Filament titer

The diameter of a filament can be calculated from the filament titer if the density... 

For yam titers it is usefiil to specify the number of filaments. For example, an aramid yam type could be indicated as 1500 denier f 1000, which means that the yam contains 1000 filaments, each of 1.5 denier. In dtex, this yarn type would be 1670 dtex f 1000, a filament titer of 1.67 dtex. 

Yarn titer [dtex] Number of filaments Filament titer [dtex]... 

This is a reasonable pressure drop not too high, but also not too low, because this would lead to an uneven distribution of the flow over the holes, which would result in filament titer differences within a yam bundle. For a lower melt viscosity (for example, 100 Pa s), narrower spinning holes (350 pm) would have been necessary. 

Partly oriented yarn (POY) is a large product spun at about 3500 m min with a round cross-section, and draw-textured (DR 1.8, at about 1000 m min ) in a separate step. Fully oriented yarn (FOY) can be spun at >6000 m min or drawn in the spin-line (hot-tube spinning, HTS), or spin-drawn. Typical yarn titers are 30, 50, 76, 110, and 176 dtex, and the filament titers 2-3 dtex, although there is a trend toward values of 1 dtex or lower. 

There is a limited field of application for low yarn titers, 200-550 dtex, in sewing yarns and fine fabrics. Most industrial yarns have titers of 1100-2200 dtex. The filament titer is usually around 5 dtex, but yams for safety belts have coarser filaments (10-15 dtex) and modern tire yarns may have finer filaments (around 3 dtex). 

Staple fiber is a large product, especially for applications in carpets. The production resembles that for polyester staple. The spinning speed is about 2000 m min , which is not problematic because the as-spun yarn is not wound but laid down in containers. The filament titer may be low (4 dtex, for velour carpet) but is usually around 20 dtex. The cross-section is profiled it may be trilobal or a square with holes. 

Yarn titers are 200-600 dtex for airbags and other fine fabrics, and 1100-2200 dtex for most other applications. Filament titers are around 5 dtex. Tenacities are between 750 and 850 mN tex, and elongations between 18 and 25%. 

The spinning solutions - caustic plus acid - are highly corrosive. The spinnerets are made of gold/platinum, round, with diameters of a few centimeters only. The capillaries are small (50-75 gm) and close to each other (< 1 mm). The number of holes must be large because the standard filament titer of rayon yarns is around 1.7 dtex. The freshly spun filaments are very weak and a tube is often placed around the spinning bundle. 

Applications of acrylics The largest application is in fiber yarns for dothing (especially sweaters), home furnishings, covers, and blankets. The filament titers vary... 

After all, the consequences for filament titers and diameters and process speeds do not differ very much from our first rough estimate. Melt-spun filaments may have a titer of 1-5 dtex, but 20-30 dtex is still possible. Their eventual diameters range from 10 to 50 pm, but they are spun from much larger holes. Dry- and wet-spun filaments often have a titer of 1.7 dtex (13 pm), and are usually spun from holes... 

Thus, the rest of the spinning process is careful washing, neutralization, further washing, drying, and winding. The standard titer of aramid yarns is 1670 dtex f 1000 (1.7 dtex filament titer). The elongation at break is around 3%, the tenacity 2100 mN tex , and the modulus > 50 N tex (75 GPa). 

Dyneema yarns have filament titers of 1-2 dtex. Spectra filaments are coarser (4-11 dtex). Filaments of 2 dtex with a density of 0.97 g cm have a diameter of 16 xm. How is this diameter produced If we assume a draw ratio of 100 and a concentration of 10% we can calculate the diameter of the undrawn gel filaments from Eq. (10) to be Dgel,undrawn = f drawn(DR/ ) = 16(100/0.1) = 506 gm. We... 

Attempts have been made to reduce the area-specific weight by using finer filament yarn titers and also finer filament titers. 

With these methods, the area-specific weight of 240 g/m of the standard quality 479 dtex f72 could essentially be reduced. A decrease of the filament titer increases the air permeability. Experiments have already been made with PA 6.6 110 dtex at an area-specific weight of 110 g/m (Siejak, 1997). 

Textile yarn (acetate fibres) is produced in a similar fashion but with much fewer filaments per spinning site (20 to 160) and overall yarn titers between 44 and 670 dtex [43]. Melt spinning is not, to the authors knowledge, found in the literature. 

Regenerated cellulosic fibers are made out of cellulose from wood or cotton lint. The most used fibers are viscose, acetate, cupro (very small quantity), and lyocell. These fibers are produced in various titers as filament (endless fiber) or staple fiber. 

It is fairly difficult and inaccurate to measure the diameter of fibers or filaments. It is much easier to weigh a certain length of filament or yam. We thus determine a linear density, or titer. The tex unit is officially included in the SI system, and has become the standard in Europe. The older unit denier stems from ffie silk industry and is still common in the USA and in many Asian countries. The definitions are ... 

Further aspects of yarn appearance are the yarn titer and the number of filaments there may be thin or thick yarn bundles. This will obviously depend on the application. 

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