We offer powder painting and application of duplex “zinc + polymer” coating on steel structures of customers.
Technology of powder coating:
The main difference between conventional liquid coloring technology and polymer powder coating technology is that the powder paint does not require a solvent and binder, and also that the powder paint is in a solid aggregate state. The painting is carried out using electrostatic spraying of charged powder particles on the surface of the metal, then there is a heat treatment in the oven at a temperature of 180-220 ° C, during which the powder paint melts and a solid crust (polymer coating) forms.
Thermoplastic polymer coating:
The technology of polymer powder coating with thermoplastic powder paints assumes the formation of a coating without chemical reactions, only by fusing the particles with heating. Polymer coatings, which are formed from them, are thermoplastic, reversible. Thermoplastic powder paints are used mainly for the production of coatings of chemically resistant, anti- corrosion, anti- friction, electrical insulation. Coatings are usually applied in thick layers – 250 μm or more.
Thermoreactive polymer coating: The technology of painting with thermosetting powder paints – a polymer coating is formed, in contrast to thermoplastic coatings, by means of chemical reactions when heated. Such coatings have a three-dimensional structure, they are non-meltable and insoluble, i.e., irreversible. Thermoset paints serve for the production, both functional coatings, and protective and decorative. For the production of functional coatings, epoxy formulations are most widely used. They are applied in layers of 100-150 μm on a heated surface in the fluidized bed apparatus (repeatedly alternating heating and immersion in a powder) or by jet spraying.
High-quality powder painting can be carried out only with the help of professional equipment, such as is provided by EUROFORMAT Stalkonstruktsiya. From the quality of powder coating depends on the durability of the product as a whole.
It is the coating that is designed to provide maximum protection of the product from the adverse effects of external factors. Powder painting has increased resistance to various physical and mechanical influences.
Advantages of powder coating:
1.Cost – effectiveness ;
2.Reducing the number of technological operations, high speed of polymerization, compactness of equipment allow to reduce the areas of painting areas;
3.Powder paint is a solid product that does not contain solvents, and the coefficient of its use is 95-98%. This is achieved by using a special powder paint recuperation system that allows the unused paint to be returned to the process and reused.
4.In the case of liquid paints, from 40 to 60% of the paint composition and more belongs to the solvent, which does not remain in the future coating, i.e. the coefficient of paint use is only 40-60%, not taking into account the inevitably arising losses of paint.
5.Speed. A significant reduction in the curing time of the coatings is due to the high rate of film formation from the melts and also because the drying of the single-layer powder coating is performed once compared to repeated drying in the case of multi-layer conventional coatings.
6. Decorativity. Use of a wide range of colors when applying a powder polymer coating, more than 5000 colors, shades and textures. The surface acquires properties that are unattainable when using traditional technologies, or the cost is several times higher. As an example, you can bring colors of gold, silver and aluminum metallic; fluorescent paints; a series of “antiques”; surface for moire, granite, structured surfaces, etc. There is also an opportunity to additionally use a variety of colors and shades, which are controlled by the degree of gloss (glossy, matte and semi-matt).
7.Easy to use. Elimination of such complex operations as viscosity control and adjustment of viscosity to the desired value, since powder paints are delivered ready-made. This provides savings and greater stability of the quality of the coatings produced. As for the cleaning of the spray equipment, it is much easier to remove the powder than the layers of liquid paint.
8. Ecological compatibility. Application of powder polymer technology eliminates environmental problems – flammable and toxic liquid solvents are not used.
9.Powder painting – without waste due to the almost complete return of the powder, not settled on the product to be painted, and its reuse.
10.The working conditions of working personnel improve dramatically.
11.Strength and durability. Increased chemical resistance and physical and mechanical properties (for impact 500 nm, for bending 1 mm) powdered polymer coatings due to the use of film-forming with a large molecular weight. Due to the fact that a layer of elastic plastic with very high adhesion is polymerized directly on the surface to be painted, an impact resistant coating with high corrosion and electrical insulation properties, resistance to alkali solutions, acids and organic solvents is created, with a temperature range from -60 to + 150 ° C. The thickness of the coating lies in the range 30 – 250 μm.
12.The possibility of obtaining thick single-layer coatings. This effect is achieved due to a 100% dry matter content, instead of more expensive multi-layer coatings in the case where liquid paints are used.
13.Possibility of complete automation of the painting process.
14.Less shrinkage and porosity of the film due to the absence of evaporation of solvents.
15.The absence of a negative effect of solvents that do not evaporate from the films on the strength properties of coatings.
16.Elimination of streaks on vertical surfaces and wrinkling of coatings during drying.
17.Thermal resistance from -60 to +120 ° С
18.Increased adhesion (adhesion of particles with a painted surf. 500 nm)
EUROFORM Stalkonstruktsiya, Kiev, Ukraine, is the only company in Ukraine that professionally provides services for applying high-tech duplex coating “zinc-polymer”, which allows to achieve a significant increase in the service life of anti- corrosion coating in comparison with classical types of coatings.
Duplex coating – combined coating, which is achieved by the joint interaction of hot-dip galvanizing systems and powder coating. In the world, this system is known as a duplex anti-corrosion protection system.
Duplex system has been successfully used in critical industries for decades, where anticorrosion protection of metal is very important – for example in the automotive industry. The studies of the world’s leading experts have proved that the application of a polymer coating over hot-dip galvanized steel is a complex process of interaction, in which it is critically important to take into account the physical and chemical properties of the metal surface, adhere to the application technology and perform work on modern equipment.
Only due to the proper preparation of the zinc surface for the application of the polymer, as well as professional work on modern equipment within a single production complex, it is possible to achieve a full-scale synergistic effect of interaction between the two types of coatings, which will be a real duplex corrosion protection system.
Thanks to the research of the International Paint and Printing Ink Council (USA) and ASTM International (USA), a method for creating a duplex coating was created, only due to which it is possible to create a duplex coating that can serve as a good protection against metal corrosion for many decades.
To achieve the most effective results when creating a true duplex corrosion protection, EUROFORMAT Stalkonstrukcia uses advanced technologies, for example “Standard technique for preparing a hot galvanized steel surface for powder coating” ASTM D7803-12. Polymer powder coating is quite strong, and with careful installation and no damage, protects the steel product from corrosion for a long time. In this case, powder coating of steel provides barrier protection of steel against corrosion.
Synergy effect of duplex coating:
A professional duplex anti- corrosive protection system consisting of hot zinc coating and powder coating provides a more sophisticated corrosion protection method, known as synergistic effect. The outer layer of the powder polymer coating slows the rate of zinc consumption. In turn, if the polymer coating layer is damaged, zinc still provides cathodic and barrier protection of the metal.
As a result, the metal structure is protected, by a period of validity from 1.5 to 2.3 times higher than the sum of the protection periods of each anti- corrosive system separately!
For example, if the zinc coating on black steel provides 50 years of protection, and the powdered polymer coating provides protection for 10 years, the integrated duplex system will protect the metal for a period of 90 to 138 years in the same operating environment!
Periodic maintenance (tinting) can in this case further increase the period of corrosion protection of the metal structure!
In the form of a mathematical formula, the synergistic effect of professional duplex coverage is as follows:
М* duplex = from 1.5 to 2,3* (М zinc + М polymer coating)
*M = time to first maintenance