The London Encyclopædia: Part II. The Practise of Dyeing. Of Dyeing Yellow.

The London Encyclopædia: Part II. The Practise of Dyeing. Of Dyeing Yellow.


Kappale teoksesta:

The London Encyclopædia, or Universal Dictionary of Science, Art, Literature, And Practical Mechanics, Comprising A Popular View of The Present State of Knowledge.

By The Original Editor of The Encyclopædia Metropolitana, Assisted By Eminent Professional And Other Gentlemen.

In Twenty-Two Volumes

Vol. VII

London:
Printed For Thomas Tegg, 73, Cheapside;
R. Griffin & Co., Glasgow; Tegg and Co., Dublin; Also J. & S. A. Tegg, Sydney and Hobart Town.

1839

Part II. The Practise of Dyeing. Of Dyeing Yellow.
s. 612-614


203. Of Dyeing Wool Yellow. - The yellow comminucated to wool by weld has little permanency, if the wool be not previously prepared by some mordant. For this purpose alum and tartar are used, by meand os which this plant gives a very pure and durable yellow. For the boiling, which is managed in the common way, Hellot adcvises four ounces of alum to every pound of wool, and only one ounce of tartar; many dyers, however, use half as much tartar as alum. Tartar renders the color paler, but more lively. The weld is boiled in a fresh bath, enclosing it in a bag of thin linen, and keeping it from rising to the top by a heavy wooden cross. Some dyers boil it till it sinks to the bottom of the copper, and then let a cross down upon it: others, when it is boiled, take it out with a rake, and throwe it away. From three to four pounds of weld, and, in some instances less, are allowed for each pound of stuff; but the quantity must be [...]lated by the depth of the shade required. Some dyers add a little quick-lime and ashes, which are found to promote the extraction of the missing matter, and at the same time heighten the color; but they thus render it more liable to the action of acids.

204. Both lighter and brighter shades can be obtained by dyeing after deeper ones, adding water at each dipping, and keeping the [...] boiling: but light shades procured in [this way?] are not so lively as when fresh baths are [...], proportioning the quantity of weld to the [...] of the shade intended to be procured. If common salt be added to the weld bath, it [...] its color richer and deeper: sulphate of [lime, or?] gypsum, also deepens it; and tartar, still [...] Sulphate of iron or vitsiol makes it [incline to?] brown.

205. According to Scheffer, by boiling the stuff for two hours with one-fourth of its weight of a solution of tin, and the same proportion of tartar, and then washing it and boiling [...] about a quarter of an hour with an equal [...] of weld, it will assume a fine yellow, which however, till not penetrate the substance of cloth.

206. Poerner recommends a process [similar?] to that used in dyeing scarlet, by which [...] the color is brighter and more permanent.

207. Since the introduction of the use of quercitron bark, the process of dyeing yellow has been much simplidies, as may be seen from the following directions of Dr. Bancroft on [the?] subject. He porposes tha the bark should be boiled with about its own weight, or [one-?] more of alum, in a suitable quantity of water for about ten minutes.

208. The substances to be dyed are [pre---] scoured, and then immersed in the [...] serving to give the higher colors first, and afterwards the paler straw colors. By [this? ...] and expeditious process, colors which are not wanted to be of a full or bright yellow, [...] obtained. The color may be [...] heightened by passing the unrinsed [...] times through hot water, to which a little [...] powdered chalk, in the proportion of [...] pound and a half for every 100 pounds of [...] has been previously added. The bark, [...] in dyeing, being first reduced to powder, [...] be tied up in a thin linen bag, and susp[...] the liquor, so that it may be occasionally [...] through it, to diffuxe the coloring matter [...] equally.

209. But although this method possesses the advantages of cheapness and expedition, and a sufficient for communicating pale yellow, [to?] obtain fuller and more permanent colors, the common mode of preparation ought to be preferred. The stuff should be boiled for [...] one hour, or an hour and a quarter, and one-sixth, or one-eight of its weight of alum is solved in a proper proportion of water. The stuff is then to be immersed, without being rinsed, into the dyeing bath, with clear water, and about the same quantity of [p...]

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the bark tied up in a bag, as that of the alum employed in the preparation. The stuff is then to be turned as usual through the boiling liquor, until the color appears to have acquired sufficient intensity. One pound of clean powdered chalk for every 100 pounds of stuff is then to be mixed with the dyeing bath, and the operation continued for eight or ten minutes longer, for the purpose of raising and brightening the color.

210. To comminucate a beautiful orange yellow to woollen stuffs, ten pounds of quercitron bark, tied up in a bag, for every hundred pounds of stuff, are to be put into the bath with hot water. At the end of six or eight minutes, an equal weight of murio-sulphate of tin is to be added, and the mixture well stirred for two or three minutes. The cloth, previously scoured, and thoroughly wetted, is then immersed in the dyeing liquor, and quickly turned for a few minutes. By this process the coloring matter fixes on the cloth so effectually, that, after the liquor begins to boil, the highest yellow may be produced in less than fifteen minutes.

