THE NEW TEXTILE FIBRES

ABSTRACT:

                  

  The textile industry is the sector where large amounts of fibres are used. Fibres are also part and parcel of many of the products we use constantly every day – all of which have to satisfy special requirements. Many products used in the household, the construction industry, in our free time and when travelling, as well as in personal hygiene and medicine, contain fibres.

                     With the advent of industrial revolution in the western world, textiles were used as sail conveyors, filter media, for reinforcement and as parts and equipments alone or in conjunction with other materials. These textiles which are manufactured primarily for their technical and performance properties are known as technical textiles. The economic scope and importance of technical textiles extends far beyond the textile industry itself and has an impact upon just about every sphere of human economic and social activity.

                     Formerly in technical textiles natural fibres were used such as cotton, wool, silk, etc. But with the advent of new requirements and possibilities, the research for better- high performance fibres began. As a result, fibres with highly exceptional properties were developed. Now fibres like Biosteel, Spectra, Solar-aloha, etc known for high chemical resistance, high tenacity, etc.

Our paper discusses the same……

INTRODUCTION:

      As a call for more comfort, it necessitates the need for development of new fibres constantly. The main focus of development of these fibres is to meet the particular requirements.  Textile is a peculiar field of science where technology changes very rapidly. The use of textiles for clothing known to mankind from primitive age was extended to household and domestic applications with progressive civilization. Textiles were started being used as erosion controller, in medical applications and in industrial applications. Owing to their wide varieties, they were categorised into Agrotech, Buildtech, Mobiltech, Oekotech, Sporttech, Geotech, etc., and these were cumulatively called as “Technical Textiles”

     So to meet the ever increasing demands and requirements of these technical textiles, new hi-tech fibres have been developed. The fibres have to withstand extreme conditions and poses peculiar properties and high functionability to be used in technical textiles.

High-tech fibres now include new functional fibres such as biodegradable fibres, chemical absorbance fibres, fibres from biomaterials and activated carbon fibres, which are not of high modulus and high strength, but have other new performance advantages. Therefore, high-tech fibres can now be redefined as fibers produced by high-technology, which are superior to those produced by conventional fiber technology, arising from the application of the newer developments in fibre science and technology.

    The integration of the application of the textiles in and with other fields like chemical, Electronics, medical and environment show the path for progress.

SPIDER SILK (BIOSTEEL) FIBRE:

Spider, small animal, often less than a millimeter across can make a substance that we humans with all our technology are unable to reproduce, a substance that is tough, stronger and more flexible than anything else we can make is surely a humble reminder of the fact that Nature created us and not the other way around.

What is spider silk made of?

Spider silk is a bio polymer fiber, its composition is a mix of an amorphous polymer (which makes the fiber elastic) It is a fibrous protein secreted as a fluid, which hardens as it oozes out of the spinnerets which are mobile finger like projections. As the fluid oozes out, the protein molecules are aligned in such a way that they form a solid. The process is not yet well understood. The spider hauls out the silk w ith its legs, stretching, fluffing it up or changing it in other ways.

    Nexia Biotechnologies Inc in Montreal, Canada has inserted silk genes into goats to produce silk proteins in their milk. This is hoped to be a better method because protein from bacteria is not as strong due to faulty crosslinking of the proteins and hard white lumps can form. Milk production in mammary glands is similar to silk protein production in spiders so it is thought that proper protein crosslinking could occur in goats. Scientists have injected the spider’s gene into a goat named Willow. Willow’s milk will be processed so the protein can be used. This silk thus produced biologically is called “biosteel”.

