KR102472560B1 - Manufacturing method of tinted stainless steel using plasma process - Google Patents

Abstract

The present invention relates to a method for manufacturing colored stainless steel using plasma treatment capable of forming a coating film of various colors through a continuous process in a general roll-to-roll method, wherein the surface of uncoiled stainless steel supplied in one direction is subjected to high-temperature plasma treatment to remove moisture from the surface of stainless steel, and a passivation film is removed by low-temperature plasma treatment, so that stainless steel is colored by painting the surface of stainless steel.

Description

Manufacturing method of colored stainless steel using plasma treatment {MANUFACTURING METHOD OF TINTED STAINLESS STEEL USING PLASMA PROCESS}

The present invention relates to a method for manufacturing colored stainless steel using plasma treatment, and more particularly, to a method for manufacturing colored stainless steel using plasma treatment capable of forming coating films of various colors through a continuous process in a general roll-to-roll method. will be.

In the case of the automobile market, in general, color painting is performed by anodizing aluminum after post-processing (Production Method 1), or a method of attaching a color film during post-processing (Production Method 2) is being promoted to improve the automotive molding parts market. .

Existing processes, including production method 1 and production method 2, had a problem of high cost.

Aluminum or aluminum alloy is widely used in that it is easy to process the material and can realize weight reduction, but because of its low structural strength, it can pose a serious threat to the safety of drivers and occupants due to damage and severe deformation in the event of a collision.

From this point of view, stainless steel, a material with excellent structural strength, is in the spotlight in the automotive molding parts market.

However, due to the nature of the material in which a chromium oxide film and a passivation film are always formed, stainless steel has a problem in that it is impossible to paint the general paint itself and coloration itself accordingly.

Invented from the above point of view, things such as Registered Patent No. 10-0897169 entitled "Method for manufacturing color steel sheet using magnetic force and color steel sheet produced by this method" (hereinafter referred to as prior art) may be mentioned.

In the prior art, after forming a chrome coating layer through a chromate coating treatment process, an undercoating material is coated on the chrome coating layer to form an undercoating layer, and carbonyl iron showing bias by magnetic force is included on the undercoating layer. After painting the top coat, applying magnetic force to form a pattern on the top coat, heat drying at 210 to 250 ° C to form a top coat layer.

However, the prior art is also economically very inefficient because it forms several coating layers and the cost of a top coat paint containing carbonyl iron is very high and cannot be easily applied at the manufacturing site.

In particular, since the prior art requires a cumbersome and complicated process of applying different paints several times to form a film, it can be said to be very inefficient in terms of manufacturing time and cost.

Registered Patent No. 10-0897169

The present invention was invented to improve the above problems, and is to provide a method for producing colored stainless steel using plasma treatment, which enables the formation of coating films of various colors through a continuous process in a general roll-to-roll method.

In order to achieve the above object, the present invention is a high-temperature plasma treatment on the surface of uncoiled stainless steel supplied in one direction to remove moisture from the surface of the stainless steel, and then a low-temperature plasma treatment and removing the passivation film to remove the stainless steel surface. It is possible to provide a method for producing colored stainless steel using plasma treatment, characterized in that it is colored by painting the surface of the steel.

Here, the flame temperature applied to the surface of the stainless steel during the high-temperature plasma treatment is 600 ° C to 800 ° C, and the surface temperature of the stainless steel is maintained at room temperature during the low-temperature plasma treatment.

On the other hand, the present invention is a first step of seating the stainless steel wound in the form of a coil on an uncoiler, uncoiling it, and supplying it in one direction; By maintaining the surface of the stainless steel at 40 ° C to 100 ° C by high-temperature plasma treatment that sprays the surface of the stainless steel with a flame formed of LPG and oxygen mixture gas at 600 ° C to 800 ° C for 6 to 18 seconds, A second step of removing moisture from the stainless steel surface; A third step of removing the passivation film of the stainless steel by maintaining the surface of the stainless steel at room temperature by low-temperature plasma treatment in which a discharge voltage of 7000 V to 8000 V is applied to the surface of the stainless steel for 0.1 to 3 seconds. ; 15 ℃ to 25 ℃ by an electrostatic painting device that forcibly sprays paint of a specific color from the ceiling side of the painting booth toward the floor side on the surface of the stainless steel from which the passivation film is removed, which is introduced into the painting booth and transported in one direction. A fourth step of coloring the paint of the specific color by painting while maintaining the; A fifth step of drying the stainless steel, which is put into a drying chamber and has been colored, at a temperature of 100° C. to 250° C.; and a sixth step of cooling and recoiling the dried stainless steel.

