Flat fiber

Aluminum, copper, brass, and zinc particulate materials manufactured in various shapes of square flake (K-102), rectangular flake (K-101). flat fiber (K-107), flake (K.-109), needle (N-101), and tadpole (T-101, T-102, T-103). The symbols in parentheses are the grades numbers for aluminum. If other metal is requested the grade number is derived from the metal number which is the first digit (1 - aluminum, 2 - copper, 3 - zinc, 4 - brass). For example, square flake from brass is K-402. 

Transmet Corporation manufactures flakes by a Rapid Solidification Technology. There are two variations of this method Melt spin and Spinning cup methods. In the Melt spin method, molten metal of any composition (pure metal or alloy) is driven through an orifice and the shape formed in the orifice (continuous sheet) is rapidly cooled on a chilling block. This metal sheet is cut into segments in the form of flakes (square and rectangular), flat fibers, and ribbons of desired... 

Also prepared is mat preforming. It is the usual flat fiber mat that is formed into a shape usually using a set of matched dies (often made of fiber reinforced epoxy). A mat is cut to the correct dimensions and... 

Natural plant cellulose is located within the cell walls of the fibers. One fiber is a dead elongated plant cell. Hollow capillary—lumen—extends along the fibers. The cellulose fibers have different sizes and shapes (loelovich and Leykin, 2008 loelovich, 2013b). Fibers of cotton, flax, and ramie have a length of several centimeters, while fibers of wood cellulose are short, 1—3 mm. The width of the various fibers is 10—30 pm and thickness of the cell wall is 3—6 pm. Cotton fibers are twisted, but fibers of wood pulp are flat fibers of flax and ramie are straight and round (Figure 9.1). 

Twisted cotton fibers (a) and flat fibers of wood cellulose (b). 

Flat fibers are manufactured by cutting an extruded film by many knives arranged in parallel. The flat fibers are then uniaxially drawn and wound. Alternatively, drawing can precede cutting. 

Resin infusion between double flexible tooling (RIDFT) Resin is injected into a flat fiber preform that is placed between two flexible tools. The flexible tools with the saturated preform in them are transferred over a tool surface, and vacuum is drawn to conform the saturated preform to the final shape of the part. Unlike RTM, here the resin redistributes or squeezes out during the applied vacuum which dynamically changes the permeability and the fiber volume fraction. 

By the mid-1980s a different approach to the production of fine fibers with novel cross sections became possible. Noncircular spinneret holes, eg, rectangular slots, allowed the large-scale production of flat fibers down to 2.2 dtex (2 den) (Fig. 6a). These I-shaped fibers were capable of replacing the inflated hollow fibers in textile applications, providing similar levels of bulk, warmth, and handle while having a much more regular shape. They were followed by the development of solid Y- and X-shaped multilimbed fibers (48) (Fig. fib), which performed like SI fiber but had much lower levels of water imbibition than the inflated version. Their shape and relative stiffness enabled them to absorb more fluid between, as opposed to inside, the fibers. They were therefore as absorbent in use as the inflated versions (49,50) but did not require the extra process chemicals, and were easier to wash and dry in production and use. They are the most important bulky rayons now in production. 

Laminating large, flat fiber reinforced structures for mat-reinforced and non-woven reinforced laminates,... 

The manufacture of high quality yarn at high takeup speeds obviously requires high speed winders. The extruder and the lower part of the spinning machine are basically the same as for conventional spinning. New processes have created a variety of new flat fibers (monofilaments, fine denier filaments, noncircular cross section filaments, staple fibers. 

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