Protection against static electricity. Occurrence and action Static electricity ESD protection

Static electricity (according to GOST 12.1.018) is a set of phenomena associated with the occurrence, conservation and relaxation of a free electric charge on the surface (or in the volume) of dielectrics or on insulated conductors.

The generation of static electricity. Static electricity charges are formed under a wide variety of industrial conditions, but most often when one dielectric is rubbed against another or dielectrics against metals. On rubbing surfaces, electric charges can accumulate, easily flowing into the ground, if the physical body is a conductor of electricity and is grounded. Electric charges are held on dielectrics for a long time, as a result of which they are called static electricity.

Static electricity arises as a result of complex processes associated with the redistribution of electrons and ions when two surfaces of inhomogeneous liquid or solid substances come into contact, having different atomic and molecular forces of surface attraction.

A measure of electrification is the charge possessed by a given substance. The intensity of the formation of charges increases with an increase in the speed of movement of materials, their resistivity, contact area and interaction force. The degree of electrification of a charged body characterizes its potential relative to the earth.

In production, the accumulation of static electricity charges is often observed when: friction of drive belts on pulleys or conveyor belts on shafts, especially with slipping; pumping flammable liquids through pipelines and filling oil products into containers; movement of dust through the air ducts; crushing, mixing and screening of dry materials and substances; compression of two dissimilar materials, one of which is a dielectric; mechanical processing of plastics; transportation of compressed and liquefied gases through pipes and their flow through openings, especially if the gases contain a finely atomized liquid, suspension or dust; movement of vehicles, trolleys on rubber tires and people on a dry insulating coating, etc.

The electrification current strength of the flow of oil products in pipelines depends on the dielectric properties and kinematic viscosity of the liquid, flow velocity, pipeline diameter and length, pipeline material, roughness and condition of its internal walls, liquid temperature. With turbulent flow in long pipelines, the current strength is proportional to the velocity of the liquid and the diameter of the pipeline. The degree of electrification of moving dielectric tapes (for example, conveyor belts) depends on the physical and chemical properties of the materials in contact, the density of their contact, the speed of movement, relative humidity, etc.

Danger of static electricity discharges. Spark discharges of static electricity are a great fire and explosion hazard. Their energy can reach 1.4 J, which is quite enough to ignite vapor, dust and gas-air mixtures of most combustible substances. For example, the minimum ignition energy of acetone vapor is 0.25 10-3 J, methane 0.28 10-3, carbon monoxide 8 10-3, wood flour 0.02, coal 0.04 J. Therefore, in accordance with GOST 12.1.018, the electrostatic safety of an object is considered achieved only if the maximum energy of discharges that can occur inside the object or from its surface does not exceed 40% of the minimum ignition energy of substances and materials.

The electrostatic charge that occurs during some manufacturing processes can reach several thousand volts. For example, when sand and dust particles rub against the bottom of the body when the car is moving, a potential of up to 3 kV is generated; when pumping gasoline through the pipeline - up to 3.6 kV; when pouring electrifying liquids (ethyl alcohol, gasoline, benzene, ethyl ether, etc.) into ungrounded tanks in the case of a free fall of a liquid jet into a vessel being filled and a high outflow rate - up to 18 ... 20 kV; during friction of the conveyor belt on the shaft - up to 45 kV; when transmission belts rub against pulleys - up to 80 kV.

In this case, it should be borne in mind that a potential of 300 V is sufficient for the explosion of gasoline vapors; at a potential difference of 3 kV, combustible gases ignite, and at 5 kV, most combustible dusts.

Static electricity can also accumulate on the human body when wearing clothes made of wool or artificial fiber, moving on a non-conductive floor covering or in dielectric shoes, in contact with dielectrics, reaching a potential of 7 kV or more in some cases. The amount of electricity accumulated on people can be quite sufficient for a spark discharge on contact with a grounded object. The physiological effect of static electricity depends on the energy released during the discharge and can be felt in the form of weak, moderate or strong pricks, and in some situations - in the form of mild, moderate and even acute convulsions. Since the current strength of the discharge of static electricity is negligible, in most cases such exposure is not dangerous. However, the reflex movements of a person arising from this phenomenon can lead to serious injuries due to a fall from a height, capture of overalls or individual parts of the body by unprotected moving parts of machines and mechanisms, etc.