Here, the high-temperature plasma treatment, the low-temperature plasma treatment, and the painting treatment are continuously performed.

At this time, in the fifth step, a plurality of different drying chambers are arranged in a row along the conveying direction of the stainless steel so that the drying temperature is gradually increased from the 100 ° C to the 250 ° C along the conveying direction. It is characterized by being placed.

According to the present invention having the configuration as described above, the following effects can be achieved.

First of all, the present invention surface-treats the stainless steel coil itself received from leading steel companies through a general roll-to-roll production method, that is, high-temperature plasma and low-temperature plasma, then paints, dries, cools, and recoils. It has the advantage of enabling mass production of highly reliable color stainless steel, that is, tinted stainless steel products.

Above all, the present invention can provide customers with stainless steel products colored with paints of various colors by breaking away from the material characteristics and restrictions of stainless steel, which cannot be colored due to the chromium oxide film and passivation film. It is very efficient in that it can actively respond to demands.

In particular, the present invention will be able to make a significant contribution to the development of the automobile industry in that it was first applied to automobile parts made of stainless steel.

1 is a block diagram showing a method for manufacturing colored stainless steel using plasma treatment according to an embodiment of the present invention.
2 to 7 are conceptual views sequentially showing a method for manufacturing colored stainless steel using plasma treatment according to another embodiment of the present invention.
8 is a perspective conceptual view showing a colored state of tinted steel manufactured through a method for manufacturing colored stainless steel using plasma treatment according to various embodiments of the present invention and an appearance of an automobile molding part manufactured through the same.

Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms.

In this specification, this embodiment is provided to complete the disclosure of the present invention, and to completely inform those skilled in the art of the scope of the invention to which the present invention belongs.

And the invention is only defined by the scope of the claims.

Thus, in some embodiments, well-known components, well-known operations and well-known techniques have not been described in detail in order to avoid obscuring the interpretation of the present invention.

In addition, like reference numerals designate like elements throughout the specification, and terms used (referred to) in this specification are for describing embodiments and are not intended to limit the present invention.

In this specification, the singular also includes the plural unless specifically stated in the phrase, and components and operations referred to as 'comprising (or including)' do not exclude the presence or addition of one or more other components and operations. .

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs.

In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless they are defined.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

First, FIG. 1 is a block diagram illustrating a method of manufacturing colored stainless steel using plasma treatment according to an embodiment of the present invention.

2 to 7 are conceptual views sequentially illustrating a method of manufacturing colored stainless steel using plasma treatment according to another embodiment of the present invention.

8 is a perspective conceptual view showing a colored state of tinted steel manufactured through a method for manufacturing colored stainless steel using plasma treatment according to various embodiments of the present invention and an appearance of an automobile molding part manufactured through the same.

As shown in the drawing, the surface of the uncoiled stainless steel 70 supplied in one direction is subjected to high-temperature plasma treatment to remove moisture on the surface of the stainless steel 70, followed by low-temperature plasma treatment and removal of the passivation film to make stainless steel ( 70) may be applied to an embodiment that is colored by painting the surface.

Of course, the present invention can be applied to the above embodiments, and also to the following various embodiments.

First of all, the flame temperature applied to the surface of the stainless steel 70 during high-temperature plasma treatment is 600 ° C to 800 ° C, and during low-temperature plasma treatment, it is preferable to maintain the surface temperature of the stainless steel 70 at room temperature for smooth painting treatment. do.

