Woven Geotextiles vs. Nonwoven Geotextiles: What's the Difference?
Geotextiles are permeable fabrics used in a variety of civil engineering applications such as roads, embankments, retaining structures, drainage systems, and erosion control. They are made from synthetic materials like polypropylene, polyester, polyethylene or polyamide and come in two main types - woven and nonwoven. But what exactly is the difference between woven and nonwoven geotextiles and how do you choose which one is right for your project? This article provides a detailed comparison of woven vs nonwoven geotextiles.
What are Geotextiles and How are They Used?
Geotextiles provide separation, filtration, drainage, and reinforcement functions when used with soil, rock or other geotechnical engineering related materials. Some key applications of geotextiles include:
Road Construction: Geotextiles are used below roadways and parking lots to provide separation between the subgrade and aggregate base course layers. This prevents the subgrade from being contaminated by finer particles migrating from the aggregates. Geotextiles also reinforce roadways and increase the bearing capacity.
Retaining Walls: Geotextiles are used as reinforcement, drainage and separation behind retaining walls. The geotextile reinforcement helps provide stability to the soil mass behind the wall. Drainage geotextiles prevent buildup of hydrostatic pressure while separation geotextiles keep backfill material from mixing with native soil.
Drainage Systems: Geotextiles are used in drainage applications like landfill leachate collection systems, pond liners, and french drains for houses. The geotextile acts as a filter that allows water to pass through while retaining soil particles.
Erosion Control: Geotextiles are used to control erosion on slopes and channels. They hold the soil particles in place while allowing water to seep through. This protects the ground surface from the erosive forces of water flow.
Geotextiles perform these vital functions through their porous structure and unique physicochemical properties. But the manufacturing process used gives woven and nonwoven geotextiles very different characteristics.
Woven geotextiles are created by weaving plastic filaments or tapes together on a loom. The most common materials used are polypropylene, polyester or polyethylene. The weaving patterns can createmonofilament, multifilament or slit film woven geotextiles with different properties.
Properties and Characteristics
Some key properties and characteristics of woven geotextiles include:
High tensile strength and low elongation
Resistant to tear and puncture forces
Less susceptible to UV degradation vs nonwoven geotextiles
Less permeable than nonwoven geotextiles
Large apparent opening size compared to nonwoven geotextiles
Low silt and sand retention capability
The strengths of woven geotextiles make them ideal for reinforcement applications where high tensile modulus and strength are required like in steep reinforced soil slopes. The large openings and lower filtration effectiveness also make them suitable as drainage geotextiles in landfill construction and road underdrains.
Benefits of Woven Geotextiles
High tensile strength to act as mechanically stabilizing reinforcement
Low elongation provides good dimensional stability under load
Durable with high resistance to installation stresses
Reinforcement of steep soil slopes and earth retaining structures
Separation and drainage layers for landfills
Filtration and separation in road edge drains and underdrains
Reinforcement of weak foundation soils or embankments over soft soils
Stabilizing bases and sub-bases under roads and parking lots
In these applications, the high strength at relatively low strains, dimensional stability, tear resistance, and adequate flow capacity of woven geotextiles are required.
In contrast to woven geotextiles, nonwoven geotextiles are made by bonding, interlocking or interlacing fibers together through mechanical, thermal or chemical means without weaving. This produces geotextiles with high filtration efficiency ideal for drainage and separation functions.
Properties and Characteristics
The properties of nonwoven geotextiles can vary based on the manufacturing method but in general they exhibit:
High permeability and small apparent opening size for enhanced filtration
Good silt and sand retention ability
Low elongation and moderate tensile strength
More susceptible to UV damage than woven geotextiles
Softer hand and drapability than woven geotextiles
The high filtration effectiveness and permeability of nonwoven geotextiles make them preferred for drainage, separation and filtration applications. The fiber network is ideal for trapping soil particles while allowing water passage.
Benefits of Nonwoven Geotextiles
Excellent filtration efficiency for fine soil particles
High permeability and flow capacity
Softer and more flexible than woven geotextiles
Can provide adequate reinforcement for some applications
Lower cost than woven geotextiles
Common Applications of Nonwoven Geotextiles
Some typical uses of nonwoven geotextiles are:
Filtration and drainage layers in landfill construction
Separation of subgrade from base course aggregates in roads
Silt fences for sediment control in erosion control applications
Trench drains, French drains and leachate collection systems
Moderate reinforcement in working platforms over very soft soils
For these applications, the high permeability, fine filtration capability, and adequate strength properties make needle punched and spunbonded nonwovens ideal.
Comparison of Key Properties
To choose the right type of geotextile for your specific project, it is important to compare some of the key property differences between woven and nonwoven geotextiles.
The tensile strength represents the maximum resistance of a geotextile to stretching forces before failure.
Woven geotextiles typically have tensile strengths from 15-200 kN/m
Nonwoven geotextile tensile strengths range from 5-40 kN/m
The high tensile strength of woven geotextiles makes them suitable for reinforcement applications.
