Metal composite veneer for decoration and production process thereof

Abstract

The production technology comprises the technological steps of material selection, pretreatment, texturing treatment, electrostatic spraying and follow-up treatment, a base plate is subjected to texturing treatment after being subjected to polishing pretreatment, the roughness of the surface of the plate is changed, the adhesion strength of a follow-up coating and the base plate is enhanced, and the surface of the base plate is subjected to electrostatic spraying; a small amount of fluorine is added into a polyester powder coating in electrostatic spraying, so that the hydrophobic and oleophobic properties of the coating are improved, the acid and alkali resistance and pollution resistance of a film layer are improved, the phenomena of cracking and embrittlement caused by long-time use are avoided, and the service life is prolonged; according to the present invention, the use amount of fluorine is reduced, the powder coating material has advantages of environmental protection, stable performance and good durability, the barium sulfate commonly used in the powder coating material is not used, the use amount of the pure polyester is increased, and the cracking phenomenon during bending, stamping and molding of the plate is improved.

Description

Technical Field

[0001] This invention relates to the field of building decorative panels, and more particularly to a decorative metal composite veneer and its manufacturing process. Background Technology

[0002] Currently, metal decorative panels are commonly used in interior and exterior decoration projects, including storefronts, floor spring doors, swing doors, various types of shop windows, partitions, shopping mall facilities, billboards, and building facades. Metal decorative panels are widely used due to their simple and lightweight structure, suitability for various shapes, customizable surface colors, and low cost.

[0003] Existing metal decorative panels, after secondary processing such as stamping, bending, or cutting, are prone to corner cracking, coating damage, and corrosion, affecting their overall performance and strength. However, to meet subsequent installation requirements, secondary processing is often necessary, necessitating its completion at the panel manufacturer. Manufacturers address this issue by shaping the panels before coating, but this introduces other problems: the resulting panels vary in shape, making transportation inconvenient, and damage during transport can exceed 10%, significantly increasing costs. Therefore, our company aims to develop a production process for metal decorative panels suitable for secondary processing, preventing cracking and damage. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention provides a decorative metal composite panel and its manufacturing process to address the aforementioned problems.

[0005] This invention is achieved through the following technical solution:

[0006] A manufacturing process for various decorative metal composite panels, characterized by the following steps:

[0007] A. Substrate selection: First, the continuous casting billet is hot-rolled, stretched, and finished to obtain a metal plate. Then, the metal plate is leveled and cut by a leveling machine and a shearing machine to obtain a flat substrate of the required length and width.

[0008] B. Pre-treatment: First, use wet sandpaper to polish the substrate to remove surface impurities. After polishing, spray cleaning is performed.

[0009] C. Texture treatment: The substrate is textured using a sander, then cleaned with a water-based cleaning agent and deionized water, and then dried.

[0010] D. Electrostatic spraying of the substrate with polyester powder coating, the distance between the spray gun and the metal plate is 200-240mm, the current is 50-60μA, the voltage is 50-65kV, the compressed air pressure is 0.5-0.75MPa, the coating thickness is 50-60μm, and it is left to stand for 4min.

[0011] E. Post-processing: The sprayed metal sheet is sent into the baking room for leveling and curing. The baking room temperature is 200-230℃ and the time is maintained for 12-15 minutes. After removal, it is cooled to room temperature to obtain the composite veneer finished product.

[0012] Further optimized, the chemical composition of the continuously cast billet mentioned in step A, by mass percentage, is: carbon 0.004-0.009%, silicon ≤0.06%, phosphorus 0.04-0.1%, sulfur 0.005-0.02%, niobium 0.04-0.1%, ALS 0.02-0.08%, with the balance being iron and unavoidable impurities.

[0013] Further optimized, the mechanical properties of the substrate are: yield strength 300-350 MPa, tensile strength 400-460 MPa, elongation 32.0-35.0, and plastic strain ratio r. 90 1.8-2.1, Hardening Index n 90 0.19-0.22.

[0014] In further optimization, in step B, the abrasive belt grit size of the rough grinding section of the sander is controlled at 50-60 grit, the abrasive belt grit size of the intermediate section is controlled at 80-110 grit, and the abrasive belt grit size of the fine grinding section is controlled at 180-200 grit. The cutting fluid is a fully synthetic water-based metalworking fluid with a concentration controlled at 1.5-2%.

[0015] Further optimized, the raw materials of the polyester powder coating include: fluorinated polyester with octafluoropentyl branching, pure polyester particles (PE), calcium carbonate, curing agent (TGIC), leveling agent (BYK-361N) and wetting leveling agent (BYK-220S).

[0016] Further optimized, the raw materials are placed in an internal mixer for melting and mixing for 10 minutes, with the internal mixer speed maintained at 80 r / min and the temperature at 100°C. Then the material is discharged and pulverized and sieved using an air classifier mill to obtain polyester powder coating.

