First, check the surface quality of the profile

The quality of the profile can be observed from the surface of the broken bridge aluminum profile. High-quality broken bridge aluminum profiles have a strong gloss, and the color of the surface spraying will appear natural, giving a smooth feeling; while the surface of the broken bridge aluminum windows and doors is rough, without gloss, and looks and feels unnatural. After a period of time, inferior broken bridge aluminum windows and doors will change color or fade, and the color will not be full.

Second, check the cross-sectional structure of the profile

High-quality broken bridge aluminum window and door profiles have accurate geometric angles in the cross-section, and the profiles will not bend or twist, and the angles are correct. And the cross-sectional thickness is sufficient. For example, for the 60 model broken bridge aluminum windows and doors you customized, 60 means the thickness of the profile is 6 cm, and the 6 cm broken bridge aluminum is full, with a smaller proportion of threads; while inferior broken bridge aluminum windows and doors will use fake 60 profiles for support, and use a threaded strip to support this thickness, with less aluminum material.

Third, check the thermal break of the profile

Thermal breaks are divided into imported and domestic ones. Domestic thermal breaks are mostly made of PVC plastic material, while imported thermal breaks are polyamide, namely nylon thermal breaks. High-quality broken bridge aluminum windows and doors use imported thermal breaks, which have better high-temperature and low-temperature resistance, low thermal conductivity, and better heat insulation, environmental protection, and energy-saving effects, saving 20%-30% of energy.

Five common "methods" of inferior broken bridge aluminum windows and doors

First, "replacing the pillar":

Replacing the glass fiber reinforced polyamide nylon (PA66) thermal break (hereinafter referred to as nylon 66 thermal break), which has been recognized in Europe for decades, with a low-cost general plastic - polyvinyl chloride (PVC) thermal break (hereinafter referred to as PVC thermal break) that is clearly stipulated by national departments to be only used for non-structural materials. Because the linear expansion coefficient of PVC (8.3*10-5K-1) and the linear expansion coefficient of aluminum alloy (2.35*10-5K-1) are very different, and its low strength (only about 30N/mm2), poor heat resistance (80°C), and poor anti-aging performance, etc., lead to the loosening of the PVC thermal break in the aluminum profile due to thermal expansion and contraction during the actual installation of the heat-insulating aluminum profile made with PVC thermal break, or even complete separation. Minor issues may lead to shape loosening and deformation, thus destroying the airtightness and water tightness of the windows and doors, while serious issues may lead to overall shape loosening and falling off.

The second is "concealment":

In the case of heat-insulating aluminum windows and doors, many companies use imported nylon 66 thermal breaks to make heat-insulating sample windows during bidding, and then use PVC thermal breaks or domestic nylon thermal breaks for actual processing, or mix imported nylon 66 thermal breaks with PVC or other thermal breaks, and the trademark logo of the imported nylon 66 thermal break faces outward. To "prove" the "quality grade identity" of the thermal break used. This "concealment" is highly concealed, and the owners of heat-insulating aluminum window and door projects can only identify it before the heat-insulating aluminum profile is processed, because at this time only two types of thermal breaks are identifiable.

Third, "muddy the waters":

The material of the thermal break is a basic guarantee of the quality of heat-insulating windows, but it is by no means the only guarantee. In 2003, domestic nylon thermal breaks began to appear on the market. In order to reduce costs, domestic nylon thermal breaks used general mineral materials (commonly known as fillers) to replace glass fiber-filled polyamide nylon in whole or in part for processing and production. Thermal breaks cannot be compared with glass fiber reinforced nylon 66 thermal breaks in terms of mechanical strength, heat resistance, and anti-aging properties. Moreover, since the national building "thermal break" industry standard is still in the final approval process, domestic nylon thermal breaks use a mixture of nylon and general minerals to make injection molded parts for relevant performance tests, and the obtained test report is used as the performance test report for its finished thermal breaks. The test data of this raw material can only represent its material characteristics, while the performance of the finished product produced during processing such as extrusion and cooling will change greatly.

