Abstract
The present invention relates to a colored metal film comprising a metal article and a plurality of pores. The plurality of pores further comprises a high layer, an intermediate layer, and a low layer, in which the three layers together forms an embossed image. The present invention also relates to a method of manufacturing colored metal films. The method is used to manufacture a flat image or an embossed image on a metal article. The method comprises a finishing process, a first coating process, a color adjustment, a first printing process, an etching process, a second coating process, a second printing process, a sealing process, and a cleaning process.
Claims
1. A colored metal film, comprising: a metal article; and multiple pores, configured on a surface of the metal article, comprising one selected from the group consisting of at least one high layer, at least one intermediate layer, at least one low layer, and the combination therefore; wherein the at least one high layer comprises a first subset of the multiple pores accommodating at least one first ink; wherein the at least one intermediate layer comprises a second subset of the multiple pores accommodating at least one second ink; and wherein the at least one low layer comprises a third subset of the multiple pores accommodating neither the at least one first ink nor the at least one second ink; wherein the color of the at least one first ink is darker than that of the at least one second ink.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a flow diagram illustrating a method of manufacturing colored metal films with flat images, according to some embodiments of the present invention.
[0021] FIG. 2 is a schematic diagram illustrating a plurality of pores, according to some embodiments of the present invention.
[0022] FIG. 3 is a flow diagram illustrating a method of manufacturing colored metal films with embossed images, according to some embodiments of the present invention.
[0023] FIG. 4 is schematic diagrams illustrating the etching process in a method of manufacturing colored metal films, according to some embodiments of the present invention.
[0024] FIG. 5 is schematic diagrams illustrating the method of manufacturing colored metal films, according to some embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] FIG. 1 is a flow diagram illustrating a method of manufacturing colored metal films with flat images, according to some embodiments of the present invention. In the embodiments, the method comprises a finishing process, a coating process, color adjustments, a printing process, a sealing process, and a cleaning process. In one embodiment, the exemplary metal article is an aluminum alloy. In the finishing process, the metal article is transferred to a polishing machine or a sander to craft a smooth surface or a hairline surface on the metal article. In the coating process, the metal article is subjected to anodization. To coat the metal article, the metal article is immersed in a 15-18 wt % sulfuric acid solution for 10-30 minutes and the anodizing condition is 15-20 V and 1-2 A/dm.sup.2. After the coating process, an oxide coating with a thickness about 11-16 μm is formed on the metal article.
[0026] FIG. 2 is a schematic diagram illustrating the plurality of pores, according to some embodiments of the present invention. The coating layer 2 on the metal article 1 is an oxide coating 3. The coating layer 2 comprises a plurality of pores 4, in which each pore of the plurality of pores 4 is perpendicular to the surface of the metal article 1. Referring to FIG. 1, in the color adjustments, software converts digital images in accordance with the ICC profile of the image input device. For example, converting a digital image in RGB profile to a digital image in CMYK profile. Photo editing software will further apply curve tool on some overexposed regions of the images, enhance the saturation of colors to cover the metallic color, alter the temperature and contrast to reproduce the natural color of the images, and increase the sharpness and brightness to improve image clarity. In one preferable embodiment, the lines of the images are clear even at a screen resolution of at least 800×600 pixels. Ink management software, on the other hand, will regulate the ink-load of each color.
[0027] In printing process, the metal article is transferred to an inkjet printer. The inkjet printer has a 0.1-0.5 μm nozzle diameter which can expel droplets at pico-liter scale (i.e., 1-2 pL per droplet). The aqueous ink, injected into the plurality of pores in the printing process, comprises 4-20% of a pigment, 15-30% of a glycol ether compound, 1-5% of a ketone compound, 60-75% of deionized water, 0.1-1% of an additive, and 0.01-0.1% of a surfactant. In the sealing process, the metal article is transferred to a steamer for steaming. The steaming condition is 85-100° C. for at least 30 minutes. During the sealing process, some oxide coating in the coating layer will be converted into the hydrate forms and form clogs to block the plurality of pores. In the cleaning process, butanone is used to clean the surface of the metal article by dissolving the excessive amount of ink remained on the surface.
[0028] FIG. 3 is a flow diagram illustrating a method of manufacturing colored metal films with embossed images, according to some embodiments of the present invention. In the embodiments, the method comprises a finishing process, a first coating process, color adjustments, a first printing process, an etching process, a second coating process, a second printing process, a sealing process, and a cleaning process. In one embodiment, the exemplary metal article is an aluminum alloy. In finishing process, the metal article is transferred to a polishing machine or a sander to craft a smooth surface or a hairline surface on the metal article. In the first coating process, the metal article is subjected to anodization. More particularly, the metal article is immersed in a 15-18 wt % sulfuric acid solution for 10-30 minutes and the anodizing condition is 15-20 V and 1-2 A/dm.sup.2. After the first coating process, a first oxide coating with a thickness about 11-16 μm is formed on the metal article. The first coating layer comprises the first oxide coating and a first plurality of pores, in which each pore of the first plurality of pores is perpendicular to the surface of the metal article.
[0029] In the color adjustments, software converts digital images in accordance with the ICC profile of the image input device. For example, converting the digital images in RGB profile to digital images in CMYK profile. Photo editing software will further apply curve tool on some overexposed regions on the images, enhance the saturation of colors to cover the metallic color, alter the temperature and contrast to reproduce the natural color, and increase the sharpness and brightness to improve the image clarity. The images are preferred to a clear even at a screen resolution of at least 800×600 pixels. Ink management software, on the other hand, will regulate the ink-load of each color. In the first printing process, the metal article is transferred to an inkjet printer. The inkjet printer has a 0.1-0.5 μm nozzle diameter which can expel droplets at pico-liter scale (i.e., 1-2 pL per droplet). The aqueous ink, injected into the first plurality of pores in the first printing process, comprises 4-20% of pigment, 15-30% of a glycol ether compound, 1-5% of a ketone compound, 60-75% of deionized water, 0.1-1% of an additive, and 0.01-0.1% of a surfactant. More particularly, the printer separates images into four plates, each representing a color, and illustrates the four plates respectively.
[0030] FIG. 4 is schematic diagrams illustrating the etching process in a method of manufacturing colored metal films, according to some embodiments of the present invention. After the first printing process, some of the first plurality of pores 4 is accommodating at least one first ink 8 (i.e., a deeper color) and some other of the first plurality of pores 4 is accommodating at least one second ink 9 (i.e., a lighter color). More particularly, the pores printed with a deeper color are filled with more aqueous ink than the pores printed with a lighter color. In the etching process, the first coating layer 2 is immersed in a 90% sodium hydroxide solution at 90° C. of for about 30 seconds to modify the surface of the metal article 1. Since the corrosion rate of regions covered by ink is slower than that of clean regions, the pores accommodating the at least one first ink 8 are consumed at a slower rate when compared with the pores accommodating the at least one second ink 9. After a period of time, the sodium hydroxide solution will remove all of the plurality of pores 4 and reach the surface of the metal article 1. However, based on the colors printed on the metal article 1, different regions of the metal article 1 will be reached by the sodium hydroxide solution at different rates and thus generated differences in depth among the plurality of pores and form an emboss-like pattern in accordance with the images printed on the surface of the metal article 1.
[0031] FIG. 5 is schematic diagrams illustrating the method of manufacturing colored metal films, according to some embodiments of the present invention. In the second coating process, the metal article 1 is subjected to anodization to form the second coating layer on the surface. The metal article 1 is immersed in the 15-18 wt % sulfuric acid solution for 10-30 minutes and the anodizing condition is 15-20 V and 1-2 A/dm.sup.2. After the second coating process, a second plurality of pores 4 has a height of 11-16 μm is formed on the metal article 1. Each pore of the second plurality of pores 4 is perpendicular to the surface of the metal article 1. In the second printing process, the metal article 1 is transferred to the inkjet printer to formed embossed images on the second plurality of pores 4. The second plurality of pores 4 can be divided into at least one high layer 5, at least one intermediate layer 6, and at least one low layer 7 after the second printing process. More particularly, the at least one high layer 5 comprises a first subset of the second plurality of pores 4 and accommodates at least one first ink, the at least one intermediate layer 6 comprises a second subset of the second plurality of pores 4 and accommodates at least one second ink, and the at least one low layer 7 comprises a third subset of the second plurality of pores 4 and accommodates neither the at least one first ink nor the at least one second ink. The at least one high layer 5, at least one intermediate layer 6, and at least one low layer 7 together form a multi-layer surface and the embossed images thus are created on the metal article 1.
[0032] In the sealing process, the metal article 1 is transferred to a steamer for steaming. The steaming condition is 85-100° C. for at least 30 minutes. And in the process, some oxide coating 3 in the coating layer 2 will be converted into the hydrate forms and form clogs to block the second plurality of pores 4. In the cleaning process, butanone is used to clean the surface of the metal article by dissolving the excessive amount of ink remained on the surface.
[0033] At least one embodiment of the present invention provides methods of manufacturing colored metal articles. Images on the colored metal films are illustrated by inkjet printing instead of conventional techniques such as dyeing and spraying. The embodiments have several advantages. One of the advantages is that the methods are environment-friendly and easy to run. More importantly, the methods are less harmful to workers. Another advantage is that the color adjustments and the printing process can produce vivid colors and detailed images. The etching process can further produce embossed images on the oxide coating. Still another advantage is that the method can create flat images and embossed images on metal articles while maintaining the high durability and light weight of metal.
[0034] There are many inventions described and illustrated above. The present inventions are neither limited to any single aspect nor embodiment thereof, nor to any combinations and/or permutations of such aspects and/or embodiments. Moreover, each of the aspects of the present inventions, and/or embodiments thereof, may be employed alone or in combination with one or more of the other aspects of the present inventions and/or embodiments thereof. For the sake of brevity, many of those permutations and combinations will not be discussed separately herein.
