Nonwoven thermally bonded

Olefin fiber is an important material for nonwovens (77). The geotextile market is stiU small, despite expectations that polypropylene is to be the principal fiber in such appHcations. Disposable nonwoven appHcations include hygienic coverstock, sanitary wipes, and medical roU goods. The two competing processes for the coverstock market are thermal-bonded carded staple and spunbond, both of which have displaced latex-bonded polyester because of improved strength, softness, and inertness. 

Fig. 2. Typical stress—strain curves of nonwoven fabrics, where (—) is woven (-), thermally bonded nonwoven and (-), needle-punched...

Nonwoven manufacturing, cotton, 3 18 Nonwoven materials, 24 620. See also Nonwoven fabrics Nonwoven processes, 17 496-497 Nonwovens. See also Nonwoven fabrics air-laid, 17 503 defined, 17 495-496 foam-bonded, 17 510 needled, 17 506, 507 thermal-bonded, 17 511-512 Nonwoven textile materials, 11 178-180 4-Nonylphenol (PNP), 2 225-226 health and safety data, 2 220t physical properties of, 2 205t Nonyl phenol, 10 429 8-Nonynoic acid, 5 34t... 

The thermal and surface properties of Nodax offer potential for binding of nonwovens such as PET Nodax could be applied in either a solid particulate or latex form to thermally bonded nonwovens. Nodax could also provide high wet strength to tissue and other papers, while at the same time preserving aesthetics and disposal options. 

Coated and laminated textiles usually consist of a textile substrate, which will typically be a woven, knitted or nonwoven fabric, combined with a thin, flexible fdm composed of a natural or synthetic polymeric substance. A coated fabric is one in which the textile substrate has a polymer film applied directly to one or both surfaces as a viscous liquid in a solvent or water, the thickness of which is controlled by application via a blade or similar aperture. A transfer coated fabric is an intermediate product in which a thermoplastic film is first prepared on a release paper prior to thermally bonding to the textile substrate. A laminated fabric usually consists of one or more textile substrates that are combined with a pre-prepared polymer film or membrane by adhesives or heat and pressure (Hall, 2000). 

Excellent thermal bonding properties (very important for nonwovens). 

R. Dharmathikary, T. Gilmore, H. Davis, S. Batra. Thermal Bonding of Nonwoven Fabrics. Textile Prog. 26(2), 1-37 (1995 published online Jan 2009)... 

Nonwoven geotextiles. Nonwoven fabrics are defined as a sheet, web, or batt of directionally or randomly oriented fibres/filaments, bonded either by friction, and/or cohesion, and/or adhesion. In general, nonwoven fabric formation can be considered as a two-step process web formation (aligning the fibres with certain orientation characteristics) and bonding these fibres by mechanical, thermal, or chemical means. This two-step process has formed the classification of nonwoven structures, i.e. carded, airlaid, spunlaid, meltblown, needlepunched, hydroentangled, adhesive bonded, thermal bonded, stitch bonded, etc. Some of the important processes that are used for the manufacture of nonwoven geotextiles are discussed below. 

Spin-bonded nonwovens are produced by allowing the filaments emerging from the fiber producing extruder to form into a random web, which is then usually thermally bonded. These nonwovens are limited commercially to the thermoplastic synthetics such as nylons, polyesters, and polyolefins. They have exceptional strength because the filaments are continuous and bonded to each other without an auxiliary bonding agent. 

There is a German supplier to the automotive industry where production waste of moulded parts of cotton and phenol resin is re-used. The waste is cut and used as a centric ply in between two layers of nonwoven. The result is a mat structure which, directly after it is achieved, is thermally bonded (Fig. 9.3). 

Figure 8.20 Thermally bonded shaped nonwovens (Brucciani, 1988).

Gong, R.H., Dong, Z., Porat, I., 2001. Single process production of 3D nonwoven shell structures part 2 CFD modelling of thermal bonding process. Int. Nonwovens J. 10 (1), 24-28. 

Wang, X.Y., Gong, R.H., 2006a. Thermally bonded nonwoven filters composed of bicomponent PP/PET fibre I. Statistical approach for minimizing the pore size. J. Appl. Polym. Sci. 101 (4), 2689-2699. 

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