Fiber combing

Heckling. The bundles are hackled or combed to separate the short and long fibers. This is done by drawiug the fibers through sets of pius, each set finer than the previous one. As a result the fibers are further cleaned and aligned parallel to one another. 

Nonabsorbable Natural Sutures. Cotton and silk are the only nonabsorbable sutures made from natural fibers that are stiH available ia the United States. Cotton suture is made from fibers harvested from various species of plants belonging to the genus Gossipium. The fiber is composed principally of ceUulose. The seeds are separated from the cotton boUs, which are carded, combed, and spun iato yams that are then braided or twisted to form sutures ia a range of sizes (Table 4). The suture is bleached with hydrogen peroxide and subsequendy coated (finished or glaced) with starch and wax. The suture may be white or dyed blue with D C Blue No. 9. 

Processes 8 and 9 again employ giUs. The purpose is to shuffle the fibers in the combed sUvet to produce a random positional distribution, and thus the most even sUvet possible. The second finisher gilling wiU also incorporate either a baU winding head, or a press that condenses top that has been deUveted into a can. This latter product is caUed bump top. Both baU and bump facUities ate usuaUy necessary to satisfy customers differing needs. Bumps or baUs wUl then be further pressed into bales for shipment. Combed wool destined for processing on the woolen system may be sucked in short lengths from the comb to form broken top. 

Other classification techniques have been developed which provide some insight on fiber lengths, typically the Ro-Tap test, the Suter-Webb Comb, and the Wash test. 

Horns and hooves were the raw materials for the early polymer preparations. These materials were ground up and treated in various ways so that they could be fabricated into such items as combs to use for ladies hair, and other specialty things of that sort. The next development was the use of cellulose from cotton or from wood as the raw material which was studied for making films and fibers. Work on the cellulose structure had provided information that it was a hydroxylated product, and by converting the hydroxyls to esters, the natural cellulose could be turned into a soluble material, which was spun into fibers and cast into films to make the first cellulose rayon-type material and cellulose films. 

While other organic esters are commercially available, namely cellulose butyrate and cellulose propionate, by far the most widely used is cellulose acetate, which is available as plastics, in films, sheets, fibers, and lacquers. Cellulose acetate is used in the manufacture of display packaging and as extruded film for decorative signs, and to coat a variety of fibers. Injected molded products include toothbrush handles, combs, and brushes. It is also used in lacquers and protective coatings for metal, glass, and paper. Cellulose acetate films are used in reverse osmosis to purify blood, fruit juices, and brackish water. Some eyeglass frames are... 

WOOL, The natural, highly crimped fiber from sheep, wool is one of the oldest fibers from the standpoint of use in textiles. Minute scales on the surface of the fibers allow them to interlock and are responsible for the ability of the fiber to felt, a phenomenon responsible for felt cloth and mill-finished worsteds. Crimpiness in wool is due to the open formation of the scales. Fine merino wool has 24 crimps per inch ( " 10 per centimeter). Luster of the fiber depends upon the size and smoothness of the scales. The basic wool protein, keratin, comprises molecular chains that are linked with sulfur. When sulfur is fed to sheep in areas deficient of the element, the quality of the wool improves. Wool fibers that fall below 3 inches (7.5 centimeters) in length are known as clothing wool fibers 3-7 inches (7.5-17.8 centimeters) long are referred to as combing wools. The wool-liber diameter ranges from 0.0025 to 0.005 inch (0.06-0.13 millimeter). See also Fibers. 

The molecular architecture of a polyphosphazene has a profound influence on properties. For example, linear and tri-star trifluoroethoxy-substituted polymers with the same molecular weight (1.2 x 104 or higher) have strikingly different properties.138 The linear polymers are white, fibrous materials that readily form films and fibers, whereas the tri-arm star polymers are viscous gums. One is crystalline and the other is amorphous. Cyclolinear polymers are usually soluble and flexible. Cyclomatrix polymers are insoluble and rigid. Linear polymers can be crystalline, but graft or comb polymers are usually amorphous. 

Mawson, S. Johnston, K. P. Combes, J. R. DeSimone, J. M. Formation of Poly(l,l,2,2-tetrahydroperfluorodecyl acrylate) Submicron Fibers and Particles from Supercritical Carbon Dioxide Solutions. Macromolecules 1995, 28, 3182-3191. 

Mawson S, Johnston KP, Combes JR et al (1995) Formation of poly(l,1,2,2-tetrahydroperfluorodecyl acrylate) submicron fibers and particles from supercritical carbon dioxide solutions. Macromolecules 28(9) 3182—3191... 

The absolute frequency of the fundamental IS — 2S transition in atomic hydrogen has now been measured to 1.8 parts in 1014, an improvement by a factor of 104 in the past twelve years. This improvement was made possible by a revolutionary new approach to optical frequency metrology with the regularly spaced frequency comb of a mode locked femto-second multiple pulsed laser broadened in a non-linear optical fiber. Optical frequency measurement and coherent mixing experiments have now superseded microwave determination of the 2S Lamb shift and have led to improved values of the fundamental constants, tests of the time variation of the fine structure constant, tests of cosmological variability of the electron-to-proton mass ratio and tests of QED by measurement of g — 2 for the electron and muon. 

Because NL(t) has the same periodicity as A(t) the comb structure of the spectrum, as derived in section 3, is not affected. In an optical fiber self-phase modulation can be quite efficient even though the nonlinear coefficient in fused silica is comparatively small. This is because the fiber core carries a high intensity over an extended length. 

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