RU2655984C1 - Coating on the rolled steel application method - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to the polymer coatings onto the steel substrate application methods and can be used for production of the rolled steel sheet rolls, flat galvanized sheets, profiled sheets, metal tiles, fastening corners and other preferably building materials. Coating onto the rolled steel products application method involves the layers sequential application onto the pre-cleaned metal surface, their drying and curing, wherein the first layer is applied with the primer with thickness of 1 to 25 mcm with intermediate curing at peak metal temperatures of 224–232 °C, second layer is applied with the smooth polyester enamel with thickness from 10 to 40 mcm with intermediate curing at peak metal temperatures of 224–232 °C, third layer is applied with the transparent or translucent polyurethane varnish with thickness of 5 to 30 mcm with curing at the peak metal temperature of 224–242 °C, at that, in order to ensure the wrinkling effect, the varnish contains the poly-hydrocarbon wax having melting point of 150–170 °C or the first layer is applied with the smooth polyester enamel with thickness of 10–40 mcm with intermediate curing at peak metal temperatures of 224–232 °C; second layer is applied with the transparent or translucent polyurethane varnish with thickness of 5 to 30 mcm with curing at peak metal temperature of 224–242 °C, at that, in order to ensure the wrinkling effect, the varnish contains the poly-hydrocarbon wax with melting point of 150–170 °C or the first layer is applied with the primer with thickness of 1 to 25 mcm with intermediate curing at peak metal temperatures of 224–232 °C, second and third layers are applied successively with the smooth polyester enamel with thickness of 10–40 mcm with intermediate curing at peak metal temperatures of 224–232 °C, fourth layer is applied with the transparent or translucent polyurethane varnish with thickness of 5 to 30 mcm with curing at peak metal temperature of 224–242 °C, at that, in order to ensure the wrinkling effect, the varnish contains the poly-hydrocarbon wax with melting point of 150–170 °C or the first layer is applied with the primer with thickness of 1 to 25 mcm with intermediate curing at peak metal temperatures of 224–232 °C, second layer is applied with the smooth polyester enamel with thickness of 10–40 mcm with intermediate curing at peak metal temperatures of 224–232 °C, third and fourth layers are applied with the transparent or translucent polyurethane varnish with thickness of 5 to 30 mcm with curing at peak metal temperature of 224–242 °C, at that, in order to ensure the wrinkling effect, the varnish contains poly-hydrocarbon wax with the melting point of 150–170 °C.

EFFECT: obtaining coating in any color with the same surface structure due to the fact that the formation of the latter occurs due to the transparent varnish layer at the substrate coloring last stage, which increases the product service life by increase in the steels resistance to physical, chemical, mechanical, corrosive effects, preserves the coating sufficient resistance to abrasion at the high coefficient of surface friction, which in turn provides safety during high-altitude works due to good adhesion to the sole of workers, who install the roofing material, and is also more resistant to the ultraviolet radiation.

4 cl, 4 ex

Description

The invention relates to methods for applying polymer coatings to a steel base and can be used for the manufacture of rolled sheet metal, flat galvanized sheets, profiled sheets, metal tiles, mounting corners and other mainly building materials.

Three-layer and multi-layer coatings are also known, see https://www.thvssenkrupp-steel.com/en/press/press-releases/press-release-10945.html, http://mils.by/kataloq/metalocherepica/metallocherepica -modulnava-blachotrapez-polsha / modulnaya-metallocherepica-qermania-simetric, which describes the coating system, which is obtained by applying a primer layer, a second varnish layer, which is applied by printing onto the first layer, and a finish color coating.

Roofs Magazine No. 4 (19) 2008 on page 64 and http://keosanq.co.ua/en/printech.html also describe a coating that is obtained by applying a primer layer, base layer, ink by offset printing, transparent varnish layer (polyester or polyvinylidene fluoride).

The disadvantage of these coatings is the need to use an additional unit on the line of applying polymer coatings for applying a coating layer by printing, which is responsible for ensuring the decorative properties of the coating system as a whole, which makes the process more expensive.

There are also known methods of applying transparent smooth varnishes to give a high gloss surface and good resistance to surface defects during mechanical stress for the automotive industry (Patent US 7687576 B2).

