Nonwoven needle punched

Spunbonded fabrics have a relatively small percentage of the coated fabric market which is dominated by other nonwovens. Needle-punched nonwovens offer more of the bulk and resiHency required for functionaHty in automotive and furniture seating. 

Because of its toughness, nylon fiber is suitable for nonwoven needle-punched floorcovering products. Nylon nonwoven fiber can be found in garment interlinings and wipes for its strength and resilience. It is also used Ni/H and Ni/Cd batteries as nonwoven separators in high performance wipes, synthetic suede, heat insulators, battery separators, and specialty papers and in automotive products, athletic wear, and conveyor belts. 

Drainage or fluid transmission Allowing water (or vapour) to be transmitted in the plane of a thick nonwoven needle-punched geotextile or a drainage geocomposite. 

Table 8.3. Permissible heights of fill (specific weight 11.8 kN/m ), when individual particles with a maximum particle size d ax he on or under a 1.5 mm thick HDPE geomembrane and this is protected by a protective nonwoven needle-punched geotextile of mass per unit areaM. If the mass per unit area is undershot or the surcharge is exceeded, pimcture of the geomembrane can be expected...

Key properties that can influence the performance characteristics of a nonwoven needle-punched geotextile are fibre type polymer, diameter, length, etc. fibre quality fibre lubrication needle shape needle density depth of penetration of needle, needfing rate, and batt areal density (Venkatappa Baneijee, 1997). 

Ramsey, B., Narejo, D. (2008). Manufacturing nonwoven needle punched geotextiles with opening size larger than 0.2 imn. Geotextile Research Development in Progress, 1—6. (Online). Available from http //www.ascelibrary.org Accessed 30.07.15. 

Bell et al., 1977). This work culminated in the first US Federal Highway Administration design and construction guidelines (Steward et al., 1977 Bell et al., 1975 Mohney, 1977 Steward et al., 1977 Bell and Steward, 1977). An altogether different application was developed in 1966 by Phillips Petroleum Co. using field bitumen-saturated nonwoven needle-punched fabrics to control reflective cracking in asphalt pavement overlays (Dykes, 1985). 

Within the plane of a nonwoven material, the fibers may be either completely isotropic or there may be a preferred fiber orientation or alignment usually with respect to a machine or processing direction. In the case of thicker dry-laid nonwovens, fiber orientation may be randomized in the third dimension, ie, that dimension which is perpendicular to the plane of the fabric, by a process known as needle-punching (7). This process serves to bind the fibers in the nonwoven by mechanical interlocking. 

Principle appHcations of needle-punched nonwovens for the 1990s include automotive, apparel components, blankets, carpeting, carpet pa dding, coating substrates, filtration, furniture, geotextiles, insulation, roofing substrates, and wall coverings. In 1990, the production of needle-punched fabric was estimated to approach 91,000 t and 606 million square meters (15). 

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

Geotextiles. Nonwoven fabrics have played an important part in the development of geotextile appHcations. Both needle-punch fabrics... 

Nonwoven fabrics are generally described by the method of production, eg, needle-punched or spun-bonded (120). ASTM D1117 discusses various physical properties to be deterrnined for nonwoven fabrics and the standard procedures used. 

Pollutant Loading Typical inlet concentrations to cartridge collectors are 1 to 23 grams per cubic meter (g/m ) (0.5 to 10 grains per cubic foot (gr/ft )). Cartridge filters, which utilize synthetic, nonwoven media such as needle punched felts fabricated of polyester or Nomex, are able to handle inlet concentrations up to 57 g/m (25 gr/ft ). 

In nonwoven geotextiles, the fibers are much thinner but far more numerous. The various types are needle-punched, resin-bond, and melt-bond. All contain a labyrinth of randomly oriented fibers that cross one another so that there is no direct line of flow. The fabric must have enough open space to allow liquid to pass through, while simultaneously retaining any upstream movement of particles. The needle-punched nonwoven type is very commonly used as a filter material. 

In gas-collector systems, either a granular soil layer or a needle-punched nonwoven geotextile is placed directly beneath the LML or clay of a composite cap system. Gas compatibility and air transmissivity are the design factors that must be considered. Methane, the most predominant gas, should be compatible with most types of geotextiles including PET, PP, and PE. 

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