Powder paint for metal: composition and technical characteristics, production and application technology. Powder coating materials

General technology system manufacturing process powder paint includes the following steps:
1 - preparation and dosing of feedstock;
2 - mixing of components;
3 - extruding the mixture (obtaining chips);
4 - grinding chips;
5 - packaging, packaging, labeling;
6 - quality control.
Quality control is singled out as a separate stage with a certain degree of conventionality. In fact, this stage is divided into separate components (sub-stages), which are an obligatory (final) part of each of the technology stages.
Preparation and dosing of feedstock. The stage begins with the receipt of raw materials to the warehouse of the plant and its acceptance. Raw materials can be supplied in bags or boxes, plastic containers volume, soft containers (big bags) weighing about 600 kg. When raw materials are accepted at the warehouse, the integrity and appearance of the packaging are checked, the quantity and name of the raw materials correspond to the data specified in the consignment note, the batch numbers are compared with the numbers in the quality passports. After acceptance, the amount of raw materials necessary for production is delivered to dosing sites using various devices, the rest of the raw materials are stored in a warehouse. A visual conformity assessment is also carried out at the dosing station appearance raw materials to certain requirements
Dosing of raw materials is carried out in the areas of small and large premixes according to the task for production. First, on a small premix, manual weighing is carried out on the scales of individual components of the PC, the content of which in the paint formulation is negligible. The operator punches and signs a check, which indicates the digital code of the weighted component and its actual amount. The mixture from the small premix is ​​then transferred to the large premix.
Large premix allows you to dose the components of the PC formulation in large quantities. The raw materials received from the warehouse are poured into separate bunkers with the help of mechanical devices. The large premix operator selects a clean mobile (on wheels) container corresponding to the amount of loading, which is installed on floor scales under the bunkers. In a certain sequence with control by weight, the individual components are poured from the hoppers into a container (mixture from a small premix - manually). At the end of dosing, the operator punches and signs a check, which indicates the number of the component and its weighted amount. Further container with technological map and two checks from premixes are transported to the mixing area.

Mixing components. Depending on the size of the mobile container loaded with the mixture, the operation is performed by industrial mixers (mixers). The mixing mode is set on the control panel timer. To prevent overheating, chilled water is supplied to the mixing head of the mixer. After mixing the components ready mix(charge) in a container is transported to the extrusion site.
extruding the mixture. The production of paint melt in 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.
The mobile container with the ready mixture is lifted to the platform of the unloading station (upper level) by means of mechanical devices and fixed on it with pneumatic grips. The operator manually opens the valve of the container, and the mixture is fed directly into the extruder (lower level) using a screw feeder. Passing through the zone of forced heating at a controlled speed, the charge is melted and by means of the screws of the extruder itself, already in this state, it is mixed to a homogeneous state.
Hot melt (temperature 110-130ºС) is squeezed out from the discharge opening of the extruder and flows onto the cooling cylinders (rollers) of the continuous cooling system. Passing between two cylinders, the alloy is rolled out to the form of a tape with a thickness of 0.5 - 1.5 mm, cools down and passes into a solid state. Further, the cooled tape is fed through a belt conveyor to a crusher, where it is crushed to the state of flakes (chips) 10x10 mm in size. Acceptance of the final size and type of chips is taken in the grinding system.
Grinding chips takes place on the plant, which includes:
- turbofan;
- impulse mill-classifier;
- a cyclone with a system of unloading locks;
- fine cleaning system.
The turbofan creates a controlled air flow, through which the chips are transferred to the classifier mill, which works on the principle of impact centrifugal grinding. Further, the air flow directs the ground product into the cyclone and further, through the system of unloading filters, to the vibrating sieve (for different PCs, the cell size of the vibrating sieve may be different). On the 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 fed to packaging.
From the cyclone, air containing powder dust enters the fine purification 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. The dust from the filters accumulates in the dust collector and from there it enters the plastic bags. Bags are replaced as they fill up.

