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Causes and detection methods of color difference in brushed alumina plates

Release time:

2021-07-09 14:58

brushed alumina is commonly used in lighting, architectural decoration, exterior decoration materials, the appearance of the color requirements is relatively high, can be measured by professional colorimeter.

In the progress of society, people's demand for material culture is also getting higher and higher. In the field of building aluminum alloy profiles, with the progress of science and technology and the rapid development of polymer chemistry, the surface treatment technology is diverse and unique.

The importance of the appearance color of the brushed alumina plate:

The brushed alumina plate refers to the plate formed by two different processes of drawing and oxidation on the surface of the aluminum plate. Wire drawing aluminum plate is a manufacturing process in which the aluminum plate is forced through the mold and pulled out the line under the action of external force. The main process is divided into three parts: deesterification, sand mill and water washing. Alumina plate is placed in the corresponding electrolyte as an anode, under specific conditions and applied current, the main process of electrolysis is divided into degreining, etching, neutralization, anodic oxidation, coloring, sealing.

After wire drawing and oxidation treatment, the plate can show a variety of different appearance colors, mainly divided into basic color and metallic color. In recent years, many aluminum products have special color requirements for the metal shell, in order to play a beautiful effect, in order to control the appearance color quality of brushed alumina, it can be detected by the color difference meter.

How is the color difference of brushed alumina formed?

After a period of use, there will be some discoloration problems. Each enterprise will specify a color difference range, and products that meet the range can be regarded as normal products. Therefore, there are many reasons for the color difference of the brushed aluminum plate, mainly including raw materials, processing methods and so on.

1. The content of metal elements contained in different batches of aluminum plates and the texture of materials are different. It is difficult to achieve exactly the same effect as the template after many adjustments and sample evaluation during coloring treatment.

2. In the process of oxidation treatment, various factors such as the composition, content, concentration, temperature and treatment time of the liquid medicine may cause different treatment effects, resulting in color difference of the aluminum plate.

3. During the closed coloring treatment of the product, the difficulty of sample, color and color adjustment increases due to the color difference already existing in the pre-treatment and production of the material.

Color difference meter to detect the color of brushed alumina plate:

Aluminum and aluminum alloy oxide coloring surface reflection characteristics are different from the normal reflection characteristics of other objects (such as opaque pigments). The visible color of the alumina-colored aluminum plate is different from the color of the usual object. Therefore, when measuring the color and color difference of the brushed alumina plate, confusion appears.

This is because the color of the brushed alumina plate has the property of conditional color development, that is, two same colors observed at a certain angle or under a certain light source become inconsistent if the observation angle or light source is changed. For example, when brushed alumina is used as the outer wall of a building, due to different environments, weather, time and different observation angles, the color that the observer sees will be different. Therefore, in order to evaluate the color of brushed alumina, it is necessary to standardize the color difference measurement standard, and the more objective way is to use the color difference meter to detect.

Under the specified observation conditions, the agreed color standard sample is used as the benchmark, the color difference meter is used to judge the color difference between the brushed alumina plate and the agreed color code, and the color difference data with L * a * B * is used to evaluate whether the product color meets the color difference standard.