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RAMIE (RHEA, CHINA-GRASS)
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See also:RAMIE (See also:RHEA, See also:CHINA-GRASS) , the product of one or more See also:species of the genus Boehmeria, a member of the See also:order Urticaceae and nearly allied to the stinging See also:nettle genus (Urtica), from which, however, it differs in See also:absence of stinging hairs. Some confusion has arisen in the use of the various terms China-grass, Ramie and Rhea. Two See also:plants are concerned. One, Boehmeria nivea, China-grass, has been cultivated by the See also:Chinese from very See also:early times under the name Tschou-ma. The other, probably a variety of the same species (Boehmeria nivea, See also:var. tenacissima), though sometimes regarded as a distinct species (B. tenacissima), is the Ramie (See also:Malay zami) of the Malay Islands and the Rhea of See also:Assam. Boehmeria nivea is a shrubby plant with the growth of the See also:common nettle but without stinging hairs, sending up each See also:season a number of straight shoots from a perennial under-ground rootstock. The See also:long-stalked leaves recall those of the nettle in their shape and serrated margin, but their backs are ' From the position of the words it is even not unlikely that " See also:Pithom and Raamses " may be the addition of a redactor, and that the first author of Exod. i. 11 only spoke generally of See also:store-cities.clothed with a downy substance and have a silvery See also:appearance. The See also:minute greenish See also:flowers are closely arranged along a slender See also:axis. This variety has been cultivated by the Chinese for many years, and the fibre, which is obtained from it by a tedious See also:hand-See also:process, has been used more or less as a substitute for See also:silk. The variety tenacissima differs in its more robust See also:habit and larger leaves, which are See also:pale See also:green on the See also:face and a very much paler green on the bark. They are not downy, however, and this affords a ready means of distinction from true China-grass. Boehmeria nivea is sometimes found See also:wild in See also:India, Malaya, China and See also:Japan, and is probably a native of further India and Malaya. China-grass and ramie are widely cultivated not only in China, See also:Formosa, Japan, India and Malaya, but also in See also:Queensland, See also:Mauritius, the Cameroons, the See also:West Indies, See also:Brazil, See also:Mexico and the See also:southern states of See also:North See also:America, and also in See also:south See also:Europe. The plant, which attains a height of from 3 to 8 ft., is grown from See also:seed, cuttings or layers, or by See also:division of the roots. It is easy to cultivate, and thrives in almost any See also:soil, but especially in a naturally See also:rich, moist, See also:light, loamy soil. For the best growth a See also:good and equally distributed rainfall is necessary. Sudden changes of See also:weather result in irregularities in growth, and these have a tendency to produce plants the See also:fibres of which vary in strength. Liberal manuring is necessaryryy, , as the plant withdraws a large quantity of valuable See also:constituency from the soil. The plants should be cut when the See also:flower is beginning to fall and the seed to See also:form. It is stated that two to four crops per season may be obtained on suitable ground, each See also:crop yielding about 4 tons of stems per See also:acre. With only two crops per See also:year, and a 4% yield of fibre, the resulting product would nearly reach one-third of a ton per acre. When proper See also:attention is given to the choice of ground, and to planting, there is not much difficulty in the way of raising a good crop; the trouble arises in the extraction of the fibre. The stems when ripe are cut down, and after the leaves and small branches have been removed, the See also:outer See also:cover and the layers of fibre are stripped off in the form of See also:ribbons. These ribbons contain the bark, the fibre and a quantity of very adhesive See also:gum. The Chinese remove this bark and as much of the gum as possible before the plant has dried. This hand-process is naturally a slow and tedious one, and many decorticators have been invented to supplant it. The See also:action of all these decorticators is very similar. The ramie stalks are fed into the See also:machine, and during their passage are beaten by i 2 to 20 rapidly revolving See also:blades. These break the stalks into small pieces, and leave the bark and fibre in long ribbons. At the same See also:time, See also:part of the gum is squeezed out between the beaters and the See also:anvil. Up to the See also:present, however, these See also:machines have not been very successful. They usually bruise or otherwise injure the