Evolution of Textile Materials Unit 1 PDF

Evolution of Textile Materials Textiles are materials made from fibers, filaments, or thin threads that are spun into yarn and processed into fabric. Textiles can be made from natural or synthetic fibers, or a combination of both. Fig. Filament...

Evolution of Textile Materials Textiles are materials made from fibers, filaments, or thin threads that are spun into yarn and processed into fabric. Textiles can be made from natural or synthetic fibers, or a combination of both. Fig. Filament Fig. Fibres Fig. Yarn Yarn is a strand of material made from numerous natural or synthetic fibers and filaments. Fibers are short pieces of hair, while filaments are long strands of a substance. Yarn is created through a process called spinning, and it is used in clothing, decorations, and more. Textile Fiber   The smallest unit of a textile material.  It's a thin, thread-like strand of material that can be natural (like cotton, wool, silk) or synthetic (like nylon, polyester, acrylic).  Fibers are the building blocks of yarns and fabrics. Textile Filament  A type of textile fiber that is continuous and very long.  They are produced by extruding molten material through tiny holes (spinnerets).  Examples of filament fibers include silk, nylon, polyester, and rayon. Yarn  A continuous strand of textile fibers or filaments twisted together.  Yarns are used to create fabrics through weaving, knitting, or other textile processes.  Yarns can be made from various fibers, including both natural and synthetic fibers. Key Differences  Fiber is the individual strand.  Filament is a specific type of fiber that is continuous and long.  Yarn is a collection of fibers or filaments twisted together. Essential and Desirable properties of Textile Fibres 1. Length and length variation Length is an important parameter that determines the usefulness of a textile fibre. When a continuous yarn is to be made out of individual fibres, it should possess a considerable length with reference to its diameter, otherwise, it would not be possible to make a yam that would hold together the constituent fibres. This is referred to as the length to breadth ratio. The most useful fibres should have length to diameter/breadth ratios of more than 100: 1. Length is the most important fibre property as far as ring spinning is concerned. As the fibre length increases the overlapping of fibres in the yarn increases. The increase in overlapping results into increased resistance to slippage. If the yarn is spun from long and short fibres, then yarn spun from long fibres has more strength. Textile fibre length varies considerably within anyone sample. The variation is as high as 40% for cotton and about 50% for wool. Man-made staple fibres are more uniform. 2. Strength The strength may be tensile strength, bending strength, bursting strength, etc. as per the direction of application of force. Fibre strength and elongation have a direct relationship with yarn strength and elongation another thing being constant. A stronger fibre result in stronger yarn and the same is true about fibre elongation. The strength of any material is derived from the load it supports at the break and is thus a measure of its limiting load-bearing capacity. Normally strength of the textile fibre is measured in tension when the fibre is loaded along its long axis and is designated as “Tensile Strength”. The tensile strength of the textile fibre is measured as the maximum tensile stress in force per unit cross-sectional area or per unit linear density, at the time of rupture called “Tenacity”, expressed in terms of grams per denier or grams per tex units 3. Uniformity A fibre possessing this property can produce reasonably even yarns. This is also important in connection with the strength of the resulting yarn. Uniform textile fibres should possess uniformity in their thickness and length. Unfortunately, none of the principal natural fibres like cotton or wool has the same length and diameter of the fibre in the same lot. Fibres in any specified qualities, grades or lots vary considerably in length and diameter. On the other hand, manmade staple fibres are more uniform as they are cut to the exact length after being spun and drawn, and even the diameter can be controlled within close tolerance limits during its manufacture. 4. Spinnability Spinnability includes several physical properties each having an effect on the ability of the fibres to be spun into yarn. Staple fibres must have to be capable of taking a twist or being twisted (Flexibility). They must have a certain degree of friction (Cohesion) against one another to stay in place when the pull is applied to the yarn. They must also be able to take on whole special finishes for lubrication during spinning or to provide additional surface resistance to abrasion. 