Static electricity can also disrupt the normal course of technological processes, interfere with the operation of electronic devices for automation and telemechanics, and radio communications.

Measures to protect against static electricity are carried out in explosion and fire hazardous rooms and areas of open installations belonging to classes B-I, B-I6, B-II and B-IIa. In rooms and areas that do not belong to the specified classes, protection is carried out in those areas of production where static electricity adversely affects the normal course of the technological process and product quality.

Measures of protection against static electricity are aimed at preventing the occurrence and accumulation of static electricity charges, creating conditions for the dissipation of charges and eliminating the danger of their harmful effects.

Prevention of the accumulation of static electricity charges is achieved by grounding the equipment and communications where they can appear, and each system of interconnected machines, equipment and structures made of metal (pneumatic dryers, mixers, gas and air compressors, mills, closed conveyors, filling and draining devices liquids with low electrical conductivity, etc.), are grounded at least in two places. Pipelines located in parallel at a distance of up to 10 cm are connected to each other by metal jumpers every 25 m. All mobile containers temporarily located under the filling or draining of liquefied combustible gases and flammable liquids are connected to the ground during filling. Refueling trucks and tank trucks are grounded with a metal chain, keeping the length of contact with the ground at least 200 mm.

Reducing the intensity of the occurrence of static electricity charges is achieved by appropriate selection of the speed of movement of substances, excluding splashing, crushing and spraying of substances, removal of an electrostatic charge, selection of friction surfaces, purification of combustible gases and liquids from impurities. Safe transport speeds of liquid and pulverulent substances depend on their specific volumetric electrical resistance ρv. So, for liquids with ρv ≤ 105 Ohm m, the allowable velocity should be no more than 10 m/s, at 105 Ohm m< pv < 109 Ом· м — до 5 м/с, а при ρv >109 ohm m speeds are set for each liquid separately, but, as a rule, not more than 1.2 m/s. When supplying liquids to tanks, it is necessary to exclude their splashing, spraying and violent mixing. The filling tube must be extended to the bottom of the vessel with the direction of the jet along its wall. During the initial filling of the tanks, the liquid is supplied at a speed not exceeding 0.5 ... 0.7 m / s.

The best way to reduce the intensity of the accumulation of static electricity in belt drives is to increase the electrical conductivity of the belts, for example, by stitching the inner surface of the belt with thin copper wire in the longitudinal direction or by lubricating its inner surface with conductive compounds (containing, for example, carbon black and graphite in a ratio of 1: 2 ,5 by weight, etc.). Attention should also be paid to adjusting the tension of the belts and, if possible, reducing their speed to 5 m/s.

If it is not possible to prevent the accumulation of static electricity charges by grounding, then measures should be taken to reduce the volume and surface dielectric resistances of the materials being processed. This is achieved by increasing the relative humidity of the air to 65 ... 70%, chemical surface treatment, the use of antistatic substances, the application of electrically conductive films, a decrease in the speed of movement of charging materials, an increase in the purity of the treatment of rubbing surfaces, etc.

If it is impossible to use means of protection against static electricity, it is recommended to neutralize the charges by air ionization in the places of their occurrence or accumulation. For this, special devices are used - ionizers, which create positive and negative ions around an electrified object. Ions that have a charge opposite to that of the dielectric are attracted to the object and neutralize it. To remove static electricity from the human body, conductive floors or grounded areas, work platforms, stair handrails, instrument handles, etc. are provided; provide workers with conductive shoes with a sole resistance of not more than 108 ohms, as well as antistatic overalls.

15.1. Measures to protect against static electricity must be carried out in accordance with current regulations.

15.2. The development of technological processes and equipment should be carried out taking into account the prevention of dangerous electrification of substances during their production and use. The main measures to prevent dangerous manifestations of static electricity should be specified in the directive technological process.

When starting a new or reconstructing production, the presence and sufficiency of the existing ESD protection devices should be checked and, if necessary, additional protection should be provided.

15.3. The technological regulation must contain the parameters of the substances processed in production, characterizing their electrical properties (electrical specific resistance) and sensitivity to electrostatic discharges (minimum ignition energy), and a description of the means of protection against static electricity, and in the technological instructions and safety instructions it must be described the order in which they are applied.

