Functional yarn, also called technical yarn, special yarn, performance yarn, is widely used in textile including sewing, crocheting, knitting, weaving, embroidery and rope making.
Here we mainly talk about functional yarn for knitting and weaving as they are biggest application areas.
1. Why we talk about Functional yarn?
Nowadays more and more consumers expect more added value from apparels and other textile products they bought, such as moisture wicking, anti-UV, thermal and so on. Therefore functional yarns have been developed and used in textile production to enhance the functionality and performance of sportswear, outdoor wear and even everyday clothing.

Functional yarns are more and more employed in textiles, report by Knitting Industry
2. What is yarn?
When we talk about functional yarn, firstly we need know what is yarn. Yarn is a long continuous length of interlocked fibers, suitable for use in the production of textiles.
It has 2 key factors:
a. Fiber (material for yarn): natural fibers and synthetic fibers.
Yarn can be made of natural or synthetic fibers, or a blend of natural and synthetic fibers. Natural fibers include cotton, silk, linen, hemp, animal fibers (such as wool and cashmere). And synthetic fibers include nylon, acrylic fiber, rayon and polyester.
Now there’s another popular material – recycled materials such as recycled cotton and recycled polyester. But anyway they still belong to natural or synthetic fibers.
b. Structure: Yarn structure can be spun or filament.
Spun yarn is made by twisting staple fibers together to make a cohesive thread, or single.
Filament yarn consists of filament fibers (very long continuous fibers) either twisted together or only grouped together.
3. What is functional yarn?
Functional yarn refers to yarns with other added values such as moisture wicking, thermo regulating, anti-bacterial, anti-mosquito, recycled, high tenacity and so on, in addition to their own basic specification.
According to the functional requirements of fabric, it can be divided into: human body protection series, comfort improvement series, environmental regeneration series and high performance series.
4. How is functional yarn manufactured?
As we talked in part 1, yarns have 2 key factors: fiber and structure, so in order to realize expected functions, yarn manufacturers must apply special fibers or yarn structures or both. We’ll introduce some popular yarns’ fabrication in part 6.
5. How is functional yarn applied?
We can see garments with hangtags of CoolMax while shopping, it means the garments are using moisture wicking polyester yarns with CoolMax fiber. We can also see Thermolite, Dralon and many other brands. All these are functional fibers and yarns.
Based on the characteristics of these functional yarns, they are widedly used in underwear, socks, gloves, bedding, medical and health care products, outdoor casual wear, sportswear, shoes and hats, home textiles, military supplies and high grade industrial cloth.
6. Introduction of popular functional yarns currently
1). Moisture Wicking yarns
Also called hygroscopic yarns, moisture absorbing yarns and so on.
Mechanism: Fiber cross-section of these yarns is usually profiled or superfine to have more spaces and channels, through which moisture can move out from body.
Available yarns: Moisture wicking yarns are usually both filament yarn and spun yarn, materials include polyester and nylon.

Fiber cross section of Hikingtex’s moisture wicking polyester yarn: WellCool.
2). Cool feeling yarns
Mechanism: This yarn needs process both on fiber and structure.
a. Fiber: Usually cool feeling yarns use some mineral particles in fiber production to increase its Qmax.
b. Structure: Special spinning technology is used to improve yarn evenness and reduce hairiness so that contact area is increased and cool feeling performance will be improved.
Available yarns: Cool feeling yarns can be both filament yarn and spun yarn, materials of nylon and polyester are mostly used.
3). Anti-UV yarns (UV protection yarns)
Mechanism: UV protection additives were employed in anti-UV yarns’ fiber to confer UV shading effects.
Available yarns: anti-UV yarns can be both filament yarn and spun yarn, materials of nylon and polyester are mostly used.
4). Thermal yarns
Mechanism: Thermal yarns can be manufactured with special fiber or structure.
Fiber: Yarns with fibers of hollow-core in cross-section makes lightweight and insulated.
Structure: Fluffy yarn structure is widely employed especially for natural fiber spun yarn such as cotton, wool.
Available yarns: With hollow-core fiber, polyester and acrylic are mostly used both in filament and spun yarn. Regarding fluffy yarn structure, besides synthetic fibers, natural fibers such as cotton and wool are also widely used.
5). Far infrared yarns
Also called thermo generation yarns and heating yarns.
Mechanism: Nano-powders (size 70~100nm) blended during polymerization process. Fibers can absorb energy from sunlight or the human body and release far infrared ray to keep body warm, expanding capillaries to improve blood circulation and accelerating metabolism.
Available yarns: Far infrared yarns can be both filament and spun yarn, polyester is mostly used material.
6). Thermo Regulation yarns
Mechanism: Thermo regulation fabric can interact with body temperature, which cools down the body when its hot and sweating, but stop cooling when it’s complete.
Available yarns: Most thermo regulation yarns are rayon spun yarns or lyocell spun yarns.
7). Anti-bacterial yarns
Mechanism: Copper, silver and zinc are mostly used in anti-microbial yarns as these substances can damage cell walls of bacteria. These anti-bacterial ions are anchored permanently in fiber polymer, providing a permanent antimicrobial effect.
Available yarns: Both filament and spun yarns are available. For materials, polyester, nylon and rayon are mostly used.
After years’ efforts, now Hikingtex can provide permanent zinc anti-bacterial cotton yarns: TechNa-Cotton.

