WO2015190628A1

WO2015190628A1 - Method for manufacturing multi-laminated color steel sheet

Info

Publication number: WO2015190628A1
Application number: PCT/KR2014/005136
Authority: WO
Inventors: 박성호; 김윤석; 서현용
Original assignee: 포스코강판 주식회사
Priority date: 2014-06-11
Filing date: 2014-06-11
Publication date: 2015-12-17

Abstract

The present invention relates to a method for manufacturing a multi-laminated color steel sheet and, more specifically, to a method for manufacturing a color-coated steel sheet which is used in the external plate material of home appliances and in interior and exterior construction materials. To this end, the present invention provides a method for manufacturing a multi-laminated color steel sheet, the method being capable of forming a multi-coating layer by a single coating-curing process.

Description

Manufacturing method of multi-layered color steel sheet

The present invention relates to a method for manufacturing a multi-layered color steel sheet, and more particularly, to a method for manufacturing a color coated steel sheet used in the exterior plate material, building interior and exterior materials of household appliances.

In general, the continuously produced coil-type color coated steel sheet is coated with a chemical conversion coating on the surface of the steel sheet in order to increase the adhesion between the steel sheet and the paint, and then dried to obtain a clear color and physical properties of the paint color. After the coating is cured, the coating is cured by applying a top coat to realize the final color.

The color steel sheet manufactured in this way is easy to operate because the color is applied to the surface by using a coating method of roller type, and it is easy to operate, and it is easy to transform the equipment into various forms for various color coatings as it is a general-purpose technology. There is this.

However, in order to produce a high-performance product by repeatedly performing one coating and one curing process, there is a problem in that the construction cost increases, the manufacturing cost increases, and the operating period becomes long, resulting in a large scale of the factory. .

In addition, the above-described technical problems may be more highlighted because a variety of surface designs and a quality of a brilliant surface treatment due to an atypical pattern are required or when applied to harsh conditions, three to ten or more coating and curing processes are required. will be.

One aspect of the present invention is to provide a color steel sheet having a beautiful surface appearance, to provide a method of manufacturing a color steel sheet which can reduce the manufacturing cost while improving productivity by simplifying a work process.

One aspect of the present invention is a manufacturing method of a color steel sheet,

Preparing a steel sheet; Forming a chemical conversion treatment layer on one surface or both surfaces of the steel sheet; Forming a multi-layered coating layer of two or more layers on one surface of the base steel sheet on which the chemical conversion treatment layer is formed; Hardening the base steel sheet on which the multiple coating layer is formed; Forming at least one color coating layer of printing, hologram and metallic on the surface of the hardened steel sheet and forming a transparent (clear) coating layer on the surface of the color coating layer, wherein the multiple coating layer is a multiple resin film Provided is a method for producing a multi-layered colored steel sheet, which is formed in a non-contact manner using a generator.

According to the present invention, a large number of facilities and a large space can be greatly reduced for the repetitive execution of the conventional coating-curing process, and thus the manufacturing cost can be reduced.

In addition, since it is possible to implement a color steel sheet of the same multi-layer structure from the simplified process, it is possible to improve the productivity of the color steel sheet, there is an advantage that it is possible to produce a stable product without quality degradation.

Figure 1 shows a schematic diagram of a process for producing a multi-layer laminated color steel sheet from one aspect of the present invention.

2 and 3 show a schematic diagram of a process for forming a multi-coat layer using a multi-resin film generator according to an aspect of the present invention.

In general, multi-layered color steel sheet is manufactured through repeated implementation of a coating-curing process, which requires a large number of processing facilities, and requires a large space to accommodate such facilities, thereby increasing manufacturing costs and increasing the cost. There has been a problem that productivity decreases due to operating time.

Thus, the present inventors have studied in depth to more easily produce a multi-layer laminated color steel sheet, when the coating of the steel sheet in a continuous process using a multi-resin film generator to produce a multi-layer coating layer in one coating-hardening process It confirmed that it could form and came to complete this invention.

Hereinafter, a method of manufacturing a multi-layer laminated color steel sheet which is an aspect of the present invention will be described in detail with FIG. 1 showing an example thereof.

Method for producing a multi-layer laminated color steel sheet provided in an aspect of the present invention, preparing a steel sheet; Forming a chemical conversion treatment layer on one surface or both surfaces of the steel sheet; Forming a multi-layered coating layer of two or more layers on one surface of the base steel sheet on which the chemical conversion treatment layer is formed; Hardening the base steel sheet on which the multiple coating layer is formed; Forming at least one color coating layer of printing, hologram and metallic on the surface of the hardened steel sheet and forming a transparent (clear) coating layer on the surface of the color coating layer, wherein the multiple coating layer is a multiple resin film It is characterized in that it is formed in a non-contact using a generator.

