Project Description
The influence of extruded aluminium process on oxidation colouring is mainly the influence of mould/die design, extrusion temperature, extrusion speed and cooling method on the surface state and tissue uniformity of extruded profiles. Mould design should be able to make the material fully fit, otherwise, it is easy to appear bright (dark trail) with defects, the same profile may appear on the colour separation; At the same time, the mould/die state and profile surface extrusion pattern also affect the oxidation colouring. Extrusion temperature, speed, cooling and cooling time are different so that the profile is not uniform but also produce colour.
Anodic oxidation has important influence on electrolytic coloring of chromatic aberration, especially in the process of vertical oxidation production line is easy to appear the two color, vertical oxidation groove depth of 7.5 m, bath and easy to produce temperature difference, temperature has important effect on the anodic oxidation, high temperature, liquid oxidation tank to increase the dissolution of oxide film, more groove on the surface of the anode oxidation membrane aperture increases, on the contrary, many grooves on the surface of the anode oxidation membrane pore size is smaller. In addition, the temperature is high, the porosity of anodic oxidation film is higher, and vice versa. Electrolytic coloring is mainly make coloring liquid metal ions in the oxide film on the surface of the microhole blocking layer electrochemical reduction reaction, make the colored liquid deposition of metal ions on the bottom of the anodic oxidation film hole of incident light scattering and show different color, deposition of microporous material, the more, the deeper the color.
In through the same power and under the condition of high temperature and low on the part of deposit the same amount of metal or metal compounds, for large aperture porosity and high surface area, average poreless sediment, so its relatively shallow color and color is deeper, thus caused the color shading material at both ends. In the process of anodic oxidation, conductivity of oxide film, can also cause color material to produce off color, the problem is mainly in the horizontal line is easy to appear, is mainly due to the oxidation on the blank in front of the oxidation process, the clamp is not tight, lead to bad individual conductive material, making it relatively different oxide film, after staining can produce off color.
Electrolytic colouring process can be directly reflected colour difference problem, the current distribution of electrolytic colouring liquid ability has a decisive influence on colouring material evenly, once the current distribution, it could cause clear off colour. The current distribution capacity of the tank is mainly related to the conductivity and polarization degree of the tank. The tinted liquid containing conductive salt, mainly in order to improve the electrical conductivity of colouring liquid, when conducting salt adding not timely, conductive ability to drop, loss of current distribution, it could cause off colour. In addition of colouring liquid additives can produce characteristic adsorption, so as to increase the degree of polarization, which consumes too much, can make the polarizability of the electrolyte is reduced, the loss of current distribution can also cause colour difference. In actual production, not only to improve the conductivity of the bath fluid, but also to guarantee the conductive rod, the copper seat has good conductivity, and the conductive bad can cause the distribution of power lines to be uneven, resulting in the colour difference.
