Needle-punched fabrics geotextiles

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). 

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

This market received a boost in the early 1990s when the EPA issued the first federal standards for municipal solid waste landfills. The main objective was to prevent leakage and protect groundwater and soil near the landfills. Needle-punched fabrics are used as a geotextile cushion specifically where there is need for puncture protection, often on top of the liner, and as blankets in drainage systems inside the landfill, as a tarpaulin on the outside of the landfill, and underneath as a foundation for erosion control. 

Nonwoven fabrics have played an important part in the development of geotextile applications. Needle-punch fabrics manufactured from either staple fibers or spunbonded continuous filaments have found worldwide acceptance on the basis of field performance. In 2000, it is estimated that North America consumed approximately 300 million m of geotextiles (62). 

In a totally different application, the US Forest Service began using needle-punched nonwoven geotextiles as wraparound walls in steep logging terrain in the Pacific Northwest in 1974. The fabric rolls were sometimes delivered by helicopters. Geotextile-reinforced embankments were constructed in Alaska beginning in 1975... 

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. 

Effect of confining pressure on needle-punched hole in geotextile fabrics G1, G2, and G3 where (a) no applied stress and (b) 50 kPa applied vertical stress is Magnification 18X. 

In some drainage and filtration applications of geotextiles, layered nonwoven fabric may perform better than single-fibre nonwoven structures. The layered fabrics are produced by needle-punched bonding, in which two or more separate layers of fibre webs are made from fibres with different linear densities (Hwang, Lu, Lin, 1999 Rakshit, Patil, Balasubramanian, 1990). 

RoUin, A.L., 1983. Characteristics of needle punched nonwovens and their influence on filtration behaviour in geotextiles. In Proceedings Conference on Nonwoven Fabrics, UMIST, Manchester, UK, 1983. 

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