Beijing Shengda Weiye Bending process characteristics and requirements
1.So-called bending is, in the premise of given pre-tension in the profiles (within the limits of tolerance), using a rotary cam to change interface of the cross-section to deform the plasticity of the profile.
2.About the length of preparation of the materials: In general materials should be length of the effective arc for the curved material plus the process section. The processed section is equal to 2.1 times the width of the deformation (t), the width of the deformation (t) is equal to the outer radius (R outer) minus inner radius (R interior)
备料长度=有效弧长+2.1 t length of preparation materials= effective arc length +2.1 t
Specific preparation length can be sets cut according to actual situation, in order to save process section.
3.About quantity of preparation: Under normal circumstances, one should increase 1 to 2 of backups on the basis of the actual needs as debugging mold, depending on different cross-sections, radius, and arc length. The backups do not include the number of losses that may occur in transportation, processing, installation and other processes.
4.Requirements on each material’s effective curved arc: under normal circumstances should not exceed 180 degrees angle in radians
5.About hardness requirements of material: When profile bending deformation elongation meet the requirements, then we should select the T5 state (e≤10%), the national standard aluminum is e≥ 8%:
e = t / R内×100% = (R外-R内) ÷R内×100%
e = t / R inside× 100%=(R outside –R inside) ÷ R inside× 100%
If not, select To ~ T4 state. Of course bending company are generally reluctant to produce T1 ~ T4 state profiles to customers.
6.About profile surface processing requirements: Under normal circumstances, one can choose anodizing or coating bending (coating elongation is much larger than profiles’ elongation); there is no relative displacement between the profiles and molds when bending, so It will not damage the profile. In profile bending, coating off is the result of insufficient adhesion of the coating. The main causes of inadequate adhesion are from improperly handling before spraying or insufficient heating. Thus, for the convenience of transportation and installation, it should be taken appropriate surface protection.
PS: The description above describes only a general sense, the specific circumstances of the project is depending on specific sub-grid, nodes and other characteristics.
We apologize for any confusion and unclearness. Corrections are really welcome.