The prototype is a two-layer polymer coating applied to steel coils when the first layer is applied to the surface of the metal, the second layer is polyester or polyurethane enamel, while the second layer can be textured by “wrinkling” (see patent RU No. 2512378 “ The method of coating metal tapes ", IPC B05D 7/14, priority from 04/30/2009, publ. 10.07.2012).

The disadvantages of this method are the low corrosion resistance and operational characteristics of steels due to the influence of environmental factors directly on the polymer layer.

To eliminate these drawbacks, the proposed method involves sequentially applying layers to a pre-cleaned metal surface, drying and curing them, while the first layer is covered with soil with a coating thickness of 1 to 25 μm with intermediate curing at peak metal temperatures of 224-242 ° C, the second layer it is coated with plain monophonic smooth polyester enamel with a thickness of 10-40 microns with intermediate curing at peak metal temperatures of 224-242 ° C, the third layer is coated with a colorless polyurethane varnish schinoy from 5 to 30 microns and is cured at a peak metal temperature of 224-242 ° C.

Examples of the method.

Example 1. The coating according to p. 1 of the formula (in three layers) is as follows.

The raw material for production is thin-sheet galvanized steel coil coated with polyester in accordance with GOST 52146 “Cold-rolled hot-rolled thin-sheet rolled products with a polymer coating from continuous lines. Technical conditions. " Preliminary preparation of the metal surface in front of the drive of the automated line includes degreasing with concentrate for degreasing, designed to remove oil and other mechanical impurities from the metal surface. Next, to remove residual degreasing solution from the metal surface, the sheet is washed with demineralized water and to remove residual liquid of chemical solutions from the metal surface, the prepared sheet is dried, which is carried out using a blower. Prepared metal enters the drive provided for continuous operation of the line. From the drive, the metal enters the final preparation unit of the metal surface for chemical treatment, where degreasing is again carried out by spray washing with concentrate for degreasing. Then, on the brush device, contaminants such as heavy oil, metal oxides, etc. are removed from the metal surface. Contamination on the surface of the strip is removed by four cleaning brushes that rotate in the opposite direction of the strip, followed by a double wash with clean water designed to remove alkaline solution from the strip. Then degrease again to finally remove oil and other contaminants from the metal surface and rinse the sheet with demineralized water to remove residual degreasing solution from the metal surface. After that, to ensure good adhesion between the soil and the metal base, a chromating solution is applied to the galvanized metal, followed by drying with hot air. The wet film of the chromatizing solution dries on the surface of the metal without washing the previous color, and thus eliminates the need for processing washing water.

Soil is applied to the cleaned metal surface on a painting machine for applying a primer with an S-shaped movement of the strip, where, using two applying shafts with reverse rotation (i.e. against the strip), the soil layer is applied from both sides simultaneously. The soil layer has a thickness of 5-7 microns. The thickness of the applied soil is controlled manually by setting gaps between the paint rolls, and also by adjusting the rotation speed of the paint, pickup and calibration shafts. After applying the soil to the strip, it moves further through the furnace for drying (curing) the soil, where the soil is sintered with the strip. To do this, the metal rolling in the furnace is heated to 232 ° C ("peak metal temperature" for the soil). The length of the furnace and the speed of the strip in the line are determined by the exposure time in the furnace to achieve the "peak temperature of the metal", as well as to remove the solvent in the ground. The furnace consists of three separate zones. The operator adjusts the temperature of each zone to achieve the necessary peak temperature at the exit of the strip from the furnace.

The dried painted metal enters the cooling section, where it is cooled with demineralized water to ambient temperature.

Plain plain polyester enamel is applied on an automated line by the roll method. To apply the enamel layer on the front side, a machine with a U-shaped movement of the strip is used, where the front coating layer with a thickness of 15-25 microns is applied with the main applying shaft with reverse rotation (that is, against the strip travel). A back coat is applied with the lower application roll. A layer for the reverse side is applied with a thickness of 5-10 μm by direct rotation (that is, along the strip). Further, the strip is moved through the drying oven, where the applied layer of polyester enamel is sintered with the soil. Why metal rolling is heated to 232 ° C ("peak metal temperature"). The length of the furnace and the speed of the strip in the line is determined by the exposure time in the furnace to achieve the "peak temperature of the metal", as well as to remove the solvent in the paint. The furnace consists of three separate zones. The operator adjusts the temperature of each zone to achieve the necessary peak temperature at the exit of the strip from the furnace.

