Can pure cotton fabric prevent static electricity?
It is generally believed that wearing cotton overalls can prevent the accumulation of static electricity in the clothing, so it is safe. Actually, this view is one-sided. This is basically the case only when the relative humidity of the air is higher than 50%; and when the relative humidity is relatively low, the charge of pure cotton products increases significantly. Tests have shown that when the relative humidity is lower than 30%, the charge of pure cotton fabric is equivalent to that of polyester; and when the relative humidity is lower than 20%, the charge of cotton fabric is even higher than that of some chemical fiber fabrics. Therefore, in dry climate areas, we cannot expect to use pure cotton products to eliminate the static electricity hazards of clothing under any circumstances.
Based on the above reasons, in order to effectively prevent the electrostatic discharge hazards of human body static electricity, the operator must wear anti-static work clothes.
Development history of anti-static carbon fiber
Organic conductive fibers were produced in the late 1960s. *The organic conductive fiber coated with carbon and black was the first to come out. Teijin and BASF have successively developed such fibers. The conductive components of the carbon black-coated conductive fiber are distributed on the surface of the fiber, so the conductive performance is good, but the carbon black is easy to fall off when the fiber is rubbed or bent, and the conductive performance will be reduced. What followed was a conductive fiber coated with metal on the surface. Rohm and Haas uses electroless plating to plate silver on the surface of nylon fibers to make conductive fiber X-Static, and Toyobo uses low-temperature molten metal to impregnate it to make conductive fiber with a metal skin. Statex's Ex-Stat uses electroless silver plating technology to make conductive fibers. Conductive fibers with metalized fiber surfaces have a large difference in mechanical properties from ordinary fibers, which makes blending more difficult, so they have not been widely used.
In 1975, Du Pont used composite spinning technology to make Antron III composite conductive fiber containing carbon black conductive core. Since then, major chemical fiber companies have begun to research and develop composite fibers using carbon black as the conductive component. The side-by-side Utron conductive fiber manufactured by Monsanto, the Belltron nylon conductive fiber developed by Kanebo, the Megana III conductive fiber developed by Unijika, the Kuracarbo of Kuracar, and the conductive fiber of Toyobo KE-9, etc., make the carbon black composite conductive fiber Has been extensively developed. By the end of the 1980s, the annual output of carbon black composite conductive fibers in Japan reached 200 tons. However, because the carbon black composite conductive fiber uses carbon black as the conductive component, the fiber is usually gray-black, and its application range is limited.
Research on the whitening of conductive fibers began in the 1980s. The commonly used method is to use copper, silver, nickel, cadmium and other metal sulfides, iodides or oxides with ordinary polymers to blend or composite spinning to make conductive fibers. For example, Rhone-poulence Company uses chemical reaction to make Rhodiastat conductive fiber with CuS conductive layer; Teijin Company makes conductive fiber T-25 with Cul on the surface; Kanebo Company makes ZnO2 conductive Belltron632 and Belltron638; Unijika Company develops Megana. The conductive properties of white conductive fibers using metal compounds or oxides as conductive materials are worse than that of carbon black composite conductive fibers. But its application is not affected by color.
Domestic research and development of conductive fibers are relatively late. The production of metal fiber and carbon fiber began in the 1980s, but the output was very small. Metal fibers such as stainless steel wire are widely used in special protective clothing fabrics such as oilfield work clothes and antistatic work clothes. In recent years, a variety of organic conductive fibers have been successfully developed in China. For example, metallized PET conductive fiber with Cu and Ni plated on the surface, CuI conductive acrylic conductive fiber, CuI/PET blended conductive fiber, carbon black composite conductive fiber and so on. The above conductive fiber has been commercialized products, but due to low output and unstable quality, the price is higher than similar foreign products.
Coated and composite organic conductive fibers have excellent physical and mechanical properties and chemical resistance, which can be adapted to conventional textile dyeing and finishing processes, and have good dyeing properties. Pure polyester plain weave fabric has good antistatic effect after adding organic conductive yarn in one direction, and has excellent durability.
The basic physical and mechanical properties of organic conductive fibers are similar to ordinary textile fibers, with good chemical resistance and dyeing properties, and long-lasting conductive properties. Adding organic conductive fibers to the fabric will not affect the feel and gloss. On May 1 this year, the 99-style new-generation shirts equipped by the Chinese People's Liberation Army adopted organic conductive fibers as antistatic materials. Practice has proved that the results are good.
The organic conductive fiber is used in the anti-static processing of civil clothing and carpets. It can also be widely used in anti-static, dust-proof and explosion-proof work clothes required in the semiconductor industry, electronics industry, medical engineering, biological engineering and other fields; used in electromagnetic wave shielding and absorption materials, heating elements of electric heating products, and industrial filter materials.