Powder paints were developed in the 60s of the XX century due to the need to protect the painted surfaces, give them an attractive appearance, reduce painting costs, and also in order to reduce environmental damage. At the same time, an electrostatic coating method and an anodizing system arose. Coatings with a metallic effect and paints resistant to adverse external factors began to appear.

Polymer powder coating is first sprayed onto the product, and then polymerized in a special oven and at a certain temperature. Powder coating technology involves the following steps:

• Surface preparation
• Application of powder paint
• Polymerization

Surface pretreatment

Pre-treatment of the product is the longest and most laborious process, which is sometimes not given the necessary attention, while the durability, quality and elasticity of the coating depend on it. Surface preparation for the painting process includes the removal of any contaminants, degreasing and phosphating in order to increase adhesion, as well as protect the metal from corrosion.

Cleaning of the treated surface can be carried out mechanically or by chemical means. In the case of mechanical cleaning, steel brushes or grinding discs are used, lapping with a clean cloth soaked in solvent is possible. As for chemical treatment, it is carried out using acidic, alkaline or neutral substances and solvents, which are selected depending on the degree of contamination, material, size and type of surface to be treated and other factors.

The application of a conversion undercoat helps to prevent penetration under the coating different kind dirt and moisture that cause peeling and subsequent destruction of the coating. Phosphating the surface with the application of a layer of inorganic paint makes it possible to increase adhesion, that is, the adhesion of the surface to the paint by 2-3 times, and protect it from rust. When removing oxides (scale, rust and oxide films), abrasive (mechanical, shot blasting, shot blasting) and chemical cleaning, that is, pickling, are very effective.

• Abrasive cleaning is carried out with the help of small particles (shot, sand), iron or steel granules, walnut shells, which high speed delivered to the surface through compressed air or centrifugal force. These particles break off pieces of metal with scale, rust or other contaminants, which significantly increases the adhesion of the coating.
• Etching is the removal of oxides, rust and other contaminants using solutions based on hydrochloric, sulfuric, nitric, phosphoric acids or caustic soda. They contain inhibitors that slow down the dissolution of the cleaned surface. Advantages chemical cleaning before abrasive - this is a great performance and ease of use. But after it, it is necessary to rinse the cleaned surface from solutions, and this, in turn, necessitates the additional use of cleaning agents.
• The final stage of surface preparation is passivation. In other words, body treatment with sodium and chromium nitrate compounds. Passivation is carried out in order to prevent the occurrence of secondary corrosion at any stage of surface preparation - after degreasing, phosphating or chromating.

After rinsing and drying the part in the oven (curing section), the surface can be considered ready for powder coating.

Applying powder paint to the surface of the product

When Preliminary processing finished, the object to be painted is placed in the spray chamber, where powder paint is directly applied to it.

The main purpose of this box is to trap powder particles that have not settled on the product to be painted, to dispose of the paint, and to prevent it from entering the room. Such a chamber is equipped with a filter system, cleaning means (vibrating screen, hoppers, etc.) and suction systems.

There are dead-end and walk-through types of boxes. In dead-end chambers, products are usually painted small size, while large items are in long ones. There are also automatic models, where the powder coating is applied in seconds with the help of manipulator guns.

The most common way to apply powder paint is electrostatic spraying, that is, applying an electrostatically charged powder to a grounded product using a pneumatic spray gun, also called a gun, applicator or spray gun.

Coating formation

When the paint has already been applied to the product, it is sent to the next stage - coating formation, which includes melting the paint layer, obtaining a coating film, curing it and cooling.

The reflow process is carried out in a special furnace or chamber. There are many types of polymerization chambers, depending on the specifics of production, their design may vary. talking plain language, such an oven is a kind of drying cabinet having electronic "stuffing". With the help of the control unit, it is possible to control temperature regime chamber and staining time, set automatic shutdown at the end of the process. The power source for the polymerization oven can be electricity, natural gas or even oil.