To apply the third layer with polyurethane varnish, the rolled metal is again loaded onto the inlet section. On an automated line, all sections are previously disabled, except for the machine for applying the upper coating with a U-shaped movement of the strip. On the front (main) side of the metal, painted in two layers, colorless polyurethane varnish is applied, by the roll method with reverse rotation (against the course of the strip). The lacquer coating has a thickness of 12-16 microns. When the varnish is applied to the strip, the strip moves through the drying oven, where the varnish is sintered with the main coating of the second layer. To do this, the metal rolling in the furnace is heated to 220 ° C ("peak temperature", which for varnish is usually 220-230 ° C). The length of the furnace and the speed of the strip in the line is determined by the exposure time in the furnace to achieve the "peak temperature of the metal", as well as to remove the solvent in the paint. The furnace consists of three separate zones. The operator adjusts the temperature of each zone to achieve the necessary peak temperature at the exit of the strip from the furnace. The layer of varnish (top layer) during the drying process acquires a coarse cellular, “wrinkled”, textured structure.

Painted rolled metal leaves the furnace at a temperature of 220-230 ° C. In order to cool it to a temperature of 40 ° C, an exhaust fan and a water cooling system are used. An exhaust fan removes air from under the strip, which slightly reduces the temperature of the strip, and then the water cooling system reduces the temperature of the strip to approximately 40 ° C. A water cooling system is a tank in which chilled water is sprayed simultaneously on both sides of a strip. The amount of sprayed cooling water is controlled by the operator. To keep the water cold, it circulates through the evaporative cooling system. After that, the strip passes through rubberized rollers to remove moisture from the strip. After that, the finished metal rolling is rolled up.

Example 2. The coating according to claim 2 of the formula.

At the beginning of the technological cycle, the metal surface is prepared for subsequent coating in the same order that is indicated in Example 1.

Next, the metal that has undergone chemical treatment enters the painting chamber, where the first layer of polyester enamel is applied to the front of the metal. The application of polyester enamel is carried out on a painting machine with an S-shaped movement of the strip with the help of two applying shafts with reverse rotation (i.e. against the strip), while the second shaft is turned off. The layer of polyester enamel has a thickness of 15-25 microns. The thickness of the applied layer is controlled manually by setting gaps between the paint shafts, and also by adjusting the rotation speed of the paint, trapping and calibration shafts.

When the paint is applied to the strip, the strip moves further through the paint drying oven, where the paint is sintered with the strip. In the furnace, the metal rolling is heated to a temperature of 232 ° C (the “peak metal temperature", which for polyester enamel is usually 224-242 ° C). The length of the furnace and the speed of the strip in the line is determined by the exposure time in the furnace to achieve the "peak temperature of the metal", as well as to remove the solvent in the paint. The furnace consists of three separate zones. The operator adjusts the temperature of each zone to achieve the necessary peak temperature at the exit of the strip from the furnace.

The dried painted metal enters the cooling section, where it is cooled with demineralized water to ambient temperature.

Next, a layer of colorless polyurethane varnish is applied to the automated line by the roll method. To do this, use a coating machine with a U-shaped movement of the strip, where the front coating layer is applied with the main application shaft with reverse rotation (i.e., against the course of the strip). The varnish layer has a thickness of 12-16 microns. On the front (main) side of the rolled metal, painted in one layer, colorless polyurethane varnish with a thickness of 10-15 microns is applied by a roll method with reverse rotation (against the course of the strip). When the varnish is applied to the strip, the strip moves through the drying oven, where the varnish is sintered with the main coating. In the furnace, metal rolling is heated to 225 ° C (to the "peak metal temperature", which for varnish is usually 220-230 ° C). The length of the furnace and the speed of the strip in the line is determined by the exposure time in the furnace to achieve the "peak temperature of the metal", as well as to remove the solvent in the paint. The operator adjusts the temperature of each zone of the furnace to achieve the required peak temperature at the exit of the strip from the furnace. The upper layer during the drying process acquires a coarse cellular, “wrinkled”, textured structure.

