Non-round cross sections

The melt flow under isothermal conditions, when it is described by the rheological equation for the Newtonian or power law liquid, has been studied in detail63 66). The flow of the non-Newtonian liquid in the channels of non-round cross section for the liquid obeying the Sutterby equation have also been studied 67). In particular, the flow in the channels of rectangular and trigonal cross section was studied. In the analysis of the non-isothermal flow, attention should be paid to the analysis 68) of pseudo-plastic Bingham media. 

Glass fiber, bilobe Fibers of non-round cross section are prepared by different methods in various geometries. The shapes provide a different fiber packing. 

Silicate glass fibers with non-round cross sections... 

Most natural fibers have a non-round cross-section and low luster (Figure 17.2) silk is the exception. Moreover, yams spun from these fibers have a high volume (bulk) and fiber ends make them hairy. All these factors are appreciated for applications in textiles and carpets. Synthetic yarn is most easily spun from round spinning holes, the filament yams have a high luster, they are flat (not textured), and hairiness is absent. This may be perfect for industrial yarn applications, but it is not desirable for most textile and all carpet yams. 

Irregularly non-round cross-section, including flat ribbon, multilobal, triangle, paralleled strip, etc. 

Design Graphs for Dies of Various Shapes, but the Same Cross-Sectional Area (a) Use Eqs. 12.6-1 and 12.6-2 and Fig. E5.1(a) to construct Q vs. AP graphs for dies that have the same cross-sectional area and the following shapes circle, ellipse, rectangle, and a rectangle with two rounded-off sides in the shape of half-circles. Use a Newtonian fluid, (b) How can the equivalent Newtonian fluid concept help you extend these shapes for non-Newtonian fluids ... 

Figure 1-31. Repeat units of some chlorofibres. temperature is low with considerable shrinkage at 70 C and have poor dyeability at moderate temperatures. These fibres are mainly used in filter cloths, flying suits (in which their property of non-flammability is an asset), curtains (owing to their resistance to degradation of light) and fishing nets (owing to their resistance to water). These fibres have regular round, dogbone or dumbell shaped cross-section and transparent, even and smooth. They are highly lustrous and silky in hand. 1.8.2 Poly (vinyl alcohol) fibres...

A typical continuous glass fiber has a solid cylindrical shape, i.e., a round fiber aoss section with a uniform diameter along its length. Special applications may require glass fibers having a non-round, e.g., a ribbon shaped or a trilobal cross section. Dual or bicomponent glass... 

Non-round fiber cross sections are characterized by their modification or mod ratio. For ribbons, the mod ratio is their width-to-thickness ratio. For trilobal fibers it is the ratio of the diameter B of the outer circle around the lobes of the fiber cross section to the diameter A of the inner circle within the core of the fiber cross section (Figure 9). The term mod ratio has been used since the early development of trilobal nylon fibers. The newer term, deformation ratio [43], is less intuitive and therefore less desirable. 

The use of non-round pitch carbon fiber cross-section provides an alternate approach to modify structure with potential enhancement of fiber adhesion to matrices, improved surface characteristics or improved conductivity. This forced filament geometry is routinely practiced with several polymeric systems in melt spinning to control product response. Ribbon and C-shaped carbon fibers have been provided to accomplish this, as... 

A round-shape lateral cross-section of voxels is preferable in most fabrications. We tried to ehminate the non-unit lateral axis ratio by polarization modification. Circularly- and non-polarized beams were realized by inserting a 780 nm antireflection-coated c-axis-cut quartz A/4 retardation plate and a visible-range double-plate-type quartz depolarizer into the light path, respectively. In both cases, there is no preferential direction of light intensity distribution at the focal spot. Experimentally a nearly perfect round shape was achieved for both cases, as shown in Fig. 30e,f. 

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