211. High shades of yellow, similar to those obtained from quercitron bark by the above process, are frequently given with young fustic and dyers' spirit; but this color is much less beautiful and permanent, while it is more expensive than what is obtained from the bark.

212. A fine bright, or golden yellow is obtained by employing ten pounds of quercitron bark, for each 100 pounds of cloth, the bark being first boiled a few minutes, and the adding seven or eight pounds of murio-sulphate of tin, with about five pounds of alum. The cloth is to be dyed in the same manner as in the process for the orange yellow. Bright yellows of less body are produced by employing a smaller proportion of bark, as well as by diminishing the quantity of murio-sulphate of tin and alum. And indeed every variety of shade of pure bright yellow may be given by varying the proportions of the ingredients.

213. The lively delicate green shades, so much admired, are produced by the addition of tartar, with the other ingredients. The tartar must be added in different proportions, according to the shade which is wanted. For a full bright yellow, delicately inclining to green, it will be proper to employ eight pounds of bark, six of murio-sulphate of tin, with six of alum, and four of tartar. An additional proportion of alum and tartar renders the yellow more delicate, and inclines it more to the green shade; but when this lively green shade is wanted in the greatest perfection, the ingredients must be used in equal proportions. The delicate green lemon yellows are seldom required to have much fulness or bory. Ten pounds of bark, with an equal quantity of the other ingredients, are sufficient to dye 300 to 400 pounds of stuffs.

214. Of Dyeing Silk Yellow. - Weld is seldom employed to give a yellow dye to silk, but when this is desired, the process differs a little from the former. The silk being scoured, alumed, and rinsed in the manner usual for dyeing bright colors, a bath is prepared, by boiling weld in water, in the proportion of double the wight of the silk for a quarter of an our, and straining off the liquor into a vat, where it is suffered to cool till the hand can be held in it. Then the silk is dipped and turned, till the color is found uniform. While this is going on, the old weld is boiled with a fresh quantity of water, and, after the silk has been dipped, one half of the exhausted bath is taken out, and the vat filled up with the second decoction. The temperature of the fresh bath may be a little higher than that of the former, but should not be too great, lest the color already fixed be dissolved. The stuff is to be turned as before, and then taken out of the bath. Some soda is to be dissolved in a part of the second decoction, and a larger or smaller quantity of the solution is to be added to the bath, according to the intensity of the shade wanted. The color is examined by taking out a skein, and wringing it.

215. To produce shades having more of a gold color, anotta is added in proportion to the depth of color required. Lighter shades, such as pale lemon color, are obtained by previously whitening the silk, and regulating the proportion of the ingredients of the bath by the shade required. To give a yellow, with a green tinge, a little indigo is added to the bath, if the silk has not been previously azured; to prevent the greenish shade being too deep, the silk should be more slightly alumed than usual.

216. Dr. Bancroft informs us that all the shades of yellow can be given at a cheaper rate by quercitron bark than by weld. To dye with this bark, a quantity of it powdered, and enclosed in a bag, in proportion to the shade wanted, from one to two pounds for every pound of silk, is put into the vat while the water is cold. Heat is applied, and when the bath is rather more than blood-warm, or of the temperature 100°m the silk, after being first alumed, is immersed and dyed in the usual way. A deeper shade may be given by adding a small quantity of chalk or pearl-ashes towards the end of the operation. To produce a more lively yellow, a small portion of murio-sulphate of tin may be employed, but it should be used cautiously, as it is apt to diminish the lustre of silk.

217. To dye silk of an aurora of orange color, after having been properly scoured, it may be immersed in an alkaline solution of anotta, the strenght of which is to be regulated by the shade required. The temperature of the bath should be between that of tepid and boiling water. When the desired shade is obtained, the silk is to be twice washed and beetled, to free it from the superfluous coloring matter, which would injure the beauty of color. When raw silk is to be dyed, that which is naturally white should be selected, and the bath should be nearly cold; for otherwise the alkali, by dissolving the gum of the silk, destroys its elasticity. Silk is dyed of an orange color by anotta, but if a redder shade be wanted, it is procured by alum, vinegar, or lemon juice. These colors are beautiful, but do not possess permanency.


218. Of Dyeing Cotton and Linen Yellow. - The process commonly observed in dyeing cotton and linen yellow, is by scouring it in a bath prepared in a lie with the ashes of green wood. It is afterwards washed, dried, and alumed, with

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one-fourth of its weight of alum. After remaining in twenty-four hours, it is taken out of the aluming and dried, but not washed. The cotton is then dyed in a weld bath, in the proportion of one pound and a quarter of weld for each pound of cotton, and turned in the bath till it has acquired the desired color.

