Stretch bending process is a kind of processing technology, many metal equipment which can not be formed at one time will be used in later processing. For example, some plates can not accurately achieve the target size when casting, they will first cast a simple model, and then through stretch bending to achieve dimensional accuracy.
(1) The door and window sash is too high and too wide, and the section size of the selected surgical material is too small to bear the torque of frequently opening and closing the door and window, and the deformation takes a long time.
(2) The quality of doors and windows is poor, such as mortise and tenon is not straight, tenon shoulder is not square, etc.
(3) Due to the influence of wall pressure or hanging heavy objects in use, the door and window leaves warpage.
(4) In use, after the paint of the door is powdered and peeled off, the section is cured in time, so that the moisture content of the wood often changes, and the wood expands and shrinks dry, causing deformation.
(5) Hardware specification is too small, improper installation, resulting in door and window leaf sagging and deformation.
There are quite a lot of aluminum profiles, and the varieties and specifications of extruded profiles have exceeded 30000. There are more than 24000 species. The second is copper profile, magnesium profile, profile steel and plastic profile. Solid extruded profiles.
Secondly, hollow extrusion profiles account for about 65% of the total extruded profiles, while profile with special profile accounts for the majority of solid profiles. Such as aluminum door and window profile stretch bending, plastic door and window profile stretch bending. The strength of extruded profiles is high. The replacement of extrusion tools is simple, compared with other methods such as rolling and die forging. It can be produced in small quantities. The complex shape is produced by extrusion. Good alloy such as hard aluminum, magnesium% 26mdash; aluminum alloy, brass, bronze, white copper, titanium, zirconium, steel and other hollow profiles can not be welded extrusion method.