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Previous Next The best candle and soap tips online! TECHNICAL TREATISE ON SOAP AND CANDLES. THE FABRICATION OF SOAPS. 317 nearly 1300 kilog. (2860 lbs.) more fat could have been saponified. There is of course no account taken as to loss ensuing in the preparation of the lye. But the deviation is, however, too great not to suppose at once an error in the hypothesis; perhaps if the oleic acid were to be increased tenfold a near correspondence of the common proportions between fat and alkali would take place in the soft soaps. We have ourselves, by investigating these soaps, repeatedly found in 100 kilog. (220 lbs.) fat as much as 21 kilog. (46 lbs.) potash. By applying 2 equivalents soda to 3 equivalents potash, the soap remains clear, if otherwise the right proportions are maintained, and alkalies of a high degree are used in the making of lyes. With equal equivalents of potash and soda, however, the soap becomes muddy; the same occurs when the soda contains much culinary salt, and the potash much sulphate of potash or chloride of potassium. Calculating the proportion, when the fats are to be boiled with | potash aud f soda. As we have already stated, that all soft soaps must be adjusted with a certain "touch," i. e., with a surplus of alkali, which on an average amounts to $ more than if we had to do with the production of a neutral soap, consideration of this matter should be taken from the first. To boil 100 kilog. (220 lbs.) into soft soap we apply 12.8 kilog. (28 lbs.) soda, or 19.5 kilog. (43 lbs.) potash. These proportions are based on the calculation made for saponification of 5000 kilog. (11,000 lbs.) fat for 3000 kilog. (6600 lbs.) with potash saponified. 3000 x 19.5 = 5g5 kilog>(1287 lbs.) caustic potash and 100 2000 x 12.8 100 2000 kilog. (4400 lbs.) with soda saponified 256 kilog. (563 lbs.) soda will be required. The potash lye applied is f at 20° to 21° B. and \ at 25° B.; the first contains 3 x 585 = 438.75 kilog. (965 lbs.) potash, 4 the latter 146.25 kilog. (322 lbs.) potash. The 20° B. lye contains 16.408 per cent, potash; there are hence to be taken of it 438-^5*?00 =2674kilog. (5883 lbs.) 16.408 or 1630 litres (431 gallons.) The 25° B. lye contains 19.803 per cent, potash, and of it should be takeni^-|A^i^? = 740 kilog. (1628 lbs.) or 610 19.80o litres (161 gallons). The soda is only applied as 20° lye, and since it contains 10.88 per cent, of soda there are required of it = 10.88 2353 kilog. (5176 lbs.) or 2028 litres (536 gallons). The total quantity of lye contains therefore:— Potash lye at 20° 2674 kilogrammes or 1630 litres " " at 25O 740 kilogrammes " 610 litres Soda lye at 20° 2353 kilogrammes " 2040 litres 5767 kg. (12,687lbs.) 4280 litres (1132 gals.) Whereas from 5000 kilog. (11,000 lbs.) fat (100 : 250) 12,500 kilog. (27,500 lbs.) soft soap are to be realized, there must needs be added to the soap mass in the kettle 1737 kilog. (3821 lbs.) of water, that is, the lyes must be diluted to the amount of 7500 kilog. (16,500 lbs.) and the evaporating water during the process of boiling must be replaced. Great competition often compels the manufacturer to enhance the yield (100 : 250) by other means, filling with salt lye, carbonate of soda, etc. With such intention the fats are also augmented by adding four to five per cent, cocoa-nut oil, and by this means the yield is still further enhanced to 300 kilog. (660 lbs.) soap from 100 kilog. (220 lbs.) fat. The Boiling of Soft Soap.—The fabrication of soft soaps offers no particular difficulties, if the proper proportions of alkali aud fat are accurately calculated and applied. The lyes and all the fat can be taken at once into the kettle, the mixture heated to boiling, and kept thus, until a perfect saponification ensues, and the soap has attained its correct consistency. More to the purpose it appears, however, either all the lye, or perhaps one-half of it, is stirred together with 318 TECHNICAL TREATISE ON SOAP AND CANDLES. THE FABRICATION OF SOAPS. 819 the fat in a temperature of 30° to 40° C. (86° to 104° F.) and to leave the mixture stand overnight. By this operation a certain emulsion is formed, and on the day following, the further union advances extremely fast. If at first only one-half of the lye had been taken, then during the continuance of boiling, the other half must be added. From time to time, the soap is tested as to its nature, whether it has an overplus of fat or alkali, whether it has steamed or not. This is ascertained by placing a small sample upon a glass plate, upon which it is cooled off in a temperature not exceeding 8° 0. (46.40° F.). The soap is good if a sample of it, held up to the light, is clear and translucent, and when the soap dropped upon the glass, after a lapse of from 12 to 15 minutes, shows but a very small ring. It must not glide or be slippery upon the glass, and when taken between two of the fingers, it must not draw into threads when the fingers are extended. Particular Remarks.—Should the soap at the commencement become thick, then it is wanting in lye, which must be added at once. If the soap turns muddy from the first, when placed upon the glass, and runs like water from the spatula, then the lye is excessive and must be relieved by adding some fat. If the soap runs out of the trial-spoon in flakes, it is too much evaporated, and must then be diluted with a corresponding quantity of potash lye of about 4° B., and again be somewhat condensed. The ring of lye and the gray fat, by the trial upon the glass, the first as a rim encircling the soap-drop, the latter as a muddy point in the centre of the drop, appears only after the soap is so far boiled that it is out of the paste, hence almost finished boiling. A small ring of lye, every soft soap must show, because every soap must needs have a certain surplus of caustic potash. On the other hand, all fatty gray (a gray spot in the centre of the soap-drop) must be removed by adding potash lye. If this is not done, then the soap after a short time turns in the kegs or barrels into a thick, slimy, and thready mas8. The barrels into which the soft soap is placed must be entirely clean and dry, or the soap will easily turn, that is, Previous Next
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