. Textile raw materials and their conversion into yarns : (the study of the raw materials and the technology of the spinning process) a text-book for textile, trade and higher technical schools, as also for self-instruction ; based upon the ordinary syllabus and curriculum of the Imperial and Royal Austrian weaving schools. rolling this product up into coils and beatingthem with mallets before and during hackling a highly prizedvariety of hemp, entirely free from shives, is obtained. Badenhemp prepared in this way is specially esteemed. Microscopic Structure and Chemical Composition.—Under the
. Textile raw materials and their conversion into yarns : (the study of the raw materials and the technology of the spinning process) a text-book for textile, trade and higher technical schools, as also for self-instruction ; based upon the ordinary syllabus and curriculum of the Imperial and Royal Austrian weaving schools. rolling this product up into coils and beatingthem with mallets before and during hackling a highly prizedvariety of hemp, entirely free from shives, is obtained. Badenhemp prepared in this way is specially esteemed. Microscopic Structure and Chemical Composition.—Under themicroscope the cells of hemp fibre (Fig. 22) greatly resemble TEXTILE RAW MATERIALS. 39 those of flax, being cylindrical, highly elongated, generallywith blunted extremities and of less regular structure. Thecell wall is fairly thick, and exhibits node-like excrescencesand displacements, as well as longitudinal fissures and lumen is somewhat broader than in flax cells. Chemically considered, hemp fibre is usually a mixture ofcellulose and bastose. Properties, {a) Colour.—Hemp is whitish, silver or pearlygrey, greenish or yellowish. The paler the colour the betterthe quality, as a rule. (6) Length.—This varies from 40 to 80 inches, the individualcells measuring about 15 to 25 mm. by o-oi6 to 0025 Fig. -Microscopic Structure of the Hemp Fibre (front view). (c) The fineness depends on the quality of the hemp, butis generally lower than that of flax. {d) Tensile strength very considerable, and appreciablygreater than that of flax. {e) Lustre.—The best hemps have a silky gloss nearlyequal to flax. (/) Resistance to Moisture.—This is fairly high, the tendencyto rot under water being slight. ig) Hygroscopicity.—Hemp absorbs up to 30 per cent, ofits own weight of moisture ; the maximum permissible limit,however, is 12 per cent. Uses.—The male hemp is employed for making best hempen 40 TEXTILE RAW MATERIALS. cloth, coarser kinds being used for weaving wrapp
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Keywords: ., bookcentury1900, bookdecade1900, booksubjecttextile, bookyear1901
