Textiles are no more limited for use as apparels clothing is just are but not the only purpose of textiles with the rapid changes in the social economic structure of our society. Many efforts are made to some and protect human life. Technical textiles are textile material and products manufactured primarily for their performance and functional properties rather then aesthetic or decorative purpose. Aesthetic properties are not much important for the Technical Textiles. Technical textiles are the fastest growing area of textile consumption in the world. In most of the developed countries, technical textiles already account for 4% of the total textile production. Even in many developing countries, the proportion is well above 10%. At present, India's contribution in this area is negligible at about 0.2%.

Some application areas will grow faster than others. Although forecasts have been downgraded from earlier studies, world demand for geotextiles is forecast to grow at a compound annual growth rate of 5.3% between 2005 and 2010, with China a major source of both consumption and production. Volume growth in developing countries will average between 4% and 5% per annum to 2010. Construction applications are also forecast to grow strongly, at a compound annual growth rate of 5.0%, over the same period, driven by new products and the increasing textile content of building. Textiles come to our help in every walk of life. Similarly, textiles enhancing the quality of human life trough protection against various hazards as well as protection of environment is today's priorities were scientist all around the world are breaking their heads. India has tremendous potential for production, Consumption and export of technical textile. In the circumstances, textiles are playing major role through its diversified applications and undoubtedly the future of this technical textiles appears tom be bright in this, lot of uses are there. They are medical textiles, protective textiles, agricultural textiles, geo textiles, automotive textiles, smart textiles and industrial textiles.

1.AUTOMOTIVE TEXTILES

The automotive industry currently faces huge challenges .The automotive industry is one of the largest industries in the United States. In 1999 15 million vehicles sold in the U.S. and 2000 saw a record 17.5 million. It creates 6.6 million direct and spin-off jobs and produces $243 billion in payroll compensation, or 5.6% of private sector compensation. Employment of automotive service technicians and mechanics is expected to increase about as fast as the average (10 20%) through the year 2012. This amounts to 82,000 164,000 new jobs between 2002 and 2012. The Indian automotive industry has flourished like never before in the recent years. This extra-ordinary growth that the Indian automotive industry has witnessed is a result of a two major factors namely, the improvement in the living standards of the middle class, and an increase in their disposable incomes.

Moreover, the liberalization steps, such as, relaxation of the foreign exchange and equity regulations, reduction of tariffs on imports, and refining the banking policies, initiated by the Government of India, have played an equally important role in bringing the Indian Automotive industry to great heights. It is estimated that the sale of passenger cars have tripled compared to their sale in the last five years. Thus, the sale of cars has reached a figure of 1 million users and is expected to increase further. According to market research, women are the most demanding customers because they want everything that men require in terms of performance, prestige and style -- but they also have additional needs. Women want their cars to offer smart storage solutions, to be easy to get into and out of, to provide good visibility, to require minimal maintenance, and to be easy to park.

2.4. Sail Types

Modern sails can be classified in to three main categories:
Main sail
Head Sail
Spinnaker or downwind sail (also termed Kite)
The mainsail is permanently hoisted while sailing, headsails and spinnakers can be changed depending on the particular weather conditions to allow better handling and speed. Spinnaker is hoisted when sailing off the wind. It is constructed of very lightweight, usually nylon, fabric it somewhat resembles a parachute in both construction and appearance

2.5. Manufacturing processes:

There are basically two manufacturing processes used to make sailcloth:
Weaving
Laminating

Wovens are made by weaving threads over and under each other to produce the sail material. The tighter a sailcloth is woven, the better it will perform.

Laminates are layers of film, scrim or taffeta that are glued together under incredibly high pressures to form a composite sail material. Composite fabrics are made from two or more constituent components.

A scrim is a grid of relatively large, unwoven, straight yarns,. Scrims have little stretch parallel to the yarns but have no off thread line integrity and are usually sandwiched between other layers of scrim in a composite fabric. A film is an extruded sheet of isotropic plastic such as Dupont's Mylar polyester film. Film's good properties are low stretch in every direction, contributing to bias stability, zero porosity, and a surface that adheres well to other elements in the laminating process. Film's weaknesses are low tear resistance and a tendency to shrink. Tafetta is a woven substrate that makes up the outside of some laminates. Taffeta is usually made from polyester and adds to the durability and chafe resistance of the laminate.