First, in the step of preparing a holding steel sheet, the holding steel sheet is not particularly limited to the material in the present invention, any material used in the normal continuous color coating process is applicable. For example, it may include a carbon steel sheet, a non-carbon steel sheet and a stainless steel sheet.

In addition, it is also preferable to use the plated steel sheet is formed of a metal coating layer in consideration of the corrosion resistance and paintability of the steel sheet.

In this case, when the plated steel sheet is manufactured by an electroplating method, the plated layer formed by the electroplating method may include one or more components of Zn, Al, Mg, Sn, Ti, Cr, Cu, Pb, W, and Zr. It is preferable that it is formed on both surfaces or one side of the steel plate. In the case of the plated steel sheet by the electroplating method, there is an effect that can ensure a beautiful surface quality.

In addition, the metal plate may be a non-carbon steel sheet in consideration of light weight, high strength, and high workability, wherein the non-carbon steel sheet is one or more components of aluminum (Al), magnesium (Mg), copper (Cu) components It is preferable that it is a steel plate mainly containing.

As described above, the step of forming the chemical conversion layer on one or both surfaces of the base steel sheet may be formed by applying and drying the chromium (Cr) or chromium-free (Cr-free) highly corrosion-resistant chemically-treated solution.

Referring to FIG. 1, the chemical conversion treatment liquid is applied to the front surface or the front / rear surface of the base steel sheet 1 using the

chemical conversion coaters

2 and 3, and dried in a subsequent hot air dryer 4. Finally, the chemical conversion layer may be formed, and the thickness of the chemical conversion layer formed after drying is preferably 1.0 to 4.0 μm in consideration of drying of the applied chemical treatment liquid and adhesion to the upper and lower layers of the laminated structure formed. Do.

In this case, the reason for forming the chemical conversion treatment layer on the base steel sheet is to increase the adhesion with the multi-coat layer to be described later in the case of the upper surface, the lower surface is to increase the adhesion with the basic coating (thin coating) layer also described later.

By the above, it is possible to form a multi-coating layer intended in the present invention on the surface of the steel sheet on which the chemical conversion treatment layer is formed. At this time, the multi-layer coating layer means a coating layer composed of two or more layers, for example, it may be a coating layer consisting of a coat layer / top coat layer.

The formation of the multi-layer coating layer is a step corresponding to the core configuration of the present invention, which has a meaning in that the step of sequentially forming the existing undercoat layer and the top coat layer in each step is performed in one step. will be.

More specifically, the present invention is characterized in that it is formed in a non-contact by using a multi-resin film generator (5) for forming a multi-film layer, wherein at least two kinds of paint is extruded from two or more divided nozzles are laminated at the same time Multiple coating layers can be formed.

On the other hand, when the steel sheet chemically processed to form the multi-layered film is transported from the side of the multiple resin film generator, air is moved along the chemically processed surface due to fluid viscosity, that is, a Coanda effect occurs. This is mixed between the steel sheet and the paint that has been processed during the multi-coating process to generate defects such as bubbles.

Therefore, it is preferable that the vacuum box 53 for removing the mixed air is provided in the multiple resin film generator 5, and the atmosphere of the vacuum box is preferably less than 760 Torr. If the atmosphere in the vacuum box is more than 760 Torr, it is formed higher than the atmospheric pressure to push out the air, there is no effect of removing the generated bubbles.

As shown in Fig. 2, the multiple resin film formers used for forming the multi-coat layer in the present invention include

nozzle lips

51, 52, vacuum boxes 53, and seams 54 located at the upper and lower parts. The lower coating material nozzle 55 is positioned between the lower nozzle lip and the shim, and the upper coating material nozzle 56 is positioned between the upper nozzle lip and the shim.

That is,

precise ejection nozzles

55 and 56 are provided to form a film having the same thickness in the width direction of the steel plate, and as shown in FIG. 3, the coating material is continuously extruded and coated from the nozzle while the steel sheet is transported. It is possible to form a multi-coat layer from, and the coating can be extruded wider than the width of the steel sheet so that it can be completely coated to the edge of the steel sheet.

At this time, the thickness of the film can be controlled by adjusting the pressure of the coating material extruded from the nozzle and the speed at which the steel sheet is conveyed. In the present invention, the thickness of the lower coating layer (eg, the lower coating layer) is 1 to 50 μm and the upper coating layer (eg, the upper coating layer) is 1 to 350 μm in terms of dry film thickness in consideration of adhesion to the upper and lower layers in the multilayer structure. Is preferably formed.

When the extrusion of two or more kinds of paint is completed according to the above, it is preferable to cure it through a continuous process.

At this time, the means applicable to the curing process is not particularly limited as long as the drying apparatus 9 that can control the temperature, for example, IR heater (Infrared Ray Heater), Induction Heater (Induction Heater), Hot air oven (Dry) using infrared It is preferable that the apparatus is capable of controlling a heat source such as an oven.

