Fibers initial form

Fiber-Reactive Dyes. These dyes can enter iato chemical reaction with the fiber and form a covalent bond to become an iategral part of the fiber polymer. They therefore have exceptional wetfastness. Thein main use is on ceUulosic fibers where they are appHed neutral and then chemical reaction is initiated by the addition of alkaH. Reaction with the ceUulose can be by either nucleophilic substitution, using, for example, dyes containing activated halogen substituents, or by addition to the double bond in, for example, vinyl sulfone, —S02CH=CH2, groups. 

Most manufactured fibers are available as staple, tow, and filament. Natural fibers are available only in the characteristic forms in which they occur, with filament silk and cotton staple as examples. All manufactured fibers are formed initially as filament yarns. The German adjective endlos (literally translated endless ) is very descriptive, as filament yams are continuous strands consisting of one or more members that for most practical purposes are infinite in length. Fine filament yarns (40-100 denier) are used in producing lightweight apparel fabrics,... 

Introducing the refractive index n = uqn2l into the wave equation (6.15) yields stable solutions that are called solitons of order N. While the fundamental soliton N = 1) has a constant time profile I t), the higher-order solitons show an oscillatory change of their time profile I(t) the pulsewidth decreases at first and then increases again. After a path length zo which depends on the refractive index of the fiber and on the pulse intensity, the soliton recovers its initial form I t) [704, 705]. 

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