Coated yarns and their applications in technical textiles: A Review
K H Prabhu informs, the selection of coating chemistries, combined with appropriate application techniques, allows tailored solutions across diverse sectors.
Today, the evolution of technical textiles has been driven by the growing demand for materials that can reliably perform under extreme mechanical, thermal, chemical and environmental conditions. Such conditions are commonly encountered in sectors including aerospace, automotive, construction, defence, medical devices and industrial filtration. The global coated technical textile market reached $16.4 billion 2022 and is expected to reach $28.0 billion by 2031, growing with CAGR of 6.9 per cent during the forecast period of 2024-2031. Unlike conventional textiles, which are primarily developed for aesthetic appeal, comfort or fashion-driven applications, technical textiles are specifically designed & developed to deliver specific functional properties such as high strength-to-weight ratios, thermal stability, chemical resistance, electrical conductivity or protective capability. As these functional requirements become increasingly complex and it is application-specific, traditional development approaches namely selecting high-performance fibres or modifying fabric structure are not up to the mark when processed separately.
In this regard, functionalisation at the yarn level is gaining considerable importance as an effective strategy to enhance textile performance due to its uniform distribution of functional agents throughout the entire textile structure, ensuring consistent performance regardless of fabric construction. Moreover, this process offers greater flexibility in fabric design as functionalised yarns can be integrated into a wide range of weaving, knitting or braiding processes without significantly altering existing manufacturing workflows. Yarn coating has emerged as one of the most versatile, cost-effective and scalable methods. Coating enables the deposition of a continuous functional chemicals or agents onto the yarn surface, which can be engineered to serve multiple purposes. For example, thermoplastic polymer coated yarns are widely used to improve abrasion resistance and processability during high-speed weaving or knitting operations. In composite and rubber reinforcement applications, such as tire cords or conveyor belts, coated yarns enhance interfacial adhesion between the fibre reinforcement and the surrounding matrix, leading to improved load transfer, durability and fatigue resistance.
Further, yarn coatings process shall be employed to introduce advanced functionalities such as conductive coatings incorporating materials such as carbon nanotubes, graphene or metallic particles enable the production of smart textiles capable of sensing, heating or electromagnetic shielding. Protective coatings can impart resistance to UV radiation, moisture, flame or chemical exposure, making the textiles suitable for protective clothing or outdoor applications. Similarly, colouration coatings can enable colouration on difficult to dye high performance fibres such as para aramid, glass etc., thereby expanding their aesthetic and identification possibilities without compromising performance since these fibre typically exhibit low surface energy, limited chemical reactivity and poor dyeability.
Overall, yarn coating technologies play a crucial role in translating the exceptional intrinsic properties of high-performance fibres into practical, application-specific textile solutions. This review summarises the functional coating classification & its materials, coating technologies and application of coated yarns in technical textile segments.
Classification of functional coated yarns Functional coated yarns can be classified based on the primary function of the coating, although many modern systems are multifunctional in nature and it is given below in Table 1
Table 1: Functionalities of yarn coatings in technical textiles
| Functional Category | Description | Common coating materials | Typical applications |
| Mechanical and Processing Functionalities | Coatings improve yarn processability by reducing abrasion, filament breakage, fuzz formation, and static during weaving or knitting. Protective sizing layers enhance tensile integrity and production efficiency, especially for high-cost technical yarns. | Starch derivatives, PVA, acrylic emulsions, polyurethane dispersions | High-speed weaving and knitting, industrial and reinforcement textiles |
| Adhesion-Enhancing Functionalities | These coatings improve bonding between yarns and rubber or polymer matrices by modifying surface chemistry and roughness, leading to enhanced load transfer and durability. | RFL systems, epoxy coatings, silane coupling agents | Tire cords, conveyor belts, hoses, fibre-reinforced composites |
| Protective and Barrier Functionalities | Protective coatings provide resistance to heat, flame, chemicals, UV radiation, and moisture, improving durability and safety without significantly increasing fabric weight. | Flame-retardant additives, fluoropolymers, silicone-based coatings | Protective clothing, industrial textiles, aerospace and outdoor fabrics |
| Electrical and Smart Functionalities | Conductive coatings enable electrical conductivity for antistatic behaviour, EMI shielding, sensing, heating, and signal transmission in smart textiles. | Carbon black, graphene, CNTs, metal particles, conductive polymers | Wearable electronics, sensors, heating textiles, EMI shielding |
| Aesthetic and Identification Functionalities | Pigment-based coatings provide surface colouration for fibres that are difficult to dye, enabling colour coding, identification, and additional functional effects. | Pigmented polymer coatings, functional pigments | Safety textiles, industrial identification, military and technical fabrics |
Yarn coating chemicals
Yarn coating formulations typically consist of polymeric binders, functional additives, and auxiliary agents, each contributing to specific performance requirements in technical textiles. The major chemical used for yarn coating are summarised in Table 2. The selection of chemicals depends on fibre type, end-use application, and processing conditions.
