Nonwoven geotextiles are formed from filaments or fibers arranged at random and bonded together into a planar structure. The filaments or the fibers are first arranged into a loose web, then bonded together using one, or a combination, of the following processes: Chemical bonding .... Thermal bonding .... Mechanical bonding by needlepunching : thousands of small barbed needles, set into a board, are punched through the loose web and withdrawn, leaving filaments or fibers entangled. One thus obtains needlepunched nonwoven geotextile. ....
Mechanically bonded geotextiles are formed by deliberately entangling the filaments to form comparatively loose bonds where the filaments cross over. As the process used to achieve this mechanical bond is known as "needle-punching" these geotextiles may also be referred to as needle-punched geotextiles. Needle-punching involves repeatedly driving thousands of barbed needles into the loose sheet of polymer filaments.