Properties of Spider Silk:
Unique combination of high strength & rupture elongation.
Strength = 1.75 Gpa
Breaking elongation = over 26%
It is interesting to see spider silk as a model for the engineering of high-energy absorption fibres, because the fineness of spider silk is on the order of 4 nm

Applications:
    Current research in spider silk involves its potential use as an incredibly strong and versatile material. The interest in spider silk is mainly due to a combination of its mechanical properties and the non-polluting way in which it is made. The production of modern man-made super-fibres such as Kevlar involves petrochemical processing, which contributes to pollution. Kevlar is also drawn from concentrated sulphuric acid. In contrast, the production of spider silk is completely environmentally friendly. It is made by spiders at ambient temperature and pressure and is drawn from water. In addition, silk is completely biodegradable.
    If the production of spider silk ever becomes industrially viable, it could replace Kevlar and be used to make a diverse range of items such as : Bulletproof clothing, Wear-resistant lightweight clothing, Ropes, nets, seat belts, parachutes, Rust-free panels on motor vehicles or boats, Biodegradable bottles, Bandages, surgical thread & Artificial tendons or ligaments, supports for weak blood vessels.

AUXETIC FIBRES:

Imagine stretching elastic and seeing it get fatter rather than thinner. It may sound bizarre, but this property is what makes auxetic materials potentially so useful. An auxetic material, which has a negative Poisson ratio so that it has the property of expanding or contracting transversely to a direction in which it is extended or compressed, is made in filamentary or fibrous form. A suitable process involves cohering and extruding heated polymer powder so that the cohesion and extrusion is effected with spinning to produce auxetic filaments. Typically the powder is heated to a temperature sufficient to allow some degree of surface melting yet not high enough to enable bulk melting.

Manufacturing:
            A conventional polymer processing technique (melt spinning) is the basis of this technique, with novel modifications. The process flow of manufacturing typical polypropylene auxetic fiber is illustrated below:

Applications:

Auxetic fibers can be used as fiber reinforcements in composite materials e.g. polyolefin auxetic fibers in a polyolefin matrix. The auxetic fibers improve resistance to fiber pull out and fiber fracture toughness, and give enhanced energy absorption properties. Sonic, ultrasonic and impact energy can be absorbed enabling superior composites to be made for sound insulation of walls of buildings, body parts for submarines or other vehicles, etc, bumpers for cars, etc.

Auxetic fibers can be used alone or in combination with other materials for personal protective clothing or equipment as a consequence of the superior energy absorption and impact resistance properties. Crash helmets and body armour (e.g. bullet proof vests) are examples of applications.

It may be desirable to make the protective material in the form of an auxetic macrostructure made from auxetic fibers (i.e. a hierarchical auxetic material). These properties should also lead to enhanced sports protective clothing, e.g. shin pads, knee pads, batting gloves etc. The possibility exists of producing protective clothing made from auxetic fibers which have equivalent protective performance to those made from non-auxetic fibers but which are lighter and/or thinner due to the benefits associated with the auxetic property.

Auxetic materials have pore size/shape and permeability variations leading to superior filtration/separation performance in several ways when compared to non-auxetic materials. Application of an applied tensile load on a non-auxetic porous material causes the pores to elongate in the direction of the applied load, which would tend to increase the filter porosity. Benefits for auxetic filter materials, therefore, include release of entrapped particulates (e.g. drug-release materials) and self-regulating filters to compensate for pressure build-up due to filter fouling

SPECTRA:

    Recently developed spectra fiber is one of the world’s strongest and lightest fibers. A bright white polyethylene, it is, pound-for-pound, ten times stronger than steel, more durable than polyester and has a specific strength that is 40 percent greater than aramid fiber. It is  best known as the super-fiber used in the Small Arms Protective Insert (SAPI) plates protecting American soldiers in Iraq and Afghanistan. Spectra fiber is used in numerous high-performance applications, including police and military ballistic-resistant vests, helmets, armored vehicles, sailcloth, fishing lines, marine cordage, lifting slings, and cut-resistant gloves and apparel..

Production (Spinning Process):

A process for making polymer filaments, which have a high tensile strength and a high modulas by stretching a polymer filament which, contains a substantial amount e.g., at least 25 wt% of polymer solvent, at a temperature between the swelling point and the melting point of polymer. A solution of the polymer may be spun to a filament through a spinning aperture and the spun filament cooled to below the dissolution temperature of the polymer without substantial evaporation of solvent from the filament and then brought to a temperature between the swelling point and the melting point of the polymer and stretched.Polymer solutions were prepared by dissolving the polymers in paraffin oil, decalin, or dodecane under a nitrogen atmosphere and in the presence of an antioxidant. The solutions were spun using the experimental setup. The extrusion temperature varied from 130 to 175⁰C for dilute solutions and was fixed at 120⁰C for concentrated solutions. The spun filaments were then quenched in cold water to form gel fibers and collected on a winder.

