Monofilament yams

All these weaves may be made from any textile fiber, natural or synthetic. They may be woven from spun staple yarns, multifilament continuous yams, or monofilament yams. The performance of the filter cloth depends on the weave and the type of yarn. 

Available forms Monofilaments, yams, bristles, molding powders, rods, bars, sheets. Microcrystalline nylon is now available. 

A study was carried out to prepare antibacterial polyamide fibres by the modification of standard monofilament yam with nitrofuiylo, to examine the liberation of biocides into water and to verify the antibacterial effects of the modified fibres by in vitro testing using Gram-positive and Gram-negative bacterial strains characteristic of hospital conditions. 22 refs. 

Manmade Organic Fibers, Except Cellulosic—Cont. lonitrile, ethylenes, amides, and related polymeric materials), in the form of monofilament, yam, staple, or tow suitable for further manufacturing on spindles, looms, knitting machines, or other textile processing equipment. Establishments primarily engaged in manufacturing textile glass fibers are classified in Industry 3229. 

Again, a combination of the above seams is used in manufacturing sportswear designed of waterproof materials. Acute needle-point needles are used on these types of products. Monofilament yams can be used on certain parts of the garment. Welding is also used particularly for waterproof zips and eyelets for cords. 

In the case of nonwoven fabrics, a reduction in pore size is achieved by compressing the fibres into a more dense structure (loads up to 300decaNm" may be necessary) and, by selection of the appropriate conditions, a more durable (Fig. 3.31) surface can also be obtained through partial fusion of the surface fibres. With woven fabrics, on the other hand, some deformation of the yams may be necessary to achieve the optimum filtration properties. This is particularly graphic in the case of fabrics woven from monofilament yams, as shown in Fig. 3.32 and Fig. 3.33. 

Table 1 Textile structural specifications (Monofilament yams are designated /I, while muhifilament yams indicate the number of filaments, e.g. /12)...

Monofilament yams consist of a single, continuous filament with a relatively smooth surface. The different sizes are specified as a measurement of the diameter in mils or in micrometers. Multifilament yams are made from many fine filaments extmded simultaneously. The different sizes are specified by a measurement of weight known as the denier. These yams are generally used for filter fabrics which require a smooth surface and relatively tight weave. Spun yams are made from filaments which are chopped in short lengths and then spun or twisted together. Spun yams are made into filter fabrics with a hairy, dense surface very suitable for filtration of very fine particles. 

In this study, we used a number of elastomeric threads to construct small-diameter grafts.i2 Twelve different woven structures were developed. The warp used was a 34 filament textured polyester yam of 111 dtex. Three different weft threads were used. One was a 311 dtex spandex core air entangled with a 78 dtex multifilament polyester, providing a total linear density of 506 dtex. The others were Aorlasten polyurethane monofilament yams of 467 and 311 dtex linear densities. Since the filling yarns had a range of compositions and linear densities, their resultant properties were quite different, as shown in Table 14.3. 

Spinneret containing a number of very fine holes produces multifilament yam. A spinneret with only one hole will yield monofilament yam. Monofilaments are also made in multihole spinnerets, but they are not twisted into a single yam before winding up as the multifills are. 

Researchers at the Electronics Department and the Wearable Computing Laboratory at the ETH in Zurich demonstrated another approach to develop a fabric circuit board. They started from a plain woven textile structure consisting of polyester (PET) monofilament yam twisted with copper thread and they developed a hybrid fabric called PETEX (Locher, 2006). In detail, PET yams have a diameter of 42 pm and copper alloy wires have 50pm (Fig. 4.12A). 

As the name implies, monofilament yams consist of a single filament. The filament size is much larger than those found in multifilament yam. Consequently, monofilament is relatively stiff and is used mainly for the production of rope and twine. The fiber size range is typically 75 to 5000 denier. 

Both woven and nonwoven geotextiles are made from four polymeric materials (polyamide, polyester, polyethylene, and polypropylene) and natural materials. Woven geotextiles may be fabricated with monofilament yams, muldfilament yams, or a combination of each. Nonwoven geotextiles are bonded by one of the several methods thermal, mechanical, or chemical. With the many combinations of materials and processes, it is not difficult to see that the physical properties of geotextiles will vary greatiy among products (Yeo, 2008). 

The case is schematically shown in Figure 9.7 where the shaded volume represents the solid cylindrical fiber (monofilament yam). 

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