The coated aluminum foil is formed by surface treatment on the basis of uncoated aluminum foil. In addition to the requirements such as the chemical composition, mechanical properties and geometrical dimensions required by the above-mentioned uncoated aluminum foil, the coated aluminum foil should have good plate type and Coating performance.
1, aluminum foil plate type
First of all, the production process of coated aluminum foil aluminum foil to have a good plate, which is a prerequisite for the production of coated aluminum foil. The unit that measures the plate index is I. General coating production equipment on the board type requirements are 20-40I or less, if greater than this value, you need to add a tension in the coating equipment before the straightening system. General coating equipment, its aluminum belt running routes are longer, processing and guide roller are more. Therefore, if not equipped with tension straightening system, once the plate is not good it is easy to run in the fold, resulting in can not produce. Air-conditioning production process of aluminum foil plate also has a higher demand. The general heat exchanger punching production lines are using vacuum suction way for aluminum foil transmission, if the aluminum plate is not good, the surface is not smooth, it will lead to the vacuum of aluminum foil can not be normal way. Therefore, the plate is not only coated aluminum foil, but also an important non-coated aluminum foil technical indicators.
2, coating performance
It has been said that there are many kinds of coated aluminum foil for heat exchangers, and the coated aluminum foil used in the former market is mainly hydrophilic aluminum foil. Therefore, only the coating performance of hydrophilic aluminum foil is discussed here.
3, coating thickness
Aluminum foil surface coating thickness is not hard, generally 3 / 1m below. Because the price of paint is generally more expensive, so meet the performance requirements under the premise of the thinner control film thickness, the lower the cost of production. The thickness of the coating directly affects the performance of the coating, so the thickness of the coating on the surface of aluminum foil to be uniform.
4, coating adhesion
Coating adhesion is the aluminum foil and its surface coating adhesion fastness index. If the coating adhesion is too small, the coated aluminum foil in the further processing and use, the surface coating is easy to fall off, and thus seriously affect the weight of coated aluminum foil, so the coating adhesion is stronger and better. Coating adhesion is generally only qualitative to detect, the main detection methods are wear-resistant test, grid test and cup method and so on.
5, hydrophilic performance
Hydrophilic aluminum foil after a period of time, because of the role of various environmental factors caused by the surface of the hydrophilic performance affected. Therefore, the hydrophilic properties are generally divided into initial hydrophilic and hydrophilic properties after the environmental test. Hydrophilic performance is mainly measured by the size of a horn. General products of the initial hydrophilic requirements of a <100, resistance to environmental testing after the hydrophilic requirements of a <250. Contact angle a measurement can use a special contact angle measuring instrument; can also be a certain amount of water droplets in the aluminum foil surface area occupied by the size of the calculated.
