Hydrophobic foil is a kind of coated aluminum foil product used for air conditioning fins with hydrophobic coating. In order to improve the lifespan of air conditioners, reduce power consumption, improve ventilation quality, and enhance refrigeration efficiency, various functional coating heat exchanger fins have been developed successively. Hydrophobic aluminium foil makes the fin surface hydrophobic, preventing condensate from adhering.
Hydrophobic aluminum foil, also known as water-repellent aluminum foil, has the opposite surface properties compared to hydrophilic aluminum foil. When condensate condenses on the surface of this aluminum foil, the contact angle formed with the aluminum foil is larger, generally above 75 degrees. The larger the angle, the better the water-repellent performance. The ultimate goal of using hydrophobic aluminum foil is the same as hydrophilic aluminum foil, which is to prevent condensate from remaining between the heat exchanger fins. The difference is that hydrophobic aluminum foil achieves the purpose of removing condensate between the fins by increasing the contact angle between the condensate and the heat exchanger fins, allowing the condensate to form water droplets that are easy to slide off.
Condensed water droplets easily form “water bridges”, which affect heat exchange efficiency and increase noise pollution. The currently effective solution is to apply a coating that can conduct water to the aluminum foil. To give the aluminum foil the function of water conduction, there are two methods: hydrophilic treatment and hydrophobic treatment. Research has shown that under wet conditions, the heat exchange efficiency of corrugated fin tube heat exchangers with a hydrophilic layer is better than those without, and both are superior to dry conditions. If hydrophobic foil is used, it is similar to dry conditions, which indicates that the heat exchange efficiency of hydrophilic foil heat exchangers is superior to that of hydrophobic foil heat exchangers. Currently, hydrophilic treatment (hydrophilic foil) is the mainstream in the air conditioning aluminum foil market and has formed a relatively mature industrial system.
The hydrophobic foil need process flow and coating performance of hydrophobic treatment, the technology’s equipment and process are simple, and after one roll coating, a surface with excellent corrosion resistance and high hydrophobicity can be obtained, making it suitable for use in domestic air conditioner aluminum foils.