As mentioned before, there are many types of coated aluminum foil for heat exchange fins. The coated aluminum foil currently used on the market is mainly hydrophilic aluminum foil. Therefore, only the coating performance indicators of hydrophilic aluminum foil will be discussed here.
There is no hard rule for the thickness of the coating film on the surface of aluminum foil, but it is generally less than 3/1m. Since coatings are generally more expensive, the thinner the coating thickness is controlled while meeting performance requirements, the lower the production cost will be. The coating thickness directly affects various performance indicators of the coating, so the coating thickness on the surface of the aluminum foil is required to be uniform.
Coating adhesion is an indicator of how fast the aluminum foil adheres to its surface coating. If the coating adhesion is too small, the surface coating of the coated aluminum foil will easily fall off during further processing and use, which will seriously affect the weight of the coated aluminum foil. Therefore, the stronger the coating adhesion, the better. Coating adhesion can generally only be tested qualitatively. The main testing methods include friction resistance test, cross-hatch test and cupping method.
