Woven Vs Non-Woven Geotextiles: What’s The Difference?
Over the past few decades, geotextiles have grown in popularity in several industries. These materials were initially derived from already-existing textiles like upholstery fabric and carpet backing.
Manufacturers then modified them to create materials suited to jobs like roadway construction. Although many people know that there are two main types of geotextiles, they are often confused about how they differ from each other.
Let’s review the difference between woven geotextiles and nonwoven geotextiles as well as their applications.
What Are Geotextiles?
Geotextile fabrics are geosynthetic textiles manufactured from polymers. About 5% of geotextiles are made from nylon, polyethylene, or polyester while the remaining 95% are made from polypropylene.
Generally used for drainage and reinforcement, these materials are vital to construction work and are used on homes, walls, roads, foundations, earth, rocks, and soil.
In hardscape projects, geotextiles are used to filter, reinforce, separate, and allow for filtration and drainage.
Beyond this, they are also utilized in other fields like clothing and fashion, engineering, erosion control, and soil stability in agriculture.
The materials from which they are made make them highly durable and extremely resistant to corrosion and rot, which explains their wide application.
There are several types of geotextiles, with each serving a different purpose. Nonetheless, the two most popular varieties and woven geotextile fabrics and nonwoven geotextile fabrics.
They differ from each other in terms of strength, usage, and weight, among other factors.
How Are Geotextiles Used Today?
As already mentioned, geotextiles have very wide industrial, commercial, and agricultural applications. You can usually find them on roads, railways, harbor works, drains, and breakwaters, among other features.
Here are the most common uses of geotextiles today:
Stabilization
Constructors will usually apply geotextiles on highly compressible materials like soft soil to create a strong base. The geotextile allows water to seep into the draining material from the soil and merge into the basement layer, which strengthens it.
Moisture Barrier
Geotextiles can be used with asphaltic suspensions to block water and make the material impermeable. This is useful in pavement rehabilitation projects.
Drainage
Geotextiles allow for seamless transmission by enabling the collection of water and gas and transporting them along its plane away from the construction material.
Filtration
While they allow water to pass through, geotextiles prevent soil and other fine particles from passing through their fabric. This makes them great at filtration projects.
Separation
Geotextile fabrics can be used to separate two layers of different materials, such as two soil types, soil, and new construction, or new and old pavement.
Reinforcement
Geotextiles are very strong and can be used as reinforcement on steep slopes, to retaining walls, to control water erosion, and in land reclamation.
Geotextiles in Construction
Geotextiles are used in construction projects to provide drainage, filtration, reinforcement, and separation.
These functions are especially crucial where winter brings several freeze-thaw cycles or subgrade materials are saturated for several months during the year.
Essentially, geotextiles create an impermeable layer that separates the base material from the subgrade material and prevents the soil subgrade from migrating into the base material.
When a pavement is exposed to force, the soul subgrade migrates into the base material. Think of what happens when you step on mud it usually shifts, with some particles moving horizontally and others upwards.
Geotextiles prevent this migration of particles by spreading the force exerted on the base material over a larger area. This, in turn, strengthens the base material.
The ability of geotextile fabrics to filter water also allows moisture to spread out over a greater area and providers more control over drainage. This is vital to preventing substrate damage and instability.
Woven Geotextile Fabric
The first common type of geotextile is woven geotextile fabric. This material is created by weaving single yarns on a loom to make a uniform length.
While the weaving technique does not change, the material used can range from monofilaments and slit films to fibrillated yarn.
Using a constant technique ensures that woven geotextiles are strong and can be used in projects involving highways, residential streets, driveways, and road constructions.
With a few exceptions, woven geotextile fabrics are not very permeable. This makes them unideal for projects that require drainage.
However, they are highly resistant to corrosion, which makes them the perfect material for long-term reinforcement and separation applications.
History of Woven Geotextiles
Initially, woven geotextile fabrics were created out of slit tapes. A slit tape is an extruded flat yarn that is woven at a 90-degree angle to create a strong and durable fabric.
It usually has a wide smooth surface that gives it low soil interaction and poor water permittivity properties. Consequently, these fabrics were not suited to civil projects, more so those done under wet conditions.
Currently, however, manufacturers use high-performance and effective materials to create woven geotextiles.
These improvements happened over time and have boosted the interaction coefficients and flow rates in these materials, making them more ideal for civil projects.
Woven geotextiles today are used for reinforcement, confinement, and separation. Their drainage and filtration have also improved.
How Are Woven Geotextiles Used?
Because they are made from threads or films that are woven together, woven geotextiles are not very porous and are relatively impermeable. This means that they should not be your go-to fabric for drainage projects.
That said, they have high tensile strength and are excellent for corrosion-resistant jobs and erosion control projects that do not include drainage.
Woven geotextiles also have an extremely high load capacity, making them perfect for parking lots, airport runways, and road construction.
The fact that they are resistant to UV-caused degradation also means they are well suited to long-term jobs.
Overall, the applications of woven geotextiles are based on the fabric’s strength. Some of the main uses of this material today include the following:
Railroad Building Near Riverbanks
The soil near a riverbank is typically very soft. When building a railroad in this area, constructors use woven geotextile fabric to strengthen the soil so the railroad tracks are sturdy enough to run heavy trains along the river.
Usually, they will lay down a layer of woven geotextile over the soft soil and then follow it with ballast. Ballast is a special type of stone used in road construction.