Fourth, "opportunistic":

Some heat-insulating aluminum window and door companies have fully studied and mastered the huge performance differences between PVC thermal breaks, domestic nylon thermal breaks, and imported nylon 66 thermal breaks, and have adopted a compromise scheme that is both economical and relatively safe: low-quality and cheap PVC or domestic nylon thermal breaks are used for window frame aluminum profiles, while high-quality imported nylon 66 thermal breaks are used for window sash aluminum profiles. They believe that: the window frame aluminum profiles are fixed to the wall, even if there are quality risks, there will be no big problems, while the window aluminum profiles actively bear the force, so there cannot and dare not be quality hidden dangers.

Fifth, "filling the quantity"

Some heat-insulating aluminum window and door companies have found in their research on people's psychology that people only care about the quality of the thermal break material and rarely consider the quality of the outer two layers of aluminum alloy. According to national standards, the aluminum alloy for building profiles is 6063 alloy, while some companies use unqualified aluminum alloy to make heat-insulating aluminum composite windows and doors, resulting in poor cornering of window sashes and frames, and making it difficult for windows and doors to insulate heat. Therefore, not only the quality of the thermal break is important, but also the aluminum alloy depends on its hardness and strength, and there are differences in electrostatic spraying and electrophoretic coating on the surface of the profile. The former is a physical change, for details, please see Baidu Encyclopedia "Electrostatic Spraying Technology", the latter is a chemical change, for details, please see Baidu Encyclopedia "Electrophoresis Process". "Electrophoresis process" originated in the 1960s, and was first applied to car primers by Ford Motor Company. Due to its excellent anti-fading and anti-corrosion functions, it was quickly widely used in the military industry. In recent years, it has been applied to the surface treatment of windows and doors. Due to its excellent quality and high environmental protection, it is gradually replacing traditional spraying. Electrophoresis is the process in which, under the action of voltage, charged coating ions move towards the cathode under the action of voltage, and an alkaline reaction occurs on the cathode surface to form an insoluble substance, thus making the coating deposit on the surface of the aluminum alloy.

In short, we can see that in the absence of a dedicated thermal break industry standard for heat-insulating aluminum alloy windows and doors, there are worrying phenomena in the heat-insulating aluminum window and door market, and the lack of comprehensive and in-depth understanding of this new technology by owners of heat-insulating window projects is the main reason for these phenomena. However, we should call on the insightful people in the window and door industry to adopt an objective and scientific attitude, regard product quality as the lifeline of the industry, and be responsible for the professional ethics of consumers, and quickly regulate this disorderly competition. A professional attitude that is responsible for product quality and people's quality of life is to establish principles, otherwise, even if relevant standards are introduced, it will be in vain. The development of standards is to check product quality, without quality awareness, everything becomes empty talk.

How do consumers buy broken bridge aluminum windows and doors?

Check materials:

High-quality aluminum alloy doors and windows use aluminum profiles that meet relevant national standards in terms of thickness, strength, and oxide film. Windows with non-elastic assembly structures should have a wall thickness exceeding 1.4 mm, and doors with non-elastic assembly structures should exceed 2.0 mm. Tensile strength should reach 157 Newtons per square millimeter, yield strength should reach 108 Newtons per square millimeter, and oxide film thickness should reach 10 micrometers. Failure to meet these standards indicates inferior aluminum alloy doors and windows, unsuitable for use.

Check Processing Status:

High-quality aluminum alloy doors and windows are characterized by precise processing, proper installation, and excellent sealing performance, ensuring smooth and easy operation. Inferior aluminum alloy doors and windows, on the other hand, often involve the careless selection of aluminum profiles and specifications, rough processing (using sawing instead of milling), improper installation, and poor sealing. This results in air and water leakage, potential glass breakage, and increased risk of scratching or impact to sliding components or glass under strong winds or external forces, potentially causing harm.

Check Price:

Under normal circumstances, high-quality aluminum alloy doors and windows are approximately 30% more expensive than inferior ones due to higher production costs. Some aluminum alloy doors and windows with wall thicknesses of only 0.6-0.8 mm have tensile and yield strengths far below relevant national standards, posing safety risks.

Furthermore, it is best to choose products from reputable aluminum alloy door and window manufacturers, as products not processed according to standards are unlikely to meet them.