After that, the metal painted in two layers is cooled using an exhaust fan and a water cooling system. After that, the finished metal rolling is rolled up.

Example 3. The coating according to claim 3 of the formula.

At the beginning of the technological cycle, the metal surface is prepared for subsequent coating in the same order that is indicated in Example 1.

Next, the metal that has undergone chemical treatment enters the painting chamber, where soil is applied to the front and back sides of the metal. Application of the soil is carried out on an automated line by the roll method. On a painting machine for applying a primer with an S-shaped movement of the strip, where using two coating rolls with reverse rotation (that is, against the stroke of the strip), a primer is applied on both sides simultaneously. The soil layer has a thickness of 5-7 microns. The thickness of the applied soil is controlled manually by setting gaps between the paint rolls, and also by adjusting the rotation speed of the paint, pickup and calibration shafts.

When the paint is applied to the strip, the strip moves further through the drying oven (curing), where the soil is sintered with the strip. To do this, the metal rolling in the furnace is heated to a temperature of 232 ° C ("peak metal temperature"), which for the soil is usually 224-242 ° C. The length of the furnace and the speed of the strip in the line is determined by the exposure time in the furnace to achieve the "peak temperature of the metal", as well as to remove the solvent in the paint. The operator adjusts the temperature of each zone of the furnace to achieve the required peak temperature at the exit of the strip from the furnace.

The dried painted metal enters the cooling section, where it is cooled with demineralized water to ambient temperature.

A layer of polyester enamel is applied on an automated line by the roll method. For its application, a coating machine with a U-shaped movement of the strip is used, where the front coating layer is applied with the main application roller with reverse rotation (i.e., against the course of the strip). The main layer has a thickness of 15-25 microns. A back coat is applied with the lower application roll. The layer for the reverse side is applied by direct rotation (that is, along the strip). The backward strip layer has a dry film thickness of 5-10 microns. When the base layer is applied to the strip, the strip moves through the paint drying oven, where the base layer is sintered with soil. In the furnace, metal rolling is heated to 232 ° C by the "peak metal temperature", which for the front side is usually 224-242 ° C. The length of the furnace and the speed of the strip in the line is determined by the exposure time in the furnace to achieve the "peak temperature of the metal", as well as to remove the solvent in the paint. The operator adjusts the temperature of each zone of the furnace to achieve the required peak temperature at the exit of the strip from the furnace.

Next, the metal is again loaded into the inlet section. On an automated line, all sections are previously disabled, except for the machine for applying the upper coating with a U-shaped movement of the strip. The second layer of polyester enamel is applied similarly to the application of the second layer described above.

Painted in three layers, the metal is again loaded into the inlet section. On an automated line, all sections are previously disabled, except for the machine for applying the upper coating with a U-shaped movement of the strip. On the front (main) side of the metal, painted in two layers, colorless polyurethane varnish is applied, by the roll method with reverse rotation (against the course of the strip). The varnish coating has a thickness of 12-16 microns. When the varnish is applied to the strip, the strip moves through the paint drying oven, where the varnish is sintered with the main coating of the second layer. In the furnace, metal rolling is heated to a certain temperature, called “peak metal temperature”, which for varnish is usually 220-230 ° С. The upper layer during the drying process acquires a coarse cellular, “wrinkled”, textured structure. After that the metal painted in four layers is cooled, the cooled, finished metal rolling is rolled up.

Example 4. The coating according to claim 4 of the formula.

At the beginning of the technological cycle, the metal surface is prepared for subsequent coating in the same order that is indicated in Example 1.

The application of soil and polyester enamel is the same as in Example 1.

Painted in two layers, the metal is again loaded onto the inlet section.

On an S-shaped strip coater, a first coat of polyurethane varnish is applied. The lacquer coating has a thickness of 12-16 microns. When the varnish is applied to the strip, the strip moves through the furnace for drying paint, where the varnish is sintered at a peak metal temperature of 230 ° C with the main coating of the second layer. The upper layer during the drying process acquires a coarse cellular, “wrinkled”, textured structure.

