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THE FLAX COMMISSION.

{Continued from our last.) I

MACHINERY. The Machines used in tbe Province of Auckland for manufacturing flax are of tlnee kinds, made respectively by Messrs Fraser and Tinne of the Phcenix Foundry, Auckland, by Messrs A. G. Price of Onehunga, and by Messrs E. Gibbons nnd Co., of Onehunga. Ali of these machines are, however, identical in principle, and vary only in details by which the principle is carried ont. This principle is, that the flax leaf is held between horizontal feed-rollers, revolving at certain speed, while as the leaf passes ©ut from tlVm, a drum armed in its circumference with iron bea'ers, and revolving more rapidly than the feed- rollers strips the epidermis and tissue away from the fibre • means being provided for adjusting the beating drum to a proper distance from tbe roller or bar against which the flax leaf is stripped, so that the leaf may neither on the one hand pass through without being crushed, nor on the other bave the fibies cut. Another contrivance common to all the machines is vulcanized India-rubber cushions, or spiral springs placed over the journals of the upper feed-roller, so as to allow different thicknesses of leaf to te passed through. The first essential of a flax machine is, of course, the quality of the fibre it produces. This depends to a certain extent upgn the shape and velocity of the beaters, but more particularly upon the ease and accuracy with which the machine can be kept in adjustment. The length of that portion of tbe tip of the leaf, which is left undressed by the machine, depends upon tbe firmness with which the feed-rollers grip the thin point of thp leaf, and .the distance of the place where the leaf is crushed, from the place where it is held by the rollers. We know that on the one hand, simple percussion with a hammer on a block of wood, and on the other scraping with a inife or shell, can each be made to j'ield good fibre ; so tbat the limits of the speed at which the beaters strike the leaf, which is necessary for making good fibre, are probably very wide. The velocity with which the beater scrapes the flax, is, of course, the difference of velocity between the beater and the leaf as it passes through the rollers, and as the blow is delivered, not at right angles to the leaf, but at first at an acute angle, which rapidly changes to the same direction as the leaf as the beater passes round with the circumference of the drum, it follows that the greater the velocity of the beaters the more will their action be one of scraping ; and the smaller the velocity, the more will their action be ©ne of percussion, or more properly detrussion. In Fraser's old machine, and in Price's smaller one, the beating drum is thirteen inches in diameter, armed with fourteen liea: ers, consequently, when making 1260 revolutions a minute, the velocity of the heaters is 715 feet per second. The velocity of the circumference of the feedrollers, or in- other words, the velocity of the leaf, is about 27 feet per second, thus Ifiaving.a velocity of 67*8 feet per second, with which the beaters pass the leaf. In Gibbon's machine, the beating drum is seventeen inches in diameter, armed with thirty-eight beaters, and revolves at only Ibalf the speed of that of Price's and Eraser's smaller machines, the feed-rollers rial! moving with the same angular velocity. Consequently, when Gibbons's drum* is making 680 revolutions per minute, the Waters have a velocity of 467 feet per second^ The feed rollers of this machine being lightly larger than the others, the velocity 8 28 feet per second, making a velocity f 43.9 feet per _ second, with which the teaters outstrip the leaf. So that the elocity of the beaters to the feed is as 1 ; ?in Gibbons's, and as 1 ; 26 in Price's, nd Fraser's old machines. In Price's ad Fraser's old machines there are foureen beaters on each drum, the feedoilers are 2 5 inches in diameter, and tbe ifum makes five revolutions to one of the fed rollers, so that each blow of a beater on an average (as the beaters are not (ui-distanr), rather more than one- ninth an inch from the one before it. In

