Indian Journal of Fibre & Research Vol. 22, December 1997, pp. 213-221

Technical -Technological and market developments and trends

Roshan L Shishoo The Swedish Institute for Fibre and Polymer Research, Molndal, Sweden

Teclmical textiles are used in various forms of fibrous structures from simple filament to complex end products. This paper reviews, in brief, the various high and high functional textiles both from the market development and application points of view. The technology and material trends in the area of technical textiles have also been discussed.

Keywords: Air bags, Composites, , High functional textiles, High performance textiles, Industrial textiles, Technical textiles

1 Introduction fabrics, protective , composites, agrotex­ At present, there is no standard definition of tiles, geotextiles, and medical and hygiene prod­ technical textiles. One of the definitions proposed ucts. is: technical textiles are semi-finished or finished Global market volume of technical textiles var­ textiles and textile products manufactured for per­ ies depending on the type of end-use applications. formance characteristics; they are used in indus­ Higher value products exist at the upper end of trial; institutional, civil eQgineering, medical, pro­ price level at lower volumes and these are used in tective and leisure applications. This definition very specialised products where the performance, clearly points out the diversity of materials, not the price, is the determining factor (Fig. 2) . chemicals and processes used to produce technical The technical textile market occupies an important textiles. Fig. 1 shows that a technical textile prod­ place in the total textile scene accounting for about uct can exist and be used in various forms of fi­ 24% of all fibres consumed in Western Europe in brous structures from simple filament to a complex 1994 (Table 1); this segment of the textile market end product. The most common textile products in is growing at a high rate. The producers of techni­ this category include high perforinance fibres, cal textiles have been concentrating their efforts in ropes, webbings, tapes, filter media, paper making improving their strategic position, productivity, and fabrics, heat and sound insulators, coated Tecbnical textiles Bulk textiles

High Carbon performance and fibre . h functional 8 composites fibre d textiles ·c ~

Woven fabrics Protective clothing Knitte household apparel Global market volume Fig. 1~low chart showing various forms of fibrous structures of technical textiles Fig. 2-Global market volume vs price for textiie product, 214 INDIAN J. FIBRE TEXT. RES., DECEMBER 1997

Table I-Per cent amount of fibres consumed for different J i:UWi::Ul 11 % Western Europe applications in European Union and USA in 1989 and 1994 China Application area Fibres consumed, % 11 % 1989 1994 USA USA C lothing and household textiles 39 35 Japan 19% Carpets 33 34 8% Technical textiles including tyres 28 31

European Union South Korea Clothing and household textiles 60 54 8% Carpets 18 22 4% Other Asia Technical textiles including lyres 24 Eastern Europe 5% 22 9% 6%

value-added products, and niche positions in order Fig. 3~eographical breakdown of world man-made fibre to expand their markets. production in 1995 (source: Akzo Nobel)

David Rigby Associates' provided a compre- a Polya..midr C Pclyacryllc.PoIYlPSlrraOthlPr synthlPtic hensive overview of the international market for ~- 100 technical textiles. According to them, it is very .: 80

much likely that the actual consumption of fibres .;o and yams for technical and industrial purposes is :;. higher 'than that assumed previously. An average ~ 2 growth rate of 4% per year caT! be expected during u: 1975 1980 1985 1990 1995 1995-2005. The biggest market is Asia with sales VlPar of $9.48 billion in 1995 ($ 14.18 billion in 2005), Fig. 4--Shares by fibre type of world synthetic fibre produc­ followed by North America with $ 8.37 billion tion during 1970-1995 (source: Akzo Nobel) ($ 10.57 billion in 2005). Hence, with an annual growth rate of over 5%, the Asian market will ex­ expected by the year 2002. The regional distribu­ pand twice as quickly as the North American mar­ tion of world fibre production will be shifting fur­ ket (2.5%) in the same period. Western Europe ther to the dynamic Asian region. Rapidly growing consumed fibres and yams worth $ 6.3 billion in market~ are India, China, Indonesia, Malaysia, 1995, a figure which is expected to rise to approx: South Korea, Taiwan, Thailand and in near future $ 8.14 billion by 2005. World-wide, the average Vietnam (Fig. 3). Shares by fibre type of world rate of growth in the consumption of techriical tex­ synthetic fibre production during 1970-1995 are tiles (woven fabrics, interlaid scrims, braiding, shown in Fig 4. There have been new develop­ knitted fabrics, nonwovens, composites and mis­ ments both in the fibre/filament and yam spinning cellaneous fabrics) amounts to 4% per year during technologies, resulting not only in higher speeds 1985-2005. At present, the total sale is estimated at but also in better quality. Some leading manufac­ turers today offer machines for take-up speeds of approx. US $ 42 billion. According to prognoses, this figure will have risen to almost US $ 61 billion as high as 8000 mlmin and the development of machines for 10000 mlmin is already under way. by the year 2005 ~ In Western Europe alone, 2.3 million tons of technical textiles were produced in Requirements to be met by technical yams and 1995. The resulting sale was worth approx. US $ fibres such as high tenacity, low elongation at 9.9 billion, which is expected to climb to US $ break, high modulus, low thermal shrinkage, high 12.9 billion by the year 2005 (ref. 1). thermal stability, high resistance to corrosive chemicals, etc. have placed great challenges to the 2 Market Developments R&D people at the major fibre producers. In many The global growth of synthetic fibres continues countries, the debate regarding environmental unbroken. Betw'een 1984 and 1994, the world loading of oil-based polymers has also influenced synthetic fibre production increased over 7 million the developm~nt of materials and products. In tons. A further increase of some 10 million tons is Europe, some important outlets for fibres, notably SHISHOO: TECHNICAL TEXTILES 215