On the other hand, as shown in FIG. 2, the stainless steel 70 wound in a coil form may be seated on an uncoiler 10, uncoiled, and supplied in one direction (S1: first step).

Thereafter, as shown in FIG. 3, the surface of the stainless steel 70 is cleaned by high-temperature plasma treatment in which a flame formed of LPG and oxygen mixture gas at 600° C. to 800° C. is sprayed for 6 to 18 seconds on the surface of the stainless steel 70. By maintaining the temperature at 40° C. to 100° C., an operation of removing moisture from the surface of the stainless steel 70 may be performed (S2: second step).

If the flame spraying time is less than 6 seconds, moisture removal may not be performed properly, and if the flame spraying time exceeds 18 seconds, there is a risk of surface deterioration and material denaturation of the stainless steel 70 as the substrate.

When the flame temperature is less than 600 ° C., moisture removal may not be performed properly, and when the flame temperature exceeds 800 ° C., there is a risk of surface deterioration and material denaturation of the stainless steel 70 as a base material.

Subsequently, as shown in FIG. 4, by low-temperature plasma treatment in which high-frequency plasma of a discharge voltage of 7000 V to 8000 V is applied to the surface of the stainless steel 70 for 0.1 seconds to 3 seconds, more preferably for 1 to 2 seconds, stainless steel ( 70) by maintaining the surface at room temperature, an operation of removing the passivation film of the stainless steel 70 can be performed (S3: third step).

If the discharge voltage is less than 7000V, the passivation film may not be completely removed, and if the discharge voltage exceeds 8000V, there is a risk of surface deterioration and material denaturation of the stainless steel 70 as a substrate.

If the application time of high-frequency plasma is less than 0.1 seconds, the passivation film may not be completely removed, and if the application time of high-frequency plasma exceeds 3 seconds, there are concerns about surface deterioration and material denaturation of the base material, stainless steel 70. there is

Next, as shown in FIG. 5, a paint of a specific color is applied from the ceiling side of the painting booth 40 to the floor side of the stainless steel 70 from which the passivation film is removed, which is introduced into the painting booth 40 and transported in one direction. An operation of coloring a paint of a specific color may be performed by performing a painting process while maintaining a temperature of 15° C. to 25° C. by means of an electrostatic painting device forcibly spraying (S4: fourth step).

If the temperature condition range of the inside of the painting booth 40 is out of the range of 15° C. to 25° C., problems such as the paint not being properly colored or flowing down on the surface of the stainless steel 70 will occur.

Thereafter, as shown in FIG. 6 , an operation of drying the stainless steel 70 that has been put into the drying chamber 50 and has been colored may be dried at a temperature of 100° C. to 250° C. (S5: fifth step).

Finally, as shown in FIG. 7 , an operation of cooling and recoiling the dried stainless steel 70 may be performed (S6: sixth step).

In the first step (S1), as shown in FIG. 2, the stainless steel 70 is seated in the uncoiler 10 and uncoiled, and then an operation of removing the packaging material of the stainless steel 70 may be additionally performed.

In the second step (S2), the surface of the stainless steel 70 is damaged by high-temperature flame sprayed through the flame spray nozzle assembly 20 as shown in FIG. 3 so that the passivation film can be smoothly removed before electrostatic painting. The process of removing moisture takes place.

In the second step (S2), an effect of removing unnecessary foreign substances along with moisture can be achieved.

It is confirmed that there is no case of performing the second step (S2) process using high-temperature plasma as a pretreatment process even in domestic leading companies.

The third step (S3) is applied to the surface of the stainless steel 70 through the high-frequency corona discharger 30 as shown in FIG. 4 so that the paint can be smoothly colored on the surface of the stainless steel 70 before electrostatic painting. It can be referred to as a process for removing the formed passivation film.

In the third step (S3), the effect of increasing surface activation, surface hydrophilicity and adhesiveness, and improving adhesion during coating of paint can be achieved.

As soon as the stainless steel 70 is exposed to the atmosphere, a chromium oxide film layer is formed on the surface, so elements cannot penetrate from the outside, so it has strong resistance to corrosion, and having such a strong resistance is said to have a high tendency to passivity. .

