What is the general outline of the powder paint production process? What are the main types of technological equipment used in the production of polymer powder paint? Powder coating

Powder painting This is a modern method of applying protective and decorative coatings to various surfaces, which can be:

• equipment housings
• aluminum profiles
• electrical cabinets
• fences
• household appliances, etc.

The basis of the paint coating application method using electric field high voltage is the attraction of particles with opposite electrical charges to each other.

Powder paints act as the initial product for manufacturing polymer coatings. Included powder paints includes several components: film-forming agents (solid particles) and a separating medium (air).

Powder paints classified by following criteria: by color, by type of film former (epoxy, polyester, polyacrylate, polyamide, etc.), by texture (shagreen, moiré, antique, hammer enamels, paints with the effect of “leather”, “wood”, etc.) Depending on the area of ​​application and purpose, there are powder paints for outdoor and interior works, for protecting pipes, for producing chemically resistant, anti-friction, electrical insulating and other coatings.

Stages technological process obtaining powder coating:

• surface preparation;
• application of powder paint;
• formation (polymerization) of the coating.

The quality of the coating will depend on compliance with technological regimes throughout the entire technological process. The technological process is individual for each product - it must take into account the conditions of use of the product and the structural material from which it is made.

Components of a line powder coating by spraying it in a high voltage electrostatic field:

1. Surface preparation system

3.Coating chamber

4.Polymerization chamber

5. Transport system

1. Surface preparation

Surface preparation is important stage in the technological process. Requirements for parts that are needed paint: no burrs, raw welds, spatter, burns, cracks or sharp edges. In addition, the surface must be dry, clean (free from scale and rust), free from all contaminants (grease, oil, etc.)

The product is brought into proper condition in a pre-treatment unit, which consists of several zones. To chemically clean the surface of a product from contaminants, two methods are used: dipping in baths or spraying a solution in a tunnel. Depending on the material, cleaning is followed by pickling, degreasing or phosphating.

2. Drying chamber to remove adhesive water

The adhesion water removal drying chamber is used to remove residual moisture after the part has gone through all the pre-treatment stages. This camera resembles polymerization oven, but has more simple design and works with temperatures up to 160 °C. The option for drying a part depends on its type; in some cases, blowing with dry air from the room is sufficient.

3. Chamber for applying powder paint

Work of this cameras is based on the principle of electrification of particles that are in an aerosol state. Particles are charged under the influence of an external field. There are 2 methods that are used for application powder paint in an electric field:

• Electrostatic (paint particles receive a charge from a current source)
• Tribostatic (particles receive charge from friction)

In practice, electrostatic spraying is more often used. Using this method, a variety of powder materials can be applied, such as epoxy, polyester or polyurethane. In turn, the tribostatic method is used to apply epoxy paints, while others require special additives. The electrostatic method is quite productive and allows you to obtain a coating good quality. With this method, you can use different types of sprayers. Most often, one channel is used for the passage of powder paint, and the other for the passage compressed air, which is necessary for spraying. The powder is charged in the gun itself at 60-70 kW. The air pressure at the sprayer is approximately 0.8 to 1.5 MPa. There are certain standards that compressed air must meet:

• oil content less than 0.01 mg/m³
• moisture content less than 1.3 g/m³
• dew point content less than 7°C
• dust content less than 1 mg/m³

For spraying on a gun can be used different types spray nozzles. Thickness of 1 coating layer: 20-150 microns.

Produce spraying powder paints need special ones application chambers. By design powder coating chambers There are different ones, but they all use the same principle: paint particles that have not settled on the surface of the part are sucked out using a fan and then passed through a filter or cyclone. The air that has been exhausted and purified is released, and the powder particles remain on the filter surface, which is used as fabric or paper. After this, the paint that has not settled is collected in a container or fed back into the spray gun.

If you need to change the paint color, you definitely need to clean it. spray chamber or change the filter, and also blow out the paint supply hoses.

How completely the paint settles depends on factors such as the specific mass charge of particles, the speed of air movement in application chamber, uniformity of paint supply, as well as the size and configuration of the part being painted. Therefore, it is necessary to comply with the required operating parameters of electrostatic powder coating installations, as well as a powder tank and spray booth.

For stable operation Electrostatic sprayers must be maintained at inlet air pressure sprayer 0.1 - 0.6 MPa and voltage at the discharge electrode 60-80 kW.

It is imperative to take into account that the most optimal parameters can only be selected experimentally, taking into account the specific dimensions of the parts and their configurations. Another important factor affecting completeness and quality powder coating- type of spray nozzle. A smooth and controlled supply of powder to the gun should be ensured by a powder tank ranging from 0 to 25 kg/h, and an air supply with a flow rate of 0-20 m³/h.

Failure to comply with the required parameters may result in coating defects. .