By placing it over the geotextile, the constructors ensure that it will not be pushed into the soft soil once they lay the railroad ties over it and trains pass on it.
Wall Reinforcement
Woven geotextile fabrics are also used in retaining walls as reinforcement. Layers of the material are placed between layers of soil behind a vertical wall to reinforce the soil and prevent it from pushing against the wall.
When this is done, the soil farthest away from the vertical wall produces an anchoring effect for the woven geotextile by creating friction that prevents the fabric from sliding out.
Parking Lot Construction
Constructors also use woven geotextiles on parking lot floors built over bad or soft soils.
A layer of this fabric is placed between the soil and the stone base underlying the asphalt to prevent loads like car tires from ripping through the asphalt and sinking into the ground.
Non-Woven Geotextile Fabric
Non-woven geotextiles are another common type of geotextile fabric. They are made by binding long and short fibers through several methods like needle punching.
Although there are multiple manufacturing processes used in the creation of non-woven geotextiles, the most common is needle punching.
Fabrics made through this process are created by interlocking many small fibers together using a barbed needle. Heat treatment may be applied to improve the strength.
Non-woven geotextile fabrics are produced from synthetic materials like polypropylene, and polyester, which are permeable.
This makes them ideal for projects involving drainage, separation, filtration, and protection. That said, non-woven geotextiles are not as strong as their woven counterparts.
History of Non-Woven Geotextiles
The manufacturing process used to make non-woven geotextiles has changed over the years as these materials grow more popular.
Today, most of these fabrics are manufactured at a lower weight but they retain their strength, which significantly cuts the associated costs.
However, there are exceptions to this such as when non-woven geotextiles are used to cushion geomembranes. This process relies more on the thickness and weight than strength and permittivity so that is where manufacturers focus.
How Are Non-Woven Geotextiles Used?
Because they have high permeability, non-woven geotextiles are not ideal for projects involving reinforcement or stabilization.
They are, nonetheless, well suited to other applications, including filtration, separation, drainage, and protection.
Their high water permeability also means they retain strength over time, more so when used underground. These fabrics are also easier to cut, which increases their industrial applications in several fields.
Woven Vs. Non-Woven Geotextiles
By now you understand that woven and non-woven geotextiles greatly differ from one another, especially in how they are manufactured and used.
The type of project you are involved in will usually determine the best fabric for your needs so it is important to know these differences.
Here is a rundown of the major factors that distinguish woven geotextiles from non-woven geotextiles:
Material
Non-woven geotextiles are usually made from synthetic materials like polyester and nylon while wovens are made from monofilaments, slit films, or fibrillated yarn.
Consequently, non-wovens feel and appear “fuzzy” while wovens feel and look like plastic.
Weight
Woven geotextile fabrics rarely have a weight specification because their weight does not play a role in their application separation and reinforcement.
On the other hand, weight is often specified on non-wovens because it is crucial to their application.
Usage
Wovens are ideal for stabilization and reinforcement but do not do great in projects requiring permittivity. Non-wovens, on the other hand, are perfect for drainage, separation, and filtration applications.
Permeability
With a few exceptions, woven geotextiles have low permeability and low flow-through rates. Non-wovens are more permeable and have high flow-through rates.
Tensile Strength and Load Capacity
Woven geotextile fabrics have higher tensile strength and load capacity than non-wovens, which is why they are often used in projects involving road or rail construction. Non-woven geotextiles are measured by weight.
Manufacturing Process
Non-woven geotextiles are made by bonding many small fibers together while woven geotextiles are made by weaving fibers together on a loom or film.
Description
Non-wovens are often described by weight while wovens are described by tensile strength and load capacity.
Cost
Overall, non-woven geotextiles take a shorter time to manufacture so they tend to cost less. Wovens require more manufacturing time and tend to be more expensive.
Elongation
Woven geotextiles will have a lower elongation than non-wovens at between 5 to 25 percent compared to more than 50 percent for non-wovens.
One of the easiest ways to differentiate between a woven and non-woven geotextile is through elongation specifications.
Non-wovens which always have a higher elongation often have more than 50% elongation while wovens maintain an elongation of between 5 and 25%.
In some cases, wovens do not come with an elongation specification. Wovens also have higher tensile strength values than non-wovens while no-wovens come out on top in terms of permittivity and flow rates.
Weight of Nonwoven Textiles
Weight is a primary distinguishing factor between woven and non-woven geotextiles. Manufacturers rarely specify the weight of woven geotextiles but this characteristic is important when describing non-woven fabrics.
In the former, the weight rarely matters because woven geotextiles are used for their ability to reinforce and separate, which does not depend on weight.
On the flip side, manufacturers often specify the weight of a non-woven geotextile. Common examples include 4–ounce, 8-ounce, 10-ounce, and 12-ounce fabrics.
These numbers mean that the material weighs 4 ounces per square yard, 8 ounces per square yard, and so on. From the weight, manufacturers are able to derive other characteristics of these fabrics, including puncture and strength.
Conclusion
Before beginning any construction project, you should familiarize yourself with the properties and differences between these two materials so you can pick the one that best meets your needs. Overall, woven geotextiles are the stronger and more durable option.
They are perfect for providing support and reinforcement and are often used in construction projects involving soft or bad soils.
However, when water comes into play, you are safer using non-woven geotextiles thanks to their high water permeability rates. These are the go-to fabrics for projects involving filtration, drainage, and protection.
