In many factories, we use a lot of anti-static products […]
In many factories, we use a lot of anti-static products, why do static damage often occur? The following article describes the common wrong anti-static methods in factories.
1. No anti-static product testing equipment
The most common mistake is that many companies purchase a lot of anti-static products, but do not purchase some commonly used anti-static product testing equipment. We know that each product has a certain period of use, and the quality is good or bad. Without some commonly used testing equipment, we do not know whether the product is damaged and whether the quality is good. In this way, there is no anti-static effect.
2. The ground connection is not good
a. The anti-static system must have an independent and reliable grounding device. The grounding resistance should generally be less than 10 Ω. The embedding and testing methods should meet the requirements of GBJ 97.
b. The anti-static ground wire shall not be connected to the zero line of the power supply and shall not be shared with the lightning protection ground wire. Because lightning strikes and other phenomena will affect the performance and personal safety of the product through the loop.
c. Use a three-phase five-wire system for power supply, and its ground wire can be used as an anti-static ground wire (but the neutral wire and ground wire must not be mixed).
d. The cross-sectional area of the grounding main line should not be less than 100mm2; the cross-sectional area of the branch line should not be less than 6mm2; the grounding wire of the equipment and the workbench should be a multi-strand plastic coated wire with a cross-sectional area not less than 1.25mm2. Is appropriate.
e. The connection of the grounding trunk line should be brazed.
f. The connection terminals of anti-static equipment should ensure reliable contact, easy to assemble and disassemble, and allow the use of various clip connectors, such as fish clips, plug seats, etc.
g. Workplaces that require high grounding resistance values should install a grounding system monitoring and alarm device.
3. Use anti-static products as ordinary products
Many companies use anti-static products as ordinary products, thinking that they can continue to be used without deformation or cracking. In fact, this is a misunderstanding. For example, anti-static wrist straps can only be used for a few months. After a period of use, the appearance may not be damaged. However, when testing, it is often found that the wrist strap is broken.
4. No attention to socks and insoles
Usually people wear socks or insoles when wearing anti-static shoes. People who are prone to sweating can also conduct static electricity. However, some people who are not prone to sweat may wear non-static anti-wear. And insoles, these socks and insoles cannot conduct static electricity, so that the static electricity of the human body cannot be introduced into the ground through the shoes. Therefore, place the "Human Body Comprehensive Resistance Tester" at the entrance of the machine room or factory building. The Human Body Comprehensive Tester can quickly and accurately detect those who wear unqualified anti-static shoes, socks and insoles. It is recommended that workers wear anti-static slippers in the summer and do n’t wear 祙 子, in winter can wear cotton socks but not nylon socks.
5. Only wear anti-static shoes and no anti-static clothes
In addition to wearing anti-static shoes, people must wear anti-static overalls to better control the static electricity of the human body. Because clothing can also carry very high static electricity, especially nowadays most clothing is chemical fiber, which can generate thousands of volts of static electricity.
6. Only wear anti-static clothing and no anti-static shoes
Experiments have shown that if people only wear anti-static work clothes without anti-static shoes and without good anti-static ground, the anti-static effect is extremely poor.
7. Anti-static clothing and shoes are worn but there is no anti-static floor and no anti-static wrist strap
We know that the static electricity of the human body is usually guided through the anti-static shoes to the anti-static floor, or to the ground through the wrist strap. If there is no anti-static floor and anti-static wrist strap, the static electricity of the person will be difficult to conduct. Qualified companies have better anti-static flooring and anti-static wrist straps. Unconditional companies should at least have anti-static wrist straps.
8. Incorrect use of wrist strap
The wrist strap is easy to damage, so it needs to be tested every day. A good wrist strap will also be too loose to be conductive due to workers wearing it, so a better method is to monitor at any time with the wrist strap online monitor. However, there are many companies that do not even have a wrist strap tester. A wrist strap can only be broken after being used for more than a year. This will not produce static electricity.