1. Uncoated aluminum foil
Uncoated aluminum foil refers to aluminum foil that has been rolled and annealed without any form of surface treatment. The aluminum foil used for air conditioning heat exchangers in my country 10 years ago and abroad about 15 years ago were all uncoated aluminum foil. About 50% of the heat exchange fins used in developed countries abroad are still uncoated aluminum foil, while in my country, this ratio is around 60%.
2. Coated aluminum foil
The so-called coated aluminum foil is to reprocess the surface of uncoated aluminum foil to give it some special functions. In countries with rapid technological development such as Japan and Germany, coated aluminum foil has been used for more than 15 years. In our country, coated aluminum foil has been used for no more than 10 years. According to the characteristics of the surface of coated aluminum foil, it can be classified as follows:
3. Corrosion-resistant aluminum foil
The surface of corrosion-resistant aluminum foil products has a certain anti-corrosion protective layer. The air-conditioning heat exchange fins made of the product can be used in harsher areas and can significantly extend the service life of the air-conditioning. At the same time, due to the improvement of the corrosion resistance of the heat exchange fins, the generation of surface corrosion powder is greatly reduced, thereby improving the ventilation quality and purifying the air in the air-conditioned room.
4. Hydrophilic aluminum foil
The surface of hydrophilic aluminum foil has strong hydrophilicity. The quality of the hydrophilic property is determined by the angle formed by water sticking to the surface of the aluminum foil, as shown in Figure 1. The smaller the angle a is, the better the hydrophilic property is, and vice versa. Generally speaking, the angle a is less than 35. That is, it has hydrophilic properties. Hydrophilic aluminum foil is generally used on the condenser of air conditioners. Its main function is to make the moisture in the hot air condense into water droplets on the heat exchanger sheet, so that it can easily spread and flow downward along the sheet. This can avoid affecting the ventilation effect of the heat exchanger due to "bridging" of water droplets between the heat exchange fins, thereby improving the heat exchange rate of the air conditioner and saving electricity under the same cooling capacity. At present, the general hydrophilic aluminum foil on the market not only has good hydrophilicity on the surface, but also has high corrosion resistance, thus making the performance of the air conditioner more optimized.
5. Hydrophobic aluminum foil
Hydrophobic aluminum foil is also called water-repellent aluminum foil, and its surface properties are exactly the opposite of hydrophilic aluminum foil. That is, when the condensed water condenses onto the surface of the aluminum foil, the contact angle with the aluminum foil is relatively large, generally 75. above. The larger the angle, the better the water repellency. The ultimate purpose of using hydrophobic aluminum foil is the same as that of hydrophilic aluminum foil, which is to prevent condensation water from remaining between the heat exchange fins. The difference is that the hydrophobic aluminum foil removes the condensed water between the heat exchange fins by increasing the contact angle between the condensed water and the heat exchange fins, causing the condensed water to form water droplets that are easy to slide off.
6. Self-lubricating aluminum foil
During the processing of air-conditioning heat exchange fins, it is generally necessary to first add lubricating oil to the surface, then punch holes and flange them, and finally use trichloride The ethylene washes away the lubricant. Since trichlorethylene is harmful to the human body, in order to reduce this process, self-lubricating aluminum foil was produced accordingly. As the name suggests, self-lubricating aluminum foil does not require separate lubricating oil during its punching process. The lubrication during punching is borne by a pre-treated film on the surface of the aluminum foil. Since there is no need to add special lubricating oil, the subsequent cleaning and drying process of trichlorethylene is omitted.
7. Mildew-proof aluminum foil
Mold-proof aluminum foil is mainly used for the indoor unit part of the air conditioner. Its main function is to prevent the surface of the heat exchanger from being used or left for a long time. mold, thereby significantly improving the ventilation quality of the air conditioner, preventing the generation of abnormal odors, and effectively improving the environment in the air-conditioned room.