Separate horizontal and vertical, continuous and dead-end, single and multi-pass furnaces. Melting and polymerization occur at a temperature of 150-220 ° C for 15-30 minutes, resulting in a film, that is, powder paint polymerizes.

The main requirement for polymerization chambers is to constantly maintain the set temperature for uniform heating of the product to be painted. The required mode for forming the coating is selected taking into account the characteristics of this product, the type of powder paint, the type of oven, etc.

At the end of polymerization, the part to be painted is cooled in air, and after it has cooled down, we can assume that the coating is ready.

When processing large-sized parts or large volumes of production, a transport system is used. Thanks to it, the painted products are easily moved from one stage of painting to another. The principle of operation is that the painted objects are fed on a special suspension or trolleys moving along rails. Such a transport system makes it possible to continuously carry out the painting process, which, in turn, can significantly increase work productivity.

Benefits of Powder Coatings

Metal powder coating technology has many advantages:

• Excellent physical, chemical and decorative properties coatings that cannot be achieved by other methods of painting, including a rich palette of possible colors.
• Good performance properties of coatings
• Durability of products painted with powder paints
• Single layer coating due to 100% dry matter content, which means economical use of powder coatings
• Small porosity
• Improved impact and corrosion resistance compared to other paints
• No need to control viscosity, as powder paints are delivered to the direct consumer in a ready-to-use form
• Losses when painting with powder paints are 1-4%, and, for example, when using liquid paints - about 40%
• Hardening of the coating within 30 minutes
• No need for large rooms for storage of powder paints
• Minimize damage to painted parts during transportation and reduce the cost of their packaging
• Ecological safety of painting with powder paints

In view of all the above advantages this method metal coloring, most industrialists today give their preference to it.

The described decorative compositions differ from traditional coatings large quantity pluses. In addition to a beautiful appearance with a characteristic sheen, the composition used may have additional consumer properties. Their final list depends on the material production technology.

The paint production process consists of 7 successive stages connected with each other. The properties of the finished product directly depend on the quality of work performed on each of them. Consider each production step in more detail:

1. Processing of raw materials that are used in the production process. First of all, experts perform the selection of the necessary components. It is about qualitative and quantitative composition. It is necessary to check the markings on the containers with raw materials and make sure that they are of good quality and comply with current standards. The components that have passed the test are dosed on special equipment, which makes it possible to very accurately measure the amount of the required components. Each action is recorded in a special protocol, on the basis of which it is possible to check the correctness of the work performed.
2. Homogenization (mixing of components). Prepared and measured raw materials enter the mixer tank, where all components are mixed with each other. The maximum uniformity of the future paint is achieved. To avoid excessive heating of the components due to friction, the mixers are equipped with cooling circuits.
3. extrusion. After mixing, the finished mixture enters the extruder. In it, the composition is heated to a temperature of 130 degrees Celsius (or another, depending on the technology). The components melt and exit the nozzle of the device in a liquid state.
4. Rolling. The mixed and melted components of the future paint are fed to a special conveyor for solidification. Rolling shafts act on them, forming a tape about one and a half millimeters thick, which gradually hardens.
5. Grinding and crushing. Cured paint in the form of a tape is exposed to knives that cut it into individual elements 1 cm long each. Then the resulting pieces are crushed in special equipment until they form a free-flowing powder with the desired particle size. Pieces that have not passed through a sieve to check their size are processed again. During the crushing process, a large number of dust to be removed. Otherwise, the quality of the paint will not meet the established standards.
6. Quality control. The finished decorative composition must be checked using special equipment. Exist different schemes checks. AT normal mode paint samples are checked selectively, but sometimes a complete check is also used.
7. Finished material packaging. The packaging technology depends on the amount of powder that is placed in one container. If the composition is intended for use in industrial scale(for example, for painting parts on manufacturing enterprises), the paint is packaged in bags weighing up to 600 kg. Small wholesale lots are supplied in packages weighing from 15 to 20 kg. Finished products stored at the enterprise or immediately sent to customers (distributors).