Gibbons's drum there are thirty -eight beaters, the feed-rolk.s are 2.6 inches in diameter, and the drum makes 2£ revolutions to one of 'the feed-rollers. Consequently, each blow is delivered rather j more than one-twelth of an inch behind the former one, and the power saved is proportionately great. Notwithstanding these differences in ve.'ocity and in number of blows to an inch, we are of opinion that all the machines when in proper adjustment,, make equally good flax. In Price's and Fraser's old machines the beaters were placed diagonally across the face of the drum, sloping alternately in opposite directions, and the spaces bptween them were filled with wood. Gibbons's new machine has the beaters set on the angle, bnt all running parallel, which allows them to be placed nearer together. In Price's new macbine the drum is 15 inches in diameter, with 26 beaters, which are of the same kind as in the smaller machines, but being placed closer together, increases the rapidity of the blow. Messrs Price tried ihe chevroned beaters, but afterwards abandoned them. In all these larger drums the wood betveen the beaters is omitted. We are of opinion that the position of tbe beaters on the drum, matters but little so far as making good flax is concerned, provided that the velocity is sufficiently great, and the striking edge of the beater round and smooth. It may here be remarked that Captain Hutton thinks that the beaters on the drum should be hard ; but that the bar or plate against which the flax is crushed should be soft. Mr Booth, ot Dunedin, is endeavoring to carry out at least a portion of this idea. The adjustments of the different machines vary considerably, but all are capable with more or less ease, of adjustment while the machine is in motion ; a point of the greatest importance. In Price's machine the flax is crushed between the beaters and the lower feed-roller. And in his earlier machines the distance between the two was regulated by means of screws, which moved the journals of the beating drum forwards and backward* on a sliding bed ; now the drum is fixed, and the whole of the standards carrying the feed-rollers are moved in the same way, which allows the feeder to adjust his own machine without moving from his place. In Fraser's new machine the flax is stripped against a thick plate rounded at the end, which is slipped under the feedrollers ; the back of the plate has a fian<r*\ which is pressed forward by two screw.-, against India-rubber, the elasticity of which pushes the plate back when the screws are loosened. This adjustment is very easily made by the feeder. In Gibbons's machine, a round bar with square ends takes the place of the plate, and being near the beating drum it leaves very little of the leaf undressed. The adjustment is given by pinching-screws, which act through the boxes carrying the journals of the beaters. The wear upon both the surfaces of metal, between which the fbi_: is dressed, is very greaf, while the slight wear prevents the machine from dressing the flax properly, so that the surfaces have to be constantly filled up or changed. In Price's machines the lower roller, against which the flax is dressed, is a cast-iron hollow cylinder. As their roller is three inches in diameter, and by constantly revolving ahvays presents different surfaces to the beaters, it lasts much longer than any | other of the machines • but when it is too ; much worn the machine has to be stopped, taken to pieces, and the old cylinder, , ground up, which is a work of considerable time, but they give a spare roller with each machine. In Gibbons's machine the round bar, having four-sided ends, can be shifted so as to show four different surfaces to the beaters as one after the other is worn out, it is then thrown away and a new one put in. It was at first thought thar eight changes might be got from each bar, by shifting it eud for end ; but this is not the case if good flax is desired, and as the cost of the bar is trifling, there is no necessity for trying it. This can easily be done while the machine is in motion. As Gibbons has two machines on one shaft, the stoppage of one necessitates the stoppage of the other. In Fraser's machine no change of face can be obtained, but the worn plate can be slipped out, and another put in in a few seconds, without stopping the machine. And the old plate can be ground up again, ready to replace the second when it is in its turn worn hollow. The cost of these plates is also small, being only 2s 6d each. The importance of dressing the leaf out to the tip is considerable, as it prevents great waste. In Gibbons's machine, and also in Fraser's new one, the feed-rollers are deeply and sharply fluted, and hold the leaf firmly to the tip , the distance, however, to the place where the leaf is stripped, is rather longer than in Price's, which, beating on the lower roller, reduces this di:-tance to a minimum. On the other hand the lower roller of Price's machine must be made smooth, as the flax is dressed on it, and so cannot take so good a hold of the thi mend of the leaf, but allows it sometimes to be pulled through by the beaters. . This can, to a certain extent, be remedied by the person feeding, either twisting the thin portion of the leaf round his forefinger as it enters the rollers, or by " tailing," the but end of one leaf to the thin point of the one before it, and so increasing the pressure on it. This " tailing on," however, must not be overdone, us the leaves are apt to entangle with the " out-taker " under the macbine. Fraser's old machine had the fault of a smooth lower roller, combined with a considerable distance, between the beating-plate and the feed-roller. In practice, when the machines are in good order,' and working well, we are of opinion tbat there is little difference between Fraser's,' Prices, aud Gibbons's machines in this respect.

Next in importance to the quality of the fibre produced comes the quantity of green flax passed jfhrough in a given time. This ; depends not only on the diameter and velocity of the feed-rollers, but also upon the size and shape of the lvaf taken through the liabiltty to stoppage _£* flax getting round tbe shafts, and the ease of clearing the machine when choked. The diameter of the feed-rollers is nearfy alike in all the machines, those of Gibbons's being the largest, and the angular velocity can of course be altered to tbe wish of the manufacturer. It is easy to drive the machines fast, and the " feeder " can put a large number of leaves through in a minute ; ' but our experience is that from thirty to thirty-five leaves a minute is quite as much as the " out-taker " can manage, without entangling or losing a large part of them, and it is in this direction that improvement is most required. It will be found that feeding at the rate of 2f feet per second will pass thirty-three average sized leaves through per minute, or a quarter of a ton per hour per machine. The size and shape of the butt of the leaf that the machine will allow through is important, for much time is lost when the machine refuses to take in big butts cut square at the ends, and it takes too long to go over all, the flax first and cut off0 ff the thick ends and point them ; to say nothing of the waste of stuff that has been paid for. In this respect both Gibbon's and Fraser's new machines, which have both feed-rollers Anted, have an advantage over Price's, the lower roller of which is compelled to he smooth. The merit of this improvement is claimed by Messrs Gibbons, and is one of the points for which they are now taking out a patent. Stoppages are sometimes occasioned by flax getting round the shafts of the drum or feed-rollers, and into the bearings yTnit with the machines in good order, this seldom now occurrs except through carelessness. As, however, it will in spite of all care happen occasionally, it is of importance that every facility should exist for clearing with as little delay as possible. Fraser's old machine was very deficient in this respect ; but his new one, and Gibbons's and Price's, leave little to be desired. Mr M'Tnrvre, of Onehunga (as instructed bv V '"iiigal, who claims to be the origiuatur of these machines) has recently begun to manufacture flax machines but as these are on the same principle as r . ii.-e's, no further notice need be taken of them, except that they have been got up with great care, and with a view to durabilitv — the bearings being all brass. Mr Mills' of Wellington, and Mr Murray, are al>o making machines ; but neither is it necessary to dwell on these, as the above remarks can be easily applied to any other machine, and its merits ascertained. [The Appendices to the report have also been published, but they are too lengthy for pnblication in our present issue.]

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THE FLAX COMMISSION., Bruce Herald, Volume VI, Issue 320, 15 June 1870

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2,298

THE FLAX COMMISSION. Bruce Herald, Volume VI, Issue 320, 15 June 1870

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