What is the main reason for the static elimination effect of the ion fan? It may not be believed that everyone is convinced that it is not the number of fans, not the size of the fan, but the small discharge needle.
The ion fan discharge needle is made of a metal material, and is generally made of a corrosion-resistant material such as stainless steel (SUS), metal iridium (Ge), nickel (Ni), titanium (Ti), or metal tungsten (W). Widely used, metal tungsten is more resistant to wear and corrosion than stainless steel.
Since the ion fan discharge needle will be polluted after long-term use, it directly affects the de-energizing performance and ion balance. Therefore, the electrode should be cleaned regularly during use, especially the DC-type discharge needle is more susceptible to contamination. The type of de-energizer should be cleaned more frequently, and the degree of wear of the positive and negative discharge needles is different. Regular ion balance detection is required. When the discharge needle is seriously worn, the discharge needle should be replaced in time. Therefore, from this point, the AC type ion fan will have better static electricity than DC.
Regular cleaning of the discharge needle is also a very troublesome thing. From the large workshop, it not only reduces the production efficiency, but also increases the maintenance cost of the fan. Recently, KESD has an automatic cleaning ion fan to solve this problem. The ion fan can be self-cleaning with a small button. Significant cost savings from maintenance.
Principle of electrostatic protection:
(1) Prevent static electricity from accumulating in places where static electricity may be generated. Take measures within the safe range.
(2) Quickly eliminate the existing static electricity accumulation and release it immediately.
5, electrostatic protection method
(1) Use of antistatic materials: Metal is a conductor, and the leakage current of the conductor is large, which may damage the device. In addition, since the insulating material is prone to triboelectric charging, metal and insulating materials cannot be used as the antistatic material. Instead, a so-called electrostatic conductor having a surface resistance of 1 × 10 5 Ω·cm or less and an electrostatic sub-conductor having a surface resistance of 1 × 10 5 -1 × 10 8 Ω·cm were used as an antistatic material. For example, a commonly used electrostatic protection material is realized by mixing conductive carbon black in rubber, and the surface resistance is controlled to be 1×10 6 Ω·cm or less.
(2) Leakage and grounding: Ground the part where static electricity may or may have occurred, and provide an electrostatic discharge channel. The method of burying the ground wire establishes an "independent" ground line. Make the resistance between ground and earth <10Ω. (See GBJl79 or SJ/T10694-1996)
Electrostatic protective material grounding method: Connect the static protective material (such as countertop mat, floor mat, anti-static wrist strap, etc.) to the conductor that leads to the independent ground wire through a 1MΩ resistor (see SJ/T10630-1995). The 1MΩ resistor is connected in series to ensure that the current is <5mA to ground, called soft ground. The device housing and electrostatic shield are usually grounded directly, called hard ground.
The grounding method of the anti-static workbench recommended in the IPC-A-610C standard is shown in Figure 1.
(3) Elimination of static electricity on the conductor: Static electricity on the conductor can be grounded to cause static electricity to leak to the earth. The voltage and release time of the discharge body can be expressed by the following formula:
UT=U0L1/RC
Voltage at the time of UT-T (V) U0 - starting voltage (V) R - equivalent resistance (Ω) C-conductor equivalent capacitance (pf)
It is generally required to leak static electricity within 1 second. That is, the voltage is reduced to a safe area below 1OOV in 1 second. This will prevent the leakage speed from being too fast and the leakage current to be too large to damage the SSD. If U0=500V, C=200pf, if you want to make the UT reach 100V in 1 second, you need R=1.28×109Ω. Therefore, the ESD protection system usually uses a 1MΩ current limiting resistor to limit the bleeder current to less than 5mA. This is designed for operational safety. If the operator is in the ESD protection system, accidentally touching the 220V industrial voltage will not pose a danger.