fibre, and they do not squeeze out the gum thoroughly. If the gum be allowed to dry on the ribbons it is difficult to remove it, and the chemicals employed in the degumming, if not thoroughly removed by washing, often injure the fibre to such an extent that the ultimate fabric or See also:article is soon decomposed. If, however, the ribbons be degummed immediately, or soon after the plants are cut down, the gum will be much more easily' extracted—indeed it might be possible to remove it then by boiling See also:water or See also:steam. The fibre cannot be expected to make much headway until the operations of decorticating and degumming are successfully carried out on or near the growing grounds; and, until a proficient decorticator is made, the fibre should be stripped by hand and the degumming operation begun immediately. By this method the least possible damage would result to the fibre, no See also:waste material would be shipped, and a clean fibre would be placed on the See also:market. The fibre possesses some very valuable properties; it is not only much stronger than any other known fibre, but almost equals silk in its brilliance. This latter See also:property, however, is now challenged by mercerized See also:cotton. It successfully resists atmospheric changes, is easily dyed and is affected but little by moisture. On the other hand, articles manufactured from it are said to crack and break easily when sharply See also:bent, and on See also:account of their hairy See also:character have not the same See also:smart appearance as those made from See also:flax. Although the fibre is in some cases 12 in. long, it varies considerably in length. This is one of the drawbacks in the preparing and See also:spinning. It is impossible to make perfect yarns from fibres of various lengths; hence it is necessary either to See also:separate the fibres into reasonable See also:groups, or to cut them into satisfactory lengths. The latter method appears, on the whole, to be the better, and it is the method adopted by Messrs See also:Greenwood & See also:Batley Limited, See also:Leeds, who make See also:special machinery for the dressing, preparing and spinning of ramie and China-grass. If no special machinery be employed, the length of the fibre will decide the class of machinery to be used. The fibre has been prepared and spun on flax, See also:wool and silk-waste machinery, but it must be understood that none of these systems are really suitable for the process. A fibre with special characteristics requires special machinery for its manufacture. When so many different opinions obtain as to which existing machinery is best adapted for the preparing and spinning of ramie, it is not surprising to find that different methods are employed in the process of manufacture. In See also:general, however, we may say that, after decortication, the first process is that of degumming. This is usually done by immersing the fibre in a See also:caustic soda See also:solution, which is then heated in a closed See also:vessel. The fibre is laid on galvanized trays, of which as many as See also:forty-four can be fitted in a cage, which is then placed inside the boiling keir, the lid of which is screwed down and the necessary pressure of steam admitted. After having been boiled a sufficient time to remove the gum, the material is lifted out, the See also:alkali neutralized, and the fibre thoroughly washed to remove all traces of chemicals. The bulk of the water is removed by a hydro-extractor. and the fibre is then hung up or laid on perforated plates to dry. To facilitate the subsequent processes, the fibre is softened by passing it through a machine fitted with fluted rollers. Then follow the operations of dressing, roving, wet spinning and doubling, and finally the See also:twisted See also:thread is passed rapidly through a See also:gas See also:flame in order' to remove all superfluous hairs. In spite of the many disappointments which have been experienced in connexion with the treatment of this fibre, we are of the See also:opinion that it will ultimately hold a good See also:place amongst commercial fibres. It is at present spun in several See also:European countries, but its use is still very limited. This is due, not to any imperfection of the fibre, but to its See also:price and to the limited See also:supply of raw material. It is at present chiefly used for gas mantles, for which it is particularly well adapted. It has also been used for See also:paper-making, See also:ropes, lines, nets, underwear, and for See also:canvas and several other fabrics. If only a good supply of clean fibre could be obtained, there is not the least doubt that manufacturers and machine-makers would quickly provide means for dealing with it. (T. Additional information and CommentsThere are no comments yet for this article.
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