Polymeric binders and film-formers: Polymeric binders form the primary coating matrix and determine mechanical integrity, flexibility, and durability. Both natural and synthetic polymers are employed, including starch and modified starches, cellulose derivatives, polyvinyl alcohol (PVA), acrylic copolymers, and polyurethane dispersions. Synthetic binders are increasingly favoured in high-performance applications due to their superior film strength, chemical resistance and process stability. Direct polymer-based coating chemicals like Ethylene-vinyl acetate (EVA) and PVC plastisols offer durability and hydrophobic properties, with epoxies and isocyanates enabling cross-linking for enhanced strength and scratch resistance on glass or synthetic fibres. These materials reduce friction and improve knittability while maintaining tensile integrity
Adhesion-promoting agents: Adhesion promoters are essential for applications involving composite or rubber reinforcement. Resorcinol–formaldehyde–latex (RFL) systems are widely used for bonding yarns to rubber matrices, while silane coupling agents and epoxy-based systems are commonly applied in fibre-reinforced polymer composites. These chemicals enhance interfacial bonding by modifying fibre surface chemistry and promoting chemical and mechanical interactions.
Lubricants: Lubricants such as paraffin waxes, silicone oils and fatty acid derivatives are often added to reduce yarn–machine friction and improve processability during high-speed textile manufacturing.
Antistatic and processing additives: Antistatic agents, including quaternary ammonium compounds and polyether-based additives, are used to control electrostatic charge build up during yarn handling. Additional processing aids such as surfactants, thickeners, defoamers and preservatives are employed to ensure coating stability, uniform application and shelf life.
Functional additives: Functional additives enable advanced performance characteristics. Flame-retardant chemicals based on phosphorus, nitrogen or inorganic mineral systems are used in protective textiles. Conductive fillers such as carbon black, graphene, carbon nanotubes, metallic particles, and intrinsically conductive polymers impart electrical conductivity for smart textile applications. Barrier and protective additives, including fluoropolymers, silicones, UV stabilizers and antioxidants, enhance resistance to environmental degradation.
Pigments and colourants: Pigment-based coatings are employed to provide coloration and identification for fibres that are difficult to dye, such as aramids and glass fibres. Organic and inorganic pigments are commonly used, with functional pigments enabling additional properties such as UV shielding, infrared reflectivity, or thermal management2.
Table 2: Major chemical components used in yarn coating formulations
| Component | Representative chemicals | Primary function |
| Polymeric binders | Starch, PVA, acrylics, polyurethane | Film formation, mechanical integrity |
| Adhesion promoters | RFL systems, silanes, epoxy resins | Fibre–matrix bonding |
| Plasticizers & lubricants | PEG, glycerol, silicone oils | Flexibility, reduced friction |
| Functional additives | Flame retardants, conductive fillers, UV stabilizers | Advanced performance |
| Pigments | Organic/inorganic pigments | Colouration, identification |
Yarn coating technologies
Modern textiles made from coated yarns are used in specialised applications such as antistatic films, wearable sensors for biochemical and health monitoring, and electromagnetic interference (EMI) shielding devices.
Single-End Yarn Sizing: Single-end yarn sizing is particularly suitable for technical and high-value yarns. It allows precise control over coating pickup, tension, and drying conditions, making it ideal for research, development, and specialty production. This method is widely used for aramid yarns, where gentle handling and controlled processing are essential.