Kevlar: A gold colored aramid made by DuPont, Kevlar's modulus is five times greater than polyester so it stretches less and sails made from it can be lighter. Although much stronger than polyester, Kevlar is not as durable in terms of fatigue and UV resistance. It is also more expensive. The original high tech fiber, Kevlar is UV sensitive and its gold color turns brown as it is affected by sunlight.

Spectra: Spectra has the highest modulus of any fiber, except carbon, used in sailcloth but has seen limited application in racing sails because of its creep property, meaning that the fiber will permanently stretch when placed under high constant load. Spectra are more expensive than Kevlar.

Technora: Technora is an aramid developed as reinforcement for drive belt applications. In sailcloth, it is dyed black to help its UV resistance. Technora has a modulus similar to Kevlar, slightly better abrasion resistance and is more expensive than Kevlar.

Certran: A high modulus polyethylene fiber. This fiber shares the same resistance to flex fatigue and UV as Spectra so its applications in sailcloth are limited to secondary fibers and areas which can take advantage of its flex, chafe and UV resistance.

Twaron: High Modulus Twaron or HMT is a fiber very similar to Kevlar. . A PPTA fiber with similar stretch resistance to Kevlar -49, but higher breaking strength. Better UV resistance than Kevlar. Bright gold in color.

Vectran: A polyester based liquid crystal fiber. Vectran has a modulus comparable to Kevlar but due to its molecular composition has better flex and abrasion resistance, although its UV properties are worse. Vectran also does not creep. These characteristics make Vectran an interesting candidate as a performance fiber, although it is more expensive than either Kevlar or Spectra.

Dyneema: Dyneema, like Spectra is a highly processed polyethylene which offers good UV resistance, high theoretical initial modulus and super breaking strength. It also shares Spectra's creep characteristics.

Pentex: polyethylene napthalate polyester fiber. Two times the stretch resistance of regular Dacron polyester, Pentex offers high modulus alternative for woven Dacrons. Best when used in a laminate form. Has similar tenacity to polyester and slightly better UV resistance.

Carbon: Carbon fibers have extremely high modulus but are not very durable.

PBO Zylon: Poly(p-phenylene-2,6-benzobisoxazole)(PBO)is a rigid-rod isotropic crystal polymer. PBO fiber is a new high performance fiber. ). PBO fiber has superior tensile strength and modulus to Aramid fibers (such as Kevlar, Technora and Twaron). It also has outstanding high flame resistance and thermal stability among organic fibers.

2.3. Important characteristics of fibers:

Tenacity
Denier
Flex Strength
Initial Modulus
UV Resistance

Maxx Laminate fiber orientation

2.6. New manufacturing methods:

North sails 3DL system
Sobstad Genesis system
And UK sail makers Tape-Drive system

North sails use large moulds mounted on hydraulics, these moulds can change shape to the desired shape of the sail. Then with a combination of robots and people suspended over the mould laminate films and fibres are laid down, consolidated and heated with an infrared lamp. The fibres are laid in a precise manner by a robotic arm, which lays them along the lines of principle loads. The resulting sail is extremely light and holds its shape much better than a sail made by stitching fabric together. The drawback of this method is that the capitol investment in the machinery and technology needed is huge. There is currently only one manufacturing center for 3DL in the world, located in the US. There is doubt on whether north sails can keep manufacturing these sails, as there is a bitter dispute with Genesis about Patent issues. North sails were accused of breaching Patent and copyright law with the use of 3DL and if Genesis gets its way then North Sails will be forced to discontinue production.

The Genesis system is similar to the North sails system, the difference being that they don't use a large moveable mould like the 3DL system. Figure 10 is a representation of the types of sail cloth available. The 3DL in fig 10 clearly shows how the fibres run in the direction of the loads.

Tape-Drive is a patented two-part construction process in which the structural strength of the sail and the skin that defines a sail's three-dimensional shape are separate elements. In this unique process, Tape-Drive marries a grid of high strength, low stretch tapes (the structural strength) to a three-dimension-ally shaped membrane (the fabric or skin). The grid carries the primary structural loads of the sail, while the membrane produces aerodynamic lift. The tapes, with breaking strengths up to 1900 pounds, radiate across the sail with a heavier concentration at the predicted high load areas, the corners and along the leech. Tape-Drive is the only high-tech construction method in which the materials can be varied to suit the specific use of the sail. Depending on the size of your boat and its sail requirements, we select the appropriate membrane material from a wide variety of custom designed laminates using scrims of Kevlar Edge, Technora, and PBO Zylon, Pentex or polyester yarns.

