geotextile 4 mansoor iqbal

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A Brief on Geotextile and its

Application in Pakistan

ARSHEEN MOIZ*, ALEEM AHMED, MUNAZZA SOHAIL.

MANSOOR IQBAL AND JAVAID MUGHAL Applied Chemistry research Centre (Textile Section),

PCSIR Labs Complex, Karachi-75280, Pakistan


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Introduction:

American Society of Testing and Materials (ASTM) define Geotextiles as “permeable textile

materials used in contact with soil, rock, earth or any other geotechnical related material as

an integral part of civil engineering project, structure, or system”. Geotextiles are permeable

fabrics which, when used in association with soil, have the ability to separate, filter,

reinforce, protect, or drain. Typically made from polypropylene or polyester, geotextile

fabrics come in three basic forms: woven (looks like mail bag sacking), needle punched

(looks like felt), or heat bonded (looks like ironed felt).Geotextile composites have been

introduced and products such as geogrids and meshes have been developed. Overall, these

materials are referred to as geosynthetics and each configuration-geonets, geogrids and others

can yield benefits in geotechnical and environmental engineering design.

Geo textile defined as "a fabric or synthetic material placed between the soil and a pipe,

gabion or retaining wall; to enhance water movement and retard soil movement and act as a

blanket to add reinforcement and separation." These are generally made up of woven,

nonwoven and knitted type of fabrics. Geo Textiles are the largest group of geo synthetics in

terms of volume and are used in geo technical engineering, heavy construction, building and

pavement construction, hydrogeology, environment engineering.

Textile are not only clothing for human body, but also for our motherland in order to protect

her. Geo-textile are effective tools in the hands of civil engineer that have proved to solve a

myriad of geo-technical problems with the availability of variety of products with differing


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characteristics, the design engineer needs to be aware of not only the application possibilities

but also more specifically the reason why he is using the geotextile and the governing geo-

textile functional properties to satisfy these functions. Design and selection of geo-textiles

based on sound engineering principles will serve the long-term interest of both the user and

the industry.

Geo-Textiles are generally made from 90% polypropylene fibre and remaining component

can be polyester, polyamide fibres. Geo-Textiles are basically utilized in road and dam

construction. Very porous structures both woven and non-woven can be made for filtration

applications. Heaviest Geo-Textile manufactured to date weighed 3000-gms/ square metres.

Woven Geo-Textiles:

Woven geo-textiles concrete bases Coastal works, water ways, embankments and in

forming. Geocell for road

Non-Woven Geo-Textile

Woven Geo -Textile

Knitted Geo -Textile

Fabric Types of Geo Textile:


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Nonwoven Geo-Textiles

Filtration, drainage, reinforcement between soil stone or aggregate and in roads, railways

works, erosion prevention and separation. As filter fabric for dams, under drainage system

liners for pile foundation, coated pvc and bitumen's to skin traction.

Knitted Geo-Textiles:

Knitted bags for protection of dam's riverbank etc. Warp knitted fabric of Kevlar yarns used

in automobile and marine application .It is also used with foundations, soil, rock, earth or any

other related material as an integral part of human man made project, structure or system.

GEOTEXTILE TYPES

Woven Nonwoven

Very strong Stronger as thickness increases

Do not "elongate" or stretch very much when

a force is applied Highly permeable

Made of woven synthetic fabric (usually

polypropylene or polyester) by weaving yarns

together...just like your dress shirt or a linen

tablecloth

Able to stretch and take the shape of the

adjacent surface

Application of non-woven

• Scope of nonwovens is very large because of their characteristics of durability,

permeability, breath ability and conductivity. Main areas of ‘Technical Textiles are:

Agrotech: Is aimed at agriculture and farming. The products possess weather and micro

organism resistance and reduce pesticide requirements, Polyester and P.P. fibers are

mainly used for Agrotech products and applications.

• Buildtech: Covers manufacture of membranes for construction of light weight structures.

• Oekotech: Stands for concepts in environmental protection, waste disposal and recycling.

• Meditech: Includes complete range of medical and hygiene products. Some of these products

have infection barrier properties to protect surgeons from infection from patients. Cotton is a

major fiber used in Meditech.


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• Indutech: Products provide solutions for mechanical engineering, chemical and electrical

industries.

• Geotech: Stands for concepts and products in civil engineering, i.e. roads, dams and waste

site construction. Polyester and polyolefin are the main fibers for Geotech.

