Air conditioner is an important achievement of material civilization in the game between human beings and nature. The role of air conditioner is irreplaceable whether human beings go to heaven or into the sea, whether they require constant temperature or high or low temperature.
The world's first air conditioning system was designed by American Willis Kelly in 1902, and the first generation of home air conditioners was born in 1928. In the 1960s and 1970s, air conditioners were first developed and popularized in the United States, Japan and other developed countries.
China began to produce air conditioners on an industrial scale in the early 1980s. After the 1990s, the popularization of household air conditioners began, and the air conditioner industry developed rapidly. With the rapid increase of air conditioner output, there is a huge market demand for aluminium foil for manufacturing heat sink fins of air conditioners, which promotes the continuous development of aluminium foil product technology of air conditioners.
Air conditioner indoor and outdoor units
Air-conditioning foil is a special material for manufacturing fins of heat exchangers of air conditioners. Aluminum foil for radiators of air conditioners is referred to as air-conditioning foil. The development of air-conditioning foil technology is accompanied by the demand of air conditioners. Aluminum foil used in the early days of air conditioner is the original surface of aluminium foil, called plain foil and light foil; in order to improve the surface performance of air conditioning foil, some kind of coating is applied on the surface of aluminium foil to become coated aluminium foil; hydrophilic coating is called hydrophilic aluminium foil.
In order to improve the performance of air-conditioning foil materials, the relevant aluminum processing enterprises all over the world are carrying out technical research. It is understood that a foreign aluminium company has introduced. A30,. A50, A100, FM02, FK03, MF03 and other air conditioning foil alloys to meet the different forming requirements of fin punches in O, H22, H24 and H26 states. China's air-conditioning foil alloy series has also roughly gone through the development process of several alloy brands such as 1060, 1050, 1100, 1200, 3102, 8011.
1. Development Trend of Air Conditioning Foil
As a modern commodity, air conditioner is constantly updated in variety, specification, model and performance, and fin processing equipment and methods are constantly improved, which drives the development of air conditioning heat exchanger to the direction of miniaturization, thin-walled, high performance and structural optimization. On the other hand, the speed of air-conditioner fin forming equipment has been improved continuously, from 200 times per minute to 350 times per minute or even 450 times per minute, and the feed rate has been increased from 50mm/2 to 100mm/4 holes, which naturally puts forward higher requirements for the mechanical properties, flatness and thickness uniformity of air-conditioner foil. For example, the newly developed ECO fin forming method has the characteristics of fast forming speed, high production efficiency, low die wear, and stringent requirements for the performance of aluminum foil materials, which requires not only high strength, but also high elongation and deep drawing performance. At present, the number of imported ECO forming equipment in China is increasing, which represents the development trend of air conditioning foil forming method.
2. Characteristics of New Air Conditioning Foil
At present, there are two production methods of air conditioning foil in China: one is casting-rolling billet method, the other is hot-rolling billet method. These two methods have their own advantages. By adjusting the appropriate process parameters and making full use of advantages and avoiding disadvantages, air conditioning foil products that meet customer requirements can be produced. It is found that the mechanical properties of air-conditioning foil can be greatly improved by developing homogenization annealing process of Cast-rolled billet. Aluminum foil with good versatility and comprehensive performance can be produced by using Cast-rolled billet, which can fully meet the forming performance requirements of high strength and high elongation of ECO method. Of course, besides studying special alloy varieties and heat treatment process, ensuring the metallurgical quality of billet, such as homogeneity of original structure of billet and cleanliness of alloy melt, is also the key. The newly developed air conditioning foil alloy contains a certain amount of Fe and Mn elements. The purpose of adding Mn element is to produce uniformly dispersed MnAI6 precipitates to improve the ultimate deep drawing thinning rate of aluminium foil and prevent edge cracks during fin forming. Fe element can reduce the segregation of Mn and refine the recrystallized grains. The formed FeAl3 strengthening phase is beneficial to improve the mechanical properties of aluminum foil.
Traditionally, casting-rolling billet is not suitable for air-conditioning foil products. The main reason is that when casting-rolling billet is used to produce air-conditioning foil, the plasticity is insufficient and the hardening speed is fast, which results in poor deep drawing performance of empty rinse foil. However, recent years'technical research and production practice show that the air conditioning foil products can also be produced by choosing appropriate alloy composition and optimizing production process. Moreover, I has obvious advantages in thinning and stretching forming method. At present, the market share of air-conditioning foil products produced by casting-rolling process in China is increasing, showing a strong development trend.
Air conditioner radiator fins
3. Forming Performance of Air Conditioning Foil
In addition to meeting the requirements of the latest ECO fin forming method, the newly developed air-conditioning foil overcomes the shortcomings of the former casting-rolling blank in producing air-conditioning foil. A breakthrough has been made in the production of air-conditioning foil in full annealing (O) state, which achieves the effects of high deep drawing rate, high ductility and high cup burst value, and fills the blank that the casting-rolling blank cannot produce soft (O) state air-conditioning foil. The new air conditioning foil can meet the performance requirements of O, H22, H24 and H26, and has good versatility and compatibility. At present, there are many kinds of air-conditioning foil forming equipment in China, and the corresponding requirements for the performance of air-conditioning foil adapt to it, which brings a lot of inconvenience to the production and operation between suppliers and customers. Therefore, it is imperative to provide an air conditioning foil product with good comprehensive performance, which can satisfy various types of aircraft at the same time. Customer tests show that the new air conditioning foil can meet the performance requirements of H22 and H26 state foil at the same time, and has good comprehensive performance.
4. Forming Method of Air Conditioner Fins
The forming methods of fins are distinguished by flange forming methods. At present, there are simple, high flange, deep drawing, thinning drawing, deep drawing (DOF) and ECO methods. Fin punches are different.