4. Powder paint polymerization chamber

The structure of the powder coating is formed during the hardening process; its nature depends both on the nature of the paintwork material and on the conditions under which the coating is formed. These conditions are specified in technical documentation To powder paint. The curing regime must be observed, otherwise the properties of the coating may be changed. So, when underheated, the mechanical properties deteriorate, and when overheated, the color and shine are distorted.

In practice, several hardening modes are used powder paints, the choice of the appropriate one depends on the production conditions and directly on the material of the part.

Please note that the documentation for the paint indicates the curing temperature that should be on the surface of the part.

With the convective method, drying takes approximately 15-25 minutes at a temperature of 160-250°C.

When drying in combined drying chamber the process takes about 10-12 minutes. Combination cameras have a number of advantages:

• less time is spent heating the part
• no need to preheat the part
• it is possible to control the process
• accelerating the hardening process of coatings on thin-walled products
• no need for a cooling zone large size
• receiving improved mechanical properties coatings
• high efficiency

5. Transport system

Devices for transporting parts are used to automate the powder painting process. Important place In the transport system, overhead and belt conveyors occupy. Many problems associated with transportation, including when processing medium-sized or heavy parts, can be solved by using single-strand or overhead conveyors. In cases where it is necessary to coat large or very long parts, as well as when working indoors small area It is best to use an installation that includes devices with and without a drive (Power+Free installation), thanks to which longitudinal and transverse movement is possible.

The cost of paint production in Russia is much cheaper than in European countries. On the other hand, of the manufacturers on the market, only half are domestic, and the need for this product is constantly growing. Therefore, the production of paints is a promising business.

Paint production technology

The concept of paint unites a large group of colored dyes that can be used in industry and in everyday life.

All paints can be divided into two groups:

• mineral (metal oxides or inorganic salts);
• organic (substances of plant or animal origin).

Each type of paint has its own characteristics. Therefore, to obtain a certain paint, appropriate technology is used. Paints can vary both in color and in physical condition: enamel, primer, putty, varnish.

The manufacturing process consists of the following stages:

• preparation of a dispersing mixture;
• grinding semi-finished products with pigments (necessary to obtain pigment paste);
• water-dispersed combination of binders with pigment paste;
• marking of paint type and its distribution among containers.

Manufacturing process enamel paints, goes a little differently:

• combining pigments and film-forming agents (occurs in a special mixer);
• grinding the mixture;
• stirring the resulting mixture with varnish or solvent;
• color adjustment;
• cleaning procedure (aimed at eliminating impurities);
• pouring into containers.

In order to obtain nitro-enamel paint, carry out:

• combining dry paints to form a paste;
• shade adjustment;
• typing;
• product purification;
• spilling into containers.

All actions necessary to obtain a certain type of paint are carried out with extreme caution and require appropriate qualifications from employees.

Paint business

The production of paints and varnishes is rightfully considered one of the most profitable investments:

• first of all, this is the most accessible remedy for finishing, which makes paint a sought-after product;
• secondly, competition in this market in our country is extremely low.

If we take into account the statistics, over the past 7 years we can see a serious increase in the level of sales of paint and varnish products. It should be noted that most of the materials sold relate to import manufacturer. And this does not indicate a low level of domestic products, but a small number of enterprises specializing in the production and sale of paints.

Despite the fact that large and small stores mostly offer imported paints, none of them are against cooperating with Russian manufacturers. This indicates that it will not be difficult for a young company producing and selling paint and varnish products to sell its products.

Paint production equipment

To obtain high-quality paint you will need professional equipment such as:

• vacuum pump;
• tank for additional additives;
• metering tank;
• dispersing reactor;
• water treatment tank;
• compressor;
• paint mixing reactor;
• filtration mechanism;
• dissolver;
• emulsion tank;
• container for powders;
• bead mill;
• line for bottling products (paint).

In order to carry out complete mixing, emulsification and dispersion, a dissolver is required. A bead mill is necessary for dispersing and homogenizing liquids.

After the paint is ready, the products go to the bottling line, which occurs automatically.

The bottling line consists of the following components:

• conveyor belt;
• container feeding and orientation system;
• system for orientation and capping of lids.

The conveyor belt consists of cylindrical rollers, the material for which is stainless steel. The control system occurs through the use of pneumatics and electronics. Automation of the manufacturing process allows you to reduce production time, reduce the percentage of material loss, and also reduce financial costs. Product quality will improve and productivity levels will increase.

Among the Russian companies offering equipment for the production of paints are:

• "BVB Alliance" - units for the production of any type of material;
• "Texa" - offers equipment for chemical development and for the technological process of producing high-quality paint;
• "YuVS" - the main direction of the plant - is the development and manufacture of containers necessary for storing paint and combining its components at the time of production.

Dissolvers for paint production

Dissolvers for paint production are necessary to homogenize pigmented granules. This process occurs in educational film. A dissolver is required for both soaking and the initial spraying stage.

If products at the last stage of manufacturing do not require the procedure of grinding pigment particles, then the mechanism can operate in an autonomous emulsion mode. An example of this is the preparation of pigmented pastes, which are used to make enamels and paints intended for markings on roadways.

