Textiles are important consumer products next to food and medicine. Given the high volatility of raw materials, particularly cotton, the textile sector is in a tailspin. Both manufacturers and consumers are feeling price pressures. In this circumstance, with adversity comes new opportunities, which is akin to the textiles sector.
The recent COVID-19 scenario has highlighted the need to develop value-added textiles from commodity materials using incremental and disruptive developments. From commercial and societal points of view, value-added textiles provide added margin, which is a timely incentive for the conventional textile industry to diversify into advanced textiles. These textiles normally focus beyond commodity interests such as improving lifestyles, enhancing lives and protecting the environment.
Ways of developing advanced textiles
A simple understanding of the need and applications of advanced textiles will enable this industry to develop many commercially viable products. There are three broader categories of advanced/technical textiles. They are consumer products, institutional products and government procurement items. The above classification helps clarify the functional requirements of different market segments, costs and margins for different products.
As is the case, consumer technology products, even though functional in nature, have less margin and more volume. Institutional procurements are bulk purchases by organizations like hospital systems, infrastructure companies and builders. Government procurement is for advanced products with high margins, technical intellectual properties and less volume.
The textile industry is facing increasing pressure to diversify and keep on innovating. The conventional sector can use its manufacturing capabilities to develop soft composites, use circularity approaches, and employ functional finishes to enhance textiles for industrial and technical textiles applications.
Conventional fabric structures like wovens, knits and nonwoven webs can be used in different combinations to harness characteristics of individual fabric structures, such as the high strength and rigidity of wovens, the elasticity of knits, porosity, and the softness of nonwoven webs.
Stiff woven and heavyweight fabrics can serve as reinforcement with applications in medical textiles, automotive textiles and infrastructure. These materials can serve as inserts with knit fabrics as outer layers giving stretchability. Tricot knits serve as an outer layer in high-end automobiles. Heavyweight fabrics serve as a base layer for high-end abrasives. Antiballistic chest shields involve woven fabric layers with nonwoven binding layers, enhancing shear resistance. There have been many incremental developments with few disruptive innovations. Incremental developments provide opportunities for existing manufacturers to penetrate the advanced textiles market with fewer capital investments.
Tightly woven heavyweight cotton fabrics find applications as base materials for developing abrasives. Kanakalakshmi Mills, based in Coimbatore, India, develops coarser fabrics for industrial uses such as abrasives, canvas belts, tarpaulin, tire cord and more using Sulzer Projectile Looms. These fabrics are made using yarns from 6 Ne to 20 Ne. (Note: The Ne count refers to the number of times the length of 1 pound of yarn can be divided by 840. So, a 6 Ne yarn would produce 5,040 yards in 1 pound of yarn.) This company demonstrates how to translate cotton fabric into a high-tech product by way of active collaboration with Carborundum Universal Ltd.
Functional finishes for conventional textiles
Textile wet processing is a major water and energy consumer. The conventional textiles sector must make strides in finishing to move toward the advanced textiles sector. One of the United Nations’ Sustainable Development Goals includes limiting global temperature rise to 1.5 degrees Celsius during this century, which puts greater demands on the conventional and advanced textiles industry to increase the use of biodegradable raw materials, use natural product chemistries, and reduce the use of water and chemicals.
Herb-based natural products are gaining attraction, particularly in developing next-to-skin medical products such as wipes.
The RVS College of Engineering and Technology in Dindigul, India, is adopting innovative approaches like blends of cotton and bamboo fibers to manufacture sanitary napkins. Researchers at RVS use a bamboo-cotton absorbent core as an alternative to superabsorbent textiles, which are synthetic-based. While these pads may be more expensive than the commercially available ones, researchers claim their absorption capacity is higher, resulting in the need for fewer pads, making them cost-effective and environmentally friendly.
Conventional and advanced textiles can adopt sustainable processing technologies like atmospheric plasma and supercritical carbon dioxide to impart functionalities. Plasma developments are enabling the commercialization of the process.
“A low-pressure plasma, produced under a vacuum, is homogenous and can process materials only batch-wise,” says Dr. Priyadarshini Rajasekaran, assistant professor in the Department of Fashion Technology at Kumaraguru College of Technology, Coimbatore, India. “This is seen as a limitation for processing textile materials that employ continuous treatments from roll to roll. In this scenario, an atmospheric pressure plasma produced in ambient air would be ideal and economical. But atmospheric-pressure plasma in ambient air is ‘inhomogeneous’ or even filamentary when a dielectric barrier discharge (DBD) arrangement is used.” Priyadarshini Rajasekaran says her research has proven that during a filamentary discharge in the air, the distribution of chemically active species over the surface of the substrate subjected to plasma treatment is uniform.
Metal oxides and ionized metals can also be added to convert commodity textiles to technical textiles. Nanoparticles are also finding applications due to added advantages. “Conventional finishes have high add-on weights and require manufacturing on a large scale, leading to a high carbon footprint and natural resources,” says Ganesh Srinivasan, CEO of Resil Chemicals, in Bengaluru, Karnataka, India. “Nanomaterials, on the other hand, add potential functionalities like antibacterial, self-cleaning, UV protection and more, at parts-per-million level dosages. It may take some time for regulations to evolve based on data on toxicology and environmental impact assessment before nanomaterials begin to lead the functional finishes in textiles,” Srinivasan says.
Graphene-added textile composites provide an opportunity to enhance strength and impart antibacterial properties. India-based Carborundum Universal, maker and developer of abrasives, ceramics, refractories, aluminum oxide grains and much more, is involved in the commercialization of graphene and its products for the materials sector.
Commodity textiles can be functionalized using greener processing technologies, adding nanoparticles and novel materials to convert them into advanced textiles.
The need to develop functional products to improve the standard of living has been growing in the past few decades. It is only recently, however, that attention has been paid to developing these products in a more sustainable way. It is no secret that such products may be expensive to start with, but in the long run, as their consumption increases, costs will likely decrease. The immediate need for stakeholders is to create awareness of the advantages of sustainable advanced textiles. Lightweight combat aircraft, water and air purifiers all involve different forms of textiles, which are advanced textiles indeed.
Seshadri Ramkumar is a professor at Texas Tech University.