Technical requirements for the production of anti-static overalls
People's life and production are all related to static electricity, and static electricity directly or potentially brings various degrees of harm to human beings from various aspects. According to expert analysis, most of the fire accidents in workplaces such as gunpowder, chemical industry, medicine, and petroleum are caused by accidental discharge sparks due to static electricity generated by human activities exceeding safety limits. The generation of static electricity is closely related to the material of the clothing worn by the human body, the strength of the activity, the type of labor tools used, the conductivity of the ground, and the temperature and humidity of the surrounding environment. For a long time, people have used grounding, shielding, neutralization and other methods to eliminate the danger of static electricity. Anti-static overalls have the function of providing static shielding to the human body, eliminating or reducing the electrostatic hazard.
Anti-static fabric
The measure to prevent static electricity accumulation is to conduct the static charge on the object as soon as possible to disperse or leak out. Therefore, anti-static overalls should be made of fabrics with good conductive fibers. The following three types of anti-static fabrics are used.
1. Utilize the humidity dependence of the antistatic effect. Through antistatic finishing, that is, adding a hydrophilic polymer (surfactant) in the spinning, the fabric is easy to absorb moisture in the air, reduce the surface impedance, reduce static electricity accumulation, and release static electricity in time.
2. Use the conductivity of the fiber. An antistatic agent and carbon black particles are added to the fiber raw material to make it into a conductive fiber, and the conductive ability of the fiber or the fabric is improved by a method of blending, cross-linking, interlacing, interlacing or weaving to form an antistatic fabric to realize electric charge. Dissipate to prevent static accumulation.
3. Mixing a certain amount of metal fiber into the fiber to make a blended fabric, which has good stability and is resistant to washing.
The "Anti-static overalls" (GB12014-1989) included in the catalogue of special labor protection articles is used to prevent static electricity from accumulating clothes and is sewn with anti-static fabrics. It is suitable for use in places with fire or explosion hazards. The antistatic fabric used is mainly made of antistatic fibers or antistatic synthetic fibers made of conductive materials of all or part of metal or organic materials at substantially equal intervals or evenly during weaving, or a mixture of the two. .
classification
According to the place of use and the object of protection, the classification of anti-static overalls is shown in the table below.
All clean work clothes, anti-static overalls and anti-static sweaters that are used as work clothes and are used in places with fire and explosion hazards are included in the scope of safety sign management.
skills requirement
The technical requirements of anti-static overalls include structure, anti-static performance and strength.
structure
The structure of the garment directly affects its anti-static effect. Therefore, the structural design of the anti-static overalls must be guaranteed:
1. Metal accessories are generally not allowed on clothing. When metal buttons and zippers are used, it should be strictly ensured that the metal accessories are not directly exposed when worn, so as to avoid sparks caused by discharge, causing fire and explosion.
2. Clothing should be all anti-static fabric, no lining. When lining (cloth bag, reinforced cloth, etc.) must be used, the exposed area of the lining should be less than 20% of the exposed area of all anti-static clothing; for anti-static clothing or other special requirements of anti-static clothing, the lining exposed area exceeds all anti-static clothing When exposed to 20% of the area, the mask and lining should be detachable.
Antistatic performance
The national standard on the anti-static performance of anti-static overalls, put forward the requirements of a single piece of clothing charged charge under certain washing conditions:
After implementing the safety signs for special labor protection articles, it is required to apply a strong and durable special labor protection product safety mark in an obvious position.