DIFFERENCES/ADVANTAGES BETWEEN WOVEN AND NON-WOVEN GEOTEXTILES

Geotextiles are geosynthetic materials used in different areas of civil engineering such as pavements, geotechnics and hydraulics in order to provide specific functions in civil works such as reinforcement, separation, filtration, drainage, containment and erosion control. According to ASTM D4439, a geotextile is a permeable geosynthetic composed solely of textiles.

 

The properties of geotextiles are a function of their fabric structure and the type of polymer from which they are made. Regarding fabric structure, they are discriminated into woven and nonwoven geotextiles. As for the type of polymer, they are commonly manufactured in PET polyester, PP polypropylene, although they also exist in fiberglass.

 

Woven Geotextiles:

Woven geotextiles are parallel arrangements of orthogonally interlocking elements. Weaving is a process of interlacing elements that can be monofilament, flat tape or multifilament in a longitudinal arrangement called warp (MD or main direction along the roll) combined with a transverse arrangement of elements called weft (TD or transverse direction along the roll). length of the roll). Within woven geotextiles there are different types of production, the flat-woven geotextiles shown in Figure 1 (a) and the knitted geotextiles manufactured by weft insertion, as seen in Figure 1 (b).

 

 

Figure 1. (a) Flat tape woven geotextile and (b) weft insert woven geotextile

 

 

Geotextiles woven by weft insertion, present horizontal and transverse fibers in two independent layers, which are intertwined by a third group of fibers that are inserted by adjusting the nodes, this allows them to be willing to assume load at the slightest deformation, maintaining its position and guaranteeing that the pore area or open area does not change by tensioning or confining the geotextile, achieving mechanical and hydraulic stability superior to flat tape woven geotextiles. Therefore, they are recommended for reinforcement, separation, filtration and drainage functions, while flat tape polypropylene geotextiles are discarded for filtration applications. (See AASHTO standard M 288, section 8.2.2 requirements for geotextiles for subdrainage).

 

Regarding the polymer, important differences stand out in terms of the resistance and elongation of the elements, for example, geotextiles made of high tenacity polyester have a high resistance to tension - deformation ratio (high mechanical modulus), that is, They provide greater reinforcement at lower elongation, greater elastic recovery capacity and long-term stability than geotextiles made of polypropylene.

 

Nonwoven geotextiles:

Nonwoven geotextiles are made from staple fibers or continuous filaments randomly layered on a moving belt to form a “fabric.” These fibers can be joined mechanically by needle punching or thermally or chemically (see Figure 2). The main applications of nonwoven geotextiles are subsurface drainage and separation.

 

 

 

Figure 2. Nonwoven geotextiles (a) mechanically bonded and (b) thermally or chemically bonded.

 

 

Finally, we recommend the following functions for the different geotextiles we handle:

 

Geotextile	Manufacturing	Polymer	Function
FORTEX BX	Weft insert weaving	High Tenacity Polyester	Reinforcement Separation Filtration Sewer system Containment
HYDROTEX	Flat weave		Filtration Reinforcement erosion control Containment
PROPYWEAVE	Plan ribbon weaving	Polypropylene	Separation
FIBER-TEX	Non Woven		Separation Filtration Sewer system