POWNALL’S PATENT FLAX-CLEANER.

Marlborough Express, Volume IV, Issue 168, 3 April 1869, Page 5

POWNALL’S PATENT FLAX-CLEANER.

[From the Engineer .] The fibre of the New Zealand flax plant (Phonuium tenax) has always commanded a ready sale in the English market, and when properly cleaned is. worth from £2O to £3O per ton. Many methods have been from time to time tried for effecting this object, and they may be classed under two heads—first, those which have attempted to remove the coloring matter and gummy residue by chemical agents; and, secondly, those which have tried to effect the same by mechanic d means. Of the former, every method has failed on account of the chemicals used not only spoiling the color of the fibre, to which much importance is attached, but also because their action on the fibre invariably reduces its tensile strength to such an extent as to render it practically valueless. The mechanical process has generally been that of stamping or pounding the leaves with heaters, having a rough or scored face, with a stream of water constantly running on them to wash away all the matter detached by the beaters; but this plan has been fund much too expensive, as it is necessary to clean about five tons of green flax to produce one ton of fibre, besides which the stamping frequently injures the fibre, and sometimes cuts it right through. A method has been lately invented by Mr. C. J. Po.vnall, by which the flax is effectually and quickly charred without damaging the fibre or spoiling its color. This gentleman has given much attention to the subject, and tried many experiments on it both in this country and New Zealand. From the engravings, which show elevation* and sec; ions of the machine, it will be seen that Mr. Pownall’s principle is that of scraping away the resin and coloring mutter. This is effected by steel knives or cutters, which pass over the flax leaf with a scraping motion—the distance between the edge of each scraper and the hard bed the leaf rests upon being accurately set with adjusting screws, so that the knives pass close enough to the leaf to scrape away all the resin, &c., on each side of it without injuring the fibre in the least. Two cast iron drums, 15 inches in diameter and 36 inches long, are used in each machine, having cutters made of bar steel, 1 inch by 1£ inches, tightly fixed with copper wedges into sloths planed along the face of the drum. The drums are placed one above the other, and are so geared that the spaces between the cutters of the upper drum serve as the bed or table for the cutters of the lower drum to scrape against, and vice versa. Thus the leaves, which are fed in through fluted rollers pressed together by strong coil springs, receive a scrape on their upper and under sides alternately, the rate of feed being so proportioned to the speed of the drums that the flax is exposed to the action of fourteen scrapers on each inch of its length, thus ensuring it being thoroughly cleaned. < The scrapers of one drum stand slightly further out from its face than those of the other drum, as the skin which has to be scraped away is always thicker on one side of the leaf than on the other. After passing through the cleaning tlrums the fibre falls on to an endless travelling table, made of thin strips of mahogany screwed on to leather bands,, by which it is delivered into a truck, andis then taken to the drying ground,! there exposed to the action of tho sim and air for about twelve hours. It is then haled in a hydraulic press, and sent into-store I ready' for' fehipmciit. A •number of, 'biff, m ipgethgf: with the ■.engines; presses, and,all necessaryplhnfc for a factory capable of cleaning twelve, fo fopr- ; teen tons of flax per day. The work? will be erectedon theAVest Coast, ; north bfrWcl-' lington, where the plant growsTh the greatest luxuriance; both; . natives ‘and “ white' people 'being glad to ifcohtract:’ ■tdthe machines for £1 per ton. The machines have been made by HayWard, Tyler, and Co., Upper Whitecross-

street, from designs and drawings by Aylmer Brothers, engineers, of 26, Parlia*> ment-street, under whose superintendence the entire plant has been made in this country, and shipped for New Zealand. Before being sent away all the machines Were tried most effectually at the factory, with flax specially procured for that purpose from the Channel Islands, where the true phorraiura tenax grows, hut not, of course, to the same perfection as in New Zealand* Specimens of this flax, cleaned under our own observation, now lie before us, and leave nothing to be desired. The get-up of the machinery is excellent, and reflects great credit on Messrs. Hayward, Tyler, and Co. [lt may be remembered that the 4 Nautilus, 1 whilst carrying the machinery to Wellington a few weeks ago, was wrecked of Manawatu, but fortunately the machinery was all recovered. Mr. PoWnall was until recently the manager of the Kopu Flax Mill Company.]