4.1 Flexibility The fibre should be sufficiently pliable; then only it can wrap around another fibre during spinning. If on the other hand, fibre is stiffer, then it is less adaptable for textile use, for example, glass and metallic fibres. 4.2 Cohesiveness Usually, rigid fibres have lower cohesiveness. It is generally assumed that a high degree of frictional resistance plays a part in the cohesiveness. It is the property of an individual fibre by virtue of which the fibres hold on to one another when the fibres are spun into yarn. This action is usually brought about by the high degree of frictional resistance offered by the surface of the fibres to separate one from the other. The wool fibres, for example, have a saw-toothed surface, so that the projecting edges on its surface, called scales, easily catch on to one another when several such fibres are twisted together during spinning. On account of this, fibres offer resistance when an attempt is made to pull them apart. Cotton fibres also possess irregular or rough surface. Further, due to the natural twist in the cotton fibre known as convolution, the fibres interlock themselves by friction when they are spun into yarns. The introduction of a crimp in synthetic fibre increases cohesion. 5. Fineness Diameter measurement of textile fibres and yarns is not possible because of compressible nature and non-uniformity in diameter throughout its length therefore in textile fineness is expressed in terms of linear density. If the fibre is finer there will be more number of fibres in the yarn cross section, which will make more surface area available for inter-fibre friction and thus will provide more resistance to slippage. Due to this fact the yarns having the samecount, yarn spun from coarse and fine fibres, the yarn spun from finer fibres will have higher strength. The fineness of cotton fibre is expressed in micrograms per inch i.e. micronaire. For wool fibre, fineness is given in microns and for manmade fibres, the fineness is given in denier or tex. Desirable Properties of Textile Fibre 1. Resilience The resistance to compression, flexing or torsion varies from fibre to fibre. Some fibres have a natural tendency to return to their original condition when any of the above-mentioned forces is applied, an important property where, for instance, recovery from creasing is required. Wool is outstanding in this respect by virtue of its natural characteristics, but cellulosic fibres may be modified in such a manner so as to greatly improve these properties. This springiness of a fibre or its mass resilience is highly desirable for carpet wool. Because of resiliency fibre/yarn/fabrics hold their shape, drape gracefully and do not wrinkle. 2. Capillarity and porosity Porosity can be defined as: Porosity facilitates the absorption of moisture, liquid lubricants, dyes, oils and steam by the fibres so as to thoroughly permeate the fibre. Porosity in fibre is important in wet processing. The natural and manmade fibres differ greatly in respect of porosity which in turn affects other properties of fibres and consequently the processing of fibres during textile manufacture. In general, natural fibres have higher porosity than synthetic fibres. 3. Lustre Natural lustre enhances the value of textile fibre, especially natural fibres. For example, the natural lustre of the silk gave it for a long time distinct advantage over the other textile fibres, and experiments were constantly made to improve the lustre of those fibres which were naturally dull. Since the introduction of viscose, however, with its extremely high and almost metallic lustre, consumer taste has gone a little in the opposite direction, and many fabrics produced today are purposely delustred in order to give the desired matt finish. Therefore, it is evident that lustre, under certain conditions and for certain purposes, may enhance the value of a fibre. On the other hand, too much of brightness may be a source of aversion to the user and hence it has to be delustred to a required degree of lustre by the delustring process. 