Choosing a paint manufacturer

The quality of the paint, the convenience of its further use, the strength and durability of the protective coating depend on how clearly the manufacturer observes the described production technology. Therefore, it is recommended to purchase only materials famous brands who provide warranties for their products. We recommend that you pay attention to the Turkish powder paint brand Mikroton, which complies with local, European and Russian regulations.

Let's paint!

Any product within 5 days. Maximum product size:
7000 x 2000 x 2000 mm

By trusting the Fasadcolor company, you get a world-class painting using materials from the best manufacturers powder coatings on the market. We give our customers a one-year quality guarantee and a multi-year factory warranty against fading. Facadecolor also provides unique opportunity decorating the surface of the profile. You can not worry about the occurrence of corrosion, discoloration of products during operation, non-painting and peeling of paint during the warranty period.

Here you can paint:

Painting of forged and iron products,
stairs, handrails, railings, railings

Coloring any
aluminum profiles

Painting any metal
components for products

Finished metal painting
products that can withstand heat
up to 200 degrees Celsius

Why choose us?

Quality certificate

Exclusive distributor

Flexible system of discounts

Individual approach

Fast shipping

Always in stock

Qualicoat Quality Certificate

An international quality mark, products with its emblem have every chance to win in the competition with non-certified, although cheaper products, and in addition, the value of the company's brand increases.

The Qualicoat certificate is issued to those enterprises whose production standards, the level of knowledge of the staff, the regulatory framework, as well as the quality of the produced paints fully comply with the requirements of the regulator. The license is issued by applying to the national association involved in the certification of production on the basis of general power of attorney Qualicoat

All tests prescribed by the company fully comply with the ISO 17025 quality standard, and authorized inspectors and laboratories are part of the Qualisurfal association. If the production ceases to meet the requirements, the license is forfeited.

Mikroton distributor

The Fasadcolor company is the exclusive distributor of Microton. Mikroton is one of the largest powder paint factories in Turkey. The main priority of the company is the constant improvement of technologies in order to achieve impeccable product quality. Technological process constantly supervised by experienced personnel with the help of high quality equipment. That is why the products fully comply with the international quality certificates ISO 9001 and Qualicoat.

Powder paints are made from environmentally friendly raw materials from leading European manufacturers and do not contain triglycidyl isocyanurate (TGIC). In accordance with the sanitary and epidemiological conclusion, Microton powder paints are intended for painting various products, including those in contact with food.

Flexible system of discounts for regular customers

The Fasadcolor company offers profitable terms partnerships for retail and wholesale buyers. The cost of our products is much lower than in other similar companies in this segment. For regular customers there are interesting bonuses and special offers that will make our cooperation mutually beneficial. We are interested in a long-term partnership and have developed flexible system discounts, which is determined by the volume of the order. This allows you to find an individual approach to each client, to provide quality service and operational service. This approach makes it possible to adjust the tariff in a way that is beneficial for the client and find optimal solutions. The system of discounts developed by us is valid for both individuals and legal entities.

Individual approach to each client

The priority direction of our company is the principle of an individual approach to each client. Speaking about an individual approach, it should be clarified that we build our cooperation taking into account all the wishes of the customer. All our work is based, first of all, on meeting the needs of the client and fulfilling their wishes. Whatever your requirements, conditions, financial possibilities, in any case, you can count on our part for understanding, readiness to meet halfway and the possibility of adjusting the tariff in the most convenient way for the client. That is why we strive to provide truly favorable conditions for each customer. We make sure that each of our clients is satisfied with the work we have done and the result, which is our common success!

Fast shipping

Why waste time hiring transport if our company provides prompt delivery service? We guarantee careful and fast transportation of your products across specified address. The Fasadcolor company organizes delivery throughout Russia. Delivery to the city of Rostov-on-Don and the region is carried out free of charge during the day. The order is shipped within two business days. Delivery to the Southern region is agreed separately with the client.

Buying powder paint with delivery is an opportunity not only to save time and cash, but also strictly follow the schedule of the planned work. Our managers will call you back, agree on everything necessary details and delivery time. We guarantee fast transportation of products, which will allow you to start the project on time.

Wide range of

In our warehouse in Rostov-on-Don, powder paints of all colors according to the RAL catalog are available. This table is an international standard and includes over a thousand shades. The powder paint offered by our company is used in various fields activities: automotive, industry, architecture, construction, manufacturing household appliances and furniture and many others. We offer only certified products from a well-known manufacturer, which has passed strict multi-level control in production and has the appropriate certificates. Powder paint is particularly durable and resistant to chemicals. At the same time, it has a high-quality structure and is environmentally friendly, which allows it to be used even in enclosed spaces.

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Powder paint is a pigmented dispersed system consisting of solid particles that can be evenly distributed on the painted surface during application and form a protective layer.

Powder paint for metal: properties and characteristics

To enjoy quality characteristics pay attention to the following indicators:

• dispersion components;
• flowability;
• bulk density;
• ability to spray;
• electrified properties;
• level of fluidization, etc.

Dispersion composition

Powdered paints are made up of small particles different sizes(polydisperse systems), which have a significant variation in value. With high dispersion, 2 types are distinguished: true and aggregates of particles (clusters of true particles that behave like a separate particle). With traditional methods of application, disaggregation is practically not observed, therefore, the true size of the particles, from the point of view of manufacturability, loses its significance. A more important technological characteristic is the granulometric composition.

If fractionation with a sieve varies in a fairly wide range from 5 to 350 µm, then optimal size particles of powders for electrostatic spraying is 10 - 100 microns. 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 particle diameter should be commensurate with the coating thickness and reach 350 μm.

The dispersion of particles should have its own 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, they are more moistened and tend to uneven deposition on the surface of products. Powders with a too wide fractional range are prone to separation and dusting, and may have an increased rejection of the coating surface.

Flowability

One of the obligatory conditions for powdered paints is the necessary indicators of flowability, which is determined by the time of expiration from a calibrated hole or by the angle of natural slope, which is 36 ... 45 °.

The score is affected by:

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

Low flowability makes it difficult to uniformly distribute the powder paint on the surface to be painted, complicates the process equipment.

The 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 the flowability, special additives are used, such as fumed silica or aerosil. Powders are protected from moisture by storage in dry warehouses in a waterproof container.

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 powders can increase up to two times. Pigmented compositions have a high density, which increases with an increase in the amount of pigments and fillers in the composition.

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

Ability to electrify

Like any dielectric, powder particles acquire electrical charges during manufacture, preparation and use. The level of charge is affected by the material of the film former, the size of the particles, the humidity of the air, the intensity and type of mechanical action, etc.

Particles of epoxy, polyvinyl buteral, epoxy-polyester and polyethylene paints are predisposed to charge, which facilitates their application by electrostatic spraying. Smaller powder particles become more electrified and retain their charge longer. At an air humidity of more than 70%, the electrification of powders drops significantly.

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

Ability to fluidize

Fluidized bed application technology requires the ability to fluidize the powders used when blowing with air. Powders from low pressure polyethylene, polyester compositions, polypropylene, polyvinyl chloride and some other materials have a low ability to fluidize. Fine powders with low flowability and high humidity may not "boil" at all. The use of special fluidized bed equipment, such as vibrovortex units, significantly increases the cost of powder coating.

The fluidization property is increased by enlarging particles, creating a spherical shape, reducing surface roughness and moisture.

Compositions of powder paints

Among the components are:

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

Film former characteristics:

1. Are solids which may be in amorphous or crystalline form.
2. They are loose powders.
3. Low melting temperature and melt viscosity.
4. A film is formed through melts when heated.
5. They have a high decomposition temperature.

Powder paints according to the type of film formers that are their basis are divided into:

• thermoplastic;
• thermosetting.

Thermoplastics do not undergo chemical changes during heating and are more widely used due to:

• the 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;
• polyvinyl buteral;
• polyvinyl chloride;
• polyamide;
• pentaplastic and others.

