Antistatic fibers are a type of chemical fiber that does not easily accumulate static charges. Under standard conditions, antistatic fibers are required to have a volume resistivity of less than 10¹⁰Ω·cm or a static charge dissipation half-life of less than 60 seconds.

Textile materials are mostly electrical insulators with relatively high specific resistance, especially synthetic fibers with low moisture absorption such as polyester, acrylic, and polyvinyl chloride fibers. During textile processing, close contact and friction between fibers and fibers or fibers and machinery parts will cause charge transfer on the surface of objects, thereby generating static electricity.

Static electricity can bring many adverse effects. For example, fibers with the same charge repel each other, and fibers with different charges attract to machinery parts, which will cause sliver fluffing, increased yarn hairiness, poor package forming, fiber sticking to machinery parts, increased yarn breakage, and scattered streaks on the fabric surface. After clothing is charged, it is easy to absorb dust and get soiled, and entanglement may occur between clothing and the human body, or between clothing and clothing, and even electric sparks may be generated. In severe cases, the static voltage can reach several thousand volts, and sparks generated by discharge may cause fires with serious consequences.

There are various methods to endow synthetic fibers and their fabrics with durable antistatic properties. For example, hydrophilic polymers or conductive low-molecular-weight polymers can be added during the polymerization or spinning of synthetic fibers; composite spinning technology can be used to produce composite fibers with a hydrophilic outer layer. In the spinning process, synthetic fibers can be blended with fibers with strong hygroscopicity, or fibers with positive charges and fibers with negative charges can be blended according to the potential sequence. Durable hydrophilic auxiliary finishing can also be applied to fabrics.

To prepare fibers with relatively durable antistatic effects, surfactants are often added to the spinning dope for blend spinning. After fiber formation, surfactants will continuously migrate and diffuse from the inside of the fiber to the surface by virtue of their own characteristics, so as to achieve the antistatic effect. There are also methods such as fixing surfactants on the fiber surface through adhesives or cross-linking them into films on the fiber surface, and the effect is similar to brushing antistatic varnish on the plastic surface.

The antistatic effect of such fibers is closely related to environmental humidity. When the humidity is high, moisture can enhance the ionic conductivity of the surfactant, and the antistatic performance is significantly improved; in dry environments, the effect will be weakened.

The core of this type of antistatic fiber is to modify the fiber-forming polymer, and enhance the hygroscopicity of the fiber by adding hydrophilic monomers or polymers, thereby endowing it with antistatic properties. In addition, copper sulfate can be mixed into the acrylic spinning dope, and after spinning and coagulation, it is treated with a sulfur-containing reducing agent, which can improve the production efficiency and conductivity durability of conductive fibers. In addition to ordinary blend spinning, the method of adding hydrophilic polymers during polymerization to form a micro-multiphase dispersion system has gradually emerged, such as adding polyethylene glycol to the caprolactam reaction mixture to enhance the durability of antistatic properties.

Metal conductive fibers are usually made of metal materials through specific fiber-forming processes. Common metals include stainless steel, copper, aluminum, nickel, etc. Such fibers have excellent electrical conductivity, can quickly conduct charges, and effectively eliminate static electricity. At the same time, they also have good heat resistance and chemical corrosion resistance. However, when applied to textiles, there are some limitations. For example, metal fibers have low cohesion, and the bonding force between fibers during spinning is insufficient, which is likely to cause yarn quality problems; the color of finished products is limited by the color of the metal itself and is relatively single. In practical applications, they are often blended with ordinary fibers, using the conductive advantage of metal fibers to endow blended products with antistatic properties, and using ordinary fibers to improve spinning performance and reduce costs.

The preparation methods of carbon conductive fibers mainly include doping, coating, carbonization, etc. Doping is to mix conductive impurities into the fiber-forming material to change the electronic structure of the material, thereby endowing the fiber with conductivity; coating is to form a conductive layer by coating a layer of carbon material with good conductivity such as carbon black on the fiber surface; carbonization generally uses viscose, acrylic, pitch, etc. as precursor fibers, and converts them into conductive carbon fibers through high-temperature carbonization. The carbon conductive fibers prepared by these methods obtain certain conductivity while retaining part of the original mechanical properties of the fibers. Although carbon fibers treated by carbonization have good conductivity, heat resistance and chemical resistance, they have high modulus, hard texture, lack of toughness, are not resistant to bending, and have no heat shrinkage ability, so their applicability is poor in some occasions where fibers need to have good flexibility and deformability.

Organic conductive fibers made of conductive polymers have a special conjugated structure, and electrons can move relatively freely on the molecular chain, thus having conductivity. Due to their unique conductive properties and organic material characteristics, such fibers have potential application value in some high-end fields with special material performance requirements and low cost sensitivity, such as specific electronic devices and aerospace fields.

This type of fiber realizes antistatic function by coating conductive substances such as carbon black and metal on the surface of ordinary synthetic fibers through surface finishing processes. The process of coating metal is relatively complex and costly, and may have a certain impact on the wearing properties such as hand feel of the fiber.

The composite spinning method is to form a single fiber with two or more different components through a special composite spinning assembly in the same spinning process by using two or more polymers with different compositions or properties. When preparing antistatic fibers, polymers with conductivity or polymers added with conductive substances are usually used as one component and compounded with ordinary fiber-forming polymers. Compared with other antistatic fiber preparation methods, the fibers prepared by composite spinning method have more stable antistatic properties and less negative impact on the original properties of the fibers.

In daily life, when the air is too dry in winter, static electricity is likely to be generated between human skin and clothing, and the instantaneous static voltage can reach tens of thousands of volts in severe cases, causing discomfort to the human body. For example, walking on carpets can generate 1500-35000 volts of static electricity, walking on vinyl resin floors can generate 250-12000 volts of static electricity, and rubbing against a chair indoors can generate more than 1800 volts of static electricity. The level of static electricity mainly depends on the humidity of the surrounding air. Usually, when the static interference exceeds 7000 volts, people will feel an electric shock.

Static electricity is harmful to the human body. Persistent static electricity can increase the alkalinity in the blood, reduce the calcium content in the serum, and increase the calcium excretion in the urine. This has a greater impact on growing children, the elderly with very low blood calcium levels, and pregnant women and lactating mothers who need a lot of calcium. Excessive accumulation of static electricity in the human body will cause abnormal current conduction of brain nerve cell membranes, affect the central nervous system, lead to changes in blood pH and oxygen characteristics of the body, affect the physiological balance of the body, and cause symptoms such as dizziness, headache, irritability, insomnia, loss of appetite, and mental trance. Static electricity can also interfere with human blood circulation, immune and nervous systems, affect the normal work of various organs (especially the heart), and may cause abnormal heart rate and premature heart beats. In winter, about one-third of cardiovascular diseases are related to static electricity. In addition, in flammable and explosive areas, static electricity on the human body may cause fires.