4. Durability A textile fibre should withstand processing treatments and should not be easily susceptible tophysical, chemical and bacteriological attack, which may result in damage and decomposition. The durability of clothing to average wear and tear depends somewhat more on the elasticity, flexibility and resistance of the fibre and fabric, rather than the absolute strength of either fibre or fabric. If a fabric possesses these three properties, its garment will absorb or counter more readily stresses and strains during wear. It will allow itself to be deformed with less resistance, thus reducing the chance of intermediate tearing or twisting. For these reasons wool garments owe much of their durability to the elasticity, resilience and flexibility of the fibre and fabric, even though wool is a weak fibre. Strength combined with these properties provides excellent durability, which is why nylon and polyester fibre fabrics seem to last forever. A raised fabric surface increases fabric resilience and provides longer resistance to abrasive surfaces, e.g. carpets, ribbed fabrics, etc.  5. Elasticity Elasticity is property by which the fibre tends to recover its original length upon the removal of stress, causing deformation. 6. Moisture Absorption Moisture absorption means the absorption of water vapor from the atmosphere by a textile fibre when it is kept in open place. The moisture absorption capacity is expressed in terms of moisture content, which means the amount of moisture content in the textile fibre and its original weight of fibers or its oven dry weight. Classification of Textile Fibres: Textile fibres classification means to the categorization of fibres based on their origin, chemical composition, and physical properties. The classification of textile fibres can be done in a number of ways. Textile fibres can be classified into two main categories: natural fibres and synthetic fibres. Natural fibres: Natural fibres are fibres that are obtained from plants, animals, and minerals. Examples of natural fibres include cotton, wool, silk, flax, hemp, jute, and ramie. These fibres are used to make a wide range of products, including textiles, paper, and building materials. They are also used in the production of bioplastics and biocomposites. Natural fibres are renewable, biodegradable and are considered as an eco-friendly alternative to synthetic fibres. Natural fibres can be classified into several categories based on their origin and properties. Some common classifications of natural fibers include: 1. Plant fibres: These fibres are obtained from plants, such as cotton, linen, hemp, and jute. 2. Animal fibres: These fibres are obtained from animals, such as wool, silk, cashmere, and alpaca. 3. Cellulosic fibres: These fibres are derived from plant cell walls, such as cotton, linen, and hemp. 4. Protein fibres: These fibres are derived from animal hair or secretions, such as wool, silk, and cashmere. 5. Bast fibres: These fibres are obtained from the stem of certain plants, such as flax, hemp, and jute. 6. Leaf fibres: These fibres are obtained from leaves of certain plants, such as sisal and abaca. 7. Seed fibres: These fibres are obtained from seeds, such as cotton and kapok. Some fibres may fit into more than one classification. For example, cotton is a plant fibre and a cellulosic fibre. Man-made fibres: Man-made fibers, also known as synthetic fibres are fibres that are artificially created from chemical compounds. These fibres are not naturally occurring and are typically manufactured from petroleum-based products. Examples of synthetic fibres include polyester, nylon, acrylic, and spandex. These fibres are often used to make a wide range of products, including clothing, upholstery, and industrial materials. Synthetic fibres are known for their durability, strength, and resistance to shrinking and wrinkling, which makes them popular for use in clothing and other textiles. They are also less expensive to produce than natural fibres, which makes them more cost- effective for many applications. However, they are not biodegradable and also require a significant amount of energy to produce which makes them environmentally unfriendly. Synthetic fibres can be classified based on their chemical composition and manufacturing process. Some common classifications include: 1. Polymer fibres: These fibres are created by polymerization of synthetic monomers, such as polyester, nylon, and acrylic. 2. Glass fibres: These fibres are made from glass and are known for their high strength and low thermal expansion. 3. Carbon fibres: These fibres are made from carbon and are known for their high strength, low weight and thermal stability. 4. Metal fibres: These fibres are made from metal, such as stainless steel and are known for their high strength and thermal stability. 5. Aromatic polyamide fibres: These fibres are made from aromatic polyamides and are known for their high strength, thermal stability, and chemical resistance.  6. Viscose rayon fibres: These fibres are made from cellulose and are known for their softness, drapability and ability to absorb moisture. 7. Acetate fibres: These fibres are made from cellulose acetate and are known for their softness, drapability and luster. 