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candles, material


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candles, material - Candles, Material
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Beeswax

Commercial beeswax is adulterated with almost every conceivable fat, cheap paraffin, etc., as well as with "make-weights" of a coarser description; by careful sampling, a keen buyer manages to escape with about 75 per cent, of pure wax. The first operation is to boil it on weak acid water, and to separate the dross by subsidence. It is bleached either by air, or by potassium bichromate and hydrochloric acid. Thus treated, however, it becomes much more crystalline, owing to the myricin being split up into palmitic and cerotic acids. When it is air-bleached, it is melted in hot water, or by steam, in a vessel either of tinned copper or of wood, and allowed to settle; the waxy superstratum is run off while fluid into a wooden trough having a row of perforations in its bottom, by which it is distributed upon horizontal wooden cylinders, made to revolve with their lower portions surrounded by cold water. The ribbons or films made in this way are then exposed to the bleaching action of the atmosphere and the sunlight, being frequently moistened and turned over during the process. It is necessary to guard against wind, which might scatter the shreds; for this purpose, large cloths are provided. The operation is continued until the wax becomes perfectly clean and white. It is usually conducted from April till September, the exigencies of the weather preventing it at other seasons. In France, it is customary to add a little cream of tartar or alum to the water in which the wax is melted, by which the long and tedious operation of bleaching is rendered much shorter. Bleaching agents, such as chlorine, cannot be employed to bleach wax, since they render it unfit for making into candles. Purified in the above manner, beeswax is perfectly white, and has neither taste nor smell; it has a sp. gr. of from 0.960 to 0.996; at a temperature of 86° F. (30° C.) it becomes soft, and melts at 154° F. (68° C.); at 32° F. (0° C.) it is hard and brittle.

Spermaceti

The first operation needed to fit spermaceti for use is technically termed "bagging." The crude sperm oil, as brought in by the whalers, is placed in a reservoir, at the bottom of which are a number of pipes leading into long bags lined with linen, and temporarily closed at the bottom by tying cords round the mouths. The pressure exerted by the body of material in the reservoir forces a large proportion of the oil through the pores of the sacking, leaving behind the solid or " head-matter," as a dingy brown mass. This so-called crude or "bagged" sperm is deprived of a further quantity of oil by the application of pressure. It is put into hempen bags, which are deposited between the plates of a hydraulic press. The pressure applied is about 80-90 tons. When the oil ceases to flow, the sperm is taken out, melted by heat, and then drawn off into trays to granulate. The brittle crystallised blocks are ground to a coarse powder by means of revolving cylinders; the powder is collected in a bin beneath, and is filled into cloths and subjected to a hydraulic pressure of about 200 tons. The oil expressed under this force contains a small amount of solid matters, and is therefore returned for re-bagging. The blocks, as turned out of the press, are melted down, and boiled for 2-3 hours with caustic soda lye at 22° Tw. (14° B.), in the proportion of 40 parts by measure of the former to 1½ of the latter. It is important to guard against an excess of alkali beyond that required for combination with the oil, as it would tend to saponify the spermaceti, and cause a waste of material. The mixture is kept at a low equable temperature, till the oil is taken up, and is allowed to remain at a gentle simmer, while the soap that has been formed rises to the surface and is skimmed off. The heat is then raised to about 250° F. (121° C.), and the mass is treated with small successive doses of water, the additional scum being carefully taken off as it rises, till the whole is clear. It is then drawn off to crystallise in flat tin dishes, whereupon the cakes are again reduced to powder, placed in linen bags, and subjected to a hot pressure in a very powerful hydraulic press heated by steam, after which the spermaceti will still contain a quantity of oil, or weak sperm, which no more pressure will remove, and which must be extracted by saponifica-tion. The final operation consists in boiling down the sperm with strong potash lye at 235° F. (112° C.), removing the scum as before. When the latter ceases to appear, further purification is effected by introducing a little water, at intervals, while the heat is lowered. The supernatant spermaceti, now perfectly colourless and transparent, is cast into blocks and crystallised.

Chinese Wax

Chinese Wax is produced by a small insect like a woodlouse, the Coccus ceriferus, whose cultivation is now an industry next to silk in importance. The statements as to the tree on which it feeds, and whose branches it covers with wax, are conflicting. Fraxinus chinensis, however, is certainly cultivated for the purpose. The wax melts at 180° F. (82° C.), and can be crystallised unchanged from boiling alcohol. It has a longitudinal crystalline fibre, like stearin or stearic acid, and yet possesses some of the flaky qualities of sperm.

