Aluminum windows and doors aluminum selection knowledge

The rational design of the sash ratio and orientation. Generally, the heat transfer coefficient is greater than with the windows facing the same area of ​​the wall heat transfer coefficient, therefore, heating energy window wall as the proportion of the heat increases. Lighting and ventilation in under the conditions allowed to control the proportion of window to wall ratio setting curtains and window insulation panels more efficient, that is smaller than the design window and wall area, the smaller the heat loss, energy-saving effect is better. Heat loss is also related with the outside windows facing south, north facing solar radiation intensity and high sunshine, window solar heat gained much.

Use energy-saving materials. Since the development of new materials, the main material composition window (frame materials, glass, seals, hardware accessories and shading, etc.) technology has made rapid progress, the use of energy-saving materials are aluminum clad wood windows and doors energy efficient way. Frame material: profiles for windows outside the window opening area of ​​about 15% to 30% percent, the energy loss of exterior windows in another weak link, so the choice of profiles for windows is also essential. Currently many types of energy-saving window frames, such as: aluminum insulation, insulation steel, plastic extrusions, aluminum alloy doors and windows aluminum and so on. Among them, aluminum insulation energy-saving effect is better, more widely used, which not only retains the advantages of aluminum, but also greatly reduces the aluminum heat transfer coefficient. Insulation aluminum is used in aluminum alloy sections in the thermal bridges (cold bridge) technology enables the profile is divided into inner and outer two. Insulation aluminum called aluminum doors and windows.

Aluminum windows and doors systems application and development of

1, the foreign development and application of aluminum alloys windows and doors

Aluminum windows and doors as early as the 1930s in Europe and the United States and other advanced industrial countries began trial application. After World War II, because the aluminum industry technology advances, aluminum doors and windows due to get a guarantee of basic materials, so that the aluminum doors and windows since the 1950s began to get a high-speed system development. Aluminum with excellent features a modern construction industry, in addition to steel other than the most widely used metal materials, aluminum doors and windows to become a major architectural metal doors and windows.

Europe and the United States aluminum doors mainly used for public buildings, profiles and more use of thermal profiles, glass are used hollow glass, window type air-tightness mainly good flat open based. Aluminum windows and doors market share in Western Europe and 27%; Northern Europe is mainly based on thermal insulation to select window type; Central Europe put windows and doors as part of the furniture to choose; Southern Europe places to choose whichever architectural features.

(2) domestic development and application of aluminum windows and doors

Aluminum windows and doors in our country is the late 1970s, after the reform and opening from Europe, America, Japan and other countries the introduction of technology, developed in the eighties a new generation of metal doors and windows. European heavy-duty windows, Japanese and American light windows are not suitable for China's national conditions. China's aluminum windows and doors industry after twenty years of development, has been fully able and has been designed to develop a variety of grades suitable for China's new products and supporting functional hardware.

In recent years, China's construction and real estate boom, to the Fenestration Industry provides a huge space for development, has now become the world's largest windows and doors market. Strong infrastructure in the country, driven by the industry for aluminum doors and windows and related hardware industry provides a rare opportunity. Since China aluminum windows and doors industry started relatively late, Europe and other countries through the introduction of windows and doors, and through the application of learning in recent years, there are some companies began to design their own doors and windows system suitable for China's national conditions.

How to ensure the quality of the hardness of aluminum

Aluminum temperature setting and control: In general, the temperature and the table show that the temperature has some errors, set the table when the temperature of the furnace according to the actual temperature setting, and pay close attention to temperature fluctuations. Aluminum heat aging: in strict accordance with requirements of the aging process, the holding time should be appropriate to avoid aging or due to aging and cause hardness is not enough. Blank frame, furnace charging

Aluminum extrusion frame can not be too close to the material and the material at intervals, especially small unventilated materials, thick interval larger pipe materials and small materials together in a single box, pipe materials is conducive to such restrictions air circulation. Furnace before charging 6 XXX will be other special alloys and common 6063 alloy aging furnace installed alone, due to production reasons and oven aging, the aging process take special alloys. Of aluminum extrusion, without limitation low hardness before and not as a product of the use, therefore, in general, have improved strength through aging. Typically, aging can be divided into two kinds of natural aging and artificial aging, the current 6 XXX aluminum production is essentially based on the latter.