Thermoplastics pass when heated chemical process polymerization and have:

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

Of the minuses of thermosetting film formers, an increase in the time of coating formation can be noted.

Thermoset types include:

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

Pigments and fillers

In powder paints, in addition to standard requirements, they additionally have:

• ease of dispersibility in the melt of the film former;
• resistance to the temperature at which the coating is formed, while not changing color and not decomposing;
• inertness to other components of the composition.

When dry-blended, pigments and fillers should promote:

• increase in flowability;
• reducing the properties of clumping and caking;
• improvement of "boiling";
• applying powders to the surface.

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

• electrified;
• heat resistance;
• thermal conductivity;
• electrical conductivity;
• magnetic properties;
• wear resistance;
• adhesive strength;
• combustibility;
• biological inertness;
• damping ability.

The use of metal powders as fillers makes it possible to obtain imitation metal surfaces. A significant difficulty in the pigmentation of powder paints is the tinting of the color in accordance with the RAL color standard.

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

plasticizers

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

• do not violate the aggregate properties of the polymer;
• not to worsen technological characteristics (flowability, granulometric composition, etc.);
• operate at film forming 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 solid and liquid are used.

Modifiers, hardeners and auxiliary additives

Modifiers able to improve performance through physical or chemical modification. At the same time, the most widely used physical modification due to the addition of various film formers. Modifiers also regulate the technological parameters of powder paint, such as melt viscosity, pour point and flowability of powders.

Hardeners are a necessary component of paints based on thermosetting film formers. To activate the curing process, accelerators are used that are appropriate for specific hardeners. 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, “starting” the curing process after the film former has melted and a liquid film has formed.

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

Auxiliary additives allow you to increase:

• atmospheric resistance of the coating by reducing the photodegradation of polymers under the influence of solar radiation;
• resistance to temperature changes;
• flowability of the powder;
• melt spreading, etc.

Technology of production of powder paints

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 liquid spray paints has not received wide distribution 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 coatings from thermoplastic materials. Production does without expensive equipment and significant labor costs. The difficulty lies in obtaining stable, non-separating during storage and use compositions with a uniform distribution of small additives.

Mixing of components in the melt gives high-quality homogeneous powders with a stable composition and structure. The method is lengthy, has many stages, and requires expensive and sophisticated equipment. It 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 the spray booth, in the ventilation system of which there are powder traps for its reuse.

When coated in a "fluidized bed", the powder is in a pseudo-liquid state due to uniform air blowing. Paint is applied to the surface of a part by dipping the part into a container of fluidized powder.

In both cases, the powder particles are given a certain electrostatic charge before being applied by a special electrode, 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. Thermoplastics additionally undergo polymerization.

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

Powder paint: application, advantages and disadvantages

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

The main consumers of powder coatings:

• hardware products (wire, tape, mesh), household and agricultural products;
• metal furniture;
• household appliances and equipment;
• products of the electrical industry;
• Automotive industry;
• agricultural and transport engineering;
• pipe production;
• metal and glass container, coating allows to reduce glass thickness up to 30%;
• chemical industry equipment;
• building construction;
• machines and equipment for the food industry.

Automated painting lines are successfully operating at automobile plants both for disks with a capacity of up to 3 million pieces per year, and for automobile chassis with dimensions up to seven meters and a capacity 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;
• the possibility of using sparingly soluble polymers;
• non-waste production of coatings, almost 100% use of paint material;
• obtaining a working coating of the required thickness in one layer;
• uniformity of the paint layer on both horizontal and vertical surfaces;
• the possibility of coating in hard-to-reach places;
• metal painted with powder paint have chemical resistance;
• durability;
• wear resistance.

Disadvantages:

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

Video: metal powder coating

It is hardly appropriate to recommend the use of powder coating materials at home. These coatings do not have unique performance properties, you can always find traditional materials, forming similar or better coatings. Acquire special equipment in order to “do it yourself” painting the disks of your car is impractical.