• Protech: Deals with latest ideas in the manufacture of protective clothing.

• Packtech: Includes products utilized in packaging, covering and transportation.

• Hometech: Represents innovative developments in furniture, upholstery, floor coverings and

carpet manufacturing.

• Clothtech: Shoe and clothing manufacture.

• Mobiltech: Latest developments in ship and aircraft constructions, automobile, railway and

space travel.

Sporttech: Includes products and ideas from the world of sports, leisure and outdoor

equipments.

Geo Textile Materials and Forms:

Geo

Textile

Materials

Textile Sheets

Non-Woven

Woven

Nets

Strips

Grids

Grids woven from strips

Sheets woven from strips

Strips made of narrow grids


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A wide range of textile materials is used as substrates for coated fabric. These may be woven,

Knitted, or non-woven materials. The types of fiber commonly used in coating are cotton,

rayon, nylon, polyester, and blends of polyester with cotton or rayon, depending on the end

use requirements polyester is the most popular in staple from the non woven materials and in

spun form for woven materials. Polypropylene is emerging as the fiber of choice because of

its low specific gravity, strength properties, chemically inert nature, and low cost. However,

its poor dye ability, adhesion, and thermal stability are disadvantages that need to overcome.

High performance fibers like Kevlar, Nomex; PBI etc are used in specialized applications.

In woven substrate, plain, twill, basket constructions are generally used. Among the knitted

constructions, circular knits are used as a substrate for upholstery fabric.

The choice of proper fabric for coating is an important as the selection of the polymer

because it offers the primary physical property to the end product for proper selection of

fabric; the following aspects need to be considered.

• Cost

• Dimensional stability.

• Environment of use.

• Adhesion requirement.

• Resistance to Acids and chemicals.

• Resistance to microbiological attack.

• Strength and modulus.

• Durability

Coating:

Properties of textiles can be improved by coating with polymers, for example home textiles

require fine coating, which renders different value added properties to the end fabrics. Coated

fabrics should be fast to dry cleaning and shrink proof. For field and out door textiles high

viscosity coating is necessary so that such textiles become fast to light, heat and are shower

proof e.g. tarpaulins and umbrellas etc.


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In order to achieve these objectives knife coating, air knife coating techniques are used.

Rotary coating is commonly used in Pakistan. For example, Zimmer is well known for

manufacture and marketing of coating equipment. They supply Magno Roller, Triplex and

Various Processes for knife coating and transfer coating.

Coating a layer of polymeric materials on a textile imparts new characteristics to the base

fabric. The resultant coated fabric may have functional properties, such as resistance to

soiling penetration of fluids, etc or have an entirely different aesthetic appeal, such as

finished leather. There are various coating methods used to apply polymer to textiles. They

can be classified on the basis of equipment used, method of metering, and the form of the

coating materials. The various methods are given below.

1. Fluid coating: The coating materials are in the form of paste, solution or lattices.

• Knife coaters, reverse roll coaters, Kiss coaters, gravure coaters, dip coater,

etc. These are premetered application systems.

• Impregnators: materials to be coated are dipped in the fluid, and the excess is

removed by squeeze roll.

• Spray coaters: The materials are sprayed directly on the web or onto a roll for

transfer.

2. Coating with dry compounds:

• Melt coating: Extrusion coating, powder coating, etc.

• Calendaring: For thermoplastic polymers and rubber compounds, zimmer

process, etc.

• Lamination.

The choice of a coating method depends on nature of the substrate, nature and characteristic

of the resin and viscosity of the coating fluid, end product and accuracy of coating desired,

economics of the process.


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Functional properties of coated fabric:

Coated textiles are flexible composites, consisting of a textile substrate and a polymeric

coating. The coating may be on one side or both sides with the same or a different polymeric

coating per side. The physical properties of a coated fabric depend on the properties of the

substrate, the coating formulation, the coating techniques, and the processing conditions

during coating. The factors responsible for different properties of a coated fabric. Properties of

textiles can be improved by coating with polymers, for example home textiles require fine coating,

which renders different value added properties to the end fabrics. Coated fabrics should be fast to dry

cleaning and shrink proof. For field and out door textiles high viscosity coating is necessary so that

such textiles become fast to light, heat and are shower proof e.g. tarpaulins and umbrellas etc.

In order to achieve these objectives knife coating, air knife coating techniques are used.

Rotary coating is commonly used in Pakistan. For example, Zimmer is well known for

manufacture and marketing of coating equipment. They supply Magno Roller, Triplex and

Various Processes for knife coating and transfer coating.

A geo textile fabric is a material that is utilized in foundations, earth, rocks, and soil. It is also

referred to as erosion control cloth, filter fabric, support membrane, and civil engineering

cloth. This fabric is used in a variety of applications. Geotextile fabrics are available in both

woven and unwoven. The woven geo textile is strong and does not stretch very much as force

is applied. Weaving synthetic fabrics together makes it. It is usually constructed of

polypropylene or polyester. Other materials that are used are nylon, polyvinylidene chloride,

polyethylene, and fiberglass. There are three different types of woven geotextiles. They are

slit tape, monofilament, and multifilament. Slitting sheets of solid of extruded film and then

weaving them together produce the slit tape. A monofilament fabric is woven from string-

like fabric and fine filaments that are adhered to each other by intermingling or twisting the

strands produce the mutifilament fabric. Other by intermingling or twisting the strands.


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Uses for Geotextile Fabrics

• Geotextile fabrics are used in civil engineering, construction, agriculture, and many

other applications. Stabilization of soil and slopes to prevent land slides.

• Landfill applications for waste disposal by municipalities.

• For lining of canals and dams to prevents water leakage by using Geo-Membrane clay

liners. Seepage of water from canals is a major problem and up to 20% water is

reported as lost in Pakistan.

• Floating covers for water reservoirs in Pakistan to prevent evaporation of water.

• Water transport utilizing Geo-Membranes.

Improvement in the use of water in agriculture in Pakistan involving the use of Geo-Membranes.

The basic functions of the fabrics are drainage, filtration, sediment control, separation,

erosion control, moisture barriers, and reinforcements. Filtration is the oldest and the most

common use of geotextile fabrics. In this application, water and small pieces of soil can pass

through the material and larger pieces are stopped. Most geotextiles can perform this function

except the slit tape because it's openings vary in size

Using Geotextile Fabrics for Erosion Control:

Erosion practice of preventing or controlling wind or water erosion in agriculture, land

development and construction. Effective erosion controls are important techniques in

preventing water pollution and soil loss.

When used in erosion control, the geotextile fabric protects the soil from erosion due to

rainfall, water, and wind. The fabric is frequently used to line ditches that contain silt or

sand. In this case the geotextile fabric is covered with gravel or secured with stakes. Newly

planted seeds can be protected from erosion by being covered in fabric until they germinate.

In the reinforcement function, the fabric is used to reinforce retaining geotextile is usually

used in this application. Structures and embankments against shear forces.Because of its

strength, a woven .The use of Geo-Textiles can increase the road life by 10 to 15 years and reduce


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cost.

How to use geotextile fabrics to construct roads

The fabric is also used in the separation process. The primary function that a geotextile will

serve in the construction of roads depends on the soil type and strength on which the road is

being constructed. This process eliminates two different materials this process eliminates two

different materials from mixing together. In this case, a layer of fabric is placed between the

two layers of material. This is frequently used when constructing a road over a soft surface.

A geotextile fabric is placed over the over the soft material, followed by a layer of gravel.

When being used as a moisture barrier, the geotextile fabric must have rubber-bitumen,

bituminous, or polymeric mixtures added to it. This is mainly used in the paving of overlay

systems. The fabric reduces the amount of water that enters the base and seals the existing

pavement. This keeps the pavement system stronger.

Good gravel roads are needed for efficient transportation on the farm. Good roads require

strong foundations, and water management is critical for maintaining the strength of the

foundation.


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.

Agricultural use of geotextile fabrics

Farmers also make use of geotextile fabrics. The vegetation is destroyed when there is a large

amount of animal traffic and the heavy use of farm equipment. If it rains, these high traffic

areas turn to mud. This creates an unhealthy environment for animals and reduces traction for

equipment. When the ground dries, footing for the animals is dangerous. It can also cause a

runoff of manure and soil. Geotextile fabrics in combination with gravel can resolve this

problem. It can create a surface that is safe for animals and humans. The treated surface

makes it easier to drive vehicles and farm equipment. It also helps to reduce soil erosion.

Although geotextile fabrics are used in large applications, they can also be utilized in

individual's homes. The most common home use is weed control. In this application, the

fabric is placed on bare soil and covered with mulch. This same method can be used as an

underlayment for patios and stone pavers. The most common home use is weed control. In

this application, the fabric is placed on bare soil and covered with mulch. This same method

can be used as an underpayment for patios and stone pavers.

