When the four roller bending machine pre bending coiled plate, both ends can be held in the pre bending machine. The steel plate is placed between the upper and lower rollers in rolling machine, steel plate surface should be parallel with the shaft roller end should be higher than the upper and lower shaft and vertical center line distance.
The side roller promoted tilted upward move, let a plate end bending, a move to a distance, to get the plate end pre bending, so the other end plate by pre bending. The pre bending length should be considered to determine the layout size of rolling machine, the quality requirements of pre bending arc in the same.
Pre bending plate should always be used to check the pre bending curvature radius, local bump or concave place, can be used as a gasket to correct the plate. With the rolling machine of pre bending, should be based on the material of the plastic bending process, thickness and curvature of the code size fraction of time.