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Previous Next The best candle and soap tips online! TECHNICAL TREATISE ON SOAP AND CANDLES. THE FABRICATION OF SOAPS. 303 by adding ultramarine for blue, vermilion for red, bole Armenia for brown, bone black for gray. This, when skilfully done, gives an attractive appearance, particularly when the soap is of a clear white color. For all cold soaps, attention must be given to have the alkalies as pure and as caustic as possible, otherwise, a complete admixture of the material is almost impossible. As a rule, lyes of 38° B. are taken. Such a lye of soda contains 0.3445 kilog. (.758 lb.) of soda to each litre (2.1 pints); so for 100 kilog. (220 lbs.) of cocoa-nut oil we require 36.8 litres (9.7 gals.), and we obtain about 150 kilog. (330 lbs.) soap having but 25 per cent, of water. This is simply an example. A larger percentage of water mny be taken, though of course the lye will be weaker, but when cocoa-nut oil is present, it is best to use strong lyes. As mechanical aid in making cold soaps facilitates the process, there are made several styles of kettles and apparatus for the purpose. We illustrate two: one being like the ordinary soap kettle with a mechanical stirrer; the Fig. 58. Fig. 57. NN other a cylinder placed horizontally, having a shaft through the centre to which are attached a number of arms like a churn; this mode of usage needs no further description. (Figs. 57, 58.) . TALLOW SOAP BY THE COLD PROCESS. Take, say, 1000 kilog. (2200 lbs.) of tallow, purified and cleared by rendering in a kettle, of twice its capacity, heated to a melting at about 37° C. to 43° C. (98.6° to 109.4° F.), and the 30° B. lye, being heated to attain the same temperature, is run from a vessel provided with a stopcock into the kettle. After having added all the lye, the entire mass is stirred gently, until it has thickened so that one part of it, spread out to a ribbon, no longer runs together with the other. The thin pasty mass is now run into the previously warmed frames, in which after a little while a tolerably strong heat takes place, which denotes the act of union between the alkali and the sebacic acid. As long as the soap is still soft, it shows a strong alkaline touch ; but after the combination has taken place, this vanishes almost entirely, provided the proportions between the alkali and the fat have previously been correctly taken. The soap thus produced is of brilliant whiteness, very hard and brittle, but will be more pliant, if about 10 per cent, of the alkali used is potash. This soap lathers very well, and is on occount of its hardness very economical for use ; a little addition of cocoa-nut oil makes it lather still more freely. COCOA-NUT OIL SOAP BY THE COLD PROCESS. The operation is performed exactly in the same way, as has been stated in the case of tallow soap, in which case it is generally perfumed and artificially marbled. The latter is done in this manner. The soap is put into the moulds in layers, upon every layer some vermilion or other coloring, mixed with a little lye, is spread, until the last layer, when it is stirred in certain directions with an iron rod. To give the soap a blue flame-like appearance, ultramarine is used in lieu of vermilion. The soap remains for twenty-four hours well covered in the frames, during which time the real combination of alkali with the sebacic acids with evolution of heat occurs. 304 TECHNICAL TREATISE ON SOAP AND CANDLES. THE FABRICATION OF SOAPS. 305 Cocoa-nut oil possesses in a high degree the property of forming soaps winch are capable of retaining large quantities of water, without thereby losing much of their hardness. Thus water, or salted water may be added in the frame, to the amount of 50 per cent. For the fabrication of all so-called Cold Soaps, the application of lyes entirely free from carbonic acid is a necessary condition, if a good product is expected, while only the absolutely required quantity of alkali needed for saponifiea-tion is used. ROSIN SOAP BY THE COLD PROCESS. The quantity of rosin, which is applied to a given quantity of fat, is from 15 to 50 per cent. The more rosin is added to a soap, the more it attains a soft and pasty nature, if the quantity of cocoa-nut oil or other fats is not correspondingly increased. The number of rosin soaps, that is the names by which they are designated, is according to the kinds of fat used, extraordinarily large, and almost every large soap manufactory has its own receipts, after which the favorite soap is made. For the saponification of the rosin suitably concentrated lyes are applied, because they furnish a firmer soap. Caustic Boda could be substituted by carbonate of soda, but, for reasons already stated, one cannot well recommend this practice. Rosin and fat are either saponified separately and afterwards stirred together, or the fat is first saponified when the pulverized rosin with the necessary quantity of lye is added to the soap and boiled until all froth disappears. So also of a mixture of 100 kilog. (220 lbs.) rosin, 55 kilog. (121 lbs.) cocoa oil, and 55 kilog. palm oil, a rosin soap may be manufactured in the cold way. These substances are melted to-_ gether, adding gradually while constantly stirring 100 kilog. (220 lbs.) or 72 litres (19.0 gallons) of a 25° B. soda lye, until it becomes stiff, when it is put in the frames. The frames are now covered up and left to rest until the next day. TRANSPARENT ROSIN SOAP. For the fabrication of this soap Dr. Deite gives the following directions: 80 kilog. (176 lbs.) cocoa-nut oil,and 20 kilog. (44 lbs.) palm oil are saponified with soda lye of 24° B., adjusting it to a very weak "touch," and boiled until the froth disappears. Then 15 kilog. (33 lbs.) of pulverized rosin are thrown into it; he then dissolves 133J grammes (4.67 ozs.) sugar of lead in 100 kilog. (220 lbs.) salt water of 10° to 20° B. which by adding soda has been enhanced to 20° B., stirs this among the soap, and then ceases the boiling. It is then run into the frames and well covered, and the result is a semi-translucent hard soap. Another receipt for making this soap is as follows:— 70 kilogrammes (154 lbs.) cocoa oil 30 kilogrammes ( 66 lbs.) palm oil 20 to 25 kilogrammes (44 to 55 lbs.) rosin, are saponified over a slow fire with a slightly carbonated caustic soda lye of .'36° B. which adjusts it for a strong touch. When this is done, the fire is extinguished, pouring 20 kilog. of a solution of potash of 20° B. over it, stirring it well under, then adding under constant stirring 70 kilog. (154 lbs.) soluble glass (40° B.), which has previously been diluted with 3 kilog. (6.6 lbs.) alcohol and 3 kilog. of a weak lye, keeping the soap covered for a period of half au hour, run it into the frames and cover. BORAX SOAP, Now touch in vogue, is generally made by the cold process. The soap is made with a weak " touch," and there is a portion of the alkali left out and substituted by a solution of borax marking about 12° B., of which about 10 per cent, is used. White greases are used, and the soap has a brilliant whiteness which is very popular. Soluble glass is also added to this soap by some makers, though it is quite likely to show in a white powder as the soap dries. 20 Previous Next
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