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Previous Next The best candle and soap tips online! TECHNICAL TREATISE ON SOAP AND CANDLES. THE FABRICATION OF SOAPS. 281 disturb it, since its mixture with the white soap would render it less neutral and less pure. When all the soap is in the frames it is well stirred so as to have it perfectly homogeneous ; if not stirred it would present veins avid even spots of color. When the soap is completely solidified in the frames, it is flattened by beating it with large wooden beaters. This operation renders the soap more compact and heavier, it is useful also to fill the vacant spaces due to the air in the soap. In conclusion, the beating of the soap fulfils two essential conditions: 1. It increases its specific gravity ; 2. It destroys its porosity. A few days after the frames are uncovered, and the soap is divided into bars or cakes by the usual methods. Recently manufactured, this soap is always a little soft. To give it the firm consistency required in commerce, it is exposed for a few days to the air in the drying-room, then it becomes solid enough to be packed in boxes. Exposure to the sun, or to too elevated a temperature, must be avoided, for heat always communicates to it a more or less yellow shade. Another method of hardening is to dip the bars of soap into a very strong lye, which hardens the surface and makes them the sooner marketable. When the soap is not to be sold immediately, the boxes containing it are stored in a cellar. A few weeks after it will have acquired the whiteness and solidity which distinguish fine Marseilles soap. Well-prepared White Soap from Olive Oil constitutes, as we have before said, the purest soap of commerce. One hundred parts of this soap are composed of: 50.20 4.60 45.20 Fatty acids Pure soda Water . Soap of scum 157 to 225 Pure white soap 2925 to 3040 Black soap . . . . . . . 675 to 790 We see by these numbers that 2250 pounds of oil give as a maximum 3040 pounds of soap, or 135 pounds of soap for every 100 pounds of oil. The black soap left in the kettle as a residuum of the operation is separated, while warm, from the weak lyes with which it is combined, by means of salted lyes at 20° to 25° B. It is then run into a frame and allowed to cool. In a regular mode of working, this black soap is utilized in a new operation, and gives by refining a new quantity of pure soap by the precipitation of the coloring matters it contains. This method is not without inconveniences, because this mass of black soap introduced into each new coction impairs the whiteness and purity of the soap. It would be more rational to use this residuum in the fabrication of marbled soaps which are not required to have the purity of color of the white soap. The formulae for the marbled soap may apply to this soap, though there should always be a large percentage of olive oil. White Castile (Marseilles) Soap, when made in countries where olive oil is not abundant and is high priced, is now usually made with but a small percentage of that expensive oil. Thus in England, Germany, and the United States are used bleached palm oil, palm-kernel oil, ground-nut oil, poppy oil, cotton-seed and hemp-seed oil, tallow oil or olein, tallow in combinations. Having a due regard to their purity and whiteness we give some suggestions of proportions : Olive oil 30 parts. Olive oil 40 parts. 30 40 Lard .... Palm-kernel oil Ground-nut oil . . 30 " Tallow 30 " 30 parts. 30 " 40 " Palm oil (bleached) . 50 parts. Sesame oil .... 20 " Tallow 30 " Olive oil . . . Cotton-seed oil. Tallow oil . . 100.00 By operating under favorable circumstances, that is, using the purest and whitest olive oil, and the best quality of artificial soda, the 2250 pounds of oil will give: TALLOW SOAP. (CURD SOAP.) The fabrication of this soap is in general the same as that of the olive oil soaps. When tallow is used it is freed 282 TECHNICAL TREATISE ON SOAP AND CANDLES. THE FABRICATION OF SOAPS. 283 from all admixtures and impurities by melting and depositing. Thus prepared, the soap may very well be finished in one boiling. When impure tallow of a brown color is used, it becomes necessary to finish the soap upon two or more waters. In this case also a lye of 2° B. at the most 6 per cent, soda is used which should be caustic and free from culinary salt. Since the tallow consists chiefly of stearin and olein with but little palmitin glyceryl oxide, the amount of materials necessary for saponification is calculated according to the heretofore mentioned equivalents of tallow, to wit, 887.0. According to this there are 100 kilog. (220 lbs.) tallow corresponding to 10.5 kilog. (23.1 lbs.) of soda (anhydrous), so that for a boiling of 2000 kilog. (4400 lbs.) 210 kilog. (462 lbs.) of soda are required, which in four portions of lye are separately brought into use. Since the first portion, or the fourth part = 52.5 kilog. (115.5 lbs.) is to be taken not above 6 per cent, lye, and whereas in 20 litres (5.29 gallons) of such a lye 1.31 kilog. (2.88 lbs.) soda are contained, there would CO C w Oft have to be taken thereof 0L_ = 800 litres (211 gallons). l.ol The lye is placed in the kettle, heated to boiling, and then the tallow is added. The melting fat mixes immediately with the lye to a milky fluid wherein fat and lye can no longer be plainly discovered, although a real chemical combination does not yet ensue. The entire mass soon begins to boil, and at first it froths very much, but gradually begins to clear, becomes more translucent and also thicker. But if an open fire be used, the heat must be diminished, to avoid burning. The entire mass becomes turned into a translucent lustrous liquid, the soap paste runs from the spatula in fine threads, the lye and fat of which upon the paddle no longer appear separate. Sometimes it takes very long before the fat and lye unite into a paste. Usually the reason for this is found : 1. In a too concentrated l}-e. The mass boils at starts, very violently, since the lye, because it cannot mix with the fat on account of its concentration, settles upon the bottom, Previous Next
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