In appearance, the dissolver resembles a mechanical mixer. The difference is that cutting occurs using a toothed cutter. Another difference from the mixer is the powerful motor. The dissolver is used to grind the pigment granules as much as possible. At the exit they must be in a liquid state. In order to convert dry powder into paste, high energy power is required, which can only be provided by a powerful apparatus.

Sometimes the dissolver is equipped with an additional mixing tool. This allows you to effectively grind pigment mixtures with high density.

Raw materials for paint production wholesale

The technologist is responsible for the raw materials necessary for the production of paints. The specialist's responsibilities include:

• purchase of equipment and raw materials;
• writing technological maps;
• calculation of consumed raw materials;
• product output.

The technologist will predict the production rate. Exact data on the names and quantities of required raw materials can be determined only after the assortment of the first batches has been approved. Therefore, each technology requires a certain type of raw material.

For starter kit To make paint you will need approximately:

• dispersion (400 kg) - will be about 60 thousand rubles;
• calcium carbonate (400 kg) - approximately 5 thousand rubles;
• defoamer (25 kg) - 7.5 thousand rubles;
• additives (coalescent, titanium dioxide, dispersant) - about 30 thousand. rubles;
• chalk - 11 thousand. rubles;
• printed adhesive labels - from 9 thousand rubles.

The approximate amount required for the initial set of raw materials will be about 120 thousand rubles.

Paints for food production wholesale

To paints for food production special requirements apply. This is due to the fact that such paints will be used to paint containers for transporting and storing food and drinks. When purchasing in bulk, it is important to take into account storage methods and the shelf life of products.

Common paints for food production are:

• XC-558 enamel is used to coat metal containers whose purpose is to store wine, fruits and vegetables. This is a one-component material that can last about 12 months;
• enamel B-EP 5297 is intended for painting containers used for storing water, juices and nectars. The components of this enamel are epoxy resins and suspension of pigments;
• varnish XC-76 is used for complex coating of containers exposed to acids, alkalis and aggressive gases;
• primer XC-010 is necessary for painting containers whose surface is in contact with alkalis, aggressive gases and acids;
• VL-05 primer is used to coat tanks containing drinking water. As a rule, the metal of such a container is single-pack and requires constant treatment to prevent corrosion;
• KO-42 paint is used to coat metal tanks in which drinking water is stored.

Paints for food production can be purchased wholesale from manufacturers or product suppliers, for example, from the SpetsEmal LKM plant or the Palitra Rusi company.

Paint for industrial premises wholesale

Required for production special paint, which has important properties - water resistance, wear resistance and quick drying.

Only special paint and varnish coatings can meet these requirements, such as:

1. "Texipol" - the paint dries quickly, which allows you not to slow down production process. Water does not destroy the coating. As for negative external influences, she is not afraid of them. It is used for floors located in workshops, hangars and retail premises.
2. "Protexil" - impregnates floors, strengthening and removing dust. Ideal for coating concrete in warehouses, as well as in hangars and production workshops. Strengthens and removes dust from floors in car repair shops, garages, transport hangars, as well as in production workshops.
3. "Texil" is a matte, quick-drying paint intended for covering floors in warehouses and garages. Texil is used for production workshops and hangars. Ideal for rooms with refrigerators.
4. Epoxy poly paint consists of two components, and has distinctive features - wear resistance, impact resistance and resistance to oily liquids. Excellent for car repair shops, garages, production workshops and warehouses. It is odorless and can give the floor a decorative appearance.
5. Epolast Soil is used both in industry and in household. The primer is excellent for cladding work in warehouses and factories. Same thing when renovating an apartment.
6. Remosil is a leveling material necessary for the repair of floors in industrial workshops, as well as in the repair of residential real estate.
7. Polybetol - enamel for the concrete floor of a room in which heavy loads are handled and periodic leakage occurs chemicals. Immune to negative external influences. Odorless.

Wholesale supplies of paint for industrial premises are offered by dealers of major retail brands in the regions.

Russian-made paint wholesale

As already mentioned, few domestic entrepreneurs have decided to connect their activities with the production of paints and varnishes.

1. "Area". Since 2008, the company has been producing and selling all types of paints. Each product name barks high level quality, environmental friendliness and durability. Acrylic and oil paints, glue, putty and primer - all this can be purchased from this trusted supplier.
2. Odilak.Zavod, a manufacturer of paint and varnish products, has been on the market for several years. All items have a high level of environmental friendliness and durability.
3. "BEZ" (Bobrovsky Experimental Plant). At the factory you can purchase all types of paint and varnish products, from waterproofing to acrylic materials. The company produces primer and enamel.
4. "Colors of Belogorye". Manufacturer, specializes in the development and production of water-based paints necessary for decorative covering. This type of material is widely used in the repair of civil objects.

Water based paint production

The main feature of this paint is the evaporation of its main component - water. Due to this, the environment does not suffer. At the same time, the paint on water based It is resistant to wear and is not afraid of moisture.