    Drawing was carried out either by stretching a gel fiber in a hot air oven and simultaneously removing the solvent to yield an essentially solvent free, highly oriented fiber or by drying the gel filaments at room temperature, then extracting traces of solvent with ethanol. The drawing experiments were carried out over a range of temperatures (70- 143⁰C) using either constant temperature or a temperature gradient.The concentration of the polymer as it was spun from solution and quenched into gel fibers appeared to be the most important process variable.

Properties of Spectra Fibers:

1. Tensile Properties

The tensile strength of spectra is higher than that of aramid fibers below ~ 100⁰C and falls below that of aramid fibers above this temperature. The capacity to withstand constant static tensile load also decrease rapidly when the temperature approaches 100⁰C, and it would be unwise to use spectra fibers at a temperature exceeding 80-90⁰C in application s in which significant loads are applied for an appreciable length of time. Spectra show an outstanding retention of properties after prolonged heat treatments (annealing) to 125⁰C. It can be seen that, after cooling, the fibers almost completely retain their original room temperature strength unless the treatments exceed 125⁰C, although modulus decreases somewhat faster. It is well known that application of tension during annealing further decreases the strength decay of fibers.

2. Effect of Twist

Outstanding tensile properties and chemical inertness make spectra fibers promising candidates for use in cords for marine applications sail cloth, protective clothing, etc. Essential for these applications is the ability to withstand twisting without sacrificing strength. This, coupled with a very low coefficient of interfilament friction and outstanding resistance to flexural fatigue, makes spectra of great interest for users of cordage.

3. Creep under Static Loa

 Spectra technology made important steps toward a dimensionally stable product,

 And these fibers are now successfully utilized in many industrial applications. Spectra’s tendency to creep under constant load is much higher than that of aramid fibers. In addition to modulus and strength, a major difference between spectra 900 and spectra 1000 is the greatly reduced creep of the 1000. Some development spectra fibers shows even less creep than spectra 1000 at elevated temperatures. Any undesirable creep can be frequently be reduced by hybridization with a minor component of carbon or Kevlar fibers.

4. Retention of Properties in Various Solvents

Very high molecular weight and exceptionally high degree of molecular orientation and crystallinity contribute to outstanding solvent resistance. The chemical inertness of polyethylene and lack of hydrolysable bonds also contribute to this property.

5. Abrasion Resistance

In addition to outstanding tensile strength and low density, Spectra fibers exhibit superior abrasion resistance, a key requirement in many applications, especially for ropes. As a rule, the abrasion resistance decreases with fiber modulus, but in the case of ultrastrong polyethylene the trend is reversed, most likely because of its low coefficient of friction.

6. Drop Weight Impact

Because of the low glass transition temperature of polyethylene, which is placed between –80⁰C and 120⁰ C, depending on the type of measurement, the thermoplastic Spectra fibers show by far the largest capability to withstand impact of all the high- performance fibers. As a result, spectra fibers retain their mechanical strength even at ballistic rates of deformation and very low temperatures. Depending on the construction, the impact resistance of spectra composites is 5 to 10 times higher than that of aramid.

7. Electrical Properties

Low dielectric constant and loss tangent of polyethylene are of great importance in applications such as radar domes (radomes). Considering that the electrical properties do not change a great deal with molecular orientation and polymer morphology, the use of ultrastrong spectra fibers offers great potential for the development of structures in which structural rigidity, ballistic protection, and low dielectric constant are simultaneously required. Due to low dielectric constant and small loss tangent, the reflection of radar waves from polyethylene composites is smaller, and therefore the transmission is higher, than with glass fiber composites. In composites of spectra fiber/PE matrix, transmission is so high that it is practically transparent to the radar wave.