15.4. The most likely occurrence and accumulation of electrostatic charges in such operations as sieving, grinding, mixing, loading and unloading from apparatuses, pneumatic and vacuum transportation. Permissible process parameters that ensure the electrostatic safety of processing each type of product are established by the developer of the directive process and process regulations.

15.5. To prevent the possibility of dangerous electrostatic discharges, it is necessary to provide the following protective measures, taking into account the specifics of production:

Grounding of electrically conductive equipment and communications;

The use of neutralizers;

Selection of pairs of contacting materials, electrified by charges of different signs;

Humidification of the surrounding atmosphere;

The use of electrically conductive materials for equipment;

The use of clothing.

15.6. To reduce the intensity of the occurrence of static electricity charges, you should:

Wherever it is technologically possible, steam and dust-air mixtures should be cleaned from suspended liquid and solid particles, liquids - from contamination by solid and liquid impurities;

Maintain the concentration of combustible media outside the explosive limits;

Wherever the production technology does not require it, to exclude splashing, crushing, spraying of substances;

Conduct technological processes in accordance with the established parameters;

Reduce the speed of transportation and processing, the turbulence of flows of dust-vapor-gas mixtures and liquids;

Exclude condensation and crystallization of vapors and gases when flowing from pipelines, hoses, nozzles, nozzles.

15.7. All technological equipment (devices, containers, communications, coverings of desktops and racks, equipment, etc.), where the formation and accumulation of static electricity charges is possible, must be made of metal or conductive materials and grounded (conductive materials are such, specific volumetric electric whose resistance does not exceed 1E5 Ohm.m).

Apparatus, containers, aggregates, pipelines in which products are moved, crushed, sprayed, sprayed, free-standing machines, aggregates, apparatus connected by pipelines to a common system of apparatus and containers must be connected to the internal ground loop using a separate branch, regardless of grounding of communications connected to them.

Sequential connection of several grounding devices, units or pipelines into the grounding bus (wire) is not allowed.

It is allowed to combine grounding devices for protection against static electricity with protective grounding of electrical equipment.

The grounding of the mixing-charging machine before loading must be carried out in accordance with clause 9.6 of these Rules.

15.8. The design documentation for process equipment must indicate the places for connecting grounding conductors and the method of their fastening.

In each production building, a grounding scheme (map) must be drawn up, in which all equipment, tooling, inventory, etc., to be grounded, must be listed.

15.9. The ground resistance of any most remote point of the inner surface of equipment made of electrically conductive (non-metallic) materials, relative to the internal ground loop, should not exceed 1E6 Ohm.

The resistance of a grounding device designed only for protection against static electricity should be no more than 100 ohms.

15.10. Grounding conductors and the ground loop must be laid open to allow their inspection. At the same time, their resistance to mechanical and chemical influences must be ensured.

Grounding conductors, external and internal ground loops must be made in accordance with the requirements of the rules for the installation of electrical installations and the rules and regulations for the lightning protection of buildings and structures.

Grounding conductors intended for protection against static electricity are painted black and applied at the points of connection to the process equipment and the internal ground loop of one transverse strip 15 mm wide red. It is allowed, in accordance with the design of the room, to paint the grounding conductors in other colors (except red) with a red stripe marking, as indicated above.

15.11. The connection of the elements of the ground loop, the connection of ground electrodes and grounded structures must be carried out by welding. If it is impossible to use welding, it is allowed to connect grounding conductors using a reliable threaded connection. In this case, the grounding conductors must have an uncut ring at the ends, electrically connected to the main core. Threaded connections must be protected against corrosion.

15.12. Pipelines located in parallel at a distance of up to 0.1 m from each other must be connected to each other by jumpers every 20 m. When crossing pipelines with each other, with metal stairs and structures at a distance of less than 0.1 m, they must also be connected by jumpers.

Protective grounding of pipelines located on external overpasses must meet the requirements of the rules and regulations for the lightning protection of buildings and structures.

Metal ventilation ducts must be grounded every 20 m using aluminum alloy conductors with a diameter of at least 5 mm, tape with a cross section of at least 24 mm2.

15.13. Moving parts of machines and devices capable of electrifying, the contact of which with a grounded body may be broken, must have special devices (current collectors) to ensure grounding.

Apparatuses in which there is an intense electrization of substances, as well as moving components of vibration equipment (vibrating trays, mechanically driven sieves, etc.) must be grounded at least at two points.

