At present, the potential quality hazards and cognitive deviation in the actual use of insulated aluminum doors and windows in China are very worrying. The professional attitude of being responsible for the quality of products and the quality of people's life is the principle of establishing people. Otherwise, even if the relevant standards are issued, it will be in vain. Setting standards is to check the quality of products. The following four are common:
1. To hide from the world-At present, there are many examples of thermal insulation aluminum doors and windows in which enterprises bid for thermal insulation sample windows with imported nylon 66 thermal insulation strips. After winning the bid, PVC thermal insulation strips or domestic nylon thermal insulation strips are used for actual processing or the imported nylon 66 thermal insulation strips are mixed with PVC or other thermal insulation strips, while the strips with trademark logo on the imported nylon 66 thermal insulation strips are facing outward to "prove" the "quality and grade identity" of the thermal insulation strips used. This kind of "hiding from the sky and crossing the sea" has strong concealment. The owner of the insulated aluminum door and window project can only identify it before the insulated aluminum profile has been processed, because only the two heat insulation strips at this time can be identified.
2. Speculation-Some heat-insulating aluminum door and window enterprises have adopted a compromise plan that is both economical and relatively safe after fully studying and grasping the large performance differences among PVC heat-insulating strips, domestic nylon heat-insulating strips and imported nylon 66 heat-insulating strips: the aluminum profile of window frames adopts low-quality and low-price PVC or domestic nylon heat-insulating strips, and the aluminum profile of window sash adopts high-quality imported nylon 66 heat-insulating strips. They believe that the aluminum profile of window frame is fixed on the wall, and there will be no big problem even if there is quality risk, while the aluminum profile of window sash is movable and bears the force alone, so it cannot and dare not have quality risks.
3. fish in troubled waters-the material of heat insulation strips is the basic guarantee for the quality of heat insulation doors and windows, but it is by no means the only guarantee. In 2003, domestic nylon heat-insulating strips came into the market. In order to reduce costs, domestic nylon heat-insulating strips are manufactured by filling polyamide nylon with general mineral materials (commonly known as fillers) instead of glass fibers in whole or in part. This kind of heat insulation strip cannot be compared with glass fiber reinforced nylon 66 heat insulation strip in terms of mechanical strength, heat resistance and aging resistance. Moreover, as the industry standard of "heat insulation strip" for national construction is still in the final approval process, the domestic nylon heat insulation strip carries out relevant performance tests on the injection molded parts made by mixing its nylon with common minerals, and takes the obtained test report as the performance test report of its finished heat insulation strip. The testing data of this raw material can only represent its material properties, and the properties of the finished products produced after hot extrusion and cooling will greatly change.
4. Stealing beams and replacing columns-replace the glass fiber reinforced polyamide nylon (PA66) heat insulation strip (hereinafter referred to as nylon 66 heat insulation strip) which has been generally accepted in Europe for decades with the common plastic-polyvinyl chloride (PVC) heat insulation strip (hereinafter referred to as PVC heat insulation strip) which is clearly stipulated by relevant departments of low-cost countries and can only be used for non-structural materials. Since the linear expansion coefficient of PVC (8.3*10-5K-1) is far different from that of aluminum alloy (2.35*10-5K-1), In addition, many defects such as low strength (only about 30N/mm2), poor heat resistance (80℃), poor aging resistance, etc. lead to the loosening or even complete detachment of PVC heat insulation strips in aluminum profiles due to thermal expansion and contraction after actual installation and use of heat insulation doors and windows made of heat insulation aluminum profiles compounded with PVC heat insulation strips. Light ones lead to loosening and deformation of windows and doors, thus damaging air tightness and water tightness of windows and doors, while heavy ones lead to overall loosening and detachment of windows and doors.