 |
Home > SAPONIFICilTION. alkali, which it does...
Previous Next The best candle and soap tips online! SAPONIFICilTION. alkali, which it does not lose until some hours, when the combination is complete and the soap neutral. Despite the fact that saponification is increased by boiling, rapid boiling is not advantageous, especially in the preliminary stages, when with the first weak lyes the emulsion, is forming. A moderate heat causes a better combination, and the beat should not be much increased until toward the end, when the mass has acquired more consistency and has absorbed sufficient alkali, when it can be boiled rapidly to & finish. When the alkali is dissolved in alcohol and mixed with the heated or melted fats or oils, the combination, is very rapid, and the resulting soap contains all the glycerine which cannot be separated except by a decompoaition with an acid and the addition of some water. By this effect the observant soap-maker is enabled to make some beautiful soaps of transparent appearance, which will be more fully explained in their proper place. Although the decomposition of the sebacic acid with caustic alkalies will take place at common temperatures, yet it is but slowly; but, as in the case of almost all chemical processes, it is essentially assisted by the aid of heat. If the melted fats or oils are mixed with the lye and left to rest, the greater density of the lye will cause it to fall to the bottom, while the fat will float upon the top, so that but a limited contact will be possible with the materials. Thus, it is necessary to cause a constant motion of all the particles by stirring or by boiling, that they may be brought; together and the soap in forming take up gradually the lye, which is being absorbed and is getting weaker, finally beconing clear when the decomposition is complete, forming a neutral salt, i, e., soap and a glycerine oxide, i. e., glycerine and water. If it were possible at all times to keep perfectly pure materials, fats and alkalie3, particularly the latter, the procesB of soap-making WQUM be very much simplified, and, when combined in the proper proportions, soap would be formed and the quality would always be uniform. But, as this is impossible, the closest attention must be paid to the action T3CHNICAL TREATISE ON SOAP AND CANDLES. SAPONIFICATION. 161 of the materials in hand, in order to learn from their action what it is necessary to use and what it is proper to do to form a pure soap. We vill find that nearly every fat or oil has a somewhat different action in contact with th.3 lye, though many will impart their peculiarities to the other. Thus tallow will impart to resin its mode of saponification, without which resin, though readily saponifiable in lyes,even in carbonated lyes, will rot make a detergent or solid soap. So cocoa-nut oil will not saponify in weak lyes, but does so readily in strong lyes; and, when mixed in certain proportions with other fats, it can be boiled in weak lyes, and will impart its property of saponifying in strong lyes when in other proportions it is mixed with other fats and oils. Thus we see that the making of soap, though a simple matter, yet requires a close attention to these peculiarities fo acquire the requisite skill. We thus find, in making soap by boiling the fatty bodies, that, though they may contain many impurities, and the alkalies or bases may have a larger percentage of foreign salts and other extraneous substances, yet by this mode of manipulation, of first forming an emulsion with a portion of the lye and boiling io a clear liquid, and in the second lyes using a portion of culinary salt (chloride of sodium), or what is called u cutting the pan," the soap that has formed will separate, and, with all the unsaponified fat, float on the surface, and the salt and most of the impurities will fall to the bottom with the mother-liquor or spent lye, which can be removed, and the soap, if finished, put in the frames, or, if not sufficiently purified, it can be again boiled with weaker lye and salt, again cat and separated, or it can be fitted or finished in weaker '.ye to give it the proper consistency, or boiled in strong lye, which also separates and can be removed, as the case may require. Culinary salt is here very useful, but it should be in rather strong solution, otherwise a portion will remain in the scap dissolved in the water. The proper concentration of the salt, solution is known by the manner in which the soap appears on the stirrer, the soap separating in curds from the liquid. The liquid in the pan separates Previous Next
|
|
