Network ion fanManufacturers answer basic knowledge of static electricity?
There are two common causes of static electricity in daily life:
1. Friction between objects (frictional electricity)
2. Separation of closely contacted bodies (separation of electricity)
However, in fact, simpler phenomena can also cause static electricity.
Insulators are usually charged, but are metals also charged?
It is generally believed that metals (conductors) are not charged. However, as shown in the figure below, when metals are in a conscious state, they will also generate static electricity due to friction and separation, just like insulators.
When grounding, static electricity will be generated through friction, separation, etc., but the static electricity will be immediately transmitted to the grounding wire and disappear.
When not grounded, static electricity generated by friction, separation, etc. cannot disappear (charged) because it has no way to go.
What are the properties of static electricity?
Static electricity is also a kind of electricity, including positive static electricity and negative static electricity. Positive and negative static electricity have the following properties:
Positive static electricity: its electrical direction is displayed as away from the charged body
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Negative static electricity: its electrical direction is displayed as pointing to the charged body
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In addition, when substances with the same polarity approach each other, substances with different polarities attract each other when they approach each other.
The force generated at this time is called "Coulomb force" (unit: N), and the relationship between the charge and the Coulomb force is expressed by "Coulomb's law".
About the charge sequence
The charge sequence is arranged according to the difficulty of various materials to be positively or negatively charged, and is used to determine what kind of charge the materials will have when they come into contact.7 In the charge sequence,
generally, the farther the arrangement, the greater the charge. (The same materials in the charge sequence will not be charged when they come into contact. However, compared with the contact of different materials in the charge sequence, the charge is smaller.)
Example
1. When glass and cotton are rubbed
Glass: positively charged
Cotton: negatively charged
2. When cotton and Teflon are rubbed
Cotton: positively charged
Teflon: negatively charged
What is separation charging?
When separating the contacting parts, for example, when removing the tape, a strong charging phenomenon will be generated. Although this phenomenon is the same as the "contact charging" in Figure 7, since the charge of the parts is generated by peeling (separation), it is generally "separation charging". When separation charging is generated, the closer the contact, the greater the static electricity generated. In addition, the amount of charge depends on the separation speed. If the separation speed is slow, small-scale static electricity will be continuously released, and the charge will be relatively small. If the separation speed is fast, static electricity will be reduced, and the charge will be relatively large.
What is the difference between frictional charging and contact charging?
Because static electricity is generally generated at the moment of contact between the two bodies, frictional charging is also a type of contact charging. However, when frictional charging (triboelectric charging) occurs, the contact surface is rubbed against each other, the contact surface area increases, and the friction increases the temperature of the surface of the body. Therefore, the static electricity generated is much larger than contact charging.
How much static electricity can the human body feel?
The static electricity that the human body can feel is generally above +3000V (+3KV). Please refer to the following table 1 for the relationship between the degree of human body electric shock and voltage.
Excerpt from the (Static Electricity Safety Guidelines) issued by the Japan Industrial Safety Research Institute
Electrostatic voltage (KV)
Electric shock level |
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1.0 2.0 3.0 5.0 6.0 7.0 8.0 9.0 11.0 12.0 | No feeling. The fingers can feel, but there is no pain. Needle-like tingling Pain in the palm and forearm Strong pain in fingers and heaviness in upper arms Strong pain and numbness in fingers and palms Numbness in palms and forearms Strong pain in wrist and numbness in hand Pain in the whole arm and feel like an electric current is passing Row" |
The fingers felt numb and the whole arm felt a strong electric shock. The whole arm felt like it was hit hard. |
