At present, there are U-shaped and C-shaped metal notches for aluminum alloy door and window profiles in the market. The use of aluminum alloy doors and windows stems from the introduction of European aluminum alloy door and window system. In European aluminum alloy door and window systems, there is only a European standard notch, namely the so-called "C" slot in the Chinese market. The U-shaped metal notch is the European standard notch of plastic steel doors and windows, Due to the special requirements of the material and structure of aluminum alloy door and window hardware, the price of aluminum alloy door and window hardware is higher, while the price of plastic steel door and window hardware is about 40% lower than that of aluminum alloy door and window hardware. Therefore, some aluminum alloy profile manufacturers transplant the metal notch of plastic steel door and window to aluminum alloy door and window profile, and the "U" shaped notch of aluminum alloy door and window appears.
The reasons why 3x European aluminum alloy door and window system does not use u-notch are as follows:
1. Hardware design principle of u-notch: u-notch (hardware) is a special hardware slot for plastic doors and windows and wooden doors and windows in Europe. The hardware connection mode of u-notch adopts self tapping screw bolt connection to install hardware. However, if it is applied to aluminum alloy doors and windows, when the self tapping screw for installing U-slot hardware bears the longitudinal shear force generated by the door and window switch, because the hardness of the self tapping screw is far greater than that of the aluminum alloy profile, the screw thread of the self tapping screw will damage the aluminum alloy profile, resulting in the expansion of the installation hole, and the screw connection of the hardware will trip in the long run. Because the lining of plastic steel doors and windows is made of steel, the material hardness is equal to that of self tapping screw, and the phenomenon of mounting hole expansion and hardware tripping will not occur. Due to the u-notch (hardware) application in aluminum alloy doors and windows does not conform to the mechanical material strength design principle in mechanical design, considering the safety of door and window hardware, u-notch (hardware) is not used in European aluminum alloy doors and windows.
As long as the U-shaped steel door and window are corroded by water, the water-proof structure of U-shaped steel door and window will be affected by water penetration.
3. Advanced design principle of c-notch Hardware: the installation of c-notch hardware relies on the tightening force of stainless steel nails and the clamping force of stainless steel lining and metal notch of machine screw to ensure the firmness of hardware installation. The top tightening of stainless steel nails will produce local deformation of about 0.5-1.0 mm on the profile surface, so that the stainless steel nails and aluminum profiles are closely combined to ensure that the hardware will not occur under stress There is displacement.
4. Convenient installation of C-type notch Hardware: no installation holes, no self tapping screw connection, easy installation, low dependence on auxiliary conditions such as electricity and gas, which can realize on-site installation.
5. Material comparison: c-notch hardware is special aluminum alloy (metal) door and window hardware, while u-notch hardware comes from plastic doors and windows, and the material requirements and hardness requirements of hardware rods are lower than those of c-notch hardware. For example, the hardware materials of c-notch hardware are mainly extruded aluminum, zinc based die-casting alloy, carbonitriding steel, stainless steel, molybdenum disulfide nylon. The surface treatment is Dacromet surface treatment, ral surface color spraying (the same as Ferrari chassis anti-corrosion treatment), after strict corrosion resistance test, alkali deposition will not occur.
6. Safety of connection structure of c-notch Hardware: c-notch hinge adopts high-hardness stainless steel lining (the lining adopts special structure). When the fastening screw is tightened, the special structure on the lining will bite into the surface of aluminum alloy profile like teeth, forming some local deformation (pits) of 0.2-0.5mm, so as to ensure the safety performance of window sash and prevent connection The hardness of screw and aluminum profile is not equal to each other, which causes tripping and causes the window (door) leaf falling off.