Two factors affecting the performance of anti-static products
Anti-static products have a good ability to conduct excess charges and eliminate static electricity. Common methods of removing static electricity are: grounding, physical neutralization, chemical neutralization, and surface resistance reduction.
Two key factors that determine the performance of anti-static products: surface resistance and friction voltage.
In the field of anti-static, the anti-static coefficient is equivalent to the surface resistance, which represents the resistance per square area of the dielectric surface to the surface leakage current between the opposite sides of the square (unit: Ω ohm).
Resistance greater than or equal to 1012Ω is an insulator;
The anti-static body is between 104Ω and 1011Ω or more (the general standard anti-static coefficient is between 106Ω and 109Ω);
Conductivity between 103Ω and 105Ω or more;
The third power of less than 10 is the electric field shielding material.
Friction voltage (also called static voltage)
Voltage: The voltage drop that the current can pass through the conductor per unit time U=IR
Friction voltage: After two substances rub against each other or come into close contact and separate, the two materials will be charged with the same amount of static charges of different signs. A voltage is generated between them, and the voltage between them is called the friction voltage. The friction voltage is related to the material, the degree of friction, and the ambient temperature and humidity, and the unit is V. Common factories have requirements for the surface resistance of anti-static products. The more stringent requirements are that the friction voltage needs to be less than 100V, and the higher requirements are less than 50V.
Anti-static products must have excellent anti-static performance to ensure the safety of electronic products, and anti-static performance indicators need to be tested regularly. Common test equipment are:
Surface resistance tester
The surface resistance tester is an instrument for testing the surface resistance of an object. Commonly used are portable surface resistance testers and heavy hammers.
Electrostatic field tester
The electrostatic field tester is divided into contact and non-contact electrostatic field testers. The shell is made of anti-static material and has a grounding button to ensure reliable measurement results.
It is mainly used to determine the electrostatic properties of textile raw materials and finished products under laboratory conditions. It can also be used to determine the electrostatic properties of other sheet and plate materials such as paper, rubber, plastic, and composite boards.