The necessary measures to be taken for antistatic protection are not the same if the material of the charged machinery is different, the wrong countermeasures will not only have any effect but on the contrary, the machinery may be charged.
Antistatic countermeasures of conductive materials can easily solve the problem of static electricity by grounding.
If a metallic (conductive, such as aluminum or iron) machinery is electrostatically charged, grounding will change its state to 0 V, antistatic measures for conductive materials are low cost and easy to apply.
Quick tips to remove static electricity from machinery
Electrostatic protection of machines in a company or workplace is generally achieved by the elimination of electromagnetic fields, shielding of high electrostatic parts, and grounding of machines.
The simplest common method to remove static electricity in machinery is the grounding of the machine. Metal wires can be used to ground the machine casing and eliminate static electricity from the machine.
When the indoor air humidity in the environment is less than 30%, the machine is very easy to rub and generate static electricity. To prevent the occurrence of static electricity, the indoor humidity should be kept at a certain level, and the relative humidity of the environment should not be less than 50%.
Specific methods include mopping the floor frequently, spraying water frequently, or humidifying with a humidifier.
In addition, eliminating static electricity from machines can also start with the general production environment, e.g. anti-static floors, floor mats and all tools involved in the production should use anti-static products as much as possible.
Other known methods to prevent static electricity from machinery
The methods to prevent static electricity in machines can be summarized in two groups:
- Electrostatic shielding method
- Electrostatic leakage method
1. Electrostatic shielding method
In this method, a shielding conductor is placed near the machine to reduce the risk of electrostatic discharge and avoid electrostatic induction. It can adopt global shielding or partial shielding as required. It can adopt a mesh shielding body or plate shielding body.
2. Electrostatic leakage method
Drains static electricity from the machine. Leakage methods include methods such as those mentioned at the beginning of the topic, such as grounding, humidifying the environment, adding antistatic agents, and applying conductive paint.
About static electricity in workshops with different machines and materials
In an environment containing only metallic (conductive) objects, grounding is only required to eliminate static electricity. However, grounding has no effect on an insulating material because it does not have the property of allowing current to pass through.
In a general manufacturing workshop, conductors and insulators are often present at the same time. In other words, it is not sufficient to prevent static electricity by grounding.
Although grounding cannot eliminate static electricity in insulators (plastic, rubber, etc.), it can be done by changing the material. Two methods can be used.
One method is to mix the product or material itself with other conductive materials (carbon, metal powder, etc.), and the other method is to apply an antistatic solution to the surface of the insulating material.
Which method is the most effective for reducing static electricity?
Although machine grounding has traditionally been known as an effective method to prevent static electricity, non-conductive (insulating) materials cannot be discharged by grounding.
Another very effective and permanent solution to reduce electrostatic charges is active ionization. The best way to do this is to use air ionizers. These generate a large number of positively and negatively charged ions in the surrounding atmosphere, which serve as mobile charge carriers in the air.
When ions are present in the air, they are attracted to oppositely charged particles and surfaces. This process leads to the rapid discharge of charged surfaces.
The method used to generate ions is a phenomenon called corona discharge. When ions are attached to objects with static electricity, charge exchange occurs, forming an electrically neutral state.
Compared with measures that use conductivity or humidity, this method can eliminate static electricity more accurately, so it is being adopted in more and more manufacturing workshops.
The frequency of electrostatic discharges is different in winter and summer. This is due to “humidity”. In summer, when humidity is high, static electricity can be released in the humidity of the air, making electrostatic discharges more difficult to occur.
In winter, on the other hand, humidity is low and static electricity accumulates easily. Therefore, electrostatic discharges are more frequent in winter than in summer.
So static electricity can be prevented by controlling the humidity of the environment, In the first tips on this topic, I explained what should be the right percentage of humidity in an environment, to reduce the chances of machinery and equipment generating static electricity.
Remember that the human body is also a conductor of electricity
The human body is also a conductor of electricity, during the operation of machinery and equipment, it is inevitable that friction or detachment will occur between people and clothing, which will generate static electricity.
If this is a very recurring problem, to solve it, you can use a special antistatic wrist strap, It can release the potential of the human body through grounding, which can prevent people from causing static electricity problems.
How is static electricity generated?
It is not really my intention to give a scientific description of how static electricity is generated, let’s just say that static electricity is a physical phenomenon that occurs naturally by the interaction of the molecular elements that make up the materials.
Friction is a constant process of contact and separation. So, electrification by friction is basically electrification by contact separation. In daily life, several objects may generate static charges due to friction or motion.
Electrification by induction is another common type of electrification. When a charged object is brought close to an uncharged object, negative and positive charges are induced at both ends of the uncharged conductor respectively.