8. Modal fibres: These fibres are made from beech tree pulp and are known for their softness, drapability and moisture-wicking properties. Introduction to Spinning, Weaving, Knitting and Nonwovens: A. Spinning is a twisting technique to form yarn from fibers. It involves drawing and twisting fibers to form a continuous thread. This yarn is then used for weaving or knitting to create fabrics. The fiber intended is drawn out, twisted, and wound onto a bobbin. Spinning consists of the following steps: Fiber Preparation (Opening and Cleaning): Raw fibers, such as cotton, wool, or synthetic fibers, are opened up to separate individual fibers and remove impurities like dust, leaves, and short fibers. This is done using machines like openers and cleaners. Carding: The fibers are further cleaned and aligned in a parallel manner using carding machines. This process removes short fibers and neps (small clumps of fibers). Combing (Optional): For finer yarns, the fibers are combed to remove short fibers and improve the parallel alignment. This is a more intensive process than carding. Drawing: The fibers are drawn or stretched to reduce their thickness and increase their length. This is done by passing the fibers through a series of rollers that rotate at increasing speeds. Roving: The drawn fibers are twisted slightly to form a loose strand called a roving. This helps hold the fibers together during the spinning process. Spinning: The roving is fed into a spinning machine, where it is further drawn and twisted to form a yarn. B. Weaving is a textile art that involves interlacing two sets of threads, called the warp and weft, to create fabric or cloth: Warp: The vertical threads that run lengthwise on the cloth. Weft: The horizontal threads that run across the cloth. Loom: A machine that holds the warp threads in place while the weft threads are woven through them. C. Non-woven fabric is a fabric-like material made from staple fibre (short) and long fibres (continuous long), bonded together by chemical, mechanical, heat or solvent treatment.  Spinning, Weaving, Knitted Nonwoven D. Knitting: Knitting is a versatile textile manufacturing technique that involves interlooping yarns to form fabric. It's primarily divided into two main categories: warp knitting and weft knitting. Weft Knitting In weft knitting, a single yarn is looped through a series of needles, creating a fabric row by row. This horizontal looping process results in a fabric with a distinct knit or purl structure. Weft-knitted fabrics are known for their elasticity and drape. Key Characteristics of Weft Knitting:  Single yarn: Uses a single yarn to create the fabric.  Horizontal looping: Yarn is looped horizontally, row by row.  Elasticity: Highly elastic due to the interlocking loops.  Drape: Good drape and softness.  Common examples: Sweaters, scarves, socks. Warp Knitting In warp knitting, multiple yarns are held vertically on a warp beam and looped individually by needles. Each needle controls a single yarn, allowing for complex patterns and structures. Warp- knitted fabrics are often characterized by their stability and durability. Key Characteristics of Warp Knitting:  Multiple yarns: Uses multiple yarns, each controlled by a separate needle.  Vertical looping: Yarn is looped vertically, creating a more structured fabric.  Stability: More stable and less stretchy than weft-knitted fabrics.  Durability: Often more durable due to the tighter weave. Introduction to Textile Industry in India The Textile Sector in India ranks next to Agriculture. Textile is one of India’s oldest industries and has a formidable presence in the national economy in as much as it contributes to about 14 per cent of manufacturing value- addition, accounts for around one-third of our gross export earnings and provides gainful employment to millions of people. The textile industry occupies a unique place in our country. One of the earliest to come into existence in India, it accounts for 14% of the total Industrial production, contributes to nearly 30% of the total exports and is the second largest employment generator. The Indian textile industry is one of the largest in the world with a massive raw material and textiles manufacturing base. Our economy is largely dependent on the textile manufacturing and trade in addition to other major industries. About 27% of the foreign exchange earnings are on account of export of textiles and clothing alone. The textiles and clothing sector contributes about 14% to the industrial production and 3% to the gross domestic product of the country. Around 8% of the total excise revenue collection is contributed by the textile industry. So much so, the textile industry accounts for as large as 21% of the total employment generated in the economy. Around 35 million people are directly employed