Multi-End Sizing: Multi-end sizing is commonly used in large-scale textile manufacturing, particularly for warp preparation. While highly productive, it offers less flexibility in controlling individual yarn parameters, making it more suitable for standardised products.
Dip Coating and Roll-Based Methods: Dip coating, kiss-roll coating, and metering roller systems are widely used to apply functional dispersions. These methods provide uniform coating and controlled add-on levels, which are critical for maintaining yarn flexibility and performance.
Surface Activation Techniques: Surface activation methods such as plasma treatment, corona discharge, and chemical primers are often employed prior to coating. These techniques increase surface energy and introduce functional groups, significantly improving coating adhesion, especially for chemically inert fibres like aramids.
Applications in technical textiles Coated yarns have emerged as a cornerstone in the development of advanced technical textiles, offering tailored functionalities that go beyond the capabilities of conventional fibres. Modern textiles made from coated yarns are used in specialised applications such as antistatic films, wearable sensors for biochemical and health monitoring, and electromagnetic interference (EMI) shielding devices. The broad applicability of coated yarns can be categorised as follows in Table
Table 3: Applications of Coated Yarns in Technical Textiles
| Application category | Primary function / Benefit | Example uses |
| Nets and ropes | High tensile strength, abrasion and moisture resistance | Industrial ropes, fishing nets, climbing ropes |
| Filtration systems | Chemical resistance, pore-size control, durability | Air filters, liquid filtration membranes, chemical filters |
| Car seatbelt fabrics | High strength, wear resistance, flame retardancy | Automotive seatbelts, safety harnesses |
| Ballistics sector | Energy absorption, inter-yarn cohesion | Bulletproof vests, helmets, ballistic fabrics |
| Composite materials | Matrix adhesion, load transfer, multifunctionality | Fibre-reinforced plastics, aerospace composites |
| Aerospace applications | Thermal stability, UV and wear resistance | Lightweight structural fabrics, thermal insulation covers |
| Military applications | Durability, flame retardancy, camouflage | Uniforms, tents, protective gear |
| Healthcare / Wearables | Biocompatibility, antimicrobial, sensing | Wound dressings, compression fabrics, wearable sensors |
| Protection gear | Thermal, chemical, and mechanical protection | Industrial gloves, fire-resistant garments, aprons |
| Furnishing | Stain resistance, flame retardancy, durability | Upholstery, curtains, carpets |
| Boating / Marine textiles | UV, moisture, and microbial resistance | Sails, marine ropes, protective covers |
| Fashion and accessories | Functional aesthetics, water resistance, conductivity | Garments, bags, shoes, smart textiles |
| Infrastructure / Telecommunication | Mechanical integrity, chemical and environmental resistance | Geotextiles, cable reinforcements, protective wraps |
| Specialty accessories | Strength, thermal/chemical resistance, colour coding | Ropes, belts, wearable devices |
Conclusion
Functional coated yarns are pivotal in advancing technical textiles, bridging the gap between high-performance fibre properties and application-specific requirements. By enabling uniform distribution of functional agents at the yarn level, coating technologies improves mechanical strength, adhesion, protective capabilities, electrical conductivity and aesthetic versatility by using respective functional chemicals. The selection of coating chemistries, combined with appropriate application techniques, allows tailored solutions across diverse sectors. As functional demands continue to grow, yarn coatings offer scalable, cost-effective, and adaptable strategies for the development of next-generation technical textiles. Ultimately, the integration of advanced coating technologies ensures that both conventional and also high-performance fibres achieve their full potential, resulting in durable, multifunctional and innovative textile solutions capable of meeting modern industrial and societal needs.
References
- https://www.datamintelligence.com/research-report/coated-technical-textile-market
- Uddin, A.J. Coatings for technical textile yarns. In Technical Textile Yarns; Elsevier: Amsterdam, The Netherlands, 2010;pp. 140–184
- https://www.swicofil.com/commerce/brands/plasma-metal-coated-yarn
- https://blog.aymsyntex.com/product-strength/overview-of-coated-yarns
About the author:
Dr KH Prabhu is the Senior Scientific Officer, Research & Development at The South India Textile Research Association (SITRA). 13/37, Avinashi Road, Aerodrome Post, Coimbatore-641014, India.
e-mail: acptl@sitra.org.in, Tel. No: +91-422-4215365
