Though several machines have been expressly designed for the treatment of this fibre, none appears as yet to have satisfied the requirements of the Indian Government.
The machine invented by C. C. Coleman, Honolulu, is shown in Fig, 635. The freshly cut ripe plants are passed through a series of rollers, being carried forward by moving wire screens; hence they are dipped into tanks containing hot water and bleaching materials. The rollers crush tbo plant, and squeeze out the gummy matter, which is removed in the bath. Tho plants are taken through the operation as many times as may be necessary to cleanse and bleach tho fibres, the squeezing between the rollers being repeated each time. The fibre is said to be neither broken nor weakened by the process, and to be cleaned at a cost of 41.-61. a ton.
Lefranc and Nagoua's machine is seen in Figs. 636 and 637. The crushing and feeding rollers a b have their peripheries grooved correspondingly ; c is a toothed support for the plant while moving into the rollers and the revolving beaters d ; e are cylinders furnished with spiral, curved, or elliptical knives!, cushioned with rubber h. The plant is fed in between the rollers b, whence it passes between a a', and under the knives!. The speed of a a' is a little less than that of 66', to avoid tension of the plant ; but the speed of the cylinders c e' is much higher than that of ad, so that the knives / shall strip the bark and pith away from the crushed stalk, as delivered by the rollers a a'. To avoid the otherwise obvious fault that the end of the stem would thus pass out unstrapped, revolving toothed beaters d, and a toothed support c, are provided. When the forward end of the stem reaches a a', the after portion passes between b b', and then falls on and between the arms of the beaters d, which, revolving rapidly in the direction of the arrow, bend the stem over the toothed support c, and strip the bark and pith off the end before it reaches a a', so that the plant is cleaned from end to end.
B000hard's machine is represented in Fig. 638. The plant is placed upon the table a, and introduced, by the lower end of the stem, between the rollers b; the small drum d effects the decor tication of the stem, while the pipe c supplies water, which partially macerates the plant ; the mass is projected by the lever e towards the large drum!, which disintegrates it, and passes it through the rollers g placed below.
Greig's machine is illustrated in Figs. 639 and 640. The green stems are spread on the travelling platform E, and are thus conveyed, small end foremost, between the fluted rollers B 0 D, by which their bark and internal pith is broken up. In this state, they pass down between the
roller B and the pressure roller F, and are conducted thence between the revolving drums g, fitted with knives or scrapers x, by means of which, the short pieces of pith, broken by the action of the fluted rollers, are separated and threshed away, while the gummy and vegetable matters are scraped off the fibres. As the strips of fibre pass from the scrapers .r, they are vertically suspended, and blown between the pressure roller I and travelling table K, by means of a revolving brush H. When the thick ends of the stems have passed through the fluted rollers, they fall down, and, being suspended by the small ends held between the pressure roller I and table K, they come into contact with the lower set of scrapers r, attached to the drums M, by which they are cleansed in the same manner as the small ends. The clean fibre is then drawn upward by the friction between the pressure roller I and the travelling table K, by which it is conducted away from the machine. In order to still further cleanse the fibre whilst it is being operated upon, a tank v is placed on the top of the frame A, and is provided with a tap to, and a rose z extending across the upper part of the machine, by which water may he discharged upon the fibre under treatment. To prevent the adhesion of the gummy and other matters to the scrapers x r, the latter revolve in contact with the brushes N. The speed of the principal parts are : First motions, 65 rev. a minute ; fluted rollers, 10 . 83 ; scraping - cylinders, 520 ; blower cylinders, 520 ; tra velling webs, feed and out let, 21.67 ft. a minute. Weight of machine, 30 cwt. The machine competed for the Indian Government prize in 1872 ; as an encourage ment to others, it received an award of 15001., though it did not fulfil the necessary conditions. It did not succeed in turning out the fibre, clean and fit for market, in one operation, and required the assistance of an ordinary scutcher. The action of the scutcher was considered too violent, and it broke up and injured the fibre to a great extent. The fluted rollers worked well in breaking the stems without injuring the fibre ; but the action of the scrapers was defective, especially when water was deficient. More than 40 gal. an hour were found necessary. The cost of preparation amounted to 351. a ton, instead of 151. ; and the resulting fibre, fit only for cordage purposes, was valued at 281. a ton, instead of 501.