[0017] Further optimized, the polyester powder coating has a particle size of 20-80 μm and a fluorine content of 0.25 wt%-3 wt%.

[0018] Further optimized, a decorative metal composite panel is obtained through the above-mentioned production process.

[0019] The beneficial effects of this invention are:

[0020] The metal composite panel of this invention is suitable for the assembly system of modern industrialized building and can replace traditional exterior decoration methods such as painting, tiling, and dry hanging. It has the advantages of low construction cost, high efficiency, and environmental protection.

[0021] In the production process of this invention, the substrate is roughened, which changes the surface roughness of the board, improves the substrate's ability to be coated with slurry, and enhances the adhesion strength between the coating and the substrate. The polyester powder coating used in this process contains a small amount of fluorine, which can significantly improve the hydrophobic and oleophobic properties of the coating, improve the acid and alkali resistance and pollution resistance of the film layer, avoid cracking and embrittlement after long-term use, and extend the service life. Fluorinated polyester powder is prepared by using fluorinated polyester with fluorocarbon segments in the branch chain and pure polyester to reduce the amount of fluorine used, which has the advantages of being environmentally friendly, having stable performance, and having good durability.

[0022] This invention does not use barium sulfate, which is commonly used in powder coatings, but increases the amount of pure polyester, which prevents the sheet from cracking during bending, stamping, and shaping. Detailed Implementation

[0023] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments. In the description of this invention, it should be noted that the terms "left," "right," "front," "rear," "inner," and "outer," etc., indicating orientation or positional relationships, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0024] Example 1:

[0025] This invention provides a manufacturing process for decorative metal composite panels, characterized by comprising the following steps:

[0026] A. Substrate Material Selection: A continuously cast billet is selected, with the following mass percentages: carbon 0.004-0.009%, silicon ≤0.06%, phosphorus 0.04-0.1%, sulfur 0.005-0.02%, niobium 0.04-0.1%, ALS 0.02-0.08%, with the balance being iron and unavoidable impurities. The continuously cast billet is hot-rolled to obtain a 2-4mm hot-rolled plate. The hot-rolled plate is then annealed, hot-dip galvanized, and then leveled and smoothed to obtain a metal sheet. The metal sheet is then leveled and sheared using a leveling machine and a cross-cutting machine to obtain a flat substrate of the required length and width. Carbon steel is generally chosen as the substrate material because it is easy to process and has a lower cost than commonly used aluminum.

[0027] B. Pre-treatment: First, the substrate is sanded with 600# wet sandpaper to remove surface impurities. Then, the sanded substrate is sprayed and cleaned at a pressure of 0.5 MPa to remove sanding impurities. Pre-treatment removes impurities, roller marks, and minor defects.

[0028] C. Roughening treatment: The substrate is roughened using a sander. The abrasive belt grit size of the rough grinding section of the sander is controlled at 60 grit, the abrasive belt grit size of the intermediate section is controlled at 100 grit, and the abrasive belt grit size of the fine grinding section is controlled at 200 grit. The cutting fluid is a fully synthetic water-based metalworking fluid with a concentration controlled at 2%. The roughened substrate is then sprayed with water-based cleaning agent and deionized water at a spray pressure of 0.5 MPa, and then the substrate is dried.

[0029] D. Electrostatic spraying of the substrate with the prepared fluorinated polyester powder coating is performed. The distance between the spray gun and the metal plate is 220mm, the current is 50-60μA, the voltage is 50-65kV, the compressed air pressure is 0.5MPa, the coating thickness is 55μm, and the coating is left to stand for 4min.

[0030] E. Post-processing: The sprayed metal sheet is sent into the baking room for leveling and curing. The baking room temperature is 200℃ and the time is maintained for 12 minutes. Then it is taken out and cooled to room temperature to obtain the composite veneer finished product.

[0031] In the above production process, the substrate is first roughened to change the surface roughness of the board, which can improve the substrate's ability to be coated with slurry and enhance the adhesion strength between the coating and the substrate.

[0032] The polyester powder coating used in the above production process has a small amount of fluorine added, which can significantly improve the hydrophobic and oleophobic properties of the coating, improve the acid and alkali resistance and pollution resistance of the film layer, avoid cracking and embrittlement after long-term use, and extend the service life. Fluorinated polyester powder is prepared by using fluorinated polyester with fluorinated carbon segments in the branch chain and pure polyester to reduce the amount of fluorine used, which has the advantages of being environmentally friendly, having stable performance and good durability.

[0033] The above production process increases the amount of pure polyester used, and with the optimal coating thickness, the sheet material will not crack during bending, stamping, and shaping.

[0034] In a preferred embodiment, the mechanical properties of the substrate are: yield strength 300-350 MPa, tensile strength 400-460 MPa, elongation 32.0-35.0, and plastic strain ratio r. 90 1.8-2.1, Hardening Index n 90 0.19-0.22.