Aluminum windows and doors leak prevention and control

1, the design and preparation phase

    a) early intervention, to participate in drawings reviewing the design defects, proposed deepening of the design requirements;

    b) structural design characteristics on the basis of engineering calculations strictly according to specifications and design, do not simply apply;

    c) the characteristics of a model based on the engineering construction window, do the preliminary prevention, process control, stage watertight test;

    d) before mass production, and truly physical performance test to determine whether the doors meet the design requirements and performance indicators;

    e) try to use the same manufacturer, same series window profiles, do not simply pieced together, try to use retaining high sash section, increasing sealing doors and windows and adding windows and doors pass locking points;
2, making the installation phase

    a) doors and the wall surrounding the hole should be controlled in the standard gap between 25mm-40mm, the maximum size should be no more than 50mm, the minimum is not less than 20mm, and the outer wall of the window frame at a distance, or should use fine concrete pouring dressing before installation and construction, prohibited the use of inferior masonry, such as mud-brick or mortar directly sintered pad level;

    b) a reasonable choice according to the project situation cement mortar filling method, one first mortar filling the cavity aluminum mounting on the wall and then a second filling; two aluminum frame is fixed before filling mortar. Both methods have advantages and disadvantages, the first chamber to ensure that no form of aluminum hollowing phenomenon, but is easy to produce in the second filling cracks and leaks; second method is easy to form the lower sides of the border and the inevitable dissatisfaction with the form filling hollowing phenomenon;

    c) To control the cement mortar filling cement mortar mix is ​​generally 1:2.5, to ensure the quality of cement mortar, it is recommended to add in cement mortar cement mortar waterproofing agent to improve anti-leakage performance, pay attention to maintenance, to avoid cracking;

    d) border around the outer wall of windows and doors 300mm range, increasing painted two waterproof coating to reduce the chance of water leakage;

    e) face the wind or rain erosion surface to prevent rainwater seeps through the windows and the wall between the filling material, sealing baffles or other appropriate consideration waterproof coating to increase the impermeability;

    f) to leave the junction sash dispensing slot width 5-8mm, inlay Note sealing materials, attention should be clear floating dust, mortar, etc., so that the sealing material and window frames, wall firmly bonded. Also check whether the continuous sealing materials, whether gaps, etc., especially if there is nonporous corner transfer position exists; wall tiles should be used for two or more sealed to avoid the patchwork capillary water penetration;

    g) Adjust ban remains in the doors and windows frame pad, a second time after removal filled with dense, filling attention reliable bonding with the substrate, in addition to clear debris outside the matrix should be moist;

    h) indoor outdoor window sill plate should be less than 20mm is appropriate, and set the downstream slope, drainage flow, to avoid water penetration. Aluminum doors and windows and the exterior have a certain distance, to avoid direct rain erosion.

    i) door and window fittings, materials, specifications, connection method should comply with local "aluminum alloy doors and technical regulations" requirement in a timely manner with concrete or mortar anchor seal, avoid moving under the action of wind load leaving the sealing material cracks.

Electrolytic capacitors to avoid common pitfalls method

Because of its low cost, aluminum electrolytic capacitors have always been a popular choice for the power supply. However, they are limited life, and vulnerable to extreme high and low temperature conditions. Electrolytic capacitors in place on both sides of paper impregnated with electrolyte foil. This electrolyte is evaporated during the life of the capacitor, thereby changing its electrical properties. If the capacitor fails, it will be a vigorous reaction: capacitor formation pressure, forcing it to release a flammable and corrosive gases.
Electrolyte temperature the rate of evaporation is closely related with the capacitor. Operating temperature dropped 10 degrees each capacitor life expectancy doubled. Capacitors rated life is usually at its maximum rated temperature the result. Typical rated life of 1000 hours at 105 degrees Celsius. Selecting these capacitors shown in Figure 1 for the long-life LED bulbs and other applications (LED lifetime of 25,000 hours), capacitor life will become a problem. To achieve 25,000 hours life, this capacitor requires working temperature does not exceed 65 degrees Celsius. The operating temperature is particularly challenging, because in this application, the ambient temperature will exceed 125 degrees Celsius. There are on the market a high temperature rated capacitor, but in most cases, the aluminum electrolytic capacitor LED lamp life will become a bottleneck components.
Temperature dependence of this life you reduce the actual impact of the capacitor rated voltage. Your first thought might be to increase the rated voltage of the capacitor dielectric to minimize the probability of failure. However, doing so causes the capacitor's equivalent series resistance (ESR) higher. Since the capacitor will generally have high ripple current stress, so this will bring additional high resistance internal power dissipation and increase the capacitor temperature. Failure rate increases with increasing temperature. In fact, the aluminum electrolytic capacitor typically use only about 80% of the rated voltage.
When the capacitor temperature is low, ESR increased dramatically. In this case,-40oC, the resistance of magnitude increase. In many ways this will affect the power performance. If the capacitor for switch mode power output, the output ripple voltage magnitude was increased. Further, the ESR and the output capacitor formed above zero frequency, it allows the loop gain is one order of magnitude, thus affecting the control loop. This generates a stable oscillation power. To accommodate this strong vibration, the control loop is usually made great compromise in space, and at higher temperatures.
In short, the electrolytic capacitor is usually the lowest cost option. However, you will need to determine whether the application of its shortcomings adversely affected. Through its work, the temperature you need to consider the length of its life. In addition, you also appropriately reduce the rated voltage, so that you can achieve the lowest temperature operation, thereby obtaining maximum life. Finally, you need to understand the need to use the ESR range, so that you can properly design the control loop, designed to meet the ripple specifications.