There are more than 50 companies producing water-based paints in Russia. This indicates the profitability of the business due to low competition.

Alkyd paint production

Alkyd paint is obtained by combining: cobalt, iron, cerium, manganese, zirconium, lead, strontium, lithium, calcium and barium.

Alkyd paint is used for painting production facilities. This material has low price, which makes it a sought-after product.

Production of water-based paint

Technological production line water-based paint consists of a dissolver, a bead mill, an automatic bottling line and packaging of finished products.

To make paint you will need: latex dispersion, pigments and fillers, plasticizer, fine chalk, functional additives (cellulose ethers, titanium dioxide, and so on.

Production of acrylic paints

Acrylic paints are the most popular type, without which it is impossible to imagine work aimed at protecting and decorating surfaces. Acrylic paint- This resistant material, which contains a minimal amount of toxins.

The basis of the production process is the dispersion of acrylic binder, fillers and additives. For this work, a dissolver is required. The raw material for this type of paint is acrylic dispersion, thickener, coalescent and inorganic pigments.

Powder paint production

High-tech lines are used for the production of powder paint.

Production technologies are divided into two types:

• dry mixing of components;
• mixing of components in the melt followed by disintegration to the required size.

The first method has the main disadvantage, which is that with simple mixing it is difficult to obtain stable compositions that do not separate during storage and use. Melt mixing makes it easier to control product quality, but the process takes much longer and requires expensive equipment.

One of the most popular powder paint manufacturers in the country is the YaZPK company. At the enterprise, the entire paint manufacturing process takes place on ultra-precise electronic equipment.

Production of oil paints

Production oil paints consists of weighing the components and then kneading. This process is carried out in special large containers. As for the paint recipe, it depends on the technologist. Therefore, the recipe for each production is unique.

To obtain oil paints you need your own chemical laboratory. Statistics show that most of the oil paint manufacturers represented at domestic market, is located outside the territory of the Russian Federation.

Production of art and watercolor paints

To obtain watercolor paints, they resort to a combination of finely dispersed pigments, vegetable glue and dextrin. The product is produced in dry form. To make watercolor paints you need large area, capable of accommodating necessary equipment. As a rule, it is 40-60 sq. meters. Another 20 square meters will be required to store raw materials.

Watercolor and artistic paints are sold through specialized stores.

Production of decorative paints

Production market decorative paints is constantly expanding. New equipment and materials appear all the time. Features of the manufacture of decorative paints depend on the scope of application, for what types of work the coating will be used indoors or outdoors. Another important factor is the planned quantity of products.

Rubber paint production

Rubber paint is used in roofing work. This paint is ideal for road markings, sports courts, swimming pools and floors in production premises. In addition to substances familiar in paint production, such as coalescent and antifreeze, upon receipt rubber coating Special additives are also used, which are usually used by the military.

The production of rubber paint is carried out by LKM USSR, a company that carries out scientific developments for the production of especially durable materials. A special feature of rubber paint is its durability. It can last more than 8 years.

Production of road paint

Road paint is used exclusively for markings on the roadway. This type of coating must be water resistant and immune to other atmospheric phenomena.

The following companies specialize in the production of road paint:

• "Empils" - the clients of this company are road construction companies and contractors involved in road repairs. The main direction of the organization is the production and sale of polyacrylic paint in white, black and yellow;
• "Pentan" - among the company's clients are regional and city organizations specializing in road repair;
• "Kraska Vo" - the company supplies own products- road paint, everything major cities countries.

Hair dye production

Hair dye is in great demand among consumers, so many entrepreneurs have concentrated on this production.

To make hair dyes you will need:

• dye reactor;
• melting reactor;
• vacuum and atmospheric reactors.

Not only cosmetic companies, but also various organizations are involved in the development and production of hair dye. For example, Gamma is famous Russian company produces more than 30 shades of hair dye at an economical cost.

Fire retardant paint production

Fire retardant coating is a material that is widely used for special purpose objects. Fire retardant paint is used at nuclear power plants, oil and gas plants, and fuel storage tanks.

Among the companies that produce fire retardant paint are:

1. Ogneprom is a large company that develops and markets fire-retardant paint. In addition, the company specializes in the production of anti-corrosion coatings, which are also necessary for industrial facilities.
2. Texotherm is a manufacturer of fire retardant paint that produces water-organic based material. The product is ideal for increasing the fire resistance of reinforced concrete and metal structures in industrial areas.

Production of facade paints

Facade paints are made using a dissolver-mixer, since it is this device that is capable of mixing the required components. If such a unit is not available, then manufacturing companies use a dissolver with a central shaft and a cutter that does not have a frame mixer.

For the production of facade paints, equipment from stainless steel. This is explained by the fact that water-dispersion paints are aggressive substances.