Then the metal coated with the first layer of polyurethane varnish enters the section for applying the upper coating with a U-shaped movement of the strip. On the front (main) side of the metal, painted in three layers, another layer of colorless polyurethane varnish is applied, by the roll method with reverse rotation (against the strip). The varnish coating has a thickness of 12-16 microns. When the varnish is applied to the strip, the strip moves through the furnace for drying paint, where the varnish is sintered at a peak metal temperature of 220-230 ° C with the coatings of the previous layers. The upper layer in the process of drying acquires a coarse cellular, “wrinkled” structure.

The proposed technical solution allows to obtain a coating in any color with the same surface structure due to the fact that its formation occurs due to the transparent lacquer layer at the last stage of painting the substrate.

In addition, the resistance of steels to physicochemical, mechanical, and corrosive influences increases, which increases the service life of the product.

The metal coating does not slip in the hands during installation due to a rough, textured surface, since there is an increase in the coefficient of friction of the coating surface on the surface of the gripping devices during installation and sufficient abrasion resistance is maintained at a high coefficient of surface friction.

Due to the large cellular structure of the coating, safety during high-altitude work is ensured due to good adhesion to the sole of workers installing roofing material.

Due to the fact that on top of the painted second layer (polyester) there is an additional - the third layer of polyurethane varnish, which scatters part of the ultraviolet rays, which destructively affect the polymer matrix and the visible and infrared rays, causing an increase in surface temperature and thermal degradation of the coating, the proposed coating It is more resistant to ultraviolet radiation.

Claims (4)

1. The method of coating steel products, comprising sequentially applying layers to a pre-cleaned metal surface, drying and curing them, characterized in that the first layer is applied with a primer from 1 to 25 μm thick with intermediate curing at peak metal temperatures of 224-232 ° C , the second layer is applied with smooth polyester enamel with a thickness of 10 to 40 microns with intermediate curing at peak metal temperatures of 224-232 ° C, the third layer is applied with a transparent or translucent polyurethane varnish thickness from 5 to 30 microns with curing at a peak metal temperature of 224-242 ° C, while to ensure the effect of wrinkling, the varnish contains polycarbon wax with a melting point of 150-170 ° C. 2. The method of coating steel products, comprising sequentially applying layers to a pre-cleaned metal surface, drying and curing, characterized in that the first layer is applied with smooth polyester enamel with a thickness of 10-40 microns with intermediate curing at peak metal temperatures of 224-232 ° FROM; the second layer is applied with a transparent or translucent polyurethane varnish with a thickness of 5 to 30 microns with curing at a peak metal temperature of 224-242 ° C, while to ensure the wrinkling effect, the varnish contains polycarbon wax with a melting point of 150-170 ° C. 3. The method of coating steel products, comprising sequentially applying layers to a pre-cleaned metal surface, drying and curing them, characterized in that the first layer is applied with a primer of 1 to 25 microns thick with intermediate curing at peak metal temperatures of 224-232 ° C , the second and third layers are applied sequentially with smooth polyester enamel with a thickness of 10-40 microns with intermediate curing at peak metal temperatures of 224-232 ° C, the fourth layer is applied transparent or translucent oliuretanovym varnish a thickness of 5 to 30 micron and cured at a peak metal temperature 224-242 ° C, thus to provide the effect of wrinkling poliuglevodorodny lacquer contains wax with a melting point of 150-170 ° C. 4. The method of coating steel products, comprising sequentially applying layers to a pre-cleaned metal surface, drying and curing, characterized in that the first layer is applied with a primer of 1 to 25 μm thick with intermediate curing at peak metal temperatures of 224-232 ° C , the second layer is applied with smooth polyester enamel with a thickness of 10-40 microns with intermediate curing at peak metal temperatures of 224-232 ° C, the third and fourth layers are applied with a transparent or translucent polyurethane la com from 5 to 30 microns thick with curing at a peak metal temperature of 224-242 ° C, while to ensure the wrinkling effect, the varnish contains polycarbon wax with a melting point of 150-170 ° C.