Formulae I and II contain about 20 per cent. fatty acids. It is possible, of course, to either increase or decrease the percentage of fatty acid by varying the amount of water. The water used in making liquid soaps, of course, should be soft, for hard water forms insoluble soaps which precipitate and cause a sediment.
USE OF HARDENED OILS IN TOILET SOAPS.
While the introduction of the hydrogenation of oils is a decided advance in the production of suitable cheaper oils for soap making, comparatively little hardened oil is employed for soap making in America up to the present time. In Europe, however, considerable advance has been made by the use of such oils for manufacturing soap therefrom and a number of plants turn out large quantities of hydrogenated oils for soap making as well as for edible purposes. Recently a company has been formed in this country for hardening oils and it is very probable that the future will see this material extensively used in our own country, as these appear to be the one present hope of the soap manufacturer as a check on the ever increasing cost of fats and oils now used in making soap.
It is an unfortunate condition that hydrogenated oils produced abroad are sold under names which give absolutely no indication as to the oil which has been hardened. The softer and cheaper oils like fish oil, linseed oil, cottonseed oil, etc., are generally hardened for soap manufacture to different degrees of hardness. While it is impossible to definitely state just what products as Candelite, Talgol, Krutolin or several other coined names of hardened oils are, various investigators have experimented with them as to their adaptability for producing toilet soaps and found that suitable toilet soaps may be made from them. While many objections were at first met with concerning soaps made from these products, as to their unsatisfactory saponification, the poor lathering quality of the soaps and their odor and consequent difficulty in perfuming, the results of most investigators along these lines indicate that these in many cases were due to prejudice against or unfamiliarity with handling oils of this type for soap making.
In manufacturing soap from hardened oils it is usually necessary to incorporate with the charge lard, tallow, tallow oil or some other soft oil of this nature. Satisfactory bases for toilet soaps, made as boiled settled soap by the use of Talgol (undoubtedly hardened fish oil), are said to be made by the formulae[10] below.
| I. | ||
| Tallow | 45 | parts |
| Talgol | 40 | " |
| Cocoanut Oil | 15 | " |
| II. | ||
| Cocoanut Oil (Ceylon) | 6 | " |
| Tallow | 12 | " |
| Talgol, Extra | 12 | " |
The method of boiling a soap of this type does not differ materially from that of making settled tallow soap base. The soap itself has a different odor than a straight tallow base, but is said to make a very satisfactory soap for milling and to be of good appearance.
Satisfactory transparent soaps are made from the hardened oil Candelite, which replaces the tallow in transparent soap formulae such as have already been given in the section under "Transparent Soaps." The method of manufacturing a soap by the use of this product varies in no way from the usual method employed for making these soaps.
Since hydrogenated oils are high in stearine, their use in shaving soaps is a decided advantage. It has previously been pointed out that potassium stearate forms an ideal lather for shaving, and in the hydrogenating process the olein is converted to stearine. Thus a hardened oil is advantageous in a shaving soap. As an example of a cold made soap for shaving the following may be taken.[11]
| Talgol Extra | 50 lbs. |
| Cocoanut Oil | 10 " |
| Lard | 10 " |
| Soda Lye, 38° B. | 20 " |
| Potash Lye, 37° B. | 21 " |