It is preferable to carry out at 100-400 degreeC at the time of baking process using the apparatus mentioned above. If the baking treatment temperature is less than 100 ° C., the top coat layer may not be completely dried. On the other hand, if the baking process temperature exceeds 400 ° C., the resin material may be deformed and deformation and damage of the coating layer may be undesirable.

When the formation of the multi-coat layer is completed, it is possible to form the desired color coating layer by performing color coating according to the customer's request.

For example, one or more color coating layers of printing, hologram, and metallic may be formed, but is not limited thereto.

In addition, according to the method for manufacturing a multi-layered color steel sheet provided in an aspect of the present invention, it is also preferable to further include forming a transparent (clear) coating layer on the color coating layer. The transparent (clear) coating layer is intended to enable the protection of the coating pattern surface and secure the physical properties of the inner components.

At this time, the formation of the transparent (clear) coating layer includes a step of applying a glossy or matte coating and drying by using a roll coating method, the gloss coating is a gloss meter of 60% incident angle reference gloss of 70% or more, Preferably, the matte paint has a glossiness of 10 to 30% based on a 60 ° incident angle. The glossiness at this time is preferably obtained at or above the standard value of a commercially available product.

In addition, according to the manufacturing method of the multi-layered color steel sheet provided in one aspect of the present invention, it is also preferable to further comprise the step of forming a base film (thin coating) layer on the lower surface of the base steel sheet on which the chemical conversion treatment layer is formed. The base coating (thin coating) layer is formed to prevent aesthetic appearance and scratches on the bottom of the color steel sheet.

On the other hand, as one preferred means for implementing the manufacturing method of the multi-layer laminated color steel sheet provided in one aspect of the present invention, the manufacturing apparatus described below may be applied. Through the description of the manufacturing apparatus provided below, the spirit of the present invention can be further embodied. However, the following manufacturing apparatus is only an example of one of the means applicable to this invention, and the manufacturing method mentioned above is not limited by this.

1 is a diagram illustrating a process of forming a coating layer in a multi-stage plate strip through an example of a multi-layer coating apparatus applicable to a method for manufacturing a multi-layer laminated color steel sheet provided by an aspect of the present invention.

1, the sheet strip 1 is introduced into the

chemical coater

2, 3, which is a chemical conversion section, for the purpose of improving adhesion and corrosion resistance with the paint, and thus, chromium (Cr) according to demand. Alternatively, after the chromium-free chemical treatment is performed, the chemically treated surface is passed through a hot air dryer 4 to dry the surface. Subsequently, the film is introduced into the multiple resin film generator 5, that is, the primer and the top coat are laminated at the same time to form a multi-film layer, which is then immediately cured through the oven 9. Thereafter, the desired color coating may be performed according to demand and then hardened to produce a final product, or a clear layer may be laminated through an additional coating device to secure durability.

[Description of the code]

(1) ... steel plate (substrate)

(2) ... top chemi-coater

(3) ... bottom chemi-coater

(4) ... hot air dryer

(5) ... Multi Resin Film Forming Machine

(6) ... # 1 backup roll

(7) ... # 2 backup roll

(8) ... catch pan

(9) ... drying equipment (oven)

(51) ... top nozzle lip

(52) ... bottom nozzle lip

(53) ... vacuum box

(54) ... seam

(55) ... top paint nozzle

(56) ... bottom paint nozzle

Claims

As a manufacturing method of colored steel sheet,

Preparing a steel sheet;

Forming a chemical conversion treatment layer on one surface or both surfaces of the steel sheet;

Forming a multi-layered coating layer of two or more layers on one surface of the base steel sheet on which the chemical conversion treatment layer is formed;

Hardening the base steel sheet on which the multiple coating layer is formed;

Forming at least one color coating layer of printing, hologram, and metallic on the surface of the hardened steel sheet;

Forming a transparent (clear) coating layer on the surface of the color coating layer;

The multi-layer coating layer is a method of manufacturing a multi-layer laminated color steel sheet characterized in that it is formed in a non-contact using a multi-resin film generator.
The method of claim 1,

The forming of the multi-layer coating layer is a method for manufacturing a multi-layered color steel sheet, characterized in that to laminate at least two kinds of paint at the same time.
The method of claim 2,

The method of manufacturing a multi-layered color steel sheet wherein the two or more kinds of paints are extruded and laminated from nozzles divided into two or more, respectively.
The method of claim 1,

The multiple resin film generator comprises a vacuum box at the front end, the internal atmosphere of the vacuum box is less than 760torr manufacturing method of a multi-layered color steel sheet.
The method of claim 1,

The hardening step is a manufacturing method of a multi-layered color steel sheet is carried out at 100 ~ 400 ℃.
The method of claim 1,

The method of manufacturing a multi-layer laminated color steel sheet further comprising the step of forming a base film (thin coating) layer on the opposite side of the surface formed with the multiple coating layer of the steel sheet formed with the chemical conversion treatment layer.