Advantages of tape drive system:

Tape-Drive sails are up to 40 percent lighter than other high-tech sails designed for similar wind ranges.
Lighter sails mean less pitching, less heeling, less weight in the boat, faster sail hoists, and faster tacking.
Tape-Drive sails can be made lighter since the skin material does not have to be load bearing.
Tape-Drive sails are easier to fold, handle, and flake.
They fold into small bundles, which mean that they take up less storage space.
Tape-Drive sails set better in light air than conventional sails, due to the lighter weight material and smaller corner patches.
Tape-Drive sails are easily repairable since the tapes prevent tears from running across the sail.

3. CIVIL ENGINEERING

3.1. Composites in Civil Engineering

Today high performance fibre reinforced plastics (FRP) are starting to challenge that most ubiquitous material, steel, in everyday applications as diverse as automobile bodies and civil infrastructure .Composite materials are formed by the combination of two or more materials that retain their respective characteristics when combined together to achieve properties (physical, chemical, etc.) that are superior to those of individual constituents. The main components of composites are reinforcing agents and matrix. Fibre reinforced composites can be further divided into those containing discontinuous or continuous fibres. Another commonly practiced classification is by the matrix used: polymer, metallic and ceramic.

Glass fibre is by far the most widely used fibre reinforcement and hence the terms "GRP" (glass reinforced plastic), "Fibreglass" and "FRP" (fibre reinforced plastic) are often used to describe articles fabricated from composites particularly for application in civil engineering. Composites are able to meet diverse design requirements with significant weight savings as well as high strength-to-weight ratio as compared to conventional materials. Some advantages of composite materials over conventional one are mentioned below:

Tensile strength of composites is four to six times greater than that of steel or aluminium.
Improved torsional stiffness and impact properties
Composites have higher fatigue endurance limit (up to 60% of the ultimate tensile strength).
Composite materials are 30-45% lighter than aluminium structures designed to the same functional requirements
Lower embedded energy compared to other structural materials like steel, aluminium etc.
Composites are less noisy while in operation and provide lower vibration transmission than metals
Composites are more versatile than metals and can be tailored to meet performance needs and complex design requirements
Long life offers excellent fatigue, impact, environmental resistance and reduced maintenance
Composites enjoy reduced life cycle cost compared to metals
Composites exhibit excellent corrosion resistance and fire retardancy
Improved appearance with smooth surfaces and readily incorporable integral decorative melamine are other characteristics of composites
Composite parts can eliminate joints/fasteners, providing part simplification and integrated design compared to conventional metallic parts

3.2. Composites for Structural Applications

Composites have long been used in the construction industry. Applications range from non-structural gratings and claddings to full structural systems for industrial supports, buildings, long span roof structures, tanks, bridge components and complete bridge systems. Their benefits of corrosion resistance and low weight have proven attractive in many low stress applications. An extension to the use of high performance FRP in primary structural applications, however, has been slower to gain acceptance although there is much development activity. Composites present immense opportunities to play increasing role as an alternate material to replace timber, steel, aluminium and concrete in buildings.

3.3. Road Bridges

Bridges account for a major sector of the construction industry and have attracted strong interest for the utilization of high performance FRP. FRP has been found quite suitable for repair, seismic retrofitting and upgrading of concrete bridges as a way to extend the service life of existing structures. FRP is also being considered as an economic solution for new bridge structures. Decks for both pedestrian and vehicle bridges across waterways, railways and roadways are bridges being built entirely from composites. The lightweight of composites is especially valuable for the construction of waterway bridges incorporating a lift-up section to permit the passage of boats, and for ease of transportation and erection in remote areas without access to heavy lifting equipment. The composite deck has six to seven times the load capacity of a reinforced concrete deck with only 20 percent of the weight.

The composite bridge decks are quite suitable for replacing conventional/old bridge decks having super structure intact. The replacement can be carried out in a short time with minimal disturbance to the traffic. Composites can significantly reduce maintenance and replacement costs because of the material's excellent resistance to corrosion and fatigue. The composite bridge decks are modular in design and can be produced in continuous lengths because of the inherent process adopted (pultrusion technique) and these lengths can be cut to size depending on the users requirement. Composite bridge decks are being used for both permanent bridges for state/national highways.