219. After being taken out of the bath, it is soaked for an hour and a half in a solution of sulphate of copper, in the proportion on one-fourth of the weight of the cotton, and then immersed, without washing, for nearly an hour, in a boiling solution of white soap, after which it is well washed and dried.

220. A deeper yellow is communicated to cotton, by omitting the process of aluming, and employing two pounds and a half of weld for each pound of cotton. To this is added a dram of verdigris, mixed with part of the bath. The cotton is then to be dipped and worked till the color become uniform. It is then taken out of the bath, and a little solution of soda added, after which it is returned, and kept for fifteen minutes. It is then wrung out and dried.

221. Other shades of yellow may be obtained by varying the proportion of ingredients. Thus, a lemon color is dyed by using only one pound of weld for every pound of cotton, and by diminishing the proportion of verdigris, or using alum as a substitute.

222. Dr. Bancroft recommends a superior process, and less expensive. He also objects to the use of salts of copper, as deepening the yellow. One pound of acetate of lead, and three pounds of alum, are to be dissolved in a sufficient quantity of warm water. The cotton or linen, after being properly rinsed, is to be soaked in this mixture, heated to the temperature of 100°, for two hours. It is then taken out, moderately pressed over a vessel, to prevent the waste of the aluminous liquor. It is then dried in a stove heat, and, after being again soaked in the aluminous solution, it is wrung out and dried a second time. Without being rinsed, it is to be barely wetted with lime water, and afterwards dried; and if a full, bright, and durable yellow is wanted, it may be necessary to soak the stuff in to wet it a second time in the lime water. After it has been soaked for the last time, it should be well rinsed in clean water, to separate the loose particles of the mordant, which might injure the application of the coloring matter. By the use of the lime-water, a greater proportion of alumina combines with the stuff, besides the addition of a certain proportion of lime.

223. In the preparation of the dyeing bath, from twelve to eighteen pounds of powdered quercitron bark are enclosed in a bag, for every 100 pounds of stuff, varying the proportion according to the depth of shade required. The bark is put into the water while it is cold; and, immediately after, the stuff is imersed and turned for an hour, or an hour and a half, during which the water should be gradually heated, and the temperature raised about to 120°. At the end of this time the heat is increased, and the dyeing liquor brought to a boiling temperature; but at this temperature the stuff must remain in it only for a few minutes. It is then taken out, rinsed, and dried.

224. Dr. Bancroft remarks, that, when the [alu?]minous mordant is employed without the [ad?]dition of water, one soaking only, and [...] immersion in lime water, may be [...] he is of opinion that greater advantage is [derived?] from the application of a more diluted [mordants?] at two different times, or even by a [...]quent immersion of the stuff alternately [...] aluminous mordant, and lime water, and [drying?] it after each immersion. By this treatmet [...] found that the color always acquired more [...] and durability.

225. Chaptal proposes a process for [...]cating to cotton a nankeen yellow, [...] it affords a durable color, has the [advantage? of?] being cheap and simple. When cotton is immersed in a solution of any salt of iron, it [...] strong an affinity for the oxide, that it [...]poses the salt, combines with the iron, and [...]sumes a yellow color. The process recommended by Chaptal is this: - The cotton to be dyed [...] into a cold solution of sulphate of iron, of the specific gravity of 1.02. It is afterwards [...] out, and immediately immersed in a lie of [...] of the specific gravity of 1.01. Tis [...] previously have been saturated with a solution [of?] alum. When the stuff has been kept for [...] five hours in this bath, it may be taken [out?,] washed, and dried. By varying the [pro...] of sulphate of iron, every variety of shade can be obtained.

226. The following curious process for dyeing linen of a durable yellow, as practised in the east, is given in the Encyclopaedia Britannica. The object of this process, which is [...] increase the affinity between the alumina and the stuff, so that it may adhere with sufficient [...] to produce a permanent color. For this [purpose?...] three mordants are employed: these are [...] and alum. The cotton is soaked in a [bath of?] oil, as it is found to answer best, is [...] Glue has also been tried, and is found to [...] very well. The soda must be in the [...] as it then combines with the oil, and [...] the cloth an equal absorotion. The stuff [...] to be washed, and afterwards put into an [...] of nut-galls of the white kind: the [infusion? ...] be used hot. The tan combines with the [...] while the gallic acid carries off any alkali which may adhere to the cloth. When the stuff is removed from the bath, it should be quickly [...] too great an excess of galls beyond [...]portion with the oil should be avoided as of [...] apt to darken the color. After this [...] the stuff is to be imersed in a solution of [...] and, in consequence of the affinity which [...] between tan and alumina, the alum is [...]posed, and its earth combines with the tan.