Soap-Making Manual Part 12

Silver Sand (fine) 60 "

To proceed place the oil in a crutcher and heat to 140 F. Sift in the pumice and mix thoroughly. The lye is then added which causes a curdling of the grain. The stirring is continued until the grain closes and the soap is smooth, after which the desired perfume is added and the soap dropped into a frame and crutched by hand. When the soap is set, it is slabbed, cut into cakes, dried slightly and pressed.

LIQUID SOAPS.

Liquid soaps are merely solutions of a potash soap, usually cocoanut oil soap, although corn oil is used to make a cheap soap. One of the difficulties encountered in liquid soap is to keep it clear. At a low temperature a sediment is often formed, but this can be overcome by the use of sugar and filtering the soap through a filter press at a low temperature. In order to prevent the soap from freezing, it is necessary to lower the freezing point by the addition of glycerine or alcohol.

To make liquid soap by any of the formulae given below, the oil is first run into a jacketed kettle with a stirring device, and heated to about 120 F. The potash lye is then added and the oil saponified. When the saponification takes place, especially when cocoanut oil is used, the ma.s.s swells rapidly and may foam over the sides of the kettle unless water is used to check this, or a kettle of about four to five times the capacity of the total charge of soap is used. When the saponification has occurred, the sugar, borax and glycerine are added, the water run in and the mixture stirred until the soap is thoroughly dissolved. Heat aids materially in dissolving the soap. The soap is then allowed to cool and if color or perfume is to be added this is stirred in, after which the soap is cooled and filtered or else run directly into barrels.

Tallow is not suitable for making a clear liquid soap since it is too high in stearine which when formed into the stearate makes an opaque solution. The formulae herewith given have been found to give good practical results.

I. lbs.

Cocoanut oil 130 Caustic potash lye, 28 B. 135 Sugar 72 Borax 2 Water 267

II. lbs.

Corn oil 130 Caustic potash lye, 26 B. 135 Sugar 72 Borax 2 Water 267

III. lbs.

Cocoanut oil 100 Caustic potash lye, 28 B. 102 Glycerine 100 Sugar 70 Water 833

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 quant.i.ties 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 pota.s.sium 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 "

This soap may be made in a crutcher by the method generally used in making soap by the cold process.

TEXTILE SOAPS.

Soap is a very important product to every branch of the textile industry. For woolen fabrics it is used for scouring, fulling and throwing the wool; in the silk industry it is necessary for degumming the raw silk, as well as for dyeing; in the cotton mills it is used to finish cotton cloth and to some extent in bleaching; it is, furthermore, employed in a number of ways in the manufacture of linen. Large quant.i.ties of soap are thus consumed in an industry of so great an extent and the requirements necessitate different soaps for the different operations. We will, therefore, consider these in detail.

SCOURING AND FULLING SOAPS FOR WOOL.

The soaps used to scour wool and for fulling the woven cloth are usually made as cheaply as possible. They are, however, generally pure soaps, as filling material such as sodium silicate does not readily rinse out of the wool and if used at all must be added very sparingly. Both cold made and boiled settled soaps are made for this purpose. The soap is generally sold in barrels, hence is run directly to these from the crutcher or soap kettle. As cold made soaps the following serve for wool scouring or fulling.

I.

Palm Oil 200 lbs.

Bone Grease 460 "

Soda Lye, 36 B. 357 "

Water 113 "

Soda Ash 50 "

Citronella 2 "

II.

Palm Oil (Calabar, unbleached) 155 "

House Grease 360 "

Soda Lye, 36 B. 324 "

Water 268 "

Sodium Silicate 83 "

III.

House Grease 185 "

Palm Oil (unbleached) 309 "

Soda Lye, 36 B. 309 "

Water 391 "

Soda Ash 70 "

Sodium Silicate 60 "

Corn Starch 10 "

These soaps are made in a crutcher by the usual process for cold-made soaps, crutched until smooth, dropped into a barrel and crutched by hand the next day or just before cooling.

As a settled soap for these operations the following charge is typical: