What Is The Roll Forming?
Roll forming is a process that uses a set of precisely placed rollers to perform incremental bending to a continuously fed strip of metal. The rollers are mounted in sets on a consecutive stand with each roller completing one small step of the process.Rollers are carefully crafted using a flower pattern, which identifies the sequential changes to the metal strip. The shape of each roller is created from the individual sections of the flower pattern.
Each of the colors in the above flower pattern illustrates one of the incremental bends used to complete the part. The individual colors are a single bending operation. CAD or CAM renderings are used to simulate the roll forming process so that errors or flaws can be prevented prior to production. Using software applications, engineers can select calibrations and profiles for folding or bending angles to create new geometries by clicking their mouse.
Roll Forming Process
Each roll forming manufacturer has a different set of steps for their roll forming process. Regardless of the variations, there are a set of basic steps all producers use.
The process begins with a large coil of sheet metal that can be from 1 inch to 30 inches wide with a thickness of 0.012 inch to 0.2 inch. Before a coil can be loaded, it has to be prepared for the process.
Roll Forming Methods
A) Roll Bending
Roll bending can be used for thick large metal plates. Three rollers bend the plate to produce the desired curve. The placement of the rollers determines the exact bend and angle, which is controlled by the distance between the rollers.
Roll Forming Bending
B) Flat Rolling
The basic form of roll forming is when the end material has a rectangular cross-section. In flat rolling, two working rollers rotate in opposite directions. The gap between the two rollers is slightly less than the thickness of the material, which is pushed through by the friction between the material and the rollers, which elongates the material due to the decrease in material thickness. The friction limits the amount of deformation in a single pass making several passes necessary.
C) Shape Rolling/Structural Shape Rolling/Profile Rolling
Shape rolling cuts different shapes in the workpiece and does not involve any change in the thickness of the metal. It produces molded sections such as irregular shaped channels and trim. Shapes formed include I-beams, L-beams, U channels, and rails for railroad tracks.
D) Ring Rolling
In ring rolling, a ring of small diameter workpiece is rolled between two rollers to form a ring of larger diameter. One roller is the drive roller, while the other roller is idle. An edging roller ensures that the metal will have a constant width. The reduction in width of the ring is compensated for by the diameter of the ring. The process is used to create seamless large rings.
Radial-axial Ring Rolling Process
E) Plate Rolling
Plate rolling machines roll sheets of metal into tightly shaped cylinders. The two different varieties of this type of equipment are four roller and three roller. With the four roller version, there is a top roller, pinch roller, and side rollers. The three roller version has all three rollers producing pressure with two on the top and one on the bottom. The diagram below is a four roller systems forming a cylinder.
Post time: Jan-04-2022