Geotextiles nonwoven geotextile manufacturing

Nonwoven geotextiles are formed by the bonding of random arrays of synthetic fibres (see chapter Geotextile manufacturing processes). Fig. 20.1(b) shows the typical random stmcture of nonwoven geotextiles which commonly are composed of polypropylene fibres but can also be composed of polyester fibres. 

Figure 3.2 Nonwoven geotextile manufacturing process flowchart.

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. 

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). 

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. 

---