[0035] In a preferred embodiment, the raw materials of the polyester powder coating include: fluorinated polyester with octafluoropentyl branching, pure polyester particles (PE), calcium carbonate, curing agent (TGIC), leveling agent (BYK-361N), and wetting leveling agent (BYK-220S). The fluorine content of the polyester powder coating is optimal at 2 wt%, at which point the hydrophobicity and fluorine content reach the optimal ratio. This raw material does not use commonly used barium sulfate, and the amount of pure polyester is increased, which prevents cracking of the board during bending, stamping, and shaping.

[0036] In a preferred embodiment, the above raw materials are placed in an internal mixer and melt-mixed for 10 minutes. The internal mixer speed is maintained at 80 r / min and the temperature is 100°C. Then the material is discharged and pulverized and sieved using an air classifier mill to obtain a polyester powder coating with a thickness of 60 μm.

[0037] As a preferred embodiment, decorative metal composite panels are produced using the above-described manufacturing process.

[0038] Example 2:

[0039] In actual production operations, the polyester powder coating can also be obtained from the following raw materials: hexadecyl fluoropolyester, pure polyester particles (PE), calcium carbonate, curing agent (TGIC), leveling agent (BYK-361N) and wetting leveling agent (BYK-220S).

[0040] At this point, the optimal fluorine content of the polyester powder coating is 0.5 wt%, which achieves the optimal ratio of hydrophobicity and fluorine content, and the contact angle between the film and water can reach 108°.

[0041] All aspects not detailed herein are well-known to those skilled in the art. Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of this invention and not intended to limit it. Although the invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this invention without departing from the spirit and scope of the invention, and all such modifications and substitutions should be covered within the scope of the claims of this invention.

Claims

1. A manufacturing process for decorative metal composite panels, characterized in that, Includes the following steps: A. Substrate selection: First, the continuous casting billet is hot-rolled, stretched, and finished to obtain a metal plate. Then, the metal plate is leveled and cut by a leveling machine and a shearing machine to obtain a flat substrate of the required length and width. B. Pre-treatment: First, use wet sandpaper to polish the substrate to remove surface impurities. After polishing, spray cleaning is performed. C. Texture treatment: Use a sander to texture the substrate, then clean the textured substrate with a water-based cleaning agent and deionized water, and then dry it. D. Spraying: Electrostatic spraying of polyester powder coating is performed on the substrate. The distance between the spray gun and the metal plate is 200-240mm, the current is 50-60μA, the voltage is 50-65kV, the compressed air pressure is 0.5-0.75MPa, the coating thickness is 50-60μm, and it is left to stand for 4min. E. Post-processing: The sprayed metal sheet is sent into the baking room for leveling and curing. The baking room temperature is 200-230℃ and the time is maintained for 12-15 minutes. After removal, it is cooled to room temperature to obtain the composite veneer finished product.

2. The decorative metal composite veneer and its manufacturing process according to claim 1, characterized in that, The chemical composition of the continuously cast billet mentioned in step A, by mass percentage, is: carbon 0.004-0.009%, silicon ≤0.06%, phosphorus 0.04-0.1%, sulfur 0.005-0.02%, niobium 0.04-0.1%, ALS 0.02-0.08%, with the balance being iron and unavoidable impurities.

3. The decorative metal composite veneer and its manufacturing process according to claim 1, characterized in that, The mechanical properties of the substrate are: yield strength 300-350 MPa, tensile strength 400-460 MPa, elongation 32.0-35.0, and plastic strain ratio r. 90 1.8-2.1, Hardening Index n 90 0.19-0.

22.

4. The decorative metal composite panel and its manufacturing process according to claim 1, characterized in that: In step B, during the roughing process, the abrasive belt grit size of the rough grinding section of the sander is controlled at 50-60 grit, the abrasive belt grit size of the intermediate section is controlled at 80-110 grit, and the abrasive belt grit size of the fine grinding section is controlled at 180-200 grit. The cutting fluid is a fully synthetic water-based metalworking fluid with a concentration controlled at 1.5-2%.

5. The decorative metal composite veneer and its manufacturing process according to claim 1, characterized in that, The raw materials of the polyester powder coating include: fluorinated polyester with octafluoropentyl branching, pure polyester particles (PE), calcium carbonate, curing agent (TGIC), leveling agent (BYK-361N) and wetting leveling agent (BYK-220S).

6. The decorative metal composite veneer and its manufacturing process according to claim 5, characterized in that: The raw materials are placed in an internal mixer and melt-mixed for 10 minutes. The internal mixer speed is maintained at 80 r / min and the temperature is 100℃. Then the material is discharged and crushed and sieved using an air classifier mill to obtain polyester powder coating.

7. The decorative metal composite panel and its manufacturing process according to claim 6, characterized in that: The polyester powder coating has a particle size of 20-80 μm and a fluorine content of 0.25 wt%-3 wt%.

8. A decorative metal composite panel, characterized in that, It is produced by the production process described in claim 1.