Fabric nonwoven

The worldwide production of nonwoven fabrics in 2002 was 3.625 MT, with an aimual growth rate of 10% and a total sales value of 9.3 billion. The United States accounted for 1.282 MT or 41% of the total productivity. West Europe 1.203 MT or 30%, and Japan 0.29 MT or 8%. These fabrics had a total area of 32.2 billion sq.m. 

Countries that are major producers of nonwoven products have heavily used these products in health and medical applications. According to 1999 statistics, 38% by weight was devoted to these usages in West Europe, 31% in the United States, and 23% in Japan. 

United States, and Japan, respectively. According to Non-Wovens World, melt-spun nonwo-ven products increased from 118 to 136 KT worldwide in 1999. About 26%, or 31 KT, of these products was used for filtration. China is rapidly catching up with 10% of the world productivity in this product segment. 

It is estimated that the worldwide consumption of nonwoven products will reach 6.3 MT by 2010, of which Europe and the United States will account for 55%. With a rapid annual growth of 10%, China will contribute about 24% of this productivity. 

As mentioned earlier, the majority of commodity thermoplastic products marketed today indude some inexpensive mineral fillers in their formulation for cost as well as performance improvement purposes. Even though nonwovens are in a similar cost sensitive market, products such as spunbond polypropylene have not followed this trend. Recent work by McAmish [23-25] has shown that certain grades of CaC03 

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As binders for fiherfill and nonwovens, the emulsions are applied to a loose web or mat, then heated to form a film that sticks the loose fibers together. Polyester (188—191), glass (192), and rayon (193) mats are bonded in this manner for a variety of end uses including quilting, clothing, disposable diapers and towels, filters, and roofing (see Nonwoven fabrics). 

D. I. Lunde, Nonwoven Fabrics Forum, Clemson Univ.,June 15—17, 1982. 

Fig. 2. Scanning electron photomicrograph of a polyester nonwoven fabric.

Textiles. A unique combination of desirable quaUties and low cost accounts for the demand for acetate ia textiles. In the United States, acetate and triacetate fibers are used ia tricot-knitting and woven constmctions, with each accounting for approximately half the total volume. This distribution changes slightly according to market trends. The main markets are women s apparel, eg, dresses, blouses, lingerie, robes, housecoats, ribbons, and decorative household appHcations, eg, draperies, bedspreads, and ensembles. Acetate has replaced rayon filament ia liner fabrics for men s suits and has been evaluated for nonwoven fabrics (79—81). 

In addition to dyeabiHty, polyesters with a high percentage of comonomer to reduce the melting poiat have found use as fusible biader fibers ia nonwoven fabrics (32,34,35). Specially designed copolymers have also been evaluated for flame-retardant PET fibers (36,37). 

Polyesters are also used in continuous filament spunbonded nonwovens (see Nonwoven fabrics). Reemay spunbonded fabric is composed of continuous filament PET with a polyester copolymer binder. These spunbonded fabrics are available in a wide range of thicknesses and basis weights and can be used for electrical insulation, coated fabric substrates, disposable apparel for clean rooms, hospitals, and geotextiles (qv). 

Nonwoven Fabric. Crimped PVA staple is being used for the manufacture of dry-laid nonwoven. Also, as an example utilising the uniqueness of the fiber, a soft sheet is prepared by shrinking and pardy dissolving in hot water a nonwoven from water-soluble PVA fiber and then insoliibili ing the fabric by acetalization or similar processes. This sheet is used as car wipers, wipers for high grade furniture, and for similar purposes. 

Other reinforcements that may be used in the substrate layers of decorative laminates and throughout the stmcture of industrial laminates are woven fabrics of glass or canvas and nonwoven fabrics of various polymeric monofilaments such as polyester, nylon, or carbon fibers. Woven and nonwoven fabrics tend to be much stronger than paper and have much more uniform strength throughout the x—y plane. They greatly enhance properties of laminates such as impact and tear strength. 

During the third quarter of the twentieth century, with improved nonwoven fabrics, man-made leathers finally succeeded in simulating leather to such an extent that they are nearly identical in appearance, physical properties, and stmcture. These leathers have enjoyed success in all leather-use areas. With the technology of microfibers, they continue to evolve both in quaUty and quantity. 

Man-Made Leathers. These materials contain a nonwoven fabric which is impregnated with a polyurethane to improve fiexibiHty, processibiHty, and conformabiHty (Fig. 9). Advanced man-made leathers contain microfibers as fine as 0.03 tex (0.3 den) or less to imitate coUagen fiber bundles, thereby attaining the soft feel and appearance essential for soft leather use. Polyurethane in the substrate is usually provided with porous stmcture by poromeric technology. The coating layer is also porous in the two-layer type man-made leathers (5—10). 

Traditional textile fabrics are made by weaving or knitting. Nonwoven fabrics are similar to woven and knitted fabrics in that both are planar, inherently flexible, porous stmctures composed of polymer-based materials. The main difference between the two is the manner in which the fabric is made. 

A nonwoven fabric can be assembled by mechanically, chemically, or thermally interlocking layers or networks of fibers, filaments, or yams. Fabrics made from textile fibers in this manner have been classified as dry-laid nonwovens. 

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