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Powder paint is a solid mixture of small dispersed components. Resins are additionally added to them during production, which have the ability to form a film on the surface of the painted products. Also, pigments are often added to them to obtain the desired shade and hardeners, which allow them to harden in air. There are also certain types of additives that give them the necessary properties under certain conditions.

Everything in the world stands out two main groups of powder paints. They are determined by their ability to form a film on a particular type of surface.

All powder type paints are divided into:

• Thermoplastic Powder Coatings

These dyes are based on thermoplastic components, which form films on the surface of the object to be painted without the method chemical interaction with him. The film is formed as a result of the melting of the paint components and their subsequent cooling. The resulting films can melt after being heated to high temperatures.

• Thermosetting powder paints.

The composition of this group of paints is the same as before use on the surface. This group of colorants includes polymer powder paint. It is based on a component such as polyvinyl butyral or polyvinyl chloride.

Powder paints are often used to protect surfaces and give them an attractive appearance. In most cases today, polymer powder paints are used, which give surfaces a rich shade and are excellent for treating walls and other indoor objects. AT modern world The scope of application of powder coatings is quite wide. They offer great opportunities for decorative finishes external facades of buildings and are ideal for holding repair work indoors.

The main technical characteristics of powder coatings are:

• Dispersion composition

Any kind of paint of this kind contains many particles. Depending on the assigned powder type of paint, their size may vary.

• Flowability

In the modern world, a large number of requirements are imposed on all powder paints. One of them is the presence of good flowability. All paint particles should be dry and easily separated from each other.

• Hygroscopicity

Any powder type paint should have excellent liquid absorption properties. When interacting with water, paints lose their ability to crumble easily, which affects their quality.

• Bulk density

This unit of measurement of the quality of powder paint is determined by how much is needed to completely cover the surface of one square meter. The norm is 800-1000 grams per square meter.

• Fluidization

This property implies that after applying the paint, a fluidized bed is formed, which is necessary in order to cover the material properly.

Important: The consumption of powder paint per 1m2 is on average approximately 100 grams per square meter. Depending on its type and on the thickness of the coating, its size may vary.

The color palette of powder paints is quite large. It allows you to choose any shade for painting objects. Powder paint ral helps to choose the most optimal shade. This scale is useful in choosing the right color for painting any object.

In the modern world, there are a large number of companies that specialize in the manufacture different types dyes for all types of surfaces. Many of them produce large volumes of powder paints, which are very popular today.

The production of powder paint is difficult process technological point of view. For this you need to have specialized equipment.

Each powder coating plant has spiral conveyors. They are connected to ribbon blenders, where the particles of the substance for the future powder are ground into very fine crumbs. Depending on the type of powder paint, the particles may have different sizes. During the production process, the ground particles fall into the tank. Then they are sent for packaging. As a result, consumers have the opportunity to purchase powder paints in the right amount.

Powder paint brands

In the modern world, different manufacturers produce a large number of powder paints. Pulver powder paint has gained great popularity due to its High Quality. The palette of its shades on the ral scale is quite large. The pigmentation of the dyes of this Turkish brand is excellent. Ultimately, this results in savings. After all, to cover one square meter very little paint is coming off.

Of the domestic brands, akzo nobel powder paint is well-known. The paints of this brand are distinguished by the fact that they do not contain the addition of solvents, which makes them suitable for use on the most different surfaces. They have protective properties. They are often used for painting radiators and pipes.

Powder coating is carried out in three stages.

They consist in:

• preparing the surface for applying a layer of paint. At this stage, it is necessary to remove large and small contaminants from the surface and thoroughly rinse and dry everything.
• applying powder paint. At this stage, it is necessary to spray the paint over the surface with a thin layer so that the subsequent painted layer is uniform. For this purpose it is necessary to have specialized equipment. It can be represented by a special pneumatic device.
• polymerization. At this stage, products with powder coating are sent to a special oven, where it is heated.

Table 1. Surface preparation before powder coating.