Carnauba wax, or stone wax

Carnauba wax, or stone wax, is found in thin films on the leaves, stalks, and berries of a Brazilian palm, Copernicia cerifera. Its sp. gr. is 0.999, and its melting point 185° F. (84° C.).

Japan wax

Japan wax is obtained by boiling the berries of several trees of the genus Ehus, from incisions in the stems of which flows the famous Japan lacquer varnish. It ought properly to rank as a fat, for it consists almost entirely of glycerine palmitate, and yields glycerin upon saponification. Its sp. gr. is 0.984-93, and its melting point 120° F. (49° C.). It is largely used in vegetable-wax candles, which are made as a substitute for beeswax.

ParaffinThe preparation and testing of paraffin scale is too large a subject for these pages, and the reader requiring information on this subject is referred to Wm. Lant Carpenter's work on soap and candles, where the subject of paraffin scale is exhaustively treated.

Ozokerit or earth waxThe colour of this mineral varies from brown to. greenish and yellow tints; its fracture is resinous. It contains about 85 per cent, of carbon, and 15 per cent, of hydrogen, and appears to consist of a group of hard, solid hydrocarbons, whose melting-points range from 140° -176° F. (60°-80°C.).

To obtain commercial products from the mineral, two processes are employed. One consists in dissolving it in some spirit, filtering the solution through charcoal, and distilling off the spirit from the filtrate. In the second, and most usual, the ozokerit is first heated with fuming sulphuric acid, and then carefully distilled with superheated steam in an apparatus.

The process of purification by acidification with strong sulphuric acid gives ceresin, a substance much resembling beeswax in consistency and fracture. By this method, the whole of the mineral is converted into a homogeneous yellow substance, without much loss, except that due to filtration, and a certain amount of charred products. This substance (ceresin) is, however, useless in candles, as it smokes persistently. By Field and Siemssen's patent, the ozokerit is melted, and introduced directly into the still, whence it is distilled by fire heat and superheated steam. This process yields about 50 per cent, of hard white material (140° M.P.), 35 per cent, of black paraffin, 170° M.P. (employed in insulating materials for electrical purposes), and 15 per cent, of oil and soft grease (ozokerine, a substitute for vaseline).

When thus purified the ozokerit resembles fine beeswax in colour, but is more translucent than wax, though less so than paraffin. The hardness and high melting-point (142° F. (61° C.)) of the candles made from this source give rise to a drawback common to wax candles, viz. the smouldering of the wick on extinction. The immediate cause of this is the fact that the cup of the candle dries and solidifies as soon as the flame is blown out, so that there is no liquid matter left to extinguish the spark. This difficulty is now overcome by a special contrivance of the wick.

Pielsticker refines crude ozokerit by agitation first with sulphuric acid, and after treatment with barium carbonate and caustic soda.

Palm oilPalm oil is distilled by methods common to the other materials noted above. The distilled mixture of palmitic and oleic acids is cut into shreds, by means of a revolving knife, and the shreds are wrapped in canvas or woollen cloths, spread in even layers between mats of cocoanut fibre, and submitted first to the cold press and afterwards to the hot press, at a temperature of 85°-90° F. (29°-32° C.). The pressed cakes of fatty acids are pared, and then melted again by steam, in large, wooden, iron-bound vessels, containing water and sulphuric acid. The whole is boiled for a time and is then allowed to stand, after which the acidulated water is drawn off. The melted fatty acids are repeatedly washed with hot water, and then run into moulds; when cold, they are quite pure, and ready for manufacture into candles, after admixture with stearic acid obtained from other fats.

Of late years, a quantity of inferior stearin (using the word in its commercial sense) has been prepared from what is technically known as " recovered grease." In spinning wool, it is necessary to lubricate it with a certain amount of oil, which afterwards has to be washed out. From these and other processes in woollen mills, large quantities of wash-waters are run to waste, containing soap in solution, and oil in suspension. In many factories, and especially in those localities where it is forbidden to pollute the rivers, these wash-waters are run into tanks, where enough mineral acid is added, to give them, after thorough agitation, a faintly acid reaction. After some hours, the contents of the tank divide themselves into(l) a greasy dirty scum, (2) clear water, (3) greasy mud on the bottom. The clear water is run away, and the residue, after draining, is packed in canvas bags and placed in hydraulic presses, which are slightly heated during the operation. Water and crude fatty acids are expressed, and separate from each other by subsidence; the fatty acids are then pressed and distilled as described above, the yellow hard portions being used for low class candles, and the oil used over again in the mill.

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