Polymer coating is a unique opportunity to protect metal surfaces. This is the most effective and modern way to combat corrosion, which sooner or later appears on metal products anyway.
What is the point?
To improve the operational properties of the metal, polymers are used that can react under certain conditions. Such coatings are dry compositions based on a fine dispersion powder, to which hardeners, fillers and pigments are added. The polymer coating was not chosen by chance to increase the protective means of the metal: metals conduct electric current, as a result, the charge is transferred to the product, resulting in the formation of an electrostatic field. It attracts powder particles, holding them on the surface of the workpiece. A feature of the polymer coating is a high degree of resistance to any kind of exposure. In addition, it is aesthetically pleasing.
How is polymerization
The powder coating workshop consists of several sections:
- Preparation area: for the polymer coating to be applied correctly and evenly, the metal product is first thoroughly cleaned of dust, rust, and dirt. It is advisable to use effective sandblasting and phosphating. The obligatory step is the degreasing of the metal surface.
- Spraying chambers: painting directly in the spray booth. The chamber is thermal, it is able to heat up to a temperature of 200 degrees and warms up evenly. The powder begins to melt, due to which an even and smooth coating is formed over the entire surface of the metal, and its pores are filled.
- The product is polymerized in a cooling chamber: here the temperature gradually drops, and the polymer film becomes harder. After 24 hours, the polymer coating is ready for use.
Painting technology: what is the point
Powder coating is carried out in several stages. On the first surface are processed. It is very important that metal products are thoroughly cleaned of contaminants, oxides, and degreasing the surface will contribute to improved adhesion. After preparation, the masking stage is performed, that is, those elements of the metal product that the powder composition should not fall on are hidden.
Parts to be processed are hung on the transport system, then sent to the painting chamber. After spraying, a powder layer forms on the metal. At the polymerization stage, a coating is formed, which is a melting of the paint layer.
What are the features?
The polymer coated metal is reliable and highly durable. This is explained by the fact that a sealed monolithic film is formed that completely covers the surface of the product and firmly adheres to it. Thanks to the polymer coating, the metal has:
- high adhesion to the surface;
- high strength and wear resistance;
- long service life while maintaining the original properties;
- rich colors;
- fast production cycle.
The polymer coating of the metal is performed on the basis of various materials and coloring powders. The choice of a specific substance depends on the purpose for which the coating is applied, how important the decorative properties are.
Polyester
For the polymer coating of metal, polyester is most often used. This is an inexpensive material with a high level of flexibility, formability, in addition, it can be used in any climatic conditions. A polyester-coated sheet based on polyester is resistant to UV radiation and corrosion. The material forms a high-quality and durable film on the surface, so that under any conditions of transportation, steel sheets are delivered intact.
Matte polyester is also widely used: the coating has a very small thickness, and the metal surface is matte. The peculiarity of this material is in high color fastness, good resistance to corrosion and mechanical stress.
Plastisol
Another popular metal polymer coating is plastisol. The composition of this decorative material is polyvinyl chloride, plasticizers; externally, it attracts attention with an embossed surface. This is the most expensive coating, and at the same time the most resistant to mechanical damage due to the large thickness of the coating. On the other hand, the material does not have high temperature resistance, and therefore, under the influence of sunlight at high temperature, the coating will deteriorate. Due to the large thickness, the corrosion resistance of the plastisol is high.
The steel with a polymer coating based on pural, which has a silky-matte structural surface, is popular. Resistance to temperature extremes and chemicals makes this composition popular for metal processing.
Characteristics of polymer coated steel
Features of materials with a polymer coating - in strength, formability, high corrosion resistance. After processing, the steel acquires a beautiful appearance, which can be given any colors and shades. Hire is performed according to GOST, the polymer coating is obtained with high quality. Painted rolled products may have one or two layers of coating; variants are possible when the substance is applied on one or both sides. Thanks to the polymer coating, the operational properties of steel are improved:
- polymer coated metal can be processed into finished products;
- the coating is distributed evenly over the surface, therefore the degree of protection is uniform;
- the absence of pores is a guarantee of a good level of protective properties;
- steel has good adhesion;
- metal can retain protective and decorative properties for more than 10 years.
From an economic point of view, galvanized steel with a polymer coating is more profitable: firstly, it contributes to high productivity and quality, as the cost of coating is reduced. Secondly, the buyer does not need to invest in additional processing of steel to protect its surface. Note that the anti-corrosion properties of galvanized steel, which is treated with a polymer coating, depends on the thickness of the layer. To increase the life of steel products, they are additionally coated with two layers of polymer, which makes the metal protection even higher.
Coating features
A polymer coating is a film that has a whole range of unique performance characteristics. Pre-painted rolled products are created on the basis of several types of polymers. Any material processed on the basis of this method — a steel sheet or a polymer-coated mesh — is shockproof, resistant to corrosion and high adhesion. It is also important that powder coating allows you to make any metal surface in terms of color, including artificially aged, for example, antique style.
Today, Coil Coating is a popular way of painting steel. The essence of the method is that the coating is applied on an automated line, that is, the rolled sheets are processed on the line, after which they are coated with roller machines. This technology has gained distribution due to the fact that there is no loss of materials, and the line itself is more productive, and therefore profitable.
As with any other finishing work, first you need to prepare the surface, after which it is painted. This technology allows high-quality processing of steel, aluminum and tinplate. Thus, a polymer coating is an opportunity to improve the operational properties of the metal, increase its protective properties and ensure the duration of operation.