Flattening, straightening & leveling

An example for the typical time required to get flat flame-cut parts (in minutes)

Originally, flattening is done by hammer and flame. Therefore, the workpiece is heated and then hammered to a flat condition. This application is highly time-intensive and is usually done by experienced staff.

Some sheet metal working companies also use bending machines to remove rough flatness defects. High requirements to flatness can hardly be achieved with this procedure, the internal stress stays in the metal part. The handling is very challenging for broad flame-cut parts. Not infrequently, the required time exceeds 25 minutes per part.

The same is true for straightening presses, that are usually used for flame-cut parts above 60mm material thickness. Time requirements of 20 minutes per part are not unusual.

The most common procedure to level laser- and flame-cut parts from 0.5 up to 50mm material thickness is roller leveling. Mechanical straighteners are used for parts with low requirements on flatness, since mechanical straighteners usually need 5 to 6 applications to produce good leveling results.

Servo-hydraulic precision levelers as the ARKU FlatMaster® do have a high-capacity leveling unit. Leveling rollers are located in minimum distance to each other and do have excellent support. In combination with small roller diameters all these features make sure that most tensions and flatness errors are removed out of sheet metal parts in just one attempt.

The precision leveler FlatMaster® is equipped with a hydraulic gap control. The gap between the upper and lower leveling rollers is critical to the leveling result. With alternating gaps during the leveling process, poor quality leveling can result. If the gap changes, the precision leveler detects this and produces a counteracting force within fractions of