At the same time, do not forget that metal -plastic windows consist of aluminum parts that are smartly connected to a plastic frame. And of course, in the usual plastic window, much more materials are used, in addition to plastic and metal, because the rubber is also used there, and if not it, it would be practically difficult to achieve high sealing the window, and it also contains any plastic glass, which In recent years in recent years, in the direction of strength has also been very enough. Of course, if it were not for aluminum details in the windows of PVC, we could talk about the much more modest limits of the temporary operation of the windows, because as if modern plastics would not be strong and quite functional, but it is not possible to do not really without metal in complex structures.