It is worth highlighting the organizations that have been producing paint for facades for several years:

• "Olympus" - production of acrylic-based paint with quartz filler. The paint is ideal for covering elements of rooms where high traffic volumes prevail;
• "Alpina" - the company produces facade paint with a high level of adhesion and excellent wear resistance. Suitable for coating outside buildings.

Manufacturers and suppliers of paint production equipment

Various companies specializing in the development, production and distribution of equipment necessary for the manufacture of paint and varnish products are taking part in the Chemistry exhibition. This large-scale event is organized by Expocentre Fairgrounds, one of the largest exhibition complexes in Russia. The exhibition is visited by Russian and foreign guests.

Powder paint is a pigmented disperse system consisting of solid particles that can be evenly distributed on the surface to be painted when applied and form protective layer.

Powder paint for metal: properties and characteristics

To possess quality characteristics, pay attention to the following indicators:

• variance components;
• flowability;
• bulk density;
• spray ability;
• electrification properties;
• fluidization level, etc.

Dispersion composition

Powder paints consist of small particles of different sizes (polydisperse systems), which have a significant variation in size. With high dispersion, two types are distinguished: true and aggregates of particles (clusters of true particles behaving like a separate particle). At traditional methods disaggregation is practically not observed, therefore the true size of the particles, from the point of view of manufacturability, loses its significance. More important technological characteristics the granulometric composition appears.

If fractionation using a sieve varies over a fairly wide range from 5 to 350 µm, then the optimal particle size of powders for electrostatic spraying is 10 – 100 µm. More stringent conditions for the size of dispersion particles are observed when obtaining thin layers - from 3 to 40 microns. And in the case of using powder in a fluidized bed, it is believed that the diameter of the particles should be commensurate with the thickness of the coating and reach 350 microns.

The dispersion of particles should have its optimal fractional range depending on the type and thickness of the coating and the method of applying the powder. Highly dispersed powders, with easier fusion and the possibility of obtaining thin coatings, are characterized by worse fluidization, are more moistened and are prone to uneven deposition on the surface of products. Powders with too wide a fractional range are prone to separation and dusting, and may have increased defects in the coating surface.

Flowability

One of mandatory conditions for powder paints there are the necessary flowability indicators, which are determined by the flow time from a calibrated hole or by the angle of natural slope of 36...45°.

The indicator is affected by:

• chemical composition;
• glass transition temperature;
• shape and size of particles, surface smoothness;
• hydration.

Low flowability makes it difficult to distribute powder paint evenly on the surface to be painted and complicates technological equipment.

Flowability increases for dispersions with spherical particles with low surface roughness and an increase in the glass transition temperature, and decreases significantly with a decrease in particle size and moistening of the powders. To increase flowability, special additives are used, such as fumed silica or aerosil. Powders are protected from moisture by storing them in dry warehouses in waterproof containers.

Bulk Density

Depends on the composition of the powders, the degree of polydispersity and the shape of the particles. Depending on the type of film former, the density of the powders can increase up to two times. Pigmented compositions have a higher density, which increases with increasing amounts of pigments and fillers in the composition.

Powder paint must have a sufficiently high density. At low bulk density, powders “boil” unsatisfactorily and are poorly distributed on the surface of the product.

Electrification ability

Like any dielectrics, powder particles acquire electric charges. The charge level is affected by the film-forming material, particle size, air humidity, intensity and type mechanical impact etc.

Particles of epoxy, polyvinylbuteral, epoxy-polyester and polyethylene paints are predisposed to charge, which makes their application easier electrostatic spraying. Smaller particles of powders become more electrified and retain their charge longer. When air humidity is more than 70%, the electrification of powders decreases significantly.

The electrification of powder paints changes them physical properties: flowability and bulk density are reduced. Excessive electrification can lead to complete loss of flowability. Reducing the degree of electrification of powder paints causes significant difficulties. Even long-term exposure of a thin layer of powder paint to a grounded metal sheet does not allow achieving a complete isoelectric state. The degree of electrification is regulated not only by surface treatment and the introduction of antistatic additives, but also by the targeted synthesis of film formers with specified electrical characteristics. The technological equipment used is made of electrically conductive materials and is properly grounded.

Fluidizing ability

The fluidized bed application technology requires the ability to fluidize the powders used when blown with air. Polyethylene powders low pressure, polyester compounds, polypropylene, polyvinyl chloride and some other materials have low fluidization ability. Fine powders with low flowability and high humidity may not “boil” at all. The use of special equipment for producing a “fluidized layer”, such as vibrating vortex installations, significantly increases the cost of applying powder coatings.

The fluidization property is enhanced by increasing the particle size, creating a spherical shape, and reducing the surface roughness and moisture content.

Powder paint compositions

Among the components are:

• film formers;
• pigments and fillers;
• plasticizers;
• modifiers;
• hardeners and accelerators;
• auxiliary additives

Characteristics of film former:

1. They are solids that can be in amorphous or crystalline form.
2. They are loose powders.
3. Low melting temperature and melt viscosity.
4. A film is formed through the melts when heated.
5. Have high temperature destruction.

