Geosynthetics Manufacturing: Woven, Non-Woven, Geogrid

Geosynthetics manufacturing uses polymer materials ( HDPE, PET, PP ) to create products that serve as structures in construction engineering. The “GEO” in GEOSYNTHETICS refers to their frequent application with soil and rock. Geosynthetics perform separation, reinforcement, filtration, drainage, protection, erosion control and containment or embankment functions.

In general, geosynthetics can be grouped by their physical form, water permeability and manufacturing process.

2. How Are Geosynthetics Manufactured?

The geosynthetics manufacturing process can be classified into 2 stages:
a. Polymer formation process

b. Liner element formation process

• Woven geotextile
  The geotextile weaving process resembles 2 sets of yarn crossing each other at right angles.

The terms warp and weft commonly distinguish the 2 yarn directions. Warp is the longitudinal yarn that runs in the machine direction or Machine Direction( MD ) . Weft is the yarn that runs across the width or in the Cross Machine Direction (CD).

• Non-woven geotextile
  Non-woven geotextile is made through a different process from woven geotextile. This process continuously lays fibers on a conveyor belt to form a loose web. The loose web then passes through equipment that bonds it mechanically, thermally or chemically. Mechanical bonding drives thousands of needles through the loose web.

• Extruded Geogrid
  Extruded geogrid is made from a polymer sheet in 2 or 3 stages.

First stage: The polymer sheet enters a punching machine, which creates apertures in a regular grid pattern.

Second stage: The perforated polymer sheet is heated and stretched in the
machine direction. This stretching orients the long-chain polymer molecules in the direction of stretching, increasing tensile strength and tensile stiffness. The process can be stopped at this stage, producing uniaxial geogrid as the final product.

Third stage: The uniaxial geogrid is heated and stretched in the transverse direction, producing biaxial geogrid.