We, as ERD Metal, supply the color integrity of our products with our attractive aluminium color anodizing. We are proud to present our customers with the most color alternative in the sector by having a wide variety of different tone options from the main colors of copper, black, yellow, brown and bronze by aluminium color anodizing.
The ability of coloring of the anodizing layer has made the aluminium products more widespread. In our company, the production of colored eloxal, has began with the dyeing process to get the porous structure of the anodic layers made with sulfuric acid applied with inorganic or organic dyestuffs.
Given the limited UV resistance ability of those dyes, several processes, especially for the architectural applications, have been developed to make the aluminium color anodizing products more resistant to sunlight; such as two-stage electrolytic coloring and integral anodizing. Integral anodizing processes gives a long-lasting, high sun-resistant, black and gray colors; however, "two-stage" coloring is generally preferred over Integral anodizing because of costly factors such as high energy consumption and precise control.
The anodic layer would be impregnated into the pores in a way that the pigment can function as itself by applying the two-stage electrolytic coloring process. With this process, we get a variety of colors in a wide range from light bronze to black and dark bronze.
Our Company's Anodic Coloring Mechanisms
Our coloring mechanisms and methods, which is pioneer in the aluminium sector, are as follows;
1) Immersion Dyeing Process:
The absorption of inorganic or organic dye pigments into the pores of the anodic aluminium layer would be done by the anodic aluminium immersed in the aqueous solutions of the special anodic coatings. Inorganic dyes can also show a chemical reaction between the anodic layer and the paint solution.
2) Integral Anodic Coloring Process:
The process of Integral anodic coloring is one of the anodic aluminium coloring method, and provides some intermetallic paricles in aluminium alloys are deposited at the metal and oxide interface or in the walls of anodic pores. These precipitated particles distribute the light within the anodic layer by depending on the thickness and density. Altough the whole wavelength of the white light is distributed or absorbed with the black color, it changes with the bronze color and long wave tile is reflected by the eloxal layer.
3) Two-Stage Coloring Process:
Because the coloring process made with copper salts is faded with the sunlight and the process parameters of the electrolytes using nickel salts are much more difficult to control, this method is not preferred by our company. Electrolytes that use tin and cobalt salts are the most commonly used methods, due to their ease of use as well as their long life colors.
The color gradient with this method is like an integral coloring. However, the distribution of the light is done with the pigments located in the bottom of the pores in the anodic layer. These pigments that are made of copper, cobalt, tin or nickel ions, located in the pores of the anodic layer. Colors resuliting from this process is getting darker when the thickness of these pigments deposited in the bottom of the anodic pores is increased.
4) Interference Coloring:
The last stage of color anodizing and coloring is the "interference coloring" method. This method, which is based on the latest anodizing aluminium coloring methods, is a process where different colors are covered, including blue and gray colors. When applying this method, the coloring and anodic parameters for color matching need to be controlled very precisely.