in the textile manufacturing activities. Indirect employment including the manpower engaged in agricultural based raw-material production like cotton and related trade and handling could be stated to be around another 60 million. A textile is the largest single industry in India (and amongst the biggest in the world), accounting for about 20% of the total industrial production. It provides direct employment to around 20 million people. Textile and clothing exports account for one- third of the total value of exports from the country. There are 1,227 textile mills with a spinning capacity of about 29 million spindles. Yarn is mostly produced in the mills, whereas fabrics are produced in the powerloom and handloom sectors as well. The Indian textile industry continues to be predominantly based on cotton, with about 65% of raw materials consumed being cotton. The yearly output of cotton cloth was about 12.8 billion m (about 42 billion ft). The manufacture of jute products (1.1 million metric tons) ranks next in importance to cotton weaving.  Sectors of Indian Textile Industry Unlike other major textile-producing countries, India’s textile industry is comprised mostly of small-scale, nonintegrated spinning, weaving, finishing, and apparel-making enterprises. This unique industry structure is primarily a legacy of government policies that have promoted labor-intensive, small-scale operations and discriminated against larger scale firms Composite Mills: Relatively large-scale mills that integrate spinning, weaving and, sometimes, fabric finishing are common in other major textile-producing countries. In India, however, these types of mills now account for about only 3 percent of output in the textile sector. About 276 composite mills are now operating in India, most owned by the public sector and many deemed financially “sick.”. Spinning: Spinning is the process of converting cotton or manmade fiber into yarn to be used for weaving and knitting. Largely due to deregulation beginning in the mid-1980s, spinning is the most consolidated and technically efficient sector in India’s textile industry. Average plant size remains small, however its technological sector is growing. In 2002/03, India’s spinning sector consisted of about 1,146 small-scale independent firms and 1,599 larger scale independent units. Bale Lap Weaving and Knitting: Weaving and knitting converts cotton, manmade, or blended yarns into woven or knitted fabrics. India’s weaving and knitting sector remains highly fragmented, small- scale, and labor-intensive. This sector consists of about 3.9 million handlooms, 380,000 “powerloom” enterprises that operate about 1.7 million looms, and just 137,000 looms in the various composite mills. “Powerlooms” are small firms, with an average loom capacity of four to five owned by independent entrepreneurs or weavers. Fabric Finishing: Fabric finishing (also referred to as processing), which includes dyeing, printing, and other cloth preparation prior to the manufacture of clothing, is also dominated by a large number of independent, small scale enterprises. Overall, about 2,300 processors are operating in India, including about 2,100 independent units and 200 units that are integrated with spinning, weaving or knitted units. Clothing: Apparel is produced by about 77,000 small-scale units classified as domestic manufacturers, manufacturer exporters, and fabricators (subcontractors). Growth of Textile Industry India has already completed more than 50 years of its independence. The analysis of the growth pattern of different segment of the industry during the last five decades of post independence era reveals that the growth of the industry during the first two decades after the independence had been gradual, though lower and growth had been considerably slower during the third decade. The growth thereafter picked up significantly during the fourth decade in each and every segment of the industry. The peak level of its growth has however been reached during the fifth decade i.e., the last ten years and more particularly in the 90s. The Textile Policy of 1985 and Economic Policy of 1991 focussing in the direction of liberalisation of economy and trade had in fact accelerated the growth in 1990s. The spinning spearheaded the growth during this period and man-made fibre industry in the organized sector. Government Schemes in Textile Sector: Scheme for Capacity Building in Textile Sector (SAMARTH) - To address the skilled manpower requirement across textile sector, the scheme was formulated, under the broad policy guidelines of “Skill India” initiative and in alignment with the framework adopted for skilling programme by Ministry of Skill Development and Entrepreneurship. The scheme is approved for implementation till March, 2024. Amended Technology Up-gradation Fund Scheme (ATUFS): In order to promote ease of doing business in the country to achieve the vision of generating employment and promoting exports through “Make in India’’ with "Zero effect and Zero defect" in manufacturing, ATUFS was launched in January 2016 to provide credit linked Capital Investment Subsidy (CIS) to units for purchase of benchmarked machinery in different segment of Textile Sectors (excluding spinning). This scheme is effective up to March, 2022.  