EA001315B1 - Method for painting elements of dielectric or low-conductivity material, apparatus and electrode therefor - Google Patents

Abstract

1. An electrode (17) in an apparatus for an electrostatic painting of elements made of dielectric or low conducting material for engaging an element to (16) be painted and for connecting to one of the poles of an power source (19), completing the apparatus, said apparatus comprises a paint spraying unit (13) including an electrode in a zone of the paint projection connected to the other pole of the power source (19), said paint spraying unit (13) serving to electrically charge the paint and spray it onto the element to be painted, characterized in that the electrode, on its external surface, having angular regions connected to each other by recess regions, said angular regions engaging at least partially the element to be painted, said angular regions where a peak electrostatic effect is obtained and this peak electrostatic effect causes a substantial deformation of the field lines which enables simultaneous paint particles to be deposited on several sides of the element (16) without paint spraying unit (13) being moved. 2. An electrode (17) according to claim 1, the angular regions (22, 23, 24, 25, 33) being created by protrusions. 3. An electrode (17) according to claim 2 having a core with the protrusions (22, 23, 24, 25, 33) located on its external surface. 4. An electrode (17) according to claim 3, each protrusion (33) being longitudinal and parallel to the electrode axis. 5. An electrode (17) according to any one of claims 2 to 4 having a longiform core whose cross section is circular, with the protrusions (22, 23, 24, 25) forming an helix-shape on fee external surface of the core. 6. An electrode (17) according to claim 5 having a cylindrical core with an external thread and at least one longitudinal groove (26, 27) extending across the thread parallel to the longitudinal direction of the core. 7. An electrode (17) according to claim 1 having a plate-like form with the protrusions being located on at least one of the faces of said plate. 8. An electrode (17) according to claim 1 having a rippled plate-like form. 9. An electrode (17) according to claim 8, the ripples of me plate being triangular. 10. An electrode (17) according to claim 2 or claim 9, the plate having protrusions on at least one of its faces. 11. Method for painting an element (16) of dielectric or low-conductivity material using a paint spraying unit (13) including a chamber connected both to a paint outlet and to a paint supply, including the steps of: mechanically and electrically connecting to the element (16) at least one electrode (17) according to any one of the above claims; creating an electrostatic field between the electrode and the paint spraying unit by applying a potential difference between the electrode and another electrode (17) housed in the chamber of the paint spraying unit (13); feeding the paint from the paint supply (46) towards the paint outlet by passage through the chamber; electrically charging the paint; and spraying said paint onto the member to be painted. 12. Method of painting according to claim 11 using a solid paint in powder form. 13. Method of painting according to claim 11 or claim 12 including the insertion of an electrode (17) inside the member to be painted. 14. Method of painting according to claim 11 or claim 12 including the placement of the electrode (17) on at least one of the external faces of the member be painted. 15. Method of painting according to any one of claims 11 to 14 including sanding the surfaces to be painted before painting. 16. Method according to claim 15 including the application of a sealant to the recesses and edges prior to the projection of the paint. 17. Method of painting according to any one of claims 11 to 16 including passing the paint through a heating chamber (39) in which low flow heating is done at lower speeds of air flow than the subsequent phases of heating. 18. Apparatus for painting members(16) made of dielectric or low-conductivity materials for implementation of the process according to any one of claims 11 to 17 including at least one electrode (17) according to any one of claims 1 to 10. 19. Apparatus according to claim 18 having a heating chamber (39) in which low flow heating is done with lower speeds of air flow than the subsequent phases of heating.

Description

The invention relates to a method of painting elements of dielectric materials or materials with low electrical conductivity, the electrode of an installation for electrostatic painting elements of dielectric materials or materials with low electrical conductivity, and an installation for painting elements of dielectric materials or materials with low electrical conductivity.

In particular, the invention is intended for use in the woodworking and furniture industry.

Known methods of applying color to wood include the operations of sanding a wooden panel, applying a primer layer, followed by a time delay before it dries, and then an operation of applying a liquid paint followed by drying and then repeating the three indicated operations in the same sequence for up to seven cycles. The edges of the panel are treated separately, and the two surfaces must be machined several times. Thus, the complete process takes from two and a half days (in the simplest case) to four days (for complex shapes with molded elements, cutouts and grooves. In addition, liquid paints do not guarantee durability for more than one year or a small number of years. The color gamut is very limited, and finally, the layers of applied paint must be uniform, that is, the number of layers on both sides of the panel must be the same, otherwise it will warp.

Other ways of processing wood panels consist in covering the panel surfaces with laminated or reinforced paper or applying a natural substance on them. Making such complex forms in such a way is very difficult or even impossible. Coatings and their connection to wood have limited mechanical resistance to shocks.

And, finally, the last method consists in applying a film of plastic material of various colors and structure to the surfaces and edges under the action of pressure or heat. This method is called the method of forming sheet thermoplastics. This method does not cover the entire panel in one cycle. In addition, the surface fiber may be visible under a layer of sheet thermoplastic. The choice of colors here is also very limited.

The problem to which the present invention is directed is to overcome these difficulties by creating a method of painting elements of dielectric materials or materials with low electrical conductivity, in particular, wood, as well as an electrode and a plant for painting such materials using this method.

The method in accordance with the invention is a method of painting elements of dielectric materials or materials with low electrical conductivity, in which a paint spraying device is used with an internal chamber that communicates, on the one hand, with a paint outlet and, on the other hand, with a source of paint (container ). The method essentially differs in that it consists of operations of mechanical and electrical connection to the element to be painted, at least one electrode, creating an electrostatic field between the electrode and the paint spraying device by creating the electric potential difference between the electrode and the other electrode placed in the chamber paint spraying device, supplying paint from the container to the paint outlet through its passage through the chamber, transfer of the electrical charge indicated to ascus and spraying paint on said subject color element (16).

Preferably, a solid paint in powder form is used, for example a polyester based powder paint.

According to another feature of the painting method, it includes the insertion of an electrode into a painted element. This arrangement allows you to completely paint all the outer surfaces of the element.

In one embodiment, the method of painting involves placing the electrode, at least on one of the outer surfaces of the element to be painted. This variant of the method limits the color of the element to only those surfaces that are not covered by the electrode or electrodes.

In accordance with the invention, the electrode of an electrostatic painting device for elements of dielectric materials or materials with low electrical conductivity is intended to be brought into contact with the element to be painted and to be connected to one of the two poles of an electrical voltage source that completes the installation, and is essentially that on its outer surface there is at least one area with sharp profile changes intended to be brought into contact with the subject color th element, the said region with sharp changes in profile forms a so called place localization peak electrostatic effect.

List of drawings

Further, in order to better understand the features, tasks and advantages of the invention, it is explained by way of examples with reference to the drawings, in which FIG. 1 represents in flowchart the sequence of operations in the method according to the invention;

FIG. 2 shows, in schematic form, a painting machine equipped with an electrode according to the invention for carrying out the method according to the invention;

FIG. 3 shows in section a first exemplary embodiment of an electrode in accordance with the invention;

FIG. 4 is a front view of the electrode of FIG. 3;

FIG. 5 shows in section a second exemplary embodiment of an electrode in accordance with the invention;

FIG. 6 is a front view of the electrode of FIG. five;

FIG. 7 represents in cross section the electric field generated by the electrode according to the invention;

FIG. 8 represents in perspective view another embodiment of an electrode according to the invention;

FIG. 9 schematically represents in a top view a thermal chamber of an installation for painting in accordance with the invention.

Examples of carrying out the invention

FIG. 1 shows a specific example of the application of the method in accordance with the invention for painting furniture wood. This furniture wood can be made from medium density fiber, that is, with a partial use of citrus wood pressed under high pressure. Wood can also be a fibreboard, as well as any other types of natural wood of all types or recycled wood used in the furniture industry. As shown in FIG. 2, the element to be painted can be a panel in the shape of a polygon, for example, a rectangular or square shape.

In the diagram of FIG. 1 shows the operations of the method

- pruning and shaping;

- drilling holes;

- grinding and edge protection;

- polishing the entire element as a whole;

- electrode connection;

- applying an electrical voltage to the electrode;

- the supply of electrical voltage to the paint;

- paint spraying;

- heat treatment at low flow;

- heat treatment with increased flow;

- edging; and

2 - varnish coating.

The operation 1 trimming and shaping is carried out in a known manner. It may include, for example, cutting a rectangle, chamfering and shaping by making cuts and grooves. The operation is to give the element a complete form. Other operations affect the surface condition of the element. The wood used should have a moisture content of preferably from 8 to 12%.

The hole drilling operation 2 consists in making the primary hole for the electrode in the element so that the installation of the electrode does not cause the element to crack. Preferably, the hole is made non-through, and in the case where the element is a panel, the hole is made in such a way that its middle axis of symmetry is perpendicular to the main planes of the panel.

Operation 2 drilling holes perform in the area, which will subsequently be subjected to processing, or will be cut when trimming edges. Preferably, the holes for the electrodes are used further, for example, for fastening the hinges or hinges or other mechanical elements connecting the furniture panels. No drilling is performed if the electrode can be directly attached to the element to be painted. Holes are also not drilled if the shape of the electrode allows you to enter it into the element to be painted without the risk of splitting it.

The operation 3 of protecting the edges of the panel is a distinctive operation of the method according to the invention. The edges of the wood element are sanded with emery paper, which may have grit, for example, 400 for medium density fiber and 220 for fiberboard, and then they are coated with a sealing coating, such as mastic for wood based on barium or varnish based on polyurethane. This operation aims to close the pores and fill the irregularities of the tree. The protection operation 3 includes a drying period which may be several hours. She allows to subject wooden elements to the subsequent heating to high temperatures.

The grinding operation 4 is also a distinctive operation of the method according to the invention. Grinding is an operation to prepare the surface before applying the composition. Grinding removes fibers, dirt, grease and scratches from the surface. According to the method of the invention, the grinding is carried out with an emery paper with a grit above 300, preferably with a grit 400. This grit corresponds to a special operation called fine grinding due to the small size of the grains of the grinding material. All surfaces of the element to be painted are polished. The use of high-grain material prevents the opening of wood fibers to such an extent that when heated in the course of operations 9 and 1 0, vapors or gases can be released. Thus, the state of the surface staining does not change. When processing panels perform grinding of all surfaces.

Operation 5 of the electrode installation consists in its mechanical fastening and electrical connection to the element to be painted. According to a preferred embodiment, the electrode is preferably introduced with force into a hole drilled during the drilling operation 2. The fastening may be performed, for example, by driving or by screwing. The electrode includes straight or curved protrusions or sharp corners. Thus, the electrode includes concave portions. This operation is the main distinguishing operation of the method according to the invention, since the shape of the electrode contributes to the creation of a spherical or flat electric field around the electrode when it is connected to a voltage source.

Step 6 of applying voltage to the electrode involves electrically connecting the electrode to a source of electrical voltage. In the preferred use case, it is desirable that the potential be zero. Preferably, the electrode is connected to a voltage source using an electric cable or a metal holder.

The operation 7 of applying voltage to the dye is carried out in a manner known in the art. It consists in the transfer of an electric charge to a dye from a solid powder, for example, powdered polyester, with the charge sign opposite to the charge sign supplied to the element being processed from the voltage source through the electrode.

Thus, the equipotential lines are distributed throughout the element being processed, and one of them is almost identical to the volume of the element. It should be noted that this effect extends to the entire element, and as a result, the angles of the element are colored in the same way as the rest of it, if not better.

Spray painting application operation 8 is a known type of operation and is usually performed by an electrostatic spray gun when the transfer of powder paint to the element being painted is provided by a carrier air flow, static electricity and an electric field that is created between the electrode and the spray gun.

The spray gun is connected to a voltage source and is designed in such a way that it transfers the electric charge of any polarity, positive or negative, to the paint.

The paint is applied by moving the spray torch, but the paint falls on the element in one continuous layer.

Operation 9 heat treatment with a small heat flux produced in the first chamber of the furnace, which is injected colored elements. The flow of hot air entering the chamber from below is restrained by means of mechanical protection. Thus, thermal shock and airflow turbulence are limited, which could disturb the paint evenness. This operation has a very short period, about two to four minutes, during which time the paint begins to stick to the base.

Operation 10 heating with increased flow refers to operations of a known type. It is carried out in the rest of the stove. These two types of heating are produced, for example, in a gas furnace, but any other type of heating chamber suitable for this function can also be used.

And, finally, for elements that sell in the form of prefabricated panels, operation 11 trimming allows you to give the elements the required dimensions and remove the holes for the electrodes drilled in step 2.

The lacquer coating operation 1 2 refers to operations of a known type and is carried out using a blower, roller, automatic or manual spray.

From the description of FIG. 1 it is clear that the distinctive steps of the method according to the invention in descending order of importance are the following using an electrode that includes straight or curved protrusions or sharp corners and thus contributes to creating a spherical or flat electric field around the electrode when it is connected to a voltage source;

performing grinding using grit above 300, preferably grit 400, which corresponds to the fine grinding operation. This polishing improves the smoothness of the surface, while at the same time preventing warping during heating.

Operation 3 edge protection that is covered with diluted mastic for wood or polyurethane varnish. Thus, this operation consists in sealing the pores of the wood and filling the irregularities of the wood surface. This edge protection operation also includes a drying phase that can last several hours.

FIG. 1 shows a specific example of the application of the method in accordance with the invention for painting furniture wood. However, the method can also be used for other objects, such as gypsum, briquettes, brick, PVC, ceramics and, more generally, for all materials of low electrical conductivity.

The method according to the invention can also be used for cardboard products made by thermal pressing from a mixture of ground mass with an adhesive based on urea. The crushed mass can be obtained from cardboard boxes with aluminum sheet coating.

It should be noted that the color can be metallized and / or provide a metal layer or create any other effect, such as the effect of graininess, embossing, embossed or smooth surface.

Products obtained using the method of FIG. 1, successfully passed impact tests with ball impacts up to 110 g, quality control of paintwork and varnish coatings, sectional strength tests of adhesion of varnish coatings, scratch resistance tests, burnout of burning cigarettes, stains from household and food products products.

According to the first embodiment, the method includes the step of coating with varnish by applying a colorless varnish with UV drying with a brightness of 25 to 100% (at the consumer's choice), without fine grinding the substrate. The consumption per square meter is preferably from 90 to 160 g with an accuracy and uniformity of up to 1 0 g.

According to the second variant, the method includes the step of coating with varnish by applying polyurethane varnish with conventional drying or by applying diluted mastic for wood with conventional drying.

According to these two options, application can be done with a robot, blower, spray gun or manually.

FIG. 2 is a schematic representation of a painting plant in accordance with the invention.

The drawing shows the spray gun 13 paint subject element to be painted 16, electrode 17, electrode holder 18, voltage source 1 9, paint 20, paint stream 21, compressor 45 and powder container 46, forming an ink supply 20.

The paint spray gun 13 is designed in such a way that it directs the flow 21 of electrically charged paint to the element 16 to be painted. This apparatus is of a known type. It includes a pistol-type body with an internal chamber, which at one end has an outlet for paint, and the other end is connected by means of a pipeline with a source 46 of paint. The paint in the form of powder is supplied with compressed air from the source 46 through the specified chamber to the outlet. An electrode (not shown) is placed inside the atomizer chamber, electrically connected through the electric circuit of the atomizer to the positive pole of the electrical voltage source 19. The other pole of the voltage source 1 9 is electrically connected to the electrode 1 7 either directly or indirectly by means of a holder 18. Thus, an electrostatic field is established between the electrode 17 and the atomizer electrode, which can be positive or negative, depending on the choice of the electric circuit. The paint is electrically charged when it passes through or is in contact with the atomizer in the chamber near the spray electrode. Preferably, the source of electrical voltage creates a potential difference of several tens of kilovolts between its poles.

The coloring element 1 6 is at the stage of spray painting application step 8 in the method described with reference to FIG. one . Consequently, the element is already ground using grain above 300, and the irregularities on the edges are already sealed.

The compressor 45 injects compressed air into the powder container 46 in a manner known per se to convey ink to the paint in the container. Paint in the form of fluid is supplied to the sprayer.

The electrode holder 1 8 serves as a support for mounting the electrode 1 7 and element 1 6 and for electrically connecting one of the poles of the source 1 9 voltage to the electrode 1 7.

Electrode 1 7 is a conductor and includes parts of angular shape, such as, for example, straight or curved protrusions or acute angles. Thus, the electrode 1 7 also includes concave portions. It is electrically connected to the electrical ground and to the element 1 6. The negative pole of the voltage source 1 9 will be connected to this electrical ground. It also serves as a support for item 1 6.

In a cross section with a plane normal to the axis of the electrode, each projection forming part of the electrode may have a triangular, trapezoidal or any other shape that forms a sharp curvature region at a distance from the specified electrode surface.

Each protrusion may be made in the form of a spike or be elongated and move away from the plane of the electrode in a straight line or along a curve, for example, along a circular arc, along a helix or another curve.

The electrode may include a core, from the outer surface of which the protrusion (ledges) radially departs (leaves). Such an electrode with a central core is designed to be installed in a hole previously made in the element to be painted.

In the case when such an electrode must be mechanically and electrically connected to a painted element in the form of a panel of a polygonal configuration, all surfaces of which are to be painted, the electrode is preferably inserted into the panel in the direction of its thickness. In this case, the longitudinal axis of the electrode core is perpendicular to the two large planes of the panel.

The core may have a rectangular cross section, but it is preferable that its cross section is round. Then the core will have a cylindrical or conical shape. The ledges of the electrode with a cylindrical or conical core can move away from it, each along one of the forming outer cylindrical or conical surface of the core or along a curve to this outer surface, for example, along a helical line, around a circle, etc. The ledges of the electrode with a cylindrical or conical core can be also formed by spikes radially extending from the core.

FIG. 3 is a sectional view of a preferred exemplary embodiment of the electrode of the present invention. FIG. 4, the same exemplary embodiment is shown in front view. The electrode is formed by a cylindrical core, has an external thread and at least one longitudinal slit, passing along the generatrix through the thread.

FIG. 3 and 4 shows an element 16, an electrode 17 with a cylindrical core, on which there is an external thread with turns 22, 23, 24 and 25 and at least one slot, an internal cavity 28, an internal thread 29, a front plane 30 and a rod 32 Preferably, two diametrically opposite slits 26, 27 are provided in the electrode. The electrode may have a greater number of slits, preferably evenly spaced around the circumference. You should pay attention to the fact that the length of the electrode is set in accordance with the thickness of the product to be painted.

In element 1 6, a hole is made, the diameter of which is approximately equal to the diameter along the depressions of the threads 22, 23, 24 and 25 of the external thread, and the depth is approximately equal to or greater than the length of the part of the electrode inserted into the panel.

The coils 22, 23, 24 and 25 of the external thread and the two slits 26, 27 are made in a single external thread with a pitch of, for example, 1 mm. With this arrangement, each coil 22, 23, 24 and 25 external thread has approximately the same length with the others, but its length is less than half of the helical coil due to the intersection with the slots 26 and 27. Thus, the electrode 1 7 includes curvilinear screw lugs and sharp corners .

The cylindrical internal cavity 28 is made through along the central longitudinal axis of the core.

Depicted in FIG. 3, the electrode does not have a stop shoulder, but in this embodiment it may include a shoulder to limit the depth of the element 1 6.

Internal thread 29 or screw thread is made along the entire length of the cavity 28.

The metal rod 32, due to its shape, makes it possible to insert the electrode 1 7 into the element 1 6 and connect the means of electrical connection to the electrode. The rod 32 is preferably cylindrical and has a thread at the end for screwing into the internal thread 29 of the electrode

17. The said rod 32 provides the mechanical and electrical connection of the electrode 1 7 with the holder 1 8. The rod may also serve as a support for the electrode.

The electrode 1 7 in the exemplary embodiment of FIG. 3 and 4 are inserted preferably by screwing. Due to the presence of slots, the electrode in this embodiment is a self-tapping element, i.e., when screwed into the hole, it itself cuts the thread in the hole. Thus, the protrusions of the electrode in the form of thread turns completely enter the panel material and are in direct contact with the element to be painted, which improves both the mechanical and the electrical connection between them.

Preferably, the depth of penetration of the electrode into the hole in the element 1 6 is substantially greater than half the thickness of the element 1 6 and less than its entire thickness.

FIG. 5 is shown in the sectional view a second embodiment of the electrode. FIG. 6 shows the electrode of FIG. 5 on the front view.

FIG. 5 and 6, the element 1 6 and the electrode 1 7 with a core, on the cylindrical surface of which external straight longitudinal projections 33 are made, are separated by longitudinal hollows 34, as well as with an internal cavity 35 and a shaft 32. The electrode has a cylindrical core.

The outer straight longitudinal projections 33 and valleys 34 form a prism with a polygonal base, for example, in the shape of a star. The cavity 35 passes through the longitudinal central axis of the electrode. The flange 31 and the rod 32, screwed at one end, are made the same and have the same functions as in the embodiment of FIG. 3 and 4.

The electrode 1 7 in the exemplary embodiment of FIG. 5 and 6 are preferably inserted with force into a hole previously made in the panel. Thus, the electrode 1 7 includes straight ridges and sharp corners.

In the framework of the invention there may be other forms of the electrode, such as, for example, screws, rods with screw thread, etc.

You can also run the electrode, for example, in the form of a thin plate of polygonal shape with outer protrusions, at least on one of the surfaces of the plate. Such an electrode can be sunk into the panel by incision without preliminary drilling, or inserted into a pre-drilled hole or reinforced on one of the surfaces of the element. The protrusions of such an electrode in the form of a thin plate can have the form of elongated spikes, etc. In any case, each protrusion will have a straight part of a triangular or trapezoidal or other shape to create a point of peak electrostatic effect.

The plate can form alternating protrusions and depressions, that is, be wavy (grooved). Waves plates may have a triangular profile. The wide surfaces of the waves can be smooth or have protrusions of the types described above (see Fig. 8).

FIG. 7 shows in cross section the electric field created by the installation according to the invention.

FIG. 7 shows the equipotential lines 36, 37 and 38, which are created when voltage is applied in the air to the recessed portion of the electrode 17.

These equipotential lines 36, 37 and 38 have an elliptical shape, and in space their surface is ellipsoidal.

Obviously, when the electrode 17 is embedded in element 1 6, the field lines take on an even more flattened shape, and one of them is essentially identical to the form of element 1 6. This is caused by the dielectric properties of the material of element 1 6 or its low electrical conductivity.

FIG. 9 shows a furnace 39, an element entry zone 40, an element exit zone 41, an increased flow heating zone 42, an inlet for hot air, provided with protection 44.

The furnace 39 includes a zone 40 for input of elements, which may be, for example, located at one end of the furnace, while the zone 41 of the exit of elements is located at its other end. An intermediate zone 42 is located between these two zones. In said furnace 39, the first stage of heating, or heat treatment, with lower air flow rates compared with subsequent stages of heating, or heat treatment, is performed so that the paint can form a gel before the element enters the zone with strong air currents. The first stage of heating is carried out in the air inlet zone, while the subsequent stages are carried out in the rest of the furnace, that is, in zones 42 and 41. It is important to note that the entire volume of the furnace has the same temperature.

The heating zone with increased flow includes zones 42 and 41. According to a preferred embodiment, the furnace is equipped with air inlets along its entire length, with air being supplied from below, and the input holes are distributed in zones 40, 41 and 42. In order to The air flow was slow in the entry area. It is equipped with a screen 44, which is formed by a removable damper placed at the bottom of the zone and closing the air inlets. In accordance with the method and installation for heating, the elements 1 6 are first subjected to heating without thermal shock and air turbulence, since these two effects can cause deterioration in the quality of the coloring of the surfaces of the element 1 6, which is still in the state of solid powder deposited on the surface of the element 1 6 .

It should be noted that the temperature and duration of heating can withstand those that are recommended for the used paints and powders, since the tree after protecting the edges and grooves with sealing means can withstand high temperatures without thermal expansion.

The method and apparatus according to the invention can also be used for painting elements of wood agglomerates, pressed wood, wood agglomerates coated with a polyvinyl film, for example, PVC, smooth or imitating a natural structure, medium density fiber, rough or PVC coated smooth. or imitating natural structure or plywood natural structure.

It should be noted that the electrode can be part of the finished finished product and in this case is not removed from the panel. Such an electrode, which in this case represents a plug-in part, can serve as a connecting element for a panel.