• Weed protection: Weeds erode trees and plants. Agro Textiles are used to control erosion.

• Wind protection: Fabrics made from polyethylene, polypropylene, polyolefin can be

used to provide protection from wind to plants and trees. Warp knitted fabrics are

used for

Hail protection. It is possible increase the yield of plants by providing wind and hail

protection.


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Tips for Selecting Geotextiles:

• Select geotextile that will perform best for your given soil, moisture, equipment,

traffic and expected amount of gravel surfacing. Find out from others who have used

geotextiles what worked best for them

• You will need to know the soil characteristics and permeability of the roadbed, and

match them to the permeability of the geotextile fabric.

• Select geotextile that can withstand installation and survive the construction period

without puncturing, tearing, bursting, or fraying.

• Use the correct type of surfacing material. If gravel is to be used for the road and

traffic will travel directly on the aggregate, then you must provide more fines (15% or

more) or the aggregate will slip off the fabric.

Installing Geotextiles:

• Shape the roadway and establish the crown. Roll the fabric down the road. Standard

roll widths usually make it necessary to use one roll per lane of road.

• If there is much wind, you may need to weight the sides and end with shovels full of

gravel, or use spikes to pin the fabric down.

• Overlap the fabric at the centerline as recommended by the manufacturer’s

instructions. The absolute minimum overlap recommended is 12”. Overlap the end of

the preceding roll over the top of the next roll in the direction that the gravel will be

spread to minimize wrinkles and shoving of the geotextile fabric during spreading and

blading of gravel.


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Dump and spread the gravel or base course material using normal methods. But make sure

you do so in the direction of the laps. A minimum of one-foot (1’) of surfacing material is

typically recommended.

Conclusions:

Market for ‘Technical Textiles’ in Asia is growing at the rate of 9.6% per annum. In

China growth in the rate of investment is about 30% per annum. India is also expected to

be one of the largest producer and consumer of ‘Technical Textiles’. In Pakistan cheaper

raw materials are available for production of nonwovens. In conclusion it may be stated

that ‘non-woven’ is a strong and growing technology all over the world. Lot of waste

material is available in Pakistan, which can be utilized to make nonwovens for

weatherproof houses in the northern areas. High strength Exotic Textiles can be produced

from Polypropylene fiber, as there are many areas of applications of ‘Exotic Textiles’.

For example smart dressings; smart filters and smart bandages can be produced.

Syntech Fibers (Pvt) Ltd. is producing climate control sports wear ‘Duradry’ which

keeps the wearer comfortable by wicking moisture away from the skin to the outer layer

where it can evaporate. Master Textiles are producing spun – bonded materials.

Companies like IHSAN SONS as well as S. Fazalilahi & Sons produce nonwovens for

medical and hygiene applications.

There are so many institutes/ organizations both in private and government sector to

promote research in the textile wet processing. Geo textile is a new field, which appears

with in the short span of time very rapidly in the world. In Pakistan a main obstacle to the

growth of geo textiles in Pakistan is the level of human expertise, another obstacle to the

growth of technical textile is the absence of legislative encouragements on part of the

government. The government should start by giving research incentives to textile

industries and end users for the production and use of geo textiles, and eventually as the

industry progress there is also a possibility of making the use of geo synthetics

mandatory. . Industrialists in Pakistan might resist the change from conventional products


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to this innovative market. There is an initial risk involved, but the idea is to create

awareness that opportunity cost is still very high.

A few institutes/ organizations doing research in a geo textile discipline, like T.I.P, NED,

PCSIR Karachi Labs complex, NTU University etc. The coating materials mainly used in

the geo synthetics we are all imported from outsides from Pakistan. If government of

Pakistan takes interest, we can use our scientific expertise in the field of geo textile, and

also save our foreign exchange and also reduced their cost, because that field is a future

demand in recent years.

References:

1. Koerner, R.M (2000 June/July). Geotextile Separation Study. GFR Magazine 18

(5)

2. Narejo, D., Marienfeld, M., Hawkins, B., Lacina, B. (2005). Long-Term

Performance Using Separation Geotextiles. GFR Magazine 23 (5)

3. Ritika, G .(2008). International Conference on Technical Textiles and

Nonwovens. IIT Delhi Business Coordination House.

4. http://noida-uttarpradesh.olx.in/geotextile-fabric-woven-and-nonwoven-both-in-

any-size-and-type-iid-56674627tions.

geotextile 4 mansoor iqbal

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