Geotextile materials woven and warp knitted

Woven geotextiles are produced from synthetic-fibre yarns, mainly PET or PP, and natural fibre yams, largely jute or coir, such as the Sulzer projectile loom P7150, used to produce woven fabric in widths of 190-540 cm.  

Woven geotextiles have the appearance of two sets of parallel threads interlaced at right angles to each other in the plane of the fabric. Warp yarns lie along the length of the fabric and weft in the transverse direction, i.e. across the width of the fabric. The type of yarns used to produce a woven geotextile may be monofilament, multifilament, a combination of each type, or slit film yarns. Two kinds of slit film yarn can be used, either flat-tape yarns or flbrillated yarns. 

Monofilament and multifilament woven fabrics are generally made from PET, the use of monofilament giving the better permeabihty, whereas multifilament is used for higher strength reinforcement. SHt film, flat-tape fabrics are usually PP materials, which are quite strong but they form a fabric that has relatively poor permeability. Alternatively, fabrics made with fibriUated-tape yarns have better permeability and more uniform interstice openings than flat-tape products. 

In weaving, the warp and weft yams are commonly referred to as picks and ends. The interlacing of the picks and ends gives a coherent structure, and the repeating pattern of the interlacing is referred to as the weave of the fabric. Woven geotextiles are commonly plain weave, but twill weave and leno weave are also used.  

Plain weave is the simplest interlacing pattern, as shown in Fig. 8.22 for jute and coir woven geotextiles in the length of the fabric a warp yam crosses over alternate wefts, and in the fabric width, a weft yarn crosses alternate warps. The frictional contact of the yarns at the interlacing points prevents each yarn slipping from its woven position, and it also increases the stiffness of the fabric. The interlacing causes the warp and weft yarns to have a 

---