15.14. To reduce the specific surface electrical resistance of substances, compositions and structural materials, where it is allowed by the process conditions, it is recommended to maintain a relative humidity of at least 65%.

15.15. Sprinkling of substances should be carried out from as low a height as possible. Everywhere it is necessary to systematically, within the time limits established by the instructions, clean the equipment, ventilation ducts and other structures in the room from settled dust with a wet method.

It is forbidden to load bulk products directly from paper, polyethylene, PVC and other electrifying bags into the hatches of apparatuses containing vapors of flammable liquids. In this case, loaders made of conductive materials should be used to ensure the least dusting of substances.

Sampling of bulk solids, measurement of technological parameters by means of introduced samplers and instruments should be carried out after dust settling.

15.16. The measurement of electrification parameters in production conditions is carried out periodically in accordance with the approved measurement schedule, but at least twice a year. To carry out measurements, devices in intrinsically safe and explosion-proof versions, approved for use in these industries, ensuring electrostatic safety of measurements and having passed state or departmental tests, should be used.

15.17. The commissioning of ESD protection devices must be carried out simultaneously with the acceptance of process and power equipment.

During the operation of devices for protection against static electricity, it is necessary:

Before starting work, check the reliability of the electrical contact of the grounding conductors at the junctions and the continuity of the electrical circuit along the entire length;

Avoid contamination, mechanical damage, prolonged exposure to alkalis, acids, organic solvents on electrically conductive coatings of technological equipment, workplaces.

15.18. Inspection and measurement of electrical resistance of grounding devices of process equipment, pipelines, etc. It is recommended to carry out simultaneously with checking the grounding of electrical equipment. The results of verification tests, as well as revisions and repairs of the grounding device, must be entered in the passport. The results of measuring the ground resistance of technological devices, equipment, mobile equipment, transport devices, equipment must be recorded in a special journal.

Static electricity arises from the conservation of charges in an electrostatic field on dielectric materials. It adversely affects human life and the operation of electrical devices. Sparks from static electricity contribute to fires and explosions. The power of energy is quite enough to ignite gas-air mixtures and dust.

A charge of static electricity can accumulate on the human body if it is wearing clothes made of wool or chemical fibers. A potential value of about 7 Joules is not dangerous to humans, but it can cause convulsions and muscle contractions. And this, in turn, can create conditions for injury at work, falls from a height, etc.

Static electricity adversely affects the functioning of precision instruments, radio communications, and causes malfunctions. Workers who are constantly exposed to static electricity are more likely to suffer from cardiovascular diseases and diseases of the nervous system.

Only protection against static electricity can reduce to zero or completely prevent the occurrence of this negative phenomenon.

Sources of static electricity

• The action of various radiations.
• A sudden change in temperature.
• The interaction of bodies with each other during motion.

This phenomenon has a negative impact and is dangerous. Protection against static electricity allows you to completely prevent or significantly reduce its effect.

In domestic conditions, a static field often occurs on animal hair, when removing synthetic clothing, combing hair, wearing rubber shoes, walking on a carpet in woolen socks, using plastic products.

The electrostatic field does not threaten human life; during the discharge, a weak current is generated, which is not capable of harming the human body too much. It can only create some uncomfortable state. To prevent this effect, you need to follow just a few simple rules: in frosty and dry weather, do not stroke animals, take off woolen clothes more slowly, or treat them with a special compound, use a wooden or metal comb when combing your hair.

The accumulation of electrostatic energy is facilitated by:

• Reinforced concrete walls of the building.
• Too dry air.

For electronic devices, the charge of the electrostatic field is the worst enemy. Some elements of electronic devices are not able to withstand the high voltages that occur during discharge. Sensing elements may fail or degrade their performance.

If flammable liquids become the object of the electric field, this will create conditions for their ignition. These liquids may become statically charged when transported in tanks. Also, the charge arises from a mechanism or a person who comes close to them. Therefore, in industrial production, where there are flammable liquids, much attention is paid to the grounding device for movable structures and mechanisms. For sewing shoes and special clothing, special fabrics are also used in production, which are not capable of accumulating an electric charge.

Operating principle

Let's figure out how a static charge is formed. In the normal state, physical bodies have the same number of negative and positive particles. Due to this balance, a neutral state of the body is created. When the neutral state is violated, the body receives an electric charge of one pole.

