POWNALL'S FLAX CLEANER.

Southland Times, Issue 1128, 22 March 1869, Page 3

POWNALL'S FLAX CLEANER.

(Prom the * Engineer/) The fibre of the New Zealand flax plant (Phormium tenax) has always commanded a ready sale in the English market, and when properly cleaned is worth £20 to £30 per ton. Many methods ' have been from time to time tried for effecting this object, and they may be classed under two heads— first, thos3 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 mechanical means. Of the former, fevery method has failed on account of the chemicals used not only spoiling the color cf 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 beaters, having a rough or scored face, with a stream of water constantly running on them to wash all the matter detached by the beaters ; but this plan lias been found much too expensive, as it is necessary to clean abut 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 J. C Pownall, 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 oh it' both in this country and New. Zealand. Mr Townall's principle is that of scraping away the resin and coloring matters. 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 on being accurately set with adjusting screws, so \t hat the. knives pass close enough to the leaf to Bcrape away all the resin, &c, on each aide of it without injuring the fibre in the least. Two cast iron drums fifteen inches diameter and thirty-six inches long,^are used in each machine, with cutters made of bar steel, one inch by one and' a quarter inches, tightly fixed with copper wedges into slots planed along the face of the drum. The drums are placed one below 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 drums 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, and is then taken to the drying ground, there exposed to the action of the sun and air for about twelve hours. It is then biled in a hydraulic press, and Bent into store ready for shipment. A number of these machines have been sent out to Jew Zealand, together with the engines, presses, and. all necessary plant for a factory capable of cleaning twelve to fourteen tons <Sf flax per day. The works will be erected on the West Coast, north of Wellington, where the plant grows in greatest luxuriance, both natives and white people being glad to contract to deliver it to the machines for £1 per ton. The machines have been made by Hayward, Tyler & Co., Upper Whitecross street, from designs and drawings, by Ay liner Brothers, engineers, of 2o Parliament street, under whose superintendence the entire plaut 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 phormium tenax grows, but 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 lea?e nothing to be desired.' -Th? get-up of the machinery is excellent/ and reflects great credit on Messsrs Hayward, Tyler & Co.