The harmful mechanism of static electricity
There are many hazards from static electricity. The first hazard comes from the interaction of charged objects. When the aircraft body rubs against air, moisture, dust and other particles, the aircraft will be charged. If no measures are taken, it will seriously interfere with the normal operation of the aircraft's radio equipment and make the aircraft "deaf" and "blind"; in the printing factory Inside, the static electricity between the paper pages will cause the paper pages to stick together, difficult to separate, and cause trouble for printing; in the pharmaceutical factory, because the static electricity attracts dust, the medicine will not reach the standard purity; the surface of the TV screen Static electricity can easily absorb dust and oil, forming a thin film of dust, which reduces the clarity and brightness of the image.
The second major hazard of static electricity is the possibility of explosion due to static sparks igniting certain combustibles. On the operating table, electric sparks can cause an anesthetic explosion, hurting doctors and patients; in coal mines, electric sparks can cause gas explosions, causing deaths and injuries to workers, and the mines being scrapped.
The harm of static electricity is obvious to all. Now more and more manufacturers have begun to implement various levels of anti-static measures and projects. However, it is necessary to realize that a complete and effective anti-static project should formulate corresponding countermeasures in accordance with the actual conditions of different enterprises and different operating objects. Anti-static measures should be systematic and comprehensive, otherwise, it may get twice the result with half the effort, or even cause destructive reaction.
Electrostatic induction is a phenomenon in which electrons flow in a substance (such as metal, that is, conduction). The electrons inside a metal object move to the surface, causing the surface to carry a charge of opposite polarity to the charged object close to it, and there are electrostatic phenomena and The discharge phenomenon occurs. If the sensing object is a good conductor with low resistance, electrostatic discharge is prone to occur, causing harm. The generation of static electricity is inevitable in industrial production, and the harm it causes can be attributed to the following two mechanisms:
1. The harm caused by electrostatic discharge (ESD)
Electrostatic discharge can cause malfunction or malfunction of electronic equipment and cause electromagnetic interference. Electrostatic discharge can break down integrated circuits and precision electronic components, or promote the aging of components, and reduce the yield of products; high-voltage electrostatic discharge can cause electric shocks and endanger personal safety; in the production of flammable, explosive products or dust and oil mist. Easy to cause explosion and fire.
2. The harm caused by electrostatic attraction (ESA) in industrial production
(1) Electronics industry. Adsorb dust, cause pollution of integrated circuits and semiconductor components, and greatly reduce the yield of products. When a charged object (dust, etc.) approaches a metal object, electrostatic induction will occur inside the metal object, causing free electrons in the object to move to the surface, making the surface in a charged state. Therefore, the potential generated by the electrostatic induction and the static electricity of the charged object (dust, etc.) are in the coulomb Attract each other under the action of force, so that the adsorption phenomenon occurs. This kind of phenomenon will cause electrostatic induction even if the metal object is grounded, and it is often unable to effectively eliminate the static electricity of the metal object.
(2) Film and plastic industry. Make the film or film roll unevenly, and the film and CD plastic disc will be contaminated with dust, which will affect the quality of the product. Due to the Coulomb force, the insulator attracts dust with opposite polar charges. For insulators or adsorbents, it is enough to eliminate static electricity on either of the two. In actual implementation, the effect of eliminating the static electricity of the insulator will be better. In addition, it is easier to eliminate static electricity from insulators than to eliminate static electricity from particles or dust in the air.
(3) Papermaking and printing industry. Uneven paper winding, inaccurate overprinting, serious dirt absorption, and even paper adhesion, affecting production.
(4) Textile industry. Causes hazards such as fluttering of roots, broken ends of entangled flowers, and tangled yarns.