Statics is the state of the body at rest, when it is without movement. In the substance of the body, polarization can occur, which is expressed in the movement of charges between parts of the body, or from a nearby object.

Substances become electrified due to the separation of bodies, changes in charges during friction, a sharp change in temperature, and irradiation. The charges of the electric field are located on the surface of the body or removed from the surface at a distance equal to the interatomic distance. If the bodies are not grounded, then the charges are concentrated on the contact area, and in the presence of grounding, the charge goes into the ground loop.

The processes of accumulation of charges and their runoff occur at the same time. The body is electrified under the condition that it receives a larger charge of energy, in comparison with the consumed charge. As a result, it becomes clear that protection against static electricity must divert the accumulated charges to the ground loop.

The amount of static electricity

All physical substances have their own characteristic on the triboelectric scale, depending on their ability to create electric charges of different poles when rubbed. The main such substances are shown in the figure.

To have an idea of ​​the size of the resulting static charges, consider a few examples:

• A rotating pulley with a drive belt is capable of charging up to 25,000 volts.
• The body of a car moving on a dry road can be charged with up to 10,000 volts.
• A person in woolen socks, when walking on a dry carpet, is able to accumulate a charge on the body up to 6000 volts.

As a result, it becomes clear that the voltage of the electrostatic field can reach significant sizes even in everyday life. This charge does not cause significant harm to a person due to its low power. The discharge flows through a large resistance and is calculated in a few fractions of a milliamp.

Humidity also reduces electrostatic charge. It affects the value of the potential of the body during touches with different materials. Therefore, protection against static electricity can be applied.

In the natural environment, there is static electricity, reaching enormous values. For example, when clouds move between them, large energy potentials arise, which are expressed in lightning discharges. The power of these discharges is quite enough to burn down a wooden house or split the trunk of a perennial tree.

In domestic conditions, during discharges of an electrostatic field, a person feels small tingling in the fingers, sparks from the friction of woolen clothes are visible, and a person’s working capacity decreases. The electrostatic field negatively affects the human condition, but does not cause obvious damage.

There are measuring instruments that can accurately measure the value of the static potential of the accumulated charge on the human body and on the body of any device.

ESD Protection

There are various methods of protection against discharges of an electrostatic field, both in everyday life and in industrial conditions. They have their differences. Let's take a closer look at each of them.

Home protection

Each person must represent the danger posed by static discharges to the body. They need to be known and be able to limit them. To solve this problem, various events are organized to teach people how to protect themselves, including TV shows.

At these events, people are explained where and how a static field appears, methods for measuring it, and methods for performing preventive work. For example, to avoid the unpleasant sensations of a static field, it is advisable to use wooden combs for combing hair instead of plastic ones. The wood has neutral characteristics, and during friction does not create charges of an electrostatic field. In stores, you can easily buy a wooden comb of any shape and type.

To prevent the formation of static potential on the car body when driving on a dry road surface, special antistatic tapes are used, which are fixed at the back of the car on the bottom of the body. In the distribution network, you can easily choose any version of such a tape.

If the car is not protected in any way from a possible discharge of the accumulated potential charge, then the voltage can be removed by temporarily grounding the car body by connecting it to the ground through a metal part. You can use the ignition key for this. It is imperative to relieve the voltage before filling the car with gasoline.

When a static charge forms on clothing made from chemical fibers, it is recommended to use Antistatic. This is a special spray can in the form of an aerosol, which is sold in stores. It removes static electricity from clothes, fabrics, synthetic car seat covers, especially in winter when the air is dry. But, in order not to use various cans and chemicals, it is recommended to wear clothes made from natural materials: cotton and linen.

If the shoe has a rubber sole, then this creates conditions for the accumulation of stress potential. To prevent this from happening, it is enough to put special antistatic insoles in the shoes, which are made from natural materials. As a result, the negative impact on the person will decrease.

Too dry air in winter in urban apartments contributes to the accumulation of an electrostatic charge. To do this, there are special devices - humidifiers. If there is no such device, then a large wet wipe, which must be placed on the battery, is quite suitable. As a result, the charge accumulation process will decrease, the situation in the apartment will improve. It is also recommended to clean regularly. This will allow you to remove dust and electrified areas in time. This way is the best.

Electrical devices in everyday life during operation also accumulate a static charge on the case. To reduce the effect of a static charge, a potential equalization system is performed. It is connected to the ground loop of the whole house. An acrylic bathtub is subject to the accumulation of static charge on it, and it must be protected by a potential equalization system. Even a cast-iron bathtub with an acrylic liner is also subject to this negative phenomenon.

Industrial ESD Protection

In industrial production, several methods are used to preserve the functionality of equipment:

• Increasing the resistance of devices and equipment to the effects of electrostatic discharge.
• Blocking the penetration of the charge into the workplace.
• Prevention of electrostatic charges.

The last two methods make it possible to protect many devices, and the first method is used only for certain types of equipment.

Provides high protection against discharges of a static field and preservation of the functionality of the device. This is a metal cage in the form of a grid with a small cell. The cage encloses the equipment from all sides. It is connected to the ground loop. Electric fields do not pass inside the cage, at the same time, the Faraday cage does not interfere with the magnetic static field. By the same principle, they protect cables by equipping them with a metal screen.

Protection against static electricity is divided according to the methods of implementation:

• Structural and technological.
• Chemical.
• Physico-mechanical.

The last two methods make it possible to reduce the formation of charges and increase the rate of their escape into the ground. The first method protects devices from charges, but does not divert them to ground.

You can optimize static charge reduction as follows:

• Increasing the electrical conductivity of materials.
• Creation of the coronation.

Such tasks are solved with the help of:

• Select materials with good bulk conductivity.
• Enlargement of working surfaces.
• Airspace ionization.

To implement these tasks, pipelines are created for the flow of static charges to the ground, bypassing the working components of the devices. If the materials have high resistance, then other methods are used.

The concept of static electricity is familiar to everyone from the school physics course. Static electricity arises in the process of the appearance of charges on conductors, surfaces of various objects. They appear as a result of friction that occurs when objects come into contact.

What is static electricity

All substances are made up of atoms. An atom has a nucleus surrounded by equal numbers of electrons and protons. They are able to move from one atom to another. When moving, negative and positive ions are formed. Their imbalance leads to the fact that static occurs. The static charge of protons and electrons in an atom is the same, but has a different polarity.

Statics appears in everyday life. Static discharge can occur at low currents but high voltages. In this case, there is no danger to people, but the discharge is dangerous for electrical appliances. During the discharge, microprocessors, transistors and other circuit elements suffer.

Causes of static electricity

Static occurs under the following conditions:

• contact or separation of two different materials;
• sudden changes in temperature;
• radiation, UV radiation, x-rays;
• operation of the paper cutting machine and cutting machines.

Static often occurs during or before a thunderstorm. Thunderclouds, when moving through air saturated with moisture, form static electricity. The discharge occurs between the cloud and the ground, between individual clouds. The device of lightning rods helps to conduct a charge to the ground. Thunderclouds create an electrical potential on metal objects that cause light shocks when touched. For a person, a blow is not dangerous, but a powerful spark can cause some objects to ignite.

Each resident has repeatedly heard a crack that is heard when removing clothes, a blow from touching the car. This is a consequence of the appearance of static. An electric discharge is felt when cutting paper, combing hair, and pouring gasoline. Free charges accompany a person everywhere. The use of various electrical devices increases their appearance. They occur when pouring and grinding solid products, pumping or pouring flammable liquids, when transporting them in tanks, when winding paper, fabrics and films.

The charge appears as a result of electrical induction. Large electric charges are created on the metal bodies of cars in the dry season. The TV screen or computer monitor is capable of being charged by exposure to a beam created in a cathode ray tube.

The harm and benefits of static electricity

Many scientists and inventors have tried to use a static charge. Bulky units were created, the benefits of which were low. The discovery by scientists of the corona discharge turned out to be useful. It is widely used in industry. With the help of an electrostatic charge, complex surfaces are painted, gases are cleaned of impurities. All this is good, but there are numerous problems. Electric shocks are of great power. They can sometimes hit a person. This happens both at home and in the workplace.

The harm of static electricity is manifested in shocks of different power when removing a synthetic sweater, when leaving the car, turning on and off the food processor and vacuum cleaner, laptop and microwave oven. These strikes can be harmful.

There is static electricity, which affects the work of the cardiovascular and nervous systems. It should be protected from it. The person himself is also often a carrier of charges. When in contact with the surfaces of electrical appliances, they become electrified. If this is a control and measuring device, the case may end in its breakdown.

The discharge current brought by a person destroys connections with its heat, breaks the tracks of microcircuits, and destroys the film of field-effect transistors. As a result, the circuit becomes unusable. Most often, this does not happen immediately, but at any stage during the operation of the tool.

In factories processing paper, plastics, textiles, materials often behave incorrectly. They stick to each other, stick to various types of equipment, repel each other, collect a lot of dust on themselves, and wind incorrectly on spools or bobbins. This is due to static electricity. Two charges of the same polarity repel each other. Others, one of which is positively charged and the other negatively, attract. Charged materials behave in the same way.

In printing plants and other places where flammable solvents are used, fire may occur. This occurs when the operator is wearing shoes with non-conductive soles and the equipment is not properly grounded. The flammability depends on the following factors:

• discharge type;
• discharge power;
• source of static discharge;
• energy;
• presence of solvents or other flammable liquids nearby.

Discharges are spark, carpal, sliding carpal. A spark discharge emanates from a person. Carpal occurs on the pointed parts of the equipment. Its energy is so small that it practically does not cause a fire hazard. A sliding brush discharge occurs on synthetic sheets, as well as on roll materials with different charges on each side of the web. It poses the same danger as a spark discharge.

Lethality is a major issue for safety professionals. If a person holds on to the bobbin and is himself in a zone of tension, his body will also be charged. Always touch ground or grounded equipment to discharge the charge. Only then will the charge go to the ground. But a person will receive a strong or weak electric shock. As a result, reflex movements occur, which sometimes lead to injury.

A long stay in a charged zone leads to irritability of a person, to a decrease in appetite, and worsening of sleep.

Dust from the production area is removed by ventilation. It accumulates in pipes and can be ignited by a static spark.

How to remove static electricity from a person

The simplest means of protection against it is equipment grounding. In production conditions, screens and other devices are used for this purpose. In liquid substances, special solvents and additives are used. Antistatic solutions are actively used. These are substances with a low molecular weight. The molecules in an antistatic agent move easily and react with moisture in the air. Due to this characteristic, static is removed from a person.

If the operator's shoes have non-conductive soles, he must necessarily touch the ground. Then the escape of static current into the ground cannot be stopped, but the person will receive a strong or weak blow. We feel the effect of static current after walking on carpets and rugs. Drivers getting out of the car receive electric shocks. It is easy to get rid of this problem: just touch the door with your hand while sitting still. The charge will drain to the ground.

Ionization helps a lot. This is done using an antistatic bar. It has many needles made of special alloys. Under the action of a current of 4-7 kV, the air around decomposes into ions. Air knives are also used. They are an antistatic bar through which air is blown and cleans the surface. Static charges are actively formed when liquids with dielectric properties are sprayed. Therefore, to reduce the action of electrons, a falling jet should not be allowed.

It is advisable to use antistatic linoleum on the floor and clean more often with household chemicals. At enterprises associated with the processing of fabrics or paper, the problem of getting rid of static is solved by wetting materials. Increased humidity prevents harmful electricity from accumulating.

To remove static, you must:

• humidify the air in the room;
• treat carpets and rugs with antistatic agents;
• wipe the seats in the car and in the rooms with antistatic wipes;
• Moisturize your skin more often
• refuse synthetic clothing;
• wear shoes with leather soles;
• prevent the appearance of static on the laundry after washing.

Indoor flowers, a boiling kettle, and special devices moisturize the atmosphere well. Antistatic compounds are sold in household chemical stores. They are sprayed over the carpet surface. You can make your own antistatic. To do this, take a fabric softener (1 cap), pour into a bottle. Then the container is filled with clean water, which is sprayed over the surface of the carpet. Wipes moistened with antistatic agent neutralize the charges on the seat upholstery.

Moisturizing the skin is done with lotion after a shower. Hands are rubbed several times a day. You should change clothes for natural. If it is charging, treat it with antistatic agents. It is recommended to wear shoes with leather soles or walk barefoot around the house. Before washing, it is advisable to pour ¼ cup of soda (food) on clothes. It removes electricity discharges and softens the fabric. When rinsing clothes, you can add vinegar (¼ cup) to the machine. It is better to dry clothes in the fresh air.

All of these measures help to neutralize static problems.