3.4. SIMCON: Slurry Infiltrated Mat Concrete

The cost of civil infrastructure constitutes a major portion of the national wealth. Its rapid deterioration has thus created an urgent need for the development of novel, long-lasting and cost-effective methods for repair, retrofit and new construction. A promising new way of resolving this problem is to selectively use advanced composites, such as High-Performance Fiber Reinforced Cementitious Composites (HPFRCCs). With such materials, novel repair, retrofit and new-construction approaches can be developed that would lead to substantially higher strengths, seismic resistance, ductility, durability, while also being faster and more cost-effective to construct than conventional methods.

Fig.3.1

Fig.3.1 SIMCON: Continuous fiber-mat High-Performance Fiber Reinforced Cementitious Composites

Conclusion

The technical textile market is respective to innovative new products. There is opportunity and need for functional, cost-effective materials. But the market is fragmented and complex. Development and lead times are often long and expensive. The market is quite small but exhibits moderately strong growth and produces are generally of high unit values. Due to increasing health and safety issues at work this may be an increasingly attractive segment. The Technical Textiles development in the present period is seems to be aggressive and real benefits will be realized soon. The integration of the application of the textiles in and with other fields like chemical, electronics, medical and environment shows the path for progress. In the coming years, Technical textile will increasingly assume huge functions. There may be long lead times much resistance to things new products to market. The truth is, we can not afford not to have the ideas and products.

References

1.Fung, W. and Hardcastle, M., 2001. Textiles in Automotive Engineering, Woodhead Publishing, Cambridge, England.
2.Bhagwat V. 2004. Automotive textiles, Asian Text. J. April, 55 61.
3.Bhagwat V 2005. Testing of automotive textiles, Asian Text. J.14 (1/2), 79.
4.Ishtalque, S, Yadhav P, Sharma, N, 2000. A new approach to improve the performance of spacer fabrics for automobiles, Man-Made Textiles in India, March 6774.
5.PowellN. B., September 2003. Mass Customization in Transportation Textiles Through Shaped Three Dimensional Knitting, Proceedings from International Textile Design and Engineering Conference, Edinburgh, Scotland.
6. www.specmaterials.com
7. www.nap.edu/books/0309096146/html
8. http://www.tifac.org.in/news/civil.htm

About the author:

Gopalkrishnan is pursuing his PG Diploma in Home Textile Management. He completed his Diploma in Textile Technology from PSG College of Technology and joined Cambodia Mills in Coimbatore as a Production and Maintenance supervisor. After working there for three years, he did his B.Tech from Polytechnic College.

Gopalkrishanan has presented 17 papers in various technical symposiums and many national & international conferences. He has participated in various technical workshops and innovative project works. He has several articles published in journals and magazines to his credit. His areas of interest include Innovative and Technical Textiles. You can contact him on: dgk_psgtech@yahoo.co.in

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1.1.Polyurethanes in automotives

Approximately one million tones of polyurethanes are used globally in automotive manufacturing, with a typical family car containing around 18 kg of polyurethane and a luxury car about 30 kg. The success of polyurethane is due to its ability to be produced in many different forms, from flexible foams (density 30 kg/cu m) for items such as headrests to more rigid, harder polyurethane systems e.g. for floor covers, bumpers and cover stock (density 1100 kg/cu m). The major sectors for polyurethanes in automotive are seating and acoustic insulation, followed by other segments such as door panels, steering wheels and dashboards.

Molding the foam to precisely fit the floor pan profile improves the acoustic efficiency of the composite through the improved contact with the floor surface. This can be further enhanced by using polyurethane foam that is designed to have an adhesive surface (tactile foam). Skin covers can be made from a variety of materials such as PVC, ABS/PVC alloys, TPO sheet or, more recently, polyurethane elastomers. Within the automotive market there is an ever increasing demand for light weight, durable and cost effective components.

1.2. Polyurethane skins

Polyurethane skin technology has been targeted to replace current PVC cover-stocks in vehicles. PUR skins are designed to have a soft feel, meet emission targets and exhibit good mechanical properties. Heat-aged and low temperature properties are becoming more important for aspects such as air bag deployment. PUR skins can be used for cover stock for instrument panels, door panels, arm rests and mid consoles. As the skins are very thin, the green strength [the strength of the material just after demold and before full cure] has to be good. In addition, the tear and tensile properties are important.The skins are unfilled and are generally either pigmented or in-mold coated [IMC]. The IMC imparts UV resistance and also influences the feel of the skin.

