Non-Woven Geotextile: Functions and Applications

Non-Woven Geotextile

Non-woven geotextile is a type of geosynthetic material widely used in construction, drainage and civil engineering projects. Unlike the woven type, this geotextile is made without weaving or interlacing yarns.

So how is it made, and what are its main functions on site?

How Is Non-Woven Geotextile Made?

While woven geotextile is made on looms that weave filament yarns into a structured fabric, non-woven geotextile is produced by joining randomly arranged synthetic fibers through bonding and interlocking.

The main raw materials are usually Polypropylene (PP) or Polyester (PET). Several bonding techniques are used:

• Needle Punching (Mechanical): The fiber web is punched with thousands of special needles until the fibers interlock with each other.

• Heat Bonding (Thermal): Heat is used to partially melt the fiber surfaces so that they stick firmly together.

• Chemical Bonding: Chemical adhesives or solvents are used to join the fiber web.

The result is a felt-like material with a dense micro-porous structure.

Non-Woven Geotextile Manufacturing

This method usually relies on mechanical means, heat, chemicals or solvents. Another method is interlocking, generally done with needle punching or stitching. The materials used to make the geotextile are polypropylene (PP) and polyester (PET). Geotextile Functions

Main Functions of Non-Woven Geotextile in Construction

• 1. Drainage: Acts as a passive medium that carries water or gas within the soil structure. It can be used on its own or combined with other drainage systems.

• 2. Filtration: Retains fine soil particles so they are not carried away by flowing water, while liquid can still pass without damaging the surrounding soil structure.

• 3. Separation: Prevents two layers of soil or materials with different physical characteristics from mixing (for example, separating a fine subgrade from the granular stone layer above it).

Its micro-porous structure makes this material permeable (liquids and gases can pass through, but solid particles are retained). Thanks to this property, non-woven geotextile has three vital functions:

Drainage

Because of its properties, non-woven geotextile can be used as a passive element to convey liquids or gases. Drainage with non-woven geotextile works without having to combine it with other materials. Even so, for optimal results it can be combined with other materials

Filtration

Geotextile filtration

The next function of non-woven geotextile is filtration. Filtration here means retaining fine aggregate particles such as soil. With filtration, fine particles are protected from scouring, so the non-woven geotextile separates the two elements (liquid and aggregate) without damaging the original structure.

Separation

Besides the functions described above, the last one is separation. For separation, non-woven geotextile can be used to divide two soil layers with different characteristics. For example, the fine soil layer (subgrade) will not enter the permeable granular layer. The most common applications are highway foundations, railway track beds, dam walls and sea dikes.