solution will materially alter the shade of the dyed fur.

A few typical formulas will serve to ill.u.s.trate the general methods of employing the Oxidation Colors:

_Brown Sable Imitation on Unsheared Rabbit_

The skins are killed with soda, soured, and washed, then mordanted with

Bichromate of soda 2 grams Copper sulphate .25 grams Cream of tartar 1 gram Water 1 liter

for 24 hours. Then washed, and dyed for 24 hours with

Fur Brown 2G[3] 3 grams Hydrogen peroxide 45 grams Water 1 liter

Wash and dry the skins, then brush the tips with

Fur Brown D[3] 20 grams Hydrogen peroxide 400 grams Water 1 liter

[3] Inasmuch as most manufacturers use the same letters to designate the various dyes, any equivalent brand of fur dye may be used in place of those here mentioned.

_Black on Sheared Muskrat_

The skins are killed with soda, soured, and washed, then chrome mordanted for 6 hours. Then they are dyed for 6 hours with

Rodol P 1.5 grams Pyrogallic acid .7 grams Ammonia 2.0 grams Hydrogen peroxide 45 grams Water 1 liter

The dyed skins are washed and dried, then tipped with

Rodol D 20 grams Rodol DB 2 grams Hydrogen peroxide 450 grams Water 1 liter

_Brown on Thibet Sheep Skin_

The killed skins are mordanted for 6 hours with a chrome mordant, then dyed for 6 hours with

Ursol P 1 gram Pyrogallic acid 1 gram Ammonia 2 grams Hydrogen peroxide 40 grams Water 1 liter

It is also possible to combine dyeings with the Oxidation Colors with Vegetable dyeings, or with Aniline Black. For example, if it be desired to produce an imitation skunk on a racc.o.o.n, and an exceptionally fast and intense and l.u.s.trous black on the tips of the hair, the skins are dyed in the bath with the Oxidation dyes, and the tips of the hair are brushed with a mixture such as described under Vegetable Colors for the production of French seal, as follows:

_Imitation Skunk on Racc.o.o.n_

The skins are killed with caustic soda, soured and washed, then mordanted with an iron-copper mordant as described, and then dyed with

Fur Grey R 3 grams Ammonia 2 grams Peroxide of hydrogen 45 grams Water 1 liter

After washing and drying, the dyed skins are brushed over with a mixture such as used for dyeing French seal with Vegetable Colors.

In a similar manner, the Oxidation Colors may be used to give a base color to furs dyed by the Aniline Black process.

It is apparent from these few ill.u.s.trations that a great variety of shades can be produced, and the dyeing of imitations of the better cla.s.s of furs on cheaper skins is a comparatively simple matter, after an understanding of the nature of the dyes has been obtained, and a certain amount of skill acquired in working with these dyes.

CHAPTER XVI

FUR DYEING

COAL TAR DYES

In addition to the Aniline Blacks and the Oxidation Colors already discussed there are certain of the synthetic coal tar dyes such as are generally used in the dyeing of textiles, which can also be applied on furs. There are several cla.s.ses of these dyes, varying somewhat in their nature, and consequently in their manner of application; in the main they produce bright shades, such as are but seldom used on furs, yet which may occasionally serve for the production of novel effects. Basic, acid and chrome colors are the types which can be employed.

Basic colors possess great fullness and tinctorial strength, but have a tendency to rub off, and the tips of the hair take a darker shade with these dyes than the rest of the hair. The addition of acetic acid and Glauber's salt to the dyebath will result in a more uniform dyeing. On account of the comparatively poor fastness to rubbing and washing, basic dyes are used only for dyeing furs which are intended for cheap carpet rugs, such as sheep and goat. They may also find use in the production of light fancy shades on other white furs. The procedure is usually as follows: The furs are killed in the customary manner with soap and soda or ammonia, or if this is insufficient, with milk of lime. A soap-bath is then prepared containing 2.56 grams of olive-oil soap per liter of water.

The temperature of the bath is brought to 40 C. To this is added the solution of the dyestuffs, prepared by mixing the required color or colors with a little acetic acid to a paste, and then pouring boiling water on the mixture until dissolved. Undissolved particles or foreign matter are removed by pa.s.sing this solution through a cotton cloth or sieve, and the clear solution then mixed with the soap-bath. The well-washed skins are then entered into the dyebath and immersed for about half an hour, or until the desired depth of shade is obtained. They are then removed, pressed or hydro-extracted and dried. For the production of light shades, the following dyes may be used: