Oiling.—The oiling of wool is an important and indispensable procesli in the manufacture of woollen thread. Its purpose is to cover the scalee of the fibre, and make a perfectly even surface, which will allow the fibres to glide over each other without interlocking, and without injury to the scales, in the proceeeee through which the wool haa to pass. Insufficiently oiled wnol loses much more fibre in its manipulation, and suffers injury to its felting property, thus yielding an inferior article at a higher coat, compared with that obtained from a properly lubrieated kook.
The plan of oiling in most general use is the hand proceee. Thte is best performed in the fol lowing manner. The blend having been properly made, and mixed in the teazer or " fearnought," a portion, say as much as can be conveniently used before coneiderable evaporation enauee, should be taken and spread over ae large an Area as convenience will admit of near the beck or feed of the machine. The spreading ahould be in thin and even layers. Each layer in aucceasion should be liberally oiled, and at every aecond layer the mass ehould he beaten down with sticks, which servea to bring all the flbree into contact with each other, and so to distribute and eneure a thorough oiling of each. The best inatrument for seeuring an even distribution of the oil ie a ean having a spout in the form of tbe letter T, both stem and crosapiece being tubes, the latter perforated with several rows of fine holes, rhilst ita ends are closed with caps which can be taken off for cleaning. The tubes should be about in. diam., and tbe crose-piece 9 in. long. The oil should be drained or filtered through a piece of thin cotton cloth or other material that would take out coarse impurities. When this has been done, the oil-can, being supplied, should be ewung backward and forward over the layer of wool, in sueh a manner ae to carefully and evenly diatribute the oil, and secure the oiling of every particle. Each layer should time be oiled in euccession, until the whole ie completed. When used, the wool, as before, ehould always be taken from the aide of the blend, oommencing at the top and drawing downward& All points coneidered, this aystem of oiling gives the most aatisfaetory results. There are, however, several plane of mechanical oiling, means for accomplishing which are attached to the teazer, fearnought, or carding-engine.
In oiling at the teazer or fearnought, a revolving brush ie generally used, which is so arranged ae, after taking up oil from a tank, to cast a fine spray of oil amongst the material just before enter ing the machine. When this aystem is adopted, it ie desirable to again pass the wool through the fearnought, to secure thorough lubrication of each fibre.
Wool is sometimes also oiled just preyiously to entering the carding-engine. It is accomplished
by a mechanical appliance, similar to that just desoribed. Advantagee are claimed for thia aystem over both the preceding, and in theory it ie perhaps euperier, and affords a better opportunity than either of the others for effecting thorough lubrication. The practical difficulties, however, have hardly been fully overcome. The syatem is therefore not yet likely to supersede the first-named.
An important matter requiring the careful consideration of manufacturers is the kind and quality of oil to be used in this operation. The objeet of oiling, as previously stated, is to cover or aheath the scales on the surface of the wool so as, in the &et instance, to prevent their becoming entangled with each other in the working process, which leads to great waste of its fibre and damage to that whieh is not loet, whereby it is injured in its felting properties; in the second, it is to preserve the latter quality intact for utilization in the fulling process. It will be obvioue that other fluida would aerve equally well, could they be retained by the wool for a eufficient length of time to permit the latter to pass through the machinery. Accordingly, numerous compoeitions are offered in the market es cheap substitutes for the more coetly oil. As a rule, however, oil maintains its poeition in the estimation of the trade as the best and most economieal lubricant, all circumstances being considered, though there are casco in which some of these compositions may be advantageously used.
A good quality of oil, very pure and free from acids, ip the best, as it is retained the longest by the wool, and does no injury to the card clothing, nor to the colour of the material. The nature of the wool being worked will, to a certain extent, always influence the selection of the oil, but apart from this consideration, experience has shown that oleine is a cheap and very satisfactory lubricant. It is expressed from animal fats, and is specifically known as tallow-, lard-, and neat's-foot oils (see p. 1367). A recent writer on the subject advocates the oleine obtained as a bye product from the manufacture of stearine candles (see p. 585). But should the oil not be cleared from the sulphuric acid used in its preparation, the card clothing will be injured, the felting property of the yarn will be damaged, and the operatives who have t,o handle the wool will suffer in their hands and arms, the acid often destroying the finger-nails. Commercial oleine always contains less or more acid, the quantity varying from per cent. upwards. Red oil is of a kindred ,nature to the above, and is usually similarly contaminated with mineral acid. A ready way of testing oils for mineral acids is to place a drop on blue litmus paper, which, if only a faint trace of acid be present, will turn red.