1.3. Headrests/armrests

Water-blown MDI foams for headrest and armrest applications.
Tear (N/m) - 170
Tensile (kPa)  128
Elongation (%) - 80

1.4. Dash Board

Semi-rigid polyurethane systems are used in dash board.
Semi-rigid polyurethane systems which provide not only a soft touch but also a passenger environmentally friendly product in terms of low emissions and fogging.
The air quality is generally monitored by two measurable factors - fogging and emissions.

1.5. Door panel

Semi-rigid polyurethane [PUR] is used to back foam door panels and instrument panels. The PUR foam is typically injected between the cover stocks.
The PU physical property requirements for areas such as door panels are high. The foam has to be designed to maintain properties after being conditioned at high temperatures [typically 120C] and high humidity.
The foam also needs to have excellent adhesion to the cover stock skins and inserts.
The polyurethane [PUR] systems can be designed to impart flexural strength and thermal stability, and are used in conjunction with glass mat or chopped glass strands, which reinforce the polyurethane matrix.
The door panels and instrument panels are used with cover stock materials example: PU skins [Elastomers ] PVC, thermoplastic films and fabric. The instrument panels and door panels may also utilize semi-rigid foam systems.

1.6. Floor Mat

Car manufacturers are increasingly applying polyurethane foams for interior sound insulation because it provides significant property advantages compared to the traditional acoustical materials

TYPICAL PHYSICAL PROPERTIES FOR HR FOAM

a range of water blown systems used for carpet underlay and dash insulator applications to dampen engine and road noise, including high resilience foams (HR), viscoelastic foams (VEF) and tactile foams.
The sound insulation foam systems can be combined with Elastomers-based heavy layer as an alternative to other materials.
As carpet underlay, the foam systems can be molded to the exact shape of the floor pan for a seamless fit and finish. As the foams have a low compression set excellent humid ageing resistance and zero shrinkage, the original shape and fit of the carpet is maintained over time.

Polyurethane [PUR] heavy layers offer

Improved physical properties
Better temperature characteristics
Excellent resistance to creep
Better low temperature impact
Low fogging and emissions
Low odor
Increased durability
Reduced cycle time
Improved styling/design opportunities

The PUR heavy layer system can be designed to fulfill most customer requirements and can be modified to improve physical properties and characteristics. In most cases, the heavy layer systems are used in conjunction with sound insulation foam systems.

1.7. Floor panel insulation

As the foams have a low compression set excellent humid ageing resistance and zero shrinkage, the original shape and fit of the carpet is maintained over time.

Table.1.1. Typical Physical properties for HR foam

1.8. Head Rest

Water-blown MDI foams system are used for headrest and armrest applications, which meeting specifications including compression, dry/humid ageing, durability, adhesion and aesthetic standards.
Specialized cream foam technologies for pour-in-place applications.
The greatest difficulty with pour-in-place applications is penetration, which causes hardening of the cover stock and extremely stiff seams.

1.9. Seating

For the seat cushions comfort and durability are of prime importance.
Polyurethane systems offer high load bearing capacity, temperature and moisture resistance and long term resilience in combination with robust processing characteristics.
MDI water blown flexible foams technology is also used for low density seat back applications (densities of 38-42 kg/cu m)

1.10. Steering Wheel

Water blown microcellular foam systems, used for applications such as steering wheels.
Polyurethane [PUR] microcellular system technology can be used with or without in-mold coatings has been designed for ease of processing, durability and comfort feel.
In-mold coatings are generally used for color matching, UV resistance and improved abrasion.

Microcellular foam systems

Property range

1.11. Polyurethane application

Co polyester Hot melt Adhesives

Co polyester Hot melts Adhesives offer new opportunities and manufacturing textile laminates for automotive interior parts. Because of their unique properties they can also be used for fuel and air filters as well as for assemblies such as headliners.

Filters

Automotive filters clean the air for passenger compartment as the engine. They absorb troublesome particles out of petrol, diesel and mineral oil.
Hot melt adhesives are in use of stabilization of the filter element and the bonding to the cartridge.

1.12. Interior Trim Parts

Decorative textiles for interior trim parts are mainly based on polyester. Back filling with upholstery fabrics impact their comfort. Because of their good resilience polyurethane foams are the material of choice. The most frequently laminations techniques used is the so-called flame bonding process where the surface of the foam is melted with an open gas flame.

