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Fiber-Processing Requirement

Each fiber producer has developed its own method for modifying the fiber-making process to prepare colored fibers from polymer and concentrate. The color concentrates may be ground to powder and fed in a proper ratio with polymer powder. Alternately, the producer can dilute the colored concentrate pellets in a proper ratio with natural pellets to produce a letdown prior to extrusion. Some systems have been designed to inject melted color concentrates directly into the melt stream during fiber preparation. Such a method proves difficult because for some colors four or more pigments must be added accurately with a concentration ratio difference of 1000 1 or more. The rest of the fiber process is quite conventional, as described elsewhere in this chapter. The extruded colored melt must be quenched, drawn, crimped, and cut to make ST or processed to make filaments with or without texturing. [Pg.184]


The open hoUow fiber shape shown ia Figure 13 is made by a unique process requiring bicomponent yam technology (145). A yam is spun with a water-soluble copolyester core and nylon sheath where the core is dissolved out with an alkaH treatment ia fabric dyeiag. [Pg.256]

In the spray-up process a reinforcement, usuaHy glass fiber, is substituted for the mat and a special spray gun simultaneously chops the glass fiber and appHes it with catalyzed resin to the mold surface. Hand rolling techniques then consoHdate the fiber and resin to conform to the mold surface contours. The shorter chopped fibers aHow for more intricate design detaHs than do mats. Both processes rely heavily on the operators skiHs for product quahty. These two processes require the least capital investment and have the largest product size capabHity of aH the processes. A single-surface mold produces a part with one controHed (usuaHy the visible) surface. [Pg.94]

The precursor fiber is subsequently washed and stretched to the low tex (denier) required for carbon fiber processing. Stretching also imparts considerable orientation to the polymer molecules and provides the basis for the highly oriented carbon stmcture that forms after carbonization. Special care is taken to avoid contamination or impurities that may form strength reducing flaws in the carbon fiber. [Pg.3]

Processing. The process requires a monofilament carbon-fiber core which is heated resistively in a tubular glass reactor shown schematically in Fig. 19.1. PI A carbon monofilament is pre-coated with a 1 pm layer of pyrolytic graphite to insure a smooth deposition surface and a constant resistivity. 1 1 SiC is then deposited by the reaction of silane and a hydrocarbon. Other precursors such as SiCl4, and CH3SiCl3 are also being investigated. A fiber cross-section is shown in Fig. 19.2.P1... [Pg.470]

Configurations used include tubes, plate-and-frame arrangements and spiral wound modules. Spiral wound modules should be treated to remove particles down to 20 to 50. im, while hollow fiber modules require particles down to 5 im to be removed. If necessary, pH should be adjusted to avoid extremes of pH. Also, oxidizing agents such as free chlorine must be removed. Because of these restrictions, reverse osmosis is only useful if the wastewater to be treated is free of heavy contamination. The concentrated waste material produced by membrane processes should be recycled if possible but might require further treatment or disposal. [Pg.586]

In contrast to fiber-forming technologies, the film process requires a comparatively reduced IV due to processing reasons, for example, the pressure along the die and therefore the evenness of thickness as well as the generation of structure, particularly with respect to crystallinity, will need to be considered. As usual, a compromise between intrinsic physical properties and processing has to be found. [Pg.473]

In vivo elastin fiber formation requires the coordination of a number of important processes. These include the control of intracellular transcription and translation of tropoelastin, intracellular processing of the protein, secretion of the protein into the extracellular space, delivery of tropoelastin monomers to sites of elastogenesis, alignment of the monomers with previously accreted tropoelastin through associating microfibrillar proteins, and finally, the conversion to the insoluble elastin polymer through the crosslinking action of lysyl oxidase (Fig. 2). [Pg.440]

Before dyeing with oxidation dyes, the furs are treated with the appropriate killing agents and then mordanted with metal salts. Iron, chromium, and copper salts, alone or in combination, are used for mordanting, and the uptake process requires several hours. Adjustment of the pH is effected with formic, acetic, or tartaric acid. The final dyeing process is carried out in paddles with the precursors and hydrogen peroxide until the actual dye lake is developed and adsorbed within the hair fiber. It takes quite a few hours at room temperature until the dyeing process is finished. [Pg.453]

N-McLhylmorpholine-N-oxidc monohydrate, a tertiary, aliphatic amine N-oxide, is able to dissolve cellulose directly, i.e. without chemical derivatization, which is used on an industrial scale as the basis of the Lyocell process [ 1, 2], This technology only requires a comparatively low number of process steps compared for instance to traditional viscose production. Cellulose material - mainly fibers - are directly obtained from the cellulose solution in NMMO no chemical derivatization, such as alkalization and xanthation for rayon fibers, is required [3]. The main advantage of the Lyocell process lies in its environmental compatibility very few process chemicals are applied, and in the idealized case NMMO and water are completely recycled, which is also an important economic factor. Even in industrial production systems NMMO recovery is greater than 99%. Thus, compared with cotton and viscose the Lyocell process pertains a significantly lower specific environmental challenge [4]. Today, Lyocell fibers are produced on an industrial scale, and other cellulosic products, such as films, beads, membranes and filaments, are also currently being developed or are already produced commercially. [Pg.159]


See other pages where Fiber-Processing Requirement is mentioned: [Pg.167]    [Pg.36]    [Pg.184]    [Pg.167]    [Pg.36]    [Pg.184]    [Pg.389]    [Pg.352]    [Pg.72]    [Pg.71]    [Pg.148]    [Pg.149]    [Pg.149]    [Pg.235]    [Pg.323]    [Pg.259]    [Pg.241]    [Pg.341]    [Pg.357]    [Pg.411]    [Pg.352]    [Pg.915]    [Pg.51]    [Pg.392]    [Pg.146]    [Pg.419]    [Pg.137]    [Pg.20]    [Pg.434]    [Pg.257]    [Pg.444]    [Pg.1224]    [Pg.180]    [Pg.189]    [Pg.599]    [Pg.364]    [Pg.115]    [Pg.235]    [Pg.323]    [Pg.389]    [Pg.79]    [Pg.444]   


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Fibers requirements

Glass fiber processing requirements

Processability Requirements

Processing requirements

Synthetic polymer fibers and their processing requirements

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