National Technical Textile Mission: Creation of National Technical Textiles Mission for a period of 4 years (2020-21 to 2023-24) was approved with an outlay of Rs.1480 crore for developing usage of technical textiles in various flagship missions, programmes of the country including strategic sectors. Production Linked Incentive (PLI) Scheme - The PLI Scheme for Textiles to promote production of MMF apparel, MMF Fabrics and Products of Technical Textiles in the country to create 60-70 global players, attract fresh investment of Rs. 19,000 crore approximately and generate almost 7.5 lakh new employment opportunities. PM-MITRA: To attract investment for ‘Make In India’ initiative and to boost employment generation through setting up of 7 (Seven) PM Mega Integrated Textile Region and Apparel (PM MITRA) Parks in Greenfield/Brownfield sites with world class infrastructure including plug and play facility with an outlay of Rs.4445 crore for a period of seven years upto 2027-28. Scheme for Integrated Textile Parks (SITP): The scheme provides support for creation of world-class infrastructure facilities for setting up of textile units. Integrated Processing Development Scheme (IPDS): In order to facilitate the textile industry to meet the required environmental standards and to support new Common Effluent Treatment Plants (CETP)/ upgradation of CEPTs in existing processing clusters as well as new processing parks specially in the Coastal Zones. Various sectoral schemes to support traditional textile sectors such as handlooms, handicraft, silk and jute. Government Initiatives: With a view to raise India's share in the global textiles trade to 10 per cent by 2015 (from the current 3 per cent), the Ministry of Textiles proposes 50 new textile parks. Out of the 50, 30 have been already sanctioned by the government (with a cost of US$ 710 million). Set up under the Scheme for Integrated Textile Parks (SITP), this initiative will not only make the industry cost competitive, but will also enhance manufacturing capacity in the sector. Apart from the above, a series of progressive measures have been planned to strengthen the textile sector in India: Technology Mission on Cotton (TMC) Technology Upgradation fund Scheme (TUFS) Setting up of Apparel Training and Design Centres (ATDCs) 100 per cent Foreign Direct Investment (FDI) in the textile sector under automatic route. Setting up two design centres in Gujarat in collaboration with National Institute of Fashion Technology. Setting up a Handloom Plaza in Ahmedabad with an estimated investment of US$ 24.6 million. Revival plans of the mills run by National Textiles Corporation (NTC). Already, for the revival of 18 textile mills, US$ 2.21 million worth of machineries has been ordered for  the upgradation and modernisation of these mills. Setting up a handloom mall with an investment of US$ 24.6 million at Jehangir Mill in Ahmedabad. Technical Textiles Sector: Technical textiles are textile products and materials that are used for their technical properties and performance. Technical textiles include a wide range of products such as agricultural textiles, automotive textiles, geotextiles, industrial textiles and medical textiles. India is one of the leading producers and exporters of technical textile products in the world. The Indian technical textile industry is expected to grow at a CAGR of around 15% during the period from 2017 to 2022. The Indian technical textile industry is broadly classified into five segments, namely, agrotech, buildtech, indutech, packtech and protech. Agrotech includes all agricultural applications of technical textiles such as crop covers, greenhouse fabrics, nets & mulches;Buildtech includes construction-related applications such as geotextiles, insulation materials and carpet backing; Indutech comprises industrial applications such as belts & hoses, conveyor belts, laminates & composites and tires;Packtech includes packaging-related applications such as bags & sacks, tarpaulins & covers and ropes & cords; Protech encompasses personal protection applications such as airbags & seat belts, gloves & garments and surgical fabrics. The different segments of Technical Textiles are listed Below: