Domestic technical textiles Industry Segment-wise consumption of ...

one or two directions for improved physical properties. Geogrids are mainly used for
reinforcement – beneath aggregate in unpaved roads, reinforcement of embankment fills/earth
dams, repairing slope failures/landslides, as inserts between geotextiles/geomembranes etc.
b) Geonets constitute another specialized segment within the geo-synthetic area. Geonets are
usually formed by a continuous extrusion of parallel sets of polymeric ribs at acute angles to
one another. When the ribs are opened, relatively large apertures are formed into a netlike
configuration. Geonets are made of polypropylene (PP) or Polyethylene (PE). Geonets are
used almost exclusively for their drainage capability for applications like water drainage
behind retaining walls, seeping rock slopes, beneath sport fields, building foundations;
leachate drainage of landfill side slopes, above landfill liners and surface water drainage
within landfill caps.
c) Geo-membranes are impermeable membranes, used where the primary function is to have an
impervious barrier for fluids. However, as the possibility of punctures or tears is high in many
areas of use, it is common to protect these membranes by use of Geotextiles. Often the
geotextiles also perform other functions besides protection of the membrane. Geomembranes
are made from continuous polymeric sheets that are very flexible, but can also be made by
impregnation of geotextile with asphalt or elastomer sprays or bitumen composites.
Geomembranes are used in applications such as liners for water canals, waste canals, solid-
waste landfills, covers for solid-waste landfills, waterproofing within tunnels, to control odors
in landfills, to prevent infiltration of water in sensitive areas, and beneath asphalt overlays as
a waterproofing layer.
d) Geo-composites: these consist of two or more geosynthetic products put together to increase
the combinations ability to optimally address the specific application (say filtration/
reinforcement etc) at minimum cost. The best features of different materials are combined in
such as way that the benefit/cost ratio is maximized. An example of this is known as wick
drains in the U.S. and prefabricated vertical drains, PVDs, in Europe. These consist of a 100
mm wide by 5 mm thick polymer cores, for conducting water, with a geotextile acting as a
filter and separator socked around the core.
e) Gabions are rectangular or cylindrical containers fabricated from polymer/metal meshes,
usually filled with stone and used for structural purposes (retaining walls, slope and
embankment protection etc). These have been used in India since 70s.
2. Product characteristics