Claims (19)

CLAIM 1. The electrode (17) of the installation for electrostatic painting of elements made of dielectric materials or materials with low electrical conductivity, intended to be brought into contact with the element to be painted (16) and to connect to one of the two poles of the voltage source (19) that complements the installation moreover, the specified installation contains a spray gun (13), including in the area of the paint passage an electrode connected to another pole of the voltage source (19), said spray gun the sprinkler (13) is designed to transmit an electric charge to the paint and spray it onto the element to be painted, characterized in that on its outer surface there are made areas with sharp changes in profile, interconnected by areas of depressions, and these areas with sharp changes in profile and areas of depressions for contacting at least partially with the element to be painted, while these areas with sudden changes in profile form a zone of localization of the peak electrostatic effect, and this the peak effect causes a significant deformation of the field lines, which ensures the simultaneous deposition of paint on all surfaces of the element (1 6) without moving the spray gun (13). 2. The electrode (17) according to claim 1, characterized in that said regions with sharp changes in profile are formed by protrusions (22, 23, 24, 25, 33). 3. The electrode (17) according to claim 2, characterized in that it contains a core, and the protrusions (22, 23, 24, 25, 33) are located on the outer surface of the core. 4. The electrode (17) according to claim 3, characterized in that each protrusion (33) is made longitudinal and parallel to the axis of the electrode. 5. The electrode (17) according to any one of claims 2 to 4, characterized in that it is provided with a straight core of circular cross section, and the protrusions (22, 23, 24, 25) are made in such a way that they form a helix on the outer surface of the core . 6. The electrode (17) according to claim 5, characterized in that it is formed by a cylindrical core equipped with turns (22, 23, 24, 25) of the external thread and at least one longitudinal slot (26, 27) passing along core forming with thread intersection. 7. The electrode (17) according to claim 1, characterized in that it is made in the form of a plate, while the protrusions are formed on at least one surface of the specified plate. 8. The electrode (17) according to claim 1, characterized in that it is formed by a wavy plate. 9. The electrode (17) according to claim 8, characterized in that the plate waves in the cross section are triangular. 10. The electrode (17) according to claim 2 or 9, characterized in that said plate is provided with protrusions on at least one of its surfaces. 11. The method of painting the element (16) of dielectric materials or materials with low electrical conductivity, which use a device (13) for spraying paint (20), including a camera communicating on one side with the outlet for the paint and on the other hand with the source (46 ) a supply of paint, characterized in that at least one electrode (17) is mechanically and electrically connected to the element (16) in accordance with any of the preceding claims; creating an electrostatic field between the electrode (1 7) and the paint spraying device (1 3) by creating a potential difference between the electrode (17) and another electrode placed in the chamber of the paint spraying device (1 3); supplying paint from a paint source (46) to a paint outlet by passing it through a chamber; electrically charge this paint (20); and spraying said paint onto the element to be painted (1 6). 12. The painting method according to claim 11, characterized in that it uses solid paint in the form of a powder. 1 3. The method of coloring according to claim 11 or 1 2, characterized in that the electrode (1 7) is introduced into the element (1 6). 1 4. The method of painting according to claim 11 or 1 2, characterized in that the electrode (1 7) is placed on at least one of the outer surfaces of the element to be painted (1 6). 15. The painting method according to any one of paragraphs.11-14, characterized in that before applying the painting to be painted the surface of the element is subjected to fine grinding. 16. The painting method according to clause 15, characterized in that before the spraying of solid paint, the unevenness of the edges and grooves of the elements is sealed by applying a sealing coating. 1 7. The painting method according to any one of paragraphs 11 -1 6, characterized in that it includes the operation of moving through the zone of the furnace (39), which produce heating with reduced air flow rates, in comparison with the subsequent stages of heating. 18. Installation for painting an element (16) of dielectric materials or materials with low electrical conductivity for implementing the method according to any one of claims 11-17, characterized in that it is equipped with at least one electrode (17) according to one of claims. 1-10 of the claims. 1 9. Installation according to claim 1, 8, characterized in that it includes a furnace (39), in which heating is carried out with reduced air flow rates, in comparison with subsequent stages of heating.