Advantages and Disadvantages of Spectra Fibers:

Compared to other high performance fibers, spectra fibers have excellent specific properties and theoretical considerations indicate that their transverse-related properties, such as shear and compressive strengths, are equal to those of aramid fibers. Therefore, spectra fibers are good candidates for rigid structural composite applications. Exploratory spectra fibers exhibiting reduced creep offer promise to broaden the applicability of the fiber.

Handling:
     Spectra fibers can usually be processed very well on a variety of textile and composite manufacturing equipment. However, the unique combination of properties of this fiber may require that process and/or equipment modifications be made when utilizing conventional equipment.
     For instance, it is essential to know that because of their unusually high strength, modulus, and amenability to high speed processing technology, Spectra fibers must be handled with maximum care. Operators unaccustomed to handling such fibers should be made aware of the potential danger of severe injuries if they are caught or entangled in a fast moving yarn.

FIG- spectra shield

Applications of Spectra Fibers and Composites:

Spectra fibers and composites have gained rapid acceptance in a broad range of technologies; this is attributable to their mechanical properties; outstanding abrasion, fatigue and cut resistance; chemical inertness; and above all, unmatched damage tolerance. It has become clear that spectra fibers and composites will play major role in the rapidly expanding technology of survival. Specific applications are discussed in detail in the sections that follow:

1. Decelerator systems

Spectra is currently being used in decelerator system suspension lines. Equal load capabilities can be achieved at smaller diameters, there by reducing the pack volume and weight of system; also, in parachute reefing, the smaller line diameter enables use of smaller grommets or reefing rings.
     When a parachute is open, lines passing through metal guides are exposed to severe amount of abrasion and must be frequently replaced due to abrasion damage. The advantages of spectra’s light weight strength go beyond tensile property, as it provides products with excellent abrasion properties. It has low frictional coefficient that is characteristic of polyethylene and as a result, even under abrasive circumstances, a relatively minimal amount of heat is generated. When the abrasion resistance of yarn to metal is evaluated, significantly greater strength retention can be found in the spectra fiber, the resistance of spectra is more than 20 times that of a comparable Kevlar braid.

2. Commercial fishing

Performance advantages of spectra cited above related to decelerator systems are equally applicable to commercial fishing applications. In addition, Spectra products have a natural buoyancy and float, whereas polyesters and steel wire products do not.

            Spectra’s superior strength greatly reduces bulk for rib lines. Head ropes, bridles, and other ropes traditionally made from polyesters or other synthetic fibers. Unlike wire rope, spectra will not corrode and damage netting materials over time. Also, regardless of their size, ropes made with spectra float, which significantly reduces the need for bulky and expensive flotation devices. Spectra winch lines, lifting slings and high strength chokers allow for easy handling and greater safety when hauling back and unloading. Spectra provide the same strength as wire rope at only 20% of the weight. This reduces bodily strain when lifting and allows more crew efficiency, especially in emergency situation.

BASALT FIBERS:

     The fiber is composed of 100% mineral continuous filaments. The focus is on the range of 9 to 13 J.tm for the filament diameters. These diameters give the best compromise between tenacity, suppleness and cost. As the product presents no hazards to health and environment, it is suitable for asbestos replacement. The natural golden brown appearance of the resulting fabrics incidentally can be covered for decorative purposes.

Forms of Basalt

Continuous Basalt fiber is a unique product derived from volcanic mineral deposits. Basalt fibers are superior to other fibers in terms of thermal stability; heat and sound insulation properties; vibration resistance and durability.

Basalt Twisted Yarn:

The main advantages of Basalt continuous fibre, roving and yam, are higher operating temperature, young's modulus and chemical resistance as compared to fiberglass. It possesses high temperature resistance and excellent mechanical properties.

Basalt woven fabrics

The Basalt fabrics have the width of 100cm with deviation +2/-1 % from the norms. The fabrics can be produced with the width up to 200cm.

