Metal polyester coating. Polymer coatings of metals

For the manufacture of metal tile, siding, professional flooring, building structures, household appliances The steel with a polymer coating is increasingly used, the so-called "polymer", "metalplastic". Polymer coatings for metal are used in Europe for more than 40 years to give building structures Decorative properties and protection against corrosion. Metals with a polymer coating combine the strength of steel with corrosion resistance of the polymer coating.

The color palette of the metal with a polymer coating is very diverse, so when choosing a color, colors usually use or color samples. The coating can be matte and brilliant, have a different texture (including imitate wood, stone, etc.).

The application of polymer coatings on galvanized steel is the most complicated process, since the steel sheet with a polymer coating has a multilayer structure: a steel sheet, a zinc layer, a passivating layer, a layer of soil, from the front side - a layer of a polymer polymer, and from the bottom side of the multi-layer pie Completes the protective paint.

As the basis for the manufacture, the steel rolled steel 0.4-2.0mm is taken. It can be applied with a layer of zinc (or aluminum) as a galvanic method and the immersion method into the melt. Sometimes the polymer coating is applied immediately on black metal (however, such metal plates are very short-lived). Then the metal is passivated, ground and covered protective layer different polymers.

The polymer coating is obtained by various methods:

• by applying a pre-made film on the lane,
• immersion strip in polymer melt,
• roll method of applying liquid polymer (coil coating),
• spraying polymer in the powder condition by electrostatic method.

The coating can be both one-sided and bilateral. Hire with one-sided polymer coating is a rolled stone with a two-layer polymer coating on the front side and a single-layer polymer coating on the reverse side.

A two-layer polymer coating is a coating consisting of a layer of soil and a layer of finishing polymer.

Single-layer coating is, as a rule, coating the reverse side of the rolled, consisting of a layer of protective enamel without regulatory requirements for appearance, thickness, corrosion resistance, etc.

Polymer coating is final stage Production of metal rolling. At the request of the customer, a protective film from polyethylene can be applied.

Thus, most often steel with polymer coating has the structure below.

1 - steel sheet

2 - zinc layer

3 - Passivating layer (anti-corrosion layer)

4 - soil layer

5 - polymer coating

6 - protective paint on the back

The primer layer is designed to provide durable clutch and high corrosion resistance of the entire system, i.e. The quality of the primer depends on how hard the polymer coating will hold.

As polymer coatings use:

• polyester (polyester) is denoted by PE. SP;
• polyester matte, modified by Teflon, PEMA;
• polar, polyurethane, modified by polyamide, PURAL;
• polyvinyl chloride plastisol, PVS;
• polyvinylidenefluoride, PVDF consists of 80% polyvinyl chloride and 20% acrylic;
• acrylic, Ay.

Polyester It is the most popular coating due to the optimal ratio of "price-quality" and has satisfactory resistance to UV radiation and corrosion. However, resistance to mechanical damage to the coatings Poural and PVDF. Purally more than polyester, but it has a higher chemical resistance, as well as to mechanical exposure and temperature drops. The most resistant to mechanical damage due to thickness, but at the same time the least resistant to temperature drops and to UV radiation is plaserisol. The durable and most expensive coating is polyvinylidenefluoride (PVDF). The least durable and unstable to mechanical and atmospheric influences is acrylic coating. All these coatings may have different textures, shine, colors. Thus, polymer coatings have different resistance to ultraviolet radiation, high and low temperatures, atmospheric, to mechanical damage and other

The above coatings are originally liquid and applied with a roll method, which is the most common and in demand in both Russia and in other countries.

The most important requirements for coatings are a durable grip (adhesion) of individual layers with each other, a lower layer with a substrate, hardness, bending and impact strength, moisture resistance, weather resistance, a set of decorative properties (transparency or shelterness, color, degree of gloss, pattern, etc. ).

The main advantages of rolled with polymer coating are as follows:

• The possibility of stamping, profiling, metal bending in finished products (metal tile, profiled flooring, details of household appliances, etc.)
• Homogeneous and stable properties over the entire surface
• Beautiful protective properties
• Weather resistance
• Preservation of protective and decorative properties for more than 10 years
• Variety of colors and textures

Metallurgical plants producing thin steel steel are most often engaged in the manufacture of metal with a polymer coating. The most famous of them: Novolipetsky Metallurgical Combine, Cherepovets Metallurgical Combine, International Concern Arcelor Mittal, Rautruuki Oy (Finland), ECO Stanl (Germany), ISPAT Karmet (Karaganda, Kazakhstan), Hogovens (Holland), British Steel (United Kingdom), Miriad (France) SSAB TUNNPLAT AB (Sweden). However, now there are more and more manufacturers that provide services for the application of polymer coatings on any needed to the customer's size of the sheet of metallurgical giants.

The polymer coating on the metal is the application of the powder layer on the metal surface with the subsequent heat treatment, due to which the polymerization occurs and the color layer of high quality is formed on the metal surface. Polymer coating steel is extremely resistant to all factors. ambient, durable, as well as allows you to most organically emphasize the structure of the structure, thanks to its external aesthetic form.

Below you can familiarize yourself with several types of polymer coatings for steel that we use, we want to draw your attention, which is not the entire list.

Polar (PU) - This is a protective - decorative polymer coating, the basis of which is polyurethane with the addition of polyamide. A coating on galvanized steel is applied and used most, since it is distinguished by resistance to ultraviolet radiation, not subject to corrosion, firmly and economically beneficial. Manufacturer's warranty is 15 years old.