Powder paints, based on the type of film formers that form their basis, are divided into:

• thermoplastic;
• thermosetting.

Thermoplastics do not undergo chemical changes when heated and have become more widespread due to:

• stability of the resulting compositions;
• rapid formation of coatings;
• availability.

The main disadvantage of thermoplastic film formers is their low adhesive strength.

Thermoplastic paints include:

• polyethylene;
• polyvinylbuteral;
• polyvinyl chloride;
• polyamide;
• pentaplast and others.

Thermosets When heated, they undergo a chemical polymerization process and have:

• increased adhesion;
• can form thin coatings of excellent appearance due to low viscosity;
• reduced temperature conditions formation;
• high-quality coating characteristics under operating conditions.

One of the disadvantages of thermosetting film formers is the increase in coating formation time.

Thermosetting types include:

• epoxy;
• polyester;
• polyacrylate;
• polyurethane;
• epoxy-polyester, etc.

Pigments and fillers

In addition to the standard requirements, powder paints additionally have:

• ease of dispersibility in the melt of the film former;
• resistance to the temperature at which the coating is formed, without changing color or decomposing at the same time;
• inertness to other components of the composition.

When produced by dry mixing, pigments and fillers should encourage:

• increased flowability;
• reducing clumping and caking properties;
• improvement of “boiling”;
• applying powders to the surface.

Using fillers and pigments, the following properties of powders and coatings can be controlled:

• electrification;
• heat resistance;
• thermal conductivity;
• electrical conductivity;
• magnetic properties;
• wear resistance;
• adhesive strength;
• flammability;
• biological inertia;
• damping capacity.

Usage metal powders as fillers, they allow one to obtain an imitation metal surfaces. A significant difficulty in pigmenting powder paints is tinting the color in accordance with the RAL color standard.

In the absence of pigments and fillers in powder coating materials, it is possible to obtain transparent varnish coatings.

Plasticizers

In powder paints, they influence both the physical and mechanical properties of coatings and the temperature and time of film formation. In addition, plasticizers must:

• do not disturb the aggregative properties of the polymer;
• do not degrade technological characteristics (flowability, granulometric composition, etc.);
• function at film formation temperature.

Solid plasticizers cope better with the requirements, the main disadvantage of which is incomplete compatibility with polymers. To eliminate this drawback, combined mixtures of solids and liquids are used.

Modifiers, hardeners and auxiliary additives

Modifiers capable of improving performance through physical or chemical modification. At the same time, physical modification through the addition of various film formers has become most widespread. Modifiers also regulate the technological parameters of powder paint, such as melt viscosity, flow temperature and powder flowability.

Hardeners are necessary component paints based on thermosetting film formers. To activate the curing process, accelerators corresponding to specific hardeners are used. If for the curing process of two-component liquid paints it is enough to mix the components, then in powder paints all components are in the original composition without interaction. Hardeners are activated only at the “sintering” temperature, “launching” the curing process after the film former has melted and a liquid film has formed.

The curing system is an important component of thermosetting paints, on which not only stability and curing conditions depend, but also the performance characteristics of the resulting coating (appearance, physical, mechanical and protective properties).

Auxiliary additives allow you to increase:

• atmospheric resistance of the coating due to reduced photodestruction of polymers when exposed to solar radiation;
• resistance to temperature changes;
• powder flowability;
• melt spreading, etc.

Powder paint production technology

Common manufacturing options:

1. Dry mixing of components.
2. Mixing of components in the melt followed by disintegration to the required size.

The method of producing powders by drying sprayed liquid paints has not become widespread due to significant losses of solvents and the high cost of paints.

Dry mixing of components is the main option for the manufacture of powder paints from thermoplastic materials. Production is done without expensive equipment and significant labor costs. The difficulty lies in obtaining stable, non-separating compositions during storage and use with a uniform distribution of small additives.

Mixing components in the melt produces high-quality homogeneous powders with stable composition and structure. The method is lengthy, has many stages, requires expensive and complex equipment. Can be used for any solid film formers, but is mainly used for thermosets.

The main methods of applying powder paints to the surface to be painted:

• electrostatic spray;
• in a "fluidized bed".

Powder spraying is carried out with a special gun in a spray booth, the ventilation system of which has powder catchers for its reuse.

When coating in a “fluidized bed”, the powder is in a pseudo-liquid state due to uniform blowing with air. The paint is applied to the surface of the part by dipping the part into a container of fluidized powder.

In both cases, before application by a special electrode, the powder particles are given a certain electrostatic charge, which ensures uniform distribution of the powder and its retention on the surface of the part to be painted.

After applying the powder, the part is heated in an oven, which forms a monolithic liquid coating. Thermoset plastics additionally undergo polymerization.

The existing method of flame spraying of powder paints and varnishes has not become widespread due to the instability of the technology and the significant influence of the human factor.

Powder paint: application, advantages and disadvantages

Powder paint for metal was originally used as a replacement for electroplating on small metal parts simple form for mass production. The cost-effectiveness and ease of mechanization of the process of obtaining coatings during continuous production have significantly expanded the use of powder paints.

Main consumers of powder coatings:

• hardware products (wire, tape, mesh), household and agricultural products;
• metal furniture;
• household appliances and equipment;
• electrical industry products;
• automotive industry;
• agricultural and transport engineering;
• pipe production;
• metal and glass containers, coating allows reducing glass thickness by up to 30%;
• chemical industry equipment;
• building structures;
• machinery and equipment for the food industry.

Automotive factories successfully operate automated painting lines for both wheels with a capacity of up to 3 million pieces per year, and automobile chassis with dimensions of up to seven meters and a productivity of up to 58 pieces per hour. In pipe production, the technology of applying powders to preheated pipes is used. Powder paints have been developed for non-metallic materials such as glass, plastic, MDF and others.

Advantages:

• ease of mechanization and automation of coating application;
• environmental friendliness, lack of organic solvents;
• low paint consumption;
• possibility of using sparingly soluble polymers;
• waste-free coating production, almost 100% use of paint material;
• obtaining working covering required thickness in one layer;
• uniformity of the paint layer on both horizontal and vertical surfaces;
• possibility of applying coating in hard-to-reach places;
• metal, painted powder paint have chemical resistance;
• durability;
• wear resistance.

Flaws:

• tendency to release dust;
• the need for specialized equipment;
• feasibility of use only in serial and mass production;
• explosiveness of powder suspension in air.

Video: powder painting of metal

It is hardly appropriate to recommend the use of powder paints and varnishes at home. These coatings do not have unique performance properties; you can always find traditional materials that form similar or higher quality coatings. It is not practical to purchase special equipment to paint your car’s rims “with your own hands.”

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Powder paints are high-tech building material, which has unique properties, inaccessible to liquid dyes. Thanks to their special composition, they exhibit high wear resistance and excellent performance. In the manufacture of this substance, a film-forming resin, coloring pigments, catalysts responsible for hardening the material and special additives are used that give the paint a certain set of properties.

Features of powder paint production

The production technology of this type of product consists of several interconnected stages. The first stage involves the preparation of raw materials. To do this, operators perform a visual inspection of the delivered materials and check whether the markings on the packages correspond to their actual contents. After successful inspection, the raw materials are sent to the dosing machine. There all components are weighed and transferred required quantity into a common mixing container.

The first stage is completed when the operator makes an entry in the work log that such and such a number of raw materials were taken for a certain brand of paint. All components are mixed until smooth using special mixers. To prevent the raw material from overheating during this procedure, the chambers are equipped with special cooling systems. The resulting powder is conveyed through a conveyor to special equipment called an extruder. It melts all constituent elements and mixing them until a homogeneous liquid. The melting point of the raw material is 110-130 degrees Celsius, depending on the selected components.

Next, the resulting melt is passed through a machine with rolling rollers. Here the material takes the form of a tape, up to 1.5 millimeters thick. After the workpiece has completely hardened, it is sent to a grinding machine. This procedure is carried out in two stages. First, the tape is cut into small plates measuring 10x10 millimeters. Then these blanks are fed to a crusher, where the final grinding to a powder state takes place.

The crusher has a centrifugal impact mechanism and a special screening filter that rejects too large particles and sends them for re-crushing. And the products that pass through the sieve are sent to the filter fine cleaning, which removes powder dust from the mixture, leaving only usable particles.

Products that have passed all levels of quality control are sent for packaging, where they are packed into containers of a certain volume. It is then delivered to the warehouse finished products or they are immediately sent to stores for sale. Powder paint is used only for industrial purposes, so it is usually packaged in large containers weighing up to 600 kilograms. Although for small auto repair shops there are also bags of 15-20 kilograms.

Application of powder paint

Requires a special approach due to the specifics of the material used. This procedure occurs in several stages, at each of which separate equipment is used. Before painting, the surface of the part is cleaned of various types of contaminants and degreased with special substances. Then coloring powder is sprayed onto the cleaned product using special guns. Work must be done in a protective suit with a mandatory respirator.

The paint itself does not contain harmful substances and is not toxic, but its entry into the respiratory system is unlikely to be beneficial to human health. The spray gun has quite complex device. It charges the powder paint inside using an electric field. Due to this, the material is attracted to the oppositely charged surface of the part and immediately bonds with it in a strong bond. This allows you to minimize paint loss during work. Thanks to the unique structure of the spray booths, all particles that do not settle on the surface of the part are captured and can be reused for painting other items.

When spraying is completed, the part is transferred to a special oven for polymerization. In this unit, under the influence of temperature, the sprayed layer is baked. Temperature is set manually and, depending on the brand of paint, has a range of 140-200 degrees Celsius. Processing time also depends on the type of paint and is set by the operator. After polymerization is complete, a durable protective layer is formed on the painted surface, which effectively resists weathering for a period of time. long period time.