General Properties of Basalt

1) Mechanical Properties

• Specific tenacity of CF Basalt fibers exceeds that of steel fibers.
• Basalt is roughly 5%denser than glass.
• The tensile modulus of CF Basalt fibers is higher than the one of E glass fibers.
• This makes CF Basalt fibers & fabrics attractive for the reinforcement of composites.
• The low elongation perfectly elastic up till rupture- results in dimensionally
• very stable fabrics.
• Basalt textiles show sufficient suppleness and drape ability.
• They exhibit good fatigue resistance.

2) Chemical Properties
• They have good acid and solvent resistances.
• They have better resistance to alkalis. .
• The inert basic material possesses, in addition to its corrosion resistance, good resistances to UV -light and biological contamination.
• In pure form, it is free of odour and has low soiling sensitivity.
• Absorption of humidity comes to Jess than 0.1 % at 65% relative air humidity
and room temperature.
• They show excellent "wet ability"

3) Thermal Properties
• They show good resistances against low and high temperatures.
• It is a non-combustible and explosion proof.
• They have excellent resistance to fire.

Applications of Basalt:

1) Surface & air transportation

•Fire protected seats in planes, trains, ships, subways,.....

• Airplane life jacket pouches.

2) Specialty furniture

• Fire proof mattresses (for hospitals, hotels, etc.).

• Fire proof seating.

3) Construction

• Fire proof curtains and partitions for indoors and outdoors.

• Fire protective clothing

• Fire resistant floor coverings: backing, reinforcement.

4) Environmental safety

• Basalt carbon heaters for clothes, rooms etc.

• Fire proofing and heat protection working cloth.

(Polyethylene Naphthalate)PEN Fibre:

    Current U.S. PEN Fibre Producer: Performance Fibres Inc.

    Basic Principles of PEN Fibre Production — PEN, a new generation polymer, is a high performance member of the polyester family. Its unique chemical structure renders it useful for fibres, packaging and films. PEN has a modulus* that is five times that of nylon, two-and-a-half times that of polyester, and double that of rayon.

PEN Fibre Characteristics

• Dimensional stability—low elongation and low shrinkage
• Engineered for strength and dimensional stability

Some major PEN Fibre uses — Engineered reinforcements, cordage, and tire cord, narrow and broad woven fabrics. High-performance sailcloth in racing.

P-phylene2, 6-benzo bisoxazole (PBO) fiber:

    These are high modulus, high dimensional stability with higher glass transition temperature, resistance to hydrolysis and high fire resistant. This makes them suitable for protective clothing applications.

    Major manufacturers are Toyobo Co., Japan (Zylon).

   The fiber zylon is probably known as today’s strongest fiber that is commercially available. With a value of approx. 37cN/dtex, its tensile strength is decidedly higher than those of the para-aramids (Kevlar and Twaron) and the high performance polyethylene’s (Dyneema and Spectra)

     ZYLON shows 100°C higher decomposition temperature than p-Aramid fiber. The limiting oxygen index is 68, which is the highest among organic super fibers.

There are two types of fibers, AS (as spun) and HM (high modulus). HM is different from

AS in modulus, moisture regain and etc.

Alginate:

    An off-white fiber comprising the calcium salt of alginic acid. Approx. 1% textile finish is applied (Polysorbate 20, BP).

   This fiber, synthesized from sodium alginate extracted from seaweed, is available in staple and filament form. It is suitable for use as moist wound dressing to aid faster healing of wound.

    Calcium alginate fiber is manufactured from sodium alginate extracted from seaweed. Capable of ion exchange with other metal ions, the fiber gels on contact with solutions of sodium salts and is highly absorbent. The fiber will dissolve in high concentrations of sodium ions.

   The ability of the product to support healing of granulation tissue and the widespread

use of alginic acid and its salts in antacid preparations for man, provide evidence for the lack

of toxicity of alginate products in general when applied to the mucous membranes.

Calcium alginate fiber is used as a material for use in wound dressings and other wound management products. Also for use in diagnostic swabs for microbiological sampling.

Alginate dressings have a leading position in advanced wound care and their usage

is established world-wide.