Therefore, the stainless steel 70 forms a passivation film with a high passivation tendency, and accordingly, it is a well-known fact in the art that the stainless steel 70 cannot be painted by a general method.

In the fourth step (S4), the surface of the stainless steel 70 is colored or tinted to enable color implementation through the bell painting equipment 41 in the painting booth 40 as shown in FIG. It can be said that it is a process for carrying out.

In order to achieve efficient electrostatic painting on uncoiled STS430 stainless steel (70) steel sheets from coils with a maximum width of 1200 mm, a pair of bell painting equipment (41), i.e., electrostatic coating devices, are placed side by side to ensure that the stainless steel (70) steel sheet is coated. Paint is sprayed onto the surface of the stainless steel 70 along the conveying direction.

In the fourth step (S4), weather resistance and workability may be improved.

To this end, it is preferable that the high-temperature plasma treatment, the low-temperature plasma treatment, and the painting treatment are continuously performed.

As described above, the high-temperature plasma treatment of the second step (S2), the low-temperature plasma treatment of the third step (S3), and the painting treatment of the fourth step (S4) must be performed continuously without resting time.

Because, after the high-temperature plasma treatment in the second step (S2), the effect of removing moisture and foreign matter according to the above-described high-temperature plasma treatment of the surface of the stainless steel 70 is lost in about 1 minute, and the low-temperature plasma treatment in the third step (S3) This is because the effect of removing the passivation film according to the above-described low-temperature plasma treatment of the surface of the stainless steel 70 after the stainless steel 70 is also lost within 1 minute.

Therefore, the high-temperature plasma processing device, the low-temperature plasma processing device, and the electrostatic coating device performing the second step (S2) to the fourth step (S4) should be continuously or in line along the transport direction of the stainless steel 70. will be.

After removing the moisture of the high-temperature plasma treatment according to the present invention, the removal of the passivation film of the low-temperature plasma treatment, and the bell painting that can be finely and uniformly applied while the state of removing the moisture and the removal of the passivation film is maintained, that is, stainless steel by the electrostatic painting method ( 70) can be referred to as a tinted painting system.

The fifth step (S5) can be said to be a process of drying the colored stainless steel 70 through the tinted painting system according to the required temperature.

In the fifth step (S5), as shown in FIG. 6, the stainless steel 70 is a plurality of different drying chambers 50 so that the drying temperature is gradually increased from 100 ° C to 250 ° C along the conveying direction. It is preferable to arrange them in a row along the conveying direction of the stainless steel 70 .

Arranging a plurality of different drying chambers 50 along the transport direction is to prevent over-curing of the colored paint on the stainless steel 70 after the fourth step (S4) is completed.

Cooling in the sixth step (S6) is performed by using a plurality of cooling fans 61 as shown in FIG. made by operation.

In the sixth step (S6), before recoiling the stainless steel 70 with respect to the recoiler 62 as shown in FIG. 7 (b), an operation of attaching a protective film to the stainless steel 70 may be additionally performed. .

Hereinafter, more specific examples ranging from painting and recoiling of the stainless steel 70 at the actual manufacturing site of the present applicant will be described as follows.

The raw material stainless steel 70 is STS430, and the maximum coil width is 1,200mm, the maximum weight is 5 tons, and the maximum length is 1,300m.

Visual inspection and import inspection of the stainless steel 70 in stock are performed, and the stainless steel coil is transferred using a hoist or a coil cart to perform the first step (S1).

After installing the uncoiler 10 and mounting the stainless steel coil, the protective film or packaging material on the surface of the stainless steel 70 is recovered and separated and removed.

The high-temperature plasma treatment through the second step (S2), the low-temperature plasma treatment through the third step (S3), and the painting treatment on the surface of the stainless steel 70 through the fourth step (S4) are continuously performed without intervals. .

An agent for drying the colored paint at a high temperature by passing the painted stainless steel 70 through a drying chamber 50 whose temperature is set to gradually increase along the transport direction of the stainless steel 70 within the range of 100 ° C to 250 ° C Step 5 (S5) is carried out.