Metal products are mainly painted with powder paint, since they have a fairly strong electric field and can withstand high polymerization temperatures without problems. Also, some types of ceramic and glass products. The color range currently includes more than three hundred shades.

Among the disadvantages of powder paints, one can highlight only the impossibility of their mass distribution. The need to adhere to a unique dyeing technology using complex and expensive equipment does not allow the use of this material at home. But in industry, this method has already practically replaced liquid paints for painting metal objects. With other substances, things are more complicated due to the need for heat treatment of the paint layer. So full replacement powder material other species are not expected in the near future.

Powder paint price domestic production is 70-120 rubles per kilogram. Imported models will cost 150-200 rubles. As for quality, it is at a comparable level. The higher cost of foreign analogues is due to transportation costs and customs duties.

General technological scheme The powder paint production process includes the following steps:
1 – preparation and dosing of raw materials;
2 – mixing components;
3 – extrusion of the mixture (production of chips);
4 – crushing chips;
5 – packaging, packaging, labeling;
6 – quality control.
Quality control is separated into a separate stage with a certain degree of convention. In fact, this stage is divided into separate components (substages), which are an obligatory (final) part of each stage of the technology.
Preparation and dosing of raw materials. The stage begins with the receipt of raw materials at the plant warehouse and its acceptance. Raw materials can be supplied in bags or boxes, plastic containers volume, soft containers (big bags) weighing about 600 kg. When receiving raw materials at the warehouse, the integrity and appearance of the packaging is checked, the quantity and name of raw materials correspond to the data specified in the delivery note, and the batch numbers are compared with the numbers in the quality passports. After acceptance, the amount of raw materials required for production using various devices delivered to the dosing areas, the remaining raw materials are stored in the warehouse. At the dosing site, a visual assessment of the compliance of the appearance of the raw materials with certain requirements is also carried out.
Dosing of raw materials is carried out in the areas of small and large premixes according to the production instructions. First, using a small premix, individual PC components, the content of which in the paint formulation is insignificant, are weighed manually on scales. The operator punches and signs a receipt, which indicates the digital code of the weighed component and its actual quantity. Then the mixture from the small premix is ​​transferred to the large premix.
A large premix allows you to dose the components of the PC formulation in large quantities. Raw materials received from the warehouse are filled into separate bins using mechanical devices. The operator of a large premix selects a clean mobile (on wheels) container corresponding to the amount of loading, which is installed on floor scales under the bins. In a certain sequence, controlled by weights, individual components are poured from bins into a container (the mixture from a small premix is ​​done manually). At the end of dosing, the operator punches and signs a receipt, which indicates the component number and its weighed quantity. Next, the container with the technological map and two premix receipts is transported to the mixing area.

Mixing components. Depending on the size of the mobile container loaded with the mixture, the operation is performed in industrial mixers (mixers). The mixing mode is set on the control panel timer. To avoid overheating, cooled water is supplied to the mixing head of the mixer. Upon completion of mixing the components, the finished mixture (charge) is transported in a container to the extrusion site.
Extruding the mixture. The production of a paint melt in a continuous mode is carried out on special equipment called an extruder. Various types extruders differ from each other mainly in performance. Conventionally, the extruder can be divided into two levels: upper and lower.
A mobile container with the finished mixture is lifted using mechanical devices to the unloading station platform (upper level) and fixed on it with pneumatic grippers. The operator manually opens the container valve, and the mixture, using a screw feeder, begins to be fed directly into the extruder (lower level). Passing with variable speed forced heating zone, the mixture is melted and, through the screws of the extruder itself, already in this state is mixed until homogeneous.
The hot melt (temperature 110-130ºС) is squeezed out of the extruder discharge hole and flows onto the cooling cylinders (rollers) of the continuous cooling system. Passing between two cylinders, the alloy is rolled out to a strip 0.5 - 1.5 mm thick, cools and turns into a solid state. Next, the cooled tape is fed through a conveyor belt to a crusher, where it is crushed into flakes (chips) measuring 10x10 mm. Acceptance final size and type of chips are taken into the grinding system.
Chips are crushed in a plant that includes:
- turbofan;
- pulse mill-classifier;
- a cyclone with a system of unloading locks;
- fine cleaning system.
The turbo fan creates a controlled air flow through which the chips are transferred to the classifier mill, which operates on the principle of impact centrifugal grinding. Next, the air flow directs the ground product into the cyclone and then, through a system of discharge filters, to the vibrating sieve (for different PCs, the cell size of the vibrating sieve may be different). On a sieve, a large fraction of particles is screened out and returned to the mill for re-grinding, and the commercial fraction of the product is supplied for packaging.
From the cyclone, air containing powder dust enters the fine cleaning system. It consists of several bag filters located in one housing. Passing through bag filters, powder dust is deposited on their surface, and the purified air is released into the atmosphere. Dust from the filters accumulates in the dust collector and from there enters the plastic bags. The bags are replaced as they are filled.