the traditional textile and apparel sectors, are in 2.1 Nonwovens-A Major Market long-term declining while other markets like tech­ The most important application field for techni­ nical textiles are continuing to expand. Mill con­ cal fibres with a share of two thirds is nonwovens sumption of man-made fibres in 1994 was nearly 3 (Table 2), with dry-laid nonwovens, based on sta­ million tons. The man-made fibre consumption in ple fibres, dominating the expansive spunbonds. technical textiles in Western Europe in 1995 is Yam manufacture accounts for only one third of shown in Table 2. Within the man-made fibre con­ the market for further processing to fabrics and sumption of technical textiles, fibres with knits. a share of 34% are still in the lead, but during the After technical nonwovens (59%), the most im­ past years fibres have caught up portant markets for technical textiles are above all considerably (80% increase within 5 years); so, by tyres, other wovens, mechanical rubber goods the year 2000 both the fibres are expected to reach (MRG) and many other small end-use products equal quantities. (Table 2). Main markets for technical nonwovens are coverstocks, building end-use products and Table 2-Market trends of man-made fibres for technical 2 textiles in Western Europe during 1995 medical textiles (Table 2). On evaluating the fibre consumption for nonwovens, it is obtained that the Fibre Consumption in Tecbnical Textiles (Total 1.1 m tons) largest share is held by polypropylene (44%) fol­ Tons x 1000 % Share lowed by polyester (28%), viscose (15%) and Polyester 350 34 polyamide (11 %). The fibre usage in spinning de­ Polypropylene 330 31 clined by 11 % from 1987 to 1994. In a sense, Polyamide 130 II nonwovens are very suitable for use in many tech­ Acrylics 30 2 nical textiles applications, ego geotextiles, filter Cellulosics 230 22 media, protective clothing, products; the Fibre Processed in Technical Textiles (Total 1.1 m tons) market is dominated by nonwovens. All nonwoven processes will have a main share of the develop­ TonsxlOOO % Share Nonwoven ment in the field of technical textiles. (staple fibres) 480 44 Spunbonds ' 250 23 3 Technical Textiles Filament 300 27 Spun yarns 70 6 3.1 Higb Performance Textiles Fibre Consumption in Tecbnical Products The development of carbon fibres and aramid fibres in 1960s triggered many developments in % Share high performance fibres and yams. Today, we have Technical nonwovens 59 Tyres 8 access to a wide variety of fibres and yams show­ Other wovens 13 ing the appropriate characteristics required for Mechillnital Rubber Goods 5 producing high-tech textiles. These include high Knits 3 moduluslhigh tenacity, heat resistance and stability Waddings 3 Ropes 3 to chemicals even at elevated temperatures. Others 6 The effects of different engineering and tech­ nological parameters on mechanical properties of Fibre Consumption in Technical Nonwovens high-modulus and high-strength polymer fibres % Share and yams are very important when designing tech­ Coverstocks 30 nical textiles and composites. This explains the Eng./construction 24 application of mathematical models that predict W~ 9 Medical 8 the mechanical properties of yams by using the Filtration 5 data on m€?chanical properties of monofilaments, Substrates 5 yam characteristics, and manufacturing process Other technoend uses 19 parameters. Such models would make it possible to _S_o_u_rc_e_: C_IRF~S..:.., _B_ru_s_se_ls______design yams with specified mechanical properties 216 INDIAN J. FIBRE TExt. RES ., DECEMBER 1997 without conducting laborious and expensive ex­ and with high thermal insulation at low thickne~ perimental studies. A number of studies have been values. These fabrics are used in workwea conducted in this direction in recent years3.4. Fur­ , protective clothing, rainwear, moistur ther efforts in developing mathematical models permeable, sweat-absorbing and with high therm, that make it possible to predict the mechanical protection and comfort. One can say that thes characteristics: especially the elastic modulus of products are basically compound materials wit twisted yams, are worthwhile. compound functions. In many of these products th The range and volume of coated and laminated requirements of comfort and fashion have succes ~ fabrics for applications such as protective clothing, fully been integrated with segmentation in use: leisure wear, workwear, building material and in­ The seemingly contradictionary requirement ( dustrial textiles are steadily growing because of the creating a liquid barrier and breathability in hig technical options for imparting a range of func­ functional fabrics has placed challenging demand tionality in the products combined with the desired on new technologies. Among the contributing fae mechanical properties and durability. tors responsible for successful marketing of suc products there have been advances in chemic, 3.2 High Functional Textiles technology and production techniques (Table 3 There has been a strong growth in development for obtaining sophisticated structures of fibre ~ and use of high functional materials used in pro­ 5 yams and fabrics . tective , surgical gowns, hospital and hy­ gienic products and sportswear. The performance 3.3 Geotextiles requirements of many apparels today demand the The determining factors for the acceptance 0 balance of widely different properties of drape, geotextiles as a normal part of civil engineering 0 thermal insulation, barrier to liquids, chemicals geotechnical construction are the availability 0 and micro-organisms, thermal resistance, fire re­ relatively low-cost synthetics and the fibres fron tardan~y , antistatic, stretch, physiological comfort, renewable resources such as and flax. Poly etc. The research in this field over the past decade propylene and polyester based materials constitutl has led to the commercial development of a variety the largest proportion of geosynthetics. The rav of new products for high functional end uses. New materials used in geotextiles are mainly synthetil technologies for producing microfibres have also polymers, viz. polyester, polyamide, polypropyl contributed towards production of high-tech arti­ ene and polyethylene. Biodegradable material, e.g cles. By designing. new processes for fabric prepa­ ration and and due to the advances in Table 3-Examples of methods for obtaining sophisticated technologies for production and application of fibrous structures suitable polymeric membranes and surface fin­ ishes, it is now possible to successfully combine Method Fibrous structure the consumer requirements of aesthetics, design Modification of exist- Hydrophilic polyester and acrylics and function in protective clothing for different ing polymers Antistatic and polyester end-use applications. Modification in the High shrinkable fibres Subsequent to the development of value-added fibre-forming stage Hollow fibres Ultrafine fibres textile products in 1970s that involved mostly di- versification of materials and improvements in Modification of fibre Combines filament yam (nylon, fi ' h' h h b h . and yam assemblies polyester) sur f:ace mlS les, t ere as een a strong growt m Tightly woven fabrics, double-knits developn-ent and use of so called high functional textiles and aJ: .arels. Since the introduction of Modification by Water and oil-repellence surface finish Antistatic Gore-rex fabr 'c i, 1976, a very large variety of Perspiration absorption light-weight breat:able high functional fabric has Laml'natt'on technt'que Bonding of fabrics to polymer film been develnT)ed, e' l xially in Japan. High func- tional fabrics are generally characterized as being Coating technique Coating of fabrics with micro- waterproof/moisture permeable, sweat-absorbing ______---!p:....:o_ro.:...u.:...s....;o_r_h:....yd_r_o'-ph_i_lic--'-po_I"-ym_e_r_la-,y_el SHISHOO: TECHNICAL TEXTILES 217 jute, is also being used for some applications. The region, Latin America and Eastern Europe. A materials include woven, nonwoven and growth ofapprox. 150% till the year 2000 has been knitted geotextiles, polymer nets and grids, mats estimated by some experts. and composites. Structure/properties relationships Air bags are usually made of coated or uncoated in geotextiles include studies of intrinsic proper­ fabrics of PA6.6 yarns' with minimum air perme­ ties, such as physical and mechanical properties, ability. The trend towards uncoated fabrics is ex­ that are called properties of a geotextile in isola­ pected to continue and so is the increased trend tion, and geotextile properties that influence soil­

