Roller bending: 2 times or more forming times, more than 85%; The rest 15% can be simply corrected; all saying that qualified rate more than 90% by once time deformation is deceptive, up to 50% (In roller bending there are high requirements for raw material, temperature, equipment and so on) .Stretch bending qualified rate can reach more than 99%, and the quality is higher.
Regarding to sampling or small production, shall choose roller bending，manual correction is one of the core processes (3D can not be corrected)
Detect inner arc or outer arc ? If outer arc stretching, internal arc will shrink or unchanged, the material must be deformed, the checking standard can only based on key point or key surface.
First order: one arc and two inner arcs
When bending, first press the material between the two arcs, and do not make the material deform in the middle when bending.
After the bending, the two inner arcs of the two inner ribs cannot be removed, and wrinkles may occur.
Solution: A punches the ribs before punching, then bends, repairs and polishes.
B side of the mold plus the slider to clamp the rib position and then bend (forcibly squeeze), it is possible that the rib position is concave, acceptable.
C is allowed to wrinkle, forged and smoothed after molding.