8). Strong and long lasting yarns
Mechanism: Usually employ high tenacity and abrasion resistance materials such as high tenacity polyester, nylon/nylon 66 and aramid.
Kevlar is a well-known brand of high tenacity aramid and Cordura is a famous brand of high tenacity nylon 66. Some manufacturers also use special spinning technology to produce high tenacity and abrasion resistance yarns.
Available yarns: Both filament and spun yarns are available. For materials, polyester, nylon and aramid are mostly used.
Iraklis by Hikingtex is a strong, long lasting cotton nylon blended yarn, strength as high as 35.2cn/tex, with good hand feelings, which is widely used in military combat uniforms and other areas.
9). Anti-static yarns
Mechanism: Metal fibers are integrated into yarns products to provide protection against electrostatic discharge (ESD).
Available yarns: Both filament and spun yarns are available. For materials, polyester, is mostly used.
10). Flame retardant yarns
Mechanism: Flame retardant yarns, also called flame resistant yarns are non-flammable due to the materials they contain. When they are exposed to a flame they won’t ignite.
Generally, flame-resistant yarns will not melt, drip, or support combustion from the air.
Available yarns: Both filament and spun yarns are available. For materials, polyester and aramid are mostly used. This includes familiar brand names like Nomex and Kevlar.
11). Recycled yarns
Mechanism: Recycled yarns consists of recycled fibers. Recycled fibers can be generally defined as converting fabric into certain fiber that can be reused in textile products.
Textile recycling is generated from two primary sources:
Pre-consumer: includes scraps created by yarn and fabric by-products
Post-consumer: includes garments, upholstery, towels, household items to be repurposed.
Popular yarns: For recycled cotton yarns, only spun yarns available. For recycled polyester, both filament yarns and spun yarns are widely used.
12). Multi-functional yarns
Multi-functional yarns are combination of several functions on a single yarn. Here’s some examples from Hikingtex:
a. Moisture wicking and anti-microbial polyester yarn: TechNa-Poly,
b. Moisture wicking, cool feeling and anti-UV polyester yarn: Hakuu-Poly,
c. Thermal and far infrared polyester yarn: WooFit-Poly.
7. Advantages of functional yarn
7. Advantages of functional yarn
Compared with classic yarns, functional yarns are responsible for developments of a whole new range of clothing and home textiles categories.
One of those categories is the entire line of athletic clothing, from wicking and thermal clothes that bring fabulous wearing experience both in summer and winter, to stretchable sportswear that doesn’t falter and snaps back into shape even after dynamic movements. Another category: more and more family start to use anti-bacterial clothes and beddings for kids and themselves to guarantee a safe bedroom especially after Covid-9.
It is not only clothing items and home textiles where functional yarns play out their full strength, functional yarns are also needed in many other areas. If you’re an outdoor person you will find a number of examples: Ropes for climbing, fishing lines, tents and many other items rely on yarns that can withstand adverse conditions, as well as compressive stockings furniture, shielding materials and safety purposes.