Then, in the sixth step (S6), the stainless steel 70 is cooled through the cooling fan 61 and sent to the recoiler 62 to manage the coating thickness, color difference and gloss of the surface of the stainless steel 70 before recoil Inspect the appearance and adhesion of the coating film.

Subsequently, just before recoil to the recoil 62 side in the sixth step (S6), the protective film is attached to the surface of the stainless steel 70 and recoiled together.

As such, the first step (S1) to the sixth step (S6) may be repeated at least twice or more in accordance with the requirements for the thickness of the coating film formed on the surface of the stainless steel 70 by the customer and the ordering party.

Therefore, the present applicant applies a primer with a thickness of 4 to 5 μm to the stainless steel surface through the first step (S1) to the sixth step (S6) at the actual manufacturing site, and then the first step (S1) to the sixth step again. (S6) was carried out to apply a specific color paint having a thickness of 12 to 14 μm, so that the final product could be manufactured.

Therefore, through the manufacturing method according to various embodiments of the present invention as described above, as shown in FIG. 8, tinted stainless steel (71 to 74) of various colors is produced, and the paint is clearly and neatly colored. Tinted molded parts 75 can also be produced.

As described above, it can be seen that the basic technical idea of the present invention is to provide a method for producing colored stainless steel using plasma treatment, which enables the formation of coating films of various colors through a continuous process in a general roll-to-roll method.

And, of course, many other modifications and applications are possible to those skilled in the art within the scope of the basic technical idea of the present invention.

10... Uncoiler
20 ... Flamejet nozzle assembly
30...high frequency corona discharger
40...painting booth
41... bell painting equipment
50 ... drying chamber
61 ... cooling fan
62 ... recoiler
65 ... conveyor
70...stainless steel
S1...first step
S2...second step
S3...third stage
S4...fourth step
S5...the fifth step
S6...Sixth step

Claims (5)

The surface of the uncoiled stainless steel supplied in one direction is subjected to high-temperature plasma treatment to remove moisture on the surface of the stainless steel, followed by low-temperature plasma treatment, removing the passivation film of the stainless steel, and painting the surface of the stainless steel to color ,
The flame temperature applied to the surface of the stainless steel during the high-temperature plasma treatment is 600 ° C to 800 ° C,
During the low-temperature plasma treatment, the surface temperature of the stainless steel is maintained at room temperature,
The method for producing colored stainless steel using plasma treatment, characterized in that the high-temperature plasma treatment, the low-temperature plasma treatment, and the painting treatment are continuously performed.
delete A first step of placing the stainless steel wound in a coil form on an uncoiler, uncoiling it, and supplying it in one direction;
By maintaining the surface of the stainless steel at 40 ° C to 100 ° C by high-temperature plasma treatment that sprays the surface of the stainless steel with a flame formed of LPG and oxygen mixture gas at 600 ° C to 800 ° C for 6 to 18 seconds, A second step of removing moisture from the stainless steel surface;
A third step of removing the passivation film of the stainless steel by maintaining the surface of the stainless steel at room temperature by low-temperature plasma treatment in which a discharge voltage of 7000 V to 8000 V is applied to the surface of the stainless steel for 0.1 to 3 seconds. ;
15 ℃ to 25 ℃ by an electrostatic painting device that forcibly sprays paint of a specific color from the ceiling side of the painting booth toward the floor side on the surface of the stainless steel from which the passivation film is removed, which is introduced into the painting booth and transported in one direction. A fourth step of coloring the paint of the specific color by painting while maintaining the;
A fifth step of drying the stainless steel, which is put into a drying chamber and has been colored, at a temperature of 100° C. to 250° C.; and
A sixth step of cooling and recoiling the dried stainless steel,
In the fifth step, the stainless steel,
Colored stainless steel using plasma treatment, characterized in that a plurality of different drying chambers are arranged in a row along the conveying direction of the stainless steel so that the drying temperature is gradually increased from the 100 ° C to the 250 ° C along the conveying direction. How to make steel.
delete delete

Images