geotextile interaction and durability. Table 4-A list of needled and speciality products used in Designing of geotextiles is done by following various fields either the specifications or functions. In use, Fields Products geotextiles are required to perform one or more Aerospace Fire blockmg fabrics, shuttle ti les and functions and the major basic functions are drain­ carbon fibre brake pads age/filtration, separation, stabilization and rein­ Agricultural Ground cover, reservoirs, seed beds forcement. The geotextiles market is dominated by and erosion control the nonwoven products with a 70% share. At pres­ Advanced reinforced plastic in aerospace, composites pipes and transport ent, number of technical options exist for produc­ Industrial Abrasives, roller linings, belting and ing nonwoven geotextiles from web forming substrates through bonding and finishing. Insulators, thennal High-temperature glass and ceramic barriers and fire insulation mats, seat fire-blocking on protection aircraft and firewall insulation 3.4 Technical Needled Fabrics Marine Carpets, wall coverings, headliners and The range of speciality products and the markets surface veils for manufacturing rein­ for technical needled fabric are extensive (Table forced plastic hulls 4). Needled fabrics in automotive application are Medical Bandages and pads, blood filters, cast bandages, artificial blood vessels and used not only as interior coverings with aesthetic medical, hygiene and cosmetic pads values but also as fuel and air filters, pac kings, Miscellaneous Carpet underlay, car wash fabric, oil­ dampers, etc. with performance value. The needled sorbent fabrics, tree root wrap, cleaning structure is an ideal media for air filtration and as fabrics and wipes, ink and liquid reser­ particulate emission control. Needled geotextiles voirs, weather stripping and piano felts Paper-making Paper machine clothing for press felts are the key geotextile products because of some fabrics ideal functional properties such as bulk, toughness Protective clothing Ballistic materials, chain saw chaps, and permeability. work gloves inserts and fire thennal barriers Sportfelts Tennis ball covers and floor coverings 3.5 Air Bags Synthetic leather, Heel and toe counters, coated fabric The opportunities and challenges for the textile shoefelts substrates and poromeric materials and making-up industries are great in the area of Wall coverings Noise abatement panels and decorative air bag production. This is because of its great" de­ panels mand, 'especially in view of the legalisation which Source: Techtextil Symposium, Frankfurt, June 1995 is already enforced in many countries and other ------"--!.---'----'------countries are also going to follow this action sooner or later. Approximately 1.42 m2 of fabric is WI 25 -+- Drive'rsideo ~ Passe'ngeorsideo go 20 -r Total required to make a driver-side air bag, and 2.5 - ..0 4.18 m2 fabric to make passenger-side air bags or -E ~ 15 .. 0 0:: driver-side bags on light trucks. These figures -= 10 't:IE point out that the air bag market is of great impor­ c ~ 5 ___~r- tance for the use of technical textiles. ., c OL-____L- ____~ ____~ ____~ ____~ __~ Figs 5 and 6 summarise development trends of 1991, 1995 1996 1997 1996 1999 2000 air bags in Western Europe and world-wide in­ Yeoar cluding USA, Western Europe, Japan, Asia-Pacific Fig. 5--Demand for air bags in Western Europe 218 INDIAN J. FIBRE TEXT. RES. , DECEMBER 1997

[a) ; V) 70 ~D"iY~r ___ PQSs.f'n9e'''-'- Total E g 60 0.- .; == 50 crE ~ ,; 40 o 0> - ~ 30 "0 ~~ 20=-_- ~; 10 o ~ OL_-.lL-_--l__ --1. __ --L::---_=:---==~ 1994 1995 !996 1997 1998 1999 2000

Yt'or

Fig. 6--Worldwide demand of equipment with air bags

towards more air bags per car and full-size bags. &.-O·~~:;tl~~le:/~ There is also technical challenge of manufacturing Fig. 7-Multiaxial DOS (Karl Mayer) [a--face, and b-side the bag using more rational techniques and ac­ view] cording to· the tough specifications formulated by the automotive industry.

'~ ______~l ~ 3.6 Multiaxial Differentially Oriented Structures (DOS) Multiaxial differentially oriented structures (DOS) made using either Karl Mayer's warp­ knitted based method with variations in axially orientation of construction yarns or LIBA's method of multiple weft- stations give very interesting possibilities of producing technical textiles for a Fig. 8--{a) Warp knit structure--inlaid weft yam lies abso­ number of end-use applications (Figs 7-9). Karl lutely straight, and (b) woven structure--weft yam bent due to Mayer's DOS incorporating thermoplastic yarns or intertwining with warp yams split-films as matrix material has been used to pro­ duce high performance composites. This material is also suitable as substrate for coated products, and this technology allows incorporating nonwov­ ens and other cellulose based materials for intro­ ducing bulk in these structures. Because the inlaid yarns in DOS are placed straight without any built­ in crimp, the resultant stress distribution is an in­ teresting factor in designing products for different Fig. 9-Multiaxial DOS (LlBA): 5 weft yam stations and warp yam applications where load-bearing aspect is impor­ tant.

3.7 Composites A composite portfolio on the basis of market volume and price IS shown in Fig. 10. In recent years, the uses of textile struc­ tures made from high performance fibres are find­ ing increasing applications in composites. High performance textile structures may be defined as materials that are highly engineered fibrous struc­ ture having high specific strength and specific modulus and designed to perform at high tem- Fig. I O---Composites portfolio SHISHOO: TECHNICAL TEXTILES 219 perature and pressure (loads) under corrosive and Table 5--Comparison between thermoplastic and thermoset­ extreme environmental conditions. ting polymers Significant developments have taken place in fibres, matrix polymers and composites manufac­ Thermoplast <" Properties > Thermoset turing techniques. The proc­ Unlimited Storage time Limited esses are less complex than injection moulding and Difficult Impregnation State of art laminating, and they have advantages in greater No Solvents needed Yes control of fibre placement and in ease of handling Mostly high Viscosity Low preforms. These textile structures may be planar 2- Minutes Processing time Hours Low Water absorption High D fabrics, e.g. woven, knitted or nonwoven materi­ Depends on polymer Creep Low als, and 3-D fabrics, e.g. woven, braided, non­ Good Impact behaviour Bad woven or knitted. Making use of the unique com­ Possible Weldability Not possible bination of light weight, flexibility, strength and Possible Recycling Not possible toughness, textile structures have long been recog­ Table &'-Properties of thermoplastic polyaromatic fibres nised as an attractive reinforcement form for many composite applications. The advantages of textile Fibre Temp.,oC Proces- Maximal LOI techniques are homogeneous distribution of matrix T.jTm sing strength temp.,oC and reinforcing fibres, high drapability, free of gpd Ksl solvents, and low financial expenditure. As a route to mass production of textile com­ PEK 144/334 240 7.5 125 28 posites, the production speed, material handling, PPS 89/285 190 5.7 90 34 CAE, material design flexibility and cost effi­ PEl 225/- 170 3.5 45 45 LCP -/322 180 27 450 35 ciency are some of the major factors determining PET 69/257 150 9.6 165 21 the suitability of a textile reinforcement production process such as , warp , braiding or ger and the fabricator. This of course becomes a nonwoven technology for a given end-use applica­ realistic approach given the fact that the matrix is tion. The use of thermoset matrices is wide spread composed of thermoplastic polymers as compared at present. The resin is applied to the textile pre­ to thermosetting polymers. A comparison of some form at the consolidation stage. or ep­ important properties between thermoplastic and oxy matrices are applied by resin transfer mould­ thermosetting polymers is shown in Table 5. ing (RTM) process. Faster cure is possible with The textile industry now has access to multi­ other resin formulation, mainly polyurethanes, filament with high tensile strength and modulus suitable for reaction injection moulding (RIM) and high resistance to chemical, heat and hydroly­ process. From the .manufacturing point of view, sis for use in high performance applications and in however, the rational composite production proc­ aggressive environment (Table 6). Some of these ess should be based on thermoplastic matrices materials can be used as matrix materials such as which can be incorporated in the textile structure the more conventional polyolefin based filaments. by the textile industry. The aromatic thermoplastic fibres of varying melt There has been a steady growth in the world­ viscosity can be selected either as meltable matrix wide advanced composites shipments in the last fibre or as reinforcing fibre of high tenacity (Fig. decade as seen in the sales of fibres and prepregs 11). Because of a marked glass transition tem­ consumed. The structure of the advanced compos­ perature in some of these polyaromatic fibres, it is ite industry today consists of fibre supplier, resin also possible to produce the necessary deforma­ supplier, fabric manufacturer, independent makers tions at prepreg stage of component manufacture. of prepregs, fabricated parts manufacturer and the The market volume of the high performance com­ end user. The possible new structure of composite posites is directly related to their price. Production industry based on textile technology could be the of prepregs made from reinforcing fibres and textile industry as the supplier of reinforcing and thermoplastic matrix fibres with textile technolo­ matrix fibres or split-films, on-the-Ioom prepreg- gies is shown in Fig. 12. 220 INDIAN 1. FIBRE TEXT. RES., DECEMBER 1997

low melt \'iscosity high that very few non-conventional and technical tex­ tile specific machinery have been put in the mar­ PEE K ket. The conventional spinning, weaving, knitting and nonwoven techniques have been used for pro­ m.urix fihn: ducing the majority of items. The coating technol­

hi~h or "«trOlal h:n .. cit~ ogy used is also that which is applicable to apparel and household textiles. This means that in terms of technology, the industry is very flexible in its abil­ Fig. II-Application of aromatic thermoplastic fibres ity to switch from conventional textiles to techni­ cal textiles. Technology advances in the industry are driven by the forces outside the pure textile sector i.e. polymer and fibre producers and, in some cases,

• lommlng,hnJ: the machinery producers of fabric fabrication tech­ niques. There is a growing need for non-textile ( 0 \\ rapping . ~ • ( "s pln",n~ application know-how in many segments of the '--__~----I technical textiles market. Textile technologists, for

thhrHt~iu" ~ -=-- =1= ====~-=--~ example, are needed who understand the civil en­ gineering aspects of potential geotextile applica­ Fi g. 12-Production of prepregs from reinforcing fibres and tions so that suitable textile structures can be pro­ thermo'plastic matrix fibres duced. Technologists have to understand the me­ chanical and production engineering aspects of The impregnation techniques for thermoplastic fibre composites in automotive and aeronautical composites include film stacking, melt-extrusion, applications to be able to design a suitable textile melt pultrusion, solvent impregnation, powder im­ or fibre-reinforced composite components. Textile pregnation and various textile forming techniques. The advantages of texti Ie techniques over the other engineers have also to start using CAD, CAM and techniques are homogeneity of matrix and rein­ CAE tools not only for designing the suitable tex­ forcing fibres, high drapability and solvent-free tile reinforcements but also to have a common lan­ process. The production of prepregs made from guagG necessary for fruitful co-operation with the reinforcing fibres and thermoplastic matrix fibres design engineers working at car companies. Textile with textile technologies will be in the form of hy­ technologists do not always understand the func­ brid yams or hybrid fabrics. This opens up a new tional requirements of particular application and field of technical application by new types of semi­ often for textile industry the newer customers do finished materials produced by the textile industry. not recognise the particular requirements of the Of course, quite a lot of scientific work still needs textile company with regards to specifications, tol­ to be carried out in order to understand the mecha­ erances, etc. nisms involving matrix-flow and fibre-matrix The equipment manufacturers are focusing on compatibility as regards bond strength. This technical textiles but mostly using the conventional knowledge is of great importance for the optimisa­ technology. There is realisation that the field offers tion of processing times for composites, a factor growth possibilities and that completely new tech­ which has proven to be the determining factor for nologies specifically for technical textiles are not market growth of composites. needed. R&D of machinery is addressing to the problems of productivity, quality and envirol1- 4 Technology and Material Trends mental loading. One can say that the technical tex­ The driving technological force in technical tiles industry is using the front line technologies textiles has thus far been materials development available but finding advanced solutions to achieve spear headed by advances in fibres, polymers and their goals. chemical technology. The mechanical processing The manufacturing, usage and disposal of tech­ has not played an important role so far in the serise nical textiles are now under close inspection be- SHISHOO: TECHNICAL TEXTILES 221 cause of ever increasing environmental legislation. The growing public interest in environmental is­ In their long-term commitment to the technical sues has led to development of different methods textiles industry, the manufacturers and suppliers for the assessment of the environmental impacts of fibres,. polymers and chemicals are consolidat­ from materials, products, processes and waste ing their efforts to look for ways and means in management techniques. Life cycle analysis of which they can reduce the environmental impact of materials and products, which helps the producers the production processes, products and consumer of technical textiles in appropriate product and products in end-use applications. The environ­ process design, is undoubtedly going to be used as mental issues related to the production, use and an important marketing strategy. waste management of technical products pose a The use of renewable cellulosic natural fibres as challenge to the technology that is possible today. reinforcing fillers in fibre composites or adding a Technological developments have to be continued fibre blend in technical textiles products is ap­ to reduce the pollution with various chemical and pealing because of the properties of the resultant physical processes in order to reduce the hazardous composites and the environment viewpoint. The substances in both air and water. advantages of bio-fibres as low cost and renewable At present, the factory waste amounts to be at biodegradable raw materials can be utilised in unnecessary high levels. This waste is simply too some technical textile products to a much greater good to throwaway and increasing attention is extent than it's being done today. being paid by technical textile producers to find new ways of recycling it. Work is being carried out on many chemical processes. An important References aspect of this work is to analyse the properties 01 I David Rigby Associates, Presentation at Techtextil lOI/ ­ Jerel/ce. Frankfurt, May 1997. the resulting secondary raw materials from the 2 Chemical Fibres Internatiol/al, 47 (February) (1997) 8. chemical recycling processes. Can they offer the 3 Davydov A R, Shishoo R & Prut E Y, Analysis of models same performance as primary raw materials or is describing the mechanical properties of yarns made of there a loss of quality or can their properties be high-strength high-modulus filaments, PolYIII Sci fA}. improved with the help of additives and compati­ 38(9) (1996) 1648-1053. 4 Hearlc J W S, Grosberg P & Backer S, Stn/ctl/ral 111 ('­ bilizers? Depending on the performance profile of chanics oj . yams al/d Jabrics (Wiley, New York). the recycled or reclaimed material, the appropriate 1969. area of application can be determined. 5 Shishoo R, Technology for comfort, Text Asia, 6 (1988).