PVF2 (PVDF) - Material consisting of 20% of acrylic and 80% of polyvinyl fluoride, the thickness of it to steel is 27 microns, obtained as a result of the coating is resistant to the Usthaphiolet, it is not exposed to burnout has a high-quality shine. This material is resistant to aggressive media and mechanical damage. The coating is a large line of color gamut, the color of "metallic" is also possible, which is achieved by adding a varnish with a metallic pigment. Best application To cover the PVF2 there will be a roof, smoke, fluorca, decor elements located on buildings for the production of chemicals or houses on the coasts of the seas, oceans. The manufacturer's warranty is 15 years.

Matte Polyester (PEMA) - This is a polyester coating with good colorfulness, due to the refractive index of sunlight. This type of coating has good resistance to corrosion, mechanical effects and resistance to climatic conditions. He will suit those who do not want his roof gloss under the influence of sunlight. Manufacturer's warranty 10 years.

Polyester (PE) - The basis of the coating is polyester paint, which has good color resistance. This is at its cost budget covering, which will suit those who want a glossy surface for the roof. Polyester requires special treatment during its transportation and installation. Does not have resistant to mechanical exposure and is subject to scratch formation. Manufacturer's warranty 5 years.

Comparative characteristics of polymer coatings

* T \u003d sheet thickness without polymer coating

Source: according to enterprises

one). Polyester (re,Sp.) The most inexpensive and popular polymers on the market polymer coatings For steel galvanized sheet , which gives the painted steel good resistance to UV radiation and corrosion, is polyester (polyester). Material has a high level of flexibility and facilities, suitable for any climatic conditions. Resistance to mechanical damage in this type of coatings is lower than that of Pural and PVDF coatings. More resistant to mechanical influences polyester with rosy quartz sand , However, it is significantly more expensive. In addition, during its transportation, a number of problems arise related to the possibility of damage to the lower layer of metal sheets (quartz sand like sandpaper scratches the surface of the overlying sheets in contact with it).

The most commonly used coatings on the basis of saturated polyesphian (Sp. , PL) .Obvious coating is polyester paint, which has good color resistance. The heat resistance indicator to the effects of sunlight to +120 ° C, and the lower temperature limit of the polyester is -60 ° C. Polyester thickness on painted steel reaches 25 microns.

2). Matte Polyester (PEMA) Polyester coating with a thickness of 35 μm with a matte surface. It is a polyester modified by Teflon. Material has a high color resistance due to the refractive index of sunlight, good corrosive and mechanical resistance, retains its properties in any climate. This material is suitable for whom the absence of a glitter of the product is important.

3). Plaserisol (PVC-200) This decorative polymer with the thick coating (200 microns) consists of polyvinyl chloride (PVC) and plasticizers, has an embossed surface. At cost - one of the most expensive coatings. Due to the high thickness of the coating, the material is one of the most resistant mechanical damage. However, it is due to low temperature resistance and low resistance to UV radiations (when heated by straight solar rays above +80 ° C, the material is rapidly aging), it is not recommended to use in the southern regions. Choosing a plaserisol for use in hot regions, you should only focus on light colors. They better reflect the light, heated less and burn out.

Having a large thickness, plastisol has a high corrosion resistance, which creates additional protection in conditions of polluted environment. The color resistance is significantly lower than polyester. With a thickness of 175 microns, the plastisol coating is only available smooth. The coating with a thickness of 200 microns can be rocked with a stamped pattern, an embossed textured surface (at the same time, the thickness of the coating layer is significantly reduced).

four). PURAL (PURAL) Polyurethane coating modified by polyamide has a silky-matte structural surface. This material is not afraid of large daily temperature differences (up to 120 ° C). Material has high chemical resistance and colorfulness. Stands to mechanical exposure. However, in comparison with the plastisol, Pural is less resistant to plastic deformation. This type of polyester is more expensive, but today it is one of the most optimal coatings on a combination of high performance and prices. The thickness of the coating is 50 microns.

five). PVDF.The coating with a thickness of 27 microns, consists of 80% of polyvinyl chloride and 20% acrylic. This is a strong, most resistant to UV radiation coating, practically does not fade, has a beautiful shine, it has self-adequacy. One of the most stable and mechanical damage, to the aggression of nature and to the roughness of the installers. The glossy PVDF surface may have a metallic shade in silvery or copper tones. To give metal shine, the standard PVDF coating is complemented by a layer of transparent lacquer with Metallic pigment. This is the most durable coating, it is applied even in aggressive environments, such as the sea coast. Ideal for walls.

6). Polymer coating acrylic It is a paint layer, which is extremely unstable, it is easy to damage it when installing the product. It has heat resistance to +120 ° C, but fades in the sun in 5 years, moreover, it has an average resistance to corrosion and after 2-3 years of operation begins to be washed. Layer thickness of 25 microns. Minimum processing temperature -10 ° C. Foreign firms refused to be applied since 1997. On sale there are only domestic materials with such a coating, however, they are recommended to use only for temporary structures.

Examples of applying anti-corrosion coatings

The above coating characteristics relate primarily for liquid materials for metal staining with a roll method, which is the most common and in demand in both Russia and in other countries. At the same time, polymeric materials were also widespread in powder painting of roll metal rolling (powder Coil Coating ). In production powder coatings The most commonly used hydroxyl functional saturated polyesters in combination with free polyisocyanate resins. Powder materials based on a mixture of acid polyester and epoxy resins are also often used.

With the current situation and forecast of the development of the Russian COIL COATING coating, you can get acquainted in the report of the Academy of Industrial Markets Conducting: