1. Look at the production
There should be no obvious damage on the decorative surface of doors and windows, which means that the protective film on the surface of doors and windows should not have scratches. The colored surfaces of adjacent components on doors and windows should not have obvious color differences. There should be no aluminum chips, burrs, oil spots or other stains on the surface of doors and windows, and there should be no spilled adhesive at the assembly joints.
2. Look at the material
Whether it is a broken bridge thermal insulation aluminum profile, the wall thickness of the main profile should be greater than 1.4mm; the color of the same aluminum profile should be the same, if the color difference is obvious, it is not suitable to buy; check the surface of the aluminum profile, there should be no depression or bulging; The thickness of the film should reach 10 microns. When purchasing, lightly scratch the surface of the profile to see if the oxide film on the surface can be wiped off.
3. Look at the assembly
Repeat the switch many times to check whether the switching force is too heavy; whether the sealing strip is firm; whether the hardware assembly is complete; whether the overlap of the window sash and frame meets the requirements (standards require not less than 6mm for casement windows and not less than 8mm for sliding windows).
4. Look at the glass
Whether it is hollow glass and whether there is coating.