1. Non-coated aluminum foil

After the rolling and  annealing,the aluminum foil whoes surface has not undergone any form of treatment is called non-coated aluminum foil. For 10 years in China and  for some15 years in abroad,the aluminum foil used for air conditionerer heat exchanger film has been non-coated aluminum foil. About 50% of the heat exchanger films used by foreign developed countries are still uncoated aluminum foil,while in China the ratio is some 60%.

2. Coated aluminum Foil

Undergoing some surface treatments,the uncoated aluminum foil will have a special performance, which makes it the coated aluminum foil.

In some countries whose technology development ,such as Japan and Germany,coated aluminum foil has ben used for more than 15 yeras.While in China,coated aluminum foil is applied in commercial purpose for no more than 10 years.Coated aluminum foil by the characteristics of the its surface,can be categorized as follows:

a)Corrosion resistant aluminum foil

Corrosion-resistant aluminum foil’s surface has a certain anti-corrosion protective layer. Air-conditioning heat exchanger that is made of corrosion-resistant aluminum foil is suitable for hositle environment and can significantly prolong the service life of air-conditions.

At the same time, because of the improvement of the corrosion resistance of the heat transfer film, the formation of the surface corrosion powder is greatly reduced,which can improve the ventilation quality and purify the air in the air conditionerer room.

b)Hydrophilic aluminum Foil

Hydrophilic aluminum foil’s surface has a strong hydrophilicity. The hydrophilic property  is determined by the size of the angle formed when the water is glued to the surface of the foil.And the smaller the angle is,the better the hydrophilic energy is. Generally speaking, if the angle is less than 35 the aluminum foil to the hydrophilic aluminum foil.

 Hydrophilic aluminum foil is generally used in air-conditioning condenser. Its main function is to make the droplet( moisture in the hot air ) on the heat transfer film easy to spread and follow down along the aluminum sheet. 

This can avoid the “bypass”engerated by the water droplets that  may affect the ventilation effect of heat exchanger, thereby improving the heat exchange rate of air-conditionis, and under the same cooling conditions, it can also save electricity.

Nowadays,the common hydrophilic aluminum foil saled on markets not only the has a good hydrophilicity, but also has a high corrosion resistance,  which willoptimize the performance of air-conditions.

c)Hydrophobic aluminum foil

Water on hydrophobic surfaces will exhibit a high contact angle,generally in 75. The greater the angle is ,the better the water repellent performance is.The purpose of using hydrophobic aluminum foil is the same as that of hydrophilic foil’s, namley to removethe droplet from the heat transfer films. While the difference is that by increasing the contact angle between condensed droplet and heat exchanger, the droplet can be easily dropped.

 d)Self-lubricating aluminum foil

In processing of air conditionering heat exchanger, lubricating oil mustbe added on its surface, and then punching and flanging are needed. Finally the aluminum foil will be washed by

trichloroethylene lubricant. However, trichloroethylene is harmful to the human body, in order to aviod this process, self-lubricating aluminum foil was invented..

As the name suggests,i n the punching processing self-lubricating, aluminum foil does not need to add lubricating oil,for the film of surface- treated aluminum foil will take place of the lubricant. Since there is no need for special lubricating oil, the following  trichloroethylene cleaning and drying process is omitted.

e) Mildew-proof aluminum foil

Anti-mildew aluminum foil is mainly used for air-conditioning indoor parts; its main function is to prevent heat transfer film from moulding. In the  he use or a longer time storage of  heat transfer film may engender mildew on its surface. Anti-mildew aluminum foil can significantly improve ventilation, prevent the emergence of abnormal odor, and effectively improve the indoor environment.