Fiber hollow fibers

Membrane shape HoUow fiber Hollow fiber Hollow fiber Flat sheet... 

Control of the regeneration conditions, together with a wide variety of modification, allows the production of a wide variety of products including high-wet modulus fibers, hollow fibers, crimped fibers, and flame-resistant fibers. While almost all rayon is produced using the... 

The diameter of hollow fibers varies over a wide range, from 50 to 3000 xm. Fibers can be made with a uniformly dense structure, but preferably are formed as a microporous structure having a dense selective layer on either the outside or the inside surface. The dense surface layer can be either integral with the fiber or a separate layer coated onto the porous support fiber. Many fibers must be packed into bundles and potted into tubes to form a membrane module modules with a surface area of even a few square meters require many kilometers of fibers. Because a module must contain no broken or defective fibers, hollow fiber production requires high reproducibility and stringent quality control. 

Titanium Dioxide Hollow Fibers. Hollow fibers of titanium dioxide can be manufactured by preparing a solution of a tetraalkyl titanate, an acid such as HC1, and an alcohol such as isopropyl alcohol, followed by spinning and drying the resultant fiber (573). 

Fiber, hollow fiber Membranes, heat exchangers, micro tools, active fiber composites, micro-reactors, fibers for functional or stmc-tural applications... 

Perusal of the published literature on the topic of extrusion shows that a wide variety of thermoplastic binder systems have been used for the fabrication of fiber, hollow fiber, tube, sheet and honeycomb structures made of ceramic materials. Generally speaking, for thermoplastic extrusion to be successful, it is necessary that the binder system used consists of a major and a minor binder component, a plasticizer and a surfactant to ensure a good wetting of the ceramic powder. 

When considering the listed advantages and disadvantages together it is clear that thermoplastic binder systems are particularly suited for the fabrication of thin structures and micro-system components. All the different cases which were considered above dealt with such fine structures (fibers, hollow fibers, thin wall tubes, thin sheets) where it has been shown in the past, that the debinding process is not so critical because of the relatively small process path-lengths involved. 

Poly(benzimidazoles) are speciality polymers that have found only a few civilian applications outside the military area and in space research. PBI fibers have been used for thermally stable protective clothing and as precursors in the production of graphite fibers. Hollow fibers and films of PBI are used to purify sea and brackish water according to the reverse osmosis process. 

Appiications cable insulation, capacitors, coatings (agitators, centrifuges, electroplating equipment, exhaust hoods, filters, piping systems, reactors, semiconductor storage tanks, vessels), films, fibers, hollow fiber membranes, pipes, printed circuits, rods, sheet, solar collectors ... 

Special fiber superfine fiber, profoled fiber, hollow fiber, antibacterial fiber,... 

Cellulose Temporary artifidal skin, natural nondigestable fibers, hollow fibers or membranes, and acoustic membranes in audiovisual equipment... 

Figure 19.3 shows a typical hemodialyzer. Device properties such as the fiber length, membrane surface area, number of fibers, hollow fiber packing density, and header design aU affect solute clearances. 

Co-electrospinning has been applied so far for the preparation of polymer core shell fibers, hollow polymer core shell fibers, hollow fibers composed not only of polymers, but also of ceramics, as well as for the immobilization of functional objects in droplets dispersed in the core that are arranged along the fiber axis. Among the examples reported in the literature are core shell fibers spun from polystyrene and polyethylene oxide, two kinds of polyethylene oxide (one with and the other without a chromophore), and core shell fibers with the electrically conductive polymer polyhexathiophene and the insulation polymer polyethylene oxide (Fig. 20). Hollow core shell fibers in which one polymer (polycaprolactone) forms the shell onto which the core material is deposited (polyethylene oxide) as inner wall is another example for the broad spectrum of fiber architectures which can be produced by coelectrospinning. The formation of the two-layer hollow fiber is based on the... 

All the different types of membranes described above can be used in the three kinds of membrane modules shown in Fig. 18.1-4. One common type is based on hollow fibers. Hollow fibers are essentially very small pipes, typically 300 pm in diameter with... 

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