Elongation measures how much a geotextile stretches as tension is applied.
Woven geotextiles generally have less than 15% elongation at failure.
Nonwovens exhibit 40-100% elongation at failure.
The low elongation of woven geotextiles provides better dimensional stability under loads.
Puncture resistance indicates the ability of a geotextile to withstand being pierced by a small probe simulating angular soil particles.
Woven geotextiles typically have puncture resistance from 500-4000 N
Nonwovens have lower puncture resistance around 150-800 N
Woven geotextiles have superior resistance to penetration forces.
Ultraviolet light degradation affects the long term performance of geotextiles.
Woven geotextiles retain 50-100% of their tensile strength after UV exposure.
Nonwoven geotextiles may retain only 30-70% of their original tensile strength.
Woven geotextiles are more resistant to damaging UV effects.
Geotextiles must withstand installation exposure to salts, acids, alkalies and fuels.
Woven and nonwoven geotextiles made from polypropylene and polyester generally have good chemical resistance.
Polyethylene geotextiles can be affected by oils and solvents.
Both woven and nonwoven geotextiles offer adequate chemical resistance for most applications.
Permeability measures the rate of water flow through the geotextile.
Nonwoven geotextiles typically have higher permeability values from 0.5 to 4 gal/min/ft2.
Woven geotextiles range from 0.1 to 1.5 gal/min/ft2.
Nonwoven geotextiles provide superior drainage capacity.
In general, nonwoven geotextiles have a lower cost per square yard compared to woven geotextiles. This can be an important consideration for larger project areas.
In summary, the main differences between woven and nonwoven geotextiles are:
Woven geotextiles have high tensile strength and puncture resistance while nonwovens have higher permeability and filtration efficiency.
Woven geotextiles perform better for reinforcement applications while nonwoven geotextiles are preferred for drainage and separation functions.
Woven geotextiles provide better dimensional stability under load while nonwovens are more flexible.
Nonwoven geotextiles are more susceptible to UV degradation.
Nonwoven geotextiles typically have a lower cost than woven materials.
The table below compares the key characteristics:
Weaving of yarns
Bonding of fibers
PP staple fibers
Uniform and ordered arrangement of tapes
Random arrangement of entangled fibers
Medium to high
Very high due to tape structure
Medium to high depending on bonding
Lower due to dense uniform structure
High permeability due to porous random fiber arrangement
High if using stabilized yarns
Lower inherently but can be improved through additives/stabilization
CBR Puncture Resistance
Medium to high
High due to fiber entanglement
Filtration, drainage, separation
Higher due to manufacturing process
Lower due to simpler production process
Usually requires sewing or bonding
Thermal or resin bonding rarely required
When selecting a geotextile, it is important to consider the primary functions required. Reinforcement applications demand high strength woven geotextiles. Drainage and filtration projects require permeable nonwovens with good filtration properties. With their different characteristics and capabilities, woven and nonwoven geotextiles both serve vital roles in geotechnical engineering construction projects.
Choosing the Right Geotextile
When choosing a geotextile, here are some key tips:
Analyze site conditions and project requirements to determine the primary geotextile functions needed - filtration, separation, reinforcement or drainage.
Select a geotextile type suitable for the main function based on the properties comparison above.
Check that the geotextile meets the minimum strength, elongation, permeability, and filtration properties recommended for the specific application. These values are provided in design standards like AASHTO M288.
Make sure the geotextile has adequate resistance to installation stresses, weathering and chemicals present on site.
Review manufacturer data sheets to compare properties of different geotextile products of the required type.
Consider cost differences but avoid choosing geotextiles solely on cost at the expense of meeting functional requirements.
With the range of geotextile types and products available, there is a suitable material for any civil engineering need. By understanding your project goals and properly evaluating woven vs nonwoven geotextile capabilities, you can be confident in selecting the right geotextile to enhance performance and durability.
I hope this article has provided a helpful overview of the key differences between woven and nonwoven geotextiles. Our company manufactures a full range of geotextile products for drainage, separation, reinforcement and filtration functions. Browse our website to find the ideal product for your next project:
Non Woven Geotextiles - We offer a range of durable needle punched and spunbonded nonwoven geotextiles with excellent filtration performance and mechanical properties.
Woven Geotextiles - Our woven geotextiles provide high strength reinforcement for steep slopes, retaining walls, roadways and other structures.
Pavement Fabrics - Keep your paved surfaces in top condition with our pavement geotextiles for separation, drainage and reflection cracking prevention.
GeoDrains - Our prefabricated geotextile drains provide quick drainage for landfills, roadways and other sites with high flows.
GeoBags - We offer versatile geotextile bags for applications like retaining walls, culverts and temporary structures.
Browse our full products catalog to find the right geotextile solution. Please reach out if you need any guidance selecting the perfect product for your next civil engineering project.