Fiber alignment

RoUer-top cards have five to seven sets of workers and strippers to mix and card the fibers carried on the cylinder. The multiple transferring action and re-introduction of new groupings of fibers to the carding zones provides a doubling effect which enhances web uniformity. Stationary-top cards have strips of metallic clothing mounted on plates positioned concavely around the upper periphery of the cylinder. The additional carding surfaces thus estabhshed provide expanded fiber alignment with minimum fiber extraction. 

Because fiber frictional properties are so important in the conversion of staple yams to spun yams, ASTM D2612 has been designed to measure the cohesive force encountered in the drafting or fiber alignment of sHver and top under static conditions. This frictional force is affected by surface lubrication, linear density, surface configuration, fiber length, and fiber crimp. 

Fig. 4 Wild-type zebrafish eleutheroembryo (57 hpf) stained with antibodies specific for slow muscle fibers (F59 a, c) or fast muscle fibers (F310 b, d). Labeling with these antibodies facilitates the analysis of muscle fiber alignments...

Figure 14.9 Photograph of a Gr/PEEK laminate in which a bend was introduced and propagated into the workpiece using the near-term demonstration machine with a variable velocity profile. Fiber alignment, surface quality, and macroscopic shape are good...

Fig. 8 Nerve cells adjust their adhesion and migration to the corresponding structure, as seen here on random (a, c) and aligned (b, d) cells, (a, b) SEM pictures of PCL nanofibers where gioma cells adhered and followed the fiber alignment (see asterisk in b). (c, d) Motion cell-tracking 20 individual trajectories were traced manually after a total tracking period of 36 h. Scale bars (a, b) 10 pm. Reprinted, with permission, from [178] copyright (2009) Mary Ann Liebert...

The fiber alignment is also a significant factor in composite properties. If the fibers in the foregoing example were randomly oriented their reinforcing effect would be less than 0.2 of the figure calculated above. 

Elzone used a long flow tube upstream of the sensing zone to provide laminar flow and fiber alignment [76] this flow is caused to join a clear liquid sheath that centralizes the fibers in the aperture. 

The foreign body response to carbon fibers is not chronic unless they fragment. One major problem has been the accumulation of wear debris near the acetabular components [129]. However, when used as ligament replacements, carbon fibers appear to induce a type of fibrosis in which collagen fibers align with the fibers. This suggests that carbon fibers can be used as a template for the formation of fibrous tissue [130] and indeed tendon fibroblast cells have been grown on a... 

Baker BM et al (2008) The potential to improve cell infiltration in composite fiber-aligned electrospun scaffolds by the selective removal of sacrificial fibers. Biomaterials 29(15) 2348-2358... 

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