Requirements for textile laminate in automotive interiors

High bonding strength
Good resilience
Resistant against ageing
Breath ability
Softness/flexibility
Low VOC content (Fogging)
Heat resistance

1.13. Laminates for Interior Trim Parts

As the laminate do not meet all the requirements hence flame bonding is used which increases the fogging values and the laminates have the low recycling capability. Composites coated and laminated with co polyester hot melt adhesives show a brilliant performance without any special treatment which fulfills the demand regarding heat resistance for headliners and softness for seats.

1.14. Non Woven

1.Global non woven production 4.75 billion.kg in 2005, expected to increase 6.32 billion.kg-2009.
2.Spun bonded non woven cheapest sold in kg basis.
3.40gms spun bond woven is Rs.4-5/sq.mtr.
4.Technologies to produce non woven are needle punch, spun bond, chemical bond, and spun lace.
5.Needle punch are used in automotive & filters, 14-15 producer in the country.

1.15. Non woven playing expanding role in automotive interiors

In the area of acoustics nonwoven serve as sound absorption & insulation material and are recent demand for light weight.
Non woven also being used in moldable trunk, wheel arch & acoustics air duct system for insulation & heat shield purpose.
PET based non woven applied in outer area car high level target for outer absorber material regarding water absorber & quick dehumidifying.
Nonwoven continue to meet tougher technical requirements their role as s replacement for traditional material has expanded.
Nonwovens can be produced from under 10 grams per square meter (g/m2) to well over 1,000g/m2 using fibers that can be many times finer than the human hair or extremely coarse.
Some of the original automotive nonwovens used for decorative trim, particularly for headliners, were almost blanket-like in appearance due to the use of coarse fibers.
A new generation of more sophisticated nonwovens is used today. The Cosmopolitan Textile Company is a leading supplier of high-quality nonwoven automotive trim. Manufacturing is carried out in both Europe and North America.
Automotive tufted carpet reinforcements also feature nonwovens, as well as trim part alternatives, headliner facings, auto cabin air filters, self-supporting roof liners and rear shelf, sunshade, sun visor, seat back and seat cushion applications
Finer denier fabrics are now being used so that trim, such as seat backs and package trays, are more cloth-like than carpet-like.

Efforts toward recyclables continue in the automotive sector, neither heightened consumer awareness nor environmental regulations are putting enough pressure on marketers to push for more environmentally friendly nonwoven materials.

Today more than 40 automotive parts are made from nonwoven materials, making the automotive market one of the largest durable markets for nonwovens.
Nonwovens can be found in automotive applications starting from the ground up from tire reinforcements to headliner facings and reinforcements.
Nonwovens can be found under the hood, in oil and carburetor filters and battery separators, as well as uses on the opposite end of a car such as trunk liners and trunk floor coverings.
Nonwoven fabrics have also found their way into cars main cabins in a plethora of uses, including carpet and carpet reinforcements, car mats, covering materials and padding for sun visors, insulation, covering for seat belts and seat belt anchorages and sound proofing.
As nonwovens are beginning to make headway by educating manufacturers and consumers about advantages such as customization, durability and cost-effectiveness.
Nonwovens are gaining market share in areas such as North America and reinforcing their marketplace in the European auto industry.
The cost savings potential for nonwovens in headlining, flooring systems and seating fabric is enormous.
Recyclables has become a major issue in the European market, resulting in the need for biodegradable nonwovens that include no hard-to-recycle materials, such as mineral, glass fibers or foam.

2. TEXTILE IN SAIL BOAT APPLICATIONS

A sail is simply a piece of fabric that is used to catch the wind to drive the boat across the water. The term sailboat has a broad meaning generally including yachts (large sailboats) and smaller vessels of many configurations, which use wind as the primary means of propulsion. Most modern sails are made of Dacron, a polyester fiber. Because the fabric is heated to meld the fibers together, the wind cannot escape through pores like those in woven cloth, and the surface has a very low friction factor. Polyester sails are also lightweight with little stretch.

2.1. Fibers used:

Dacron: The DuPont trade name for man made Polyester fiber. This fiber is the foundation of traditional woven sailcloth.

Polyester: The most common fiber used for both woven sailcloth and laminates. A proven fiber for durability, polyester has been replaced by higher modulus fibers for most racing applications.