   The dressings are easy to use and, due to gel formation, are non- adherent, and may be removed without causing pain or trauma.

   Major manufacturers are Acordis Speciality Fibers, UK.

Solar-aloha:

    Solar-Aloha, developed by Descente and Unitika in Japan, absorbs light of less than 2um wavelength and converts it to heat owing to its zirconium carbide content. Winter sports equipment made from these materials use the cold winter sun to capture more than 90% of this incident energy to keep the wearer warm.

Cripy65:

    Cripy65 is a scented fiber produced by Mitsubishi Rayon (R) who has enclosed a fragrant essence in isolated cavities along the length of hollow polyester fibers. The scent is gradually released to give a consistent and pleasant aroma. Pillows and bed linen made from these materials are claimed to improve sleep and sleeping disorders.

In addition to single polymer yarns and fibers, there are also many uses for combinations of different polymers specially engineered for specific end uses. These are mainly in the form of bicomponent fibers or graft copolymers. Few of examples of bicomponent fibers are listed below:

• Al- and Es- ranges: polyethylene/ polypropylene fibers produced by ES Fiber Visions, Denmark for use in medical and hygiene textiles.
• Ethylene vinyl alcohol (EVOH): copolymer with EVOH sheath and polyester or polypropylene in core produced by Kuraray Co. Ltd., Japan suitable for specialty papers and non wovens.
• Visil 33 AP: silica/ cellulosic fibers produced by Sateri Oy, Finland are an inherently flame retardant fiber suitable for upholstery and insulation barriers.

Conclusion-

Application area	polymer	fiber	Spun staple	multifilament	monofilament	Tape/ split film	Total
Agrotech	80	40	291	435	360	751	1957
Buildtech	272	1923	52	250	85	10	2592
Clothtech	81	994	372	171	38	0	1656
Geotech	38	163	12	122	19	58	412
Hometech	351	1443	607	99	32	321	2853
Indutech	118	2333	214	537	50	5	3257
Medtech	1026	1212	136	4	0	0	2378
Mobiltech	75	1512	106	1568	2	74	3337
Packtech	56	69	1832	38	27	1584	3606
Protech	86	3	68	183	0	0	340
Sporttech	43	108	348	741	12	130	1382
Total	2227	9799	4039	4147	628	2933	23770

Table: application-wise global consumption of fiber/filament/split film (2010)

(Volume in ‘000 tonnes)

As seen above these fibres have become the Heart of the Technical Textile Industry. They play an important role in deciding its applications. The use of various fibres in various stream of technical textiles are continuously increasing and can be seen below.

Fibers were the basics of textiles, which are taking off now and will encompass almost every area of the host economy and they are not going to stop by any means. These rapid changes in the fiber-manufacturing world will definitely going to conquer the globalization era of the free trade commission and the changes will continuously growing. It is as simple as that “a rich man’s appetite can never be fulfilled”, so the textiles are now becoming the multifunctional …..

References:

Ø  Hiroshi Mera, Tadahiko Takata "High-Performance Fibers" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.

Ø  Handbook of technical textiles by Horrock and Anand

Ø  Review of the expert committee on Technical Textiles- part 1, Textile Ministry, Govt. of India.

Ø  ‘New fibers’ by Tatsuya Hongu and Philips

Ø  Handbook of industrial textiles by Sabit Adanur

Ø  ‘New Fibres for 21st century’, Rijavec T. & Bukosek V., Tekstilec 2004, 47/102, 13-25. World Textile Abstract 2004.

Ø  ‘Corn Fibres: Dawn of new Era in Eco Textiles’, N.Arun, Man-made Textiles in India, April 2003, 130-135.

Ø  ‘Novel properties of PLA fibres’, Karthik T., Synthetic Fibres, 2004, 33/4, 5-10.

Ø  ‘BioSteel – A future fibre’, Asian Textile Journal, December 2004, 83-90.

Ø  ‘Spider Silk’, P. Madhavamoorthi, Synthetic Fibres, June 2004.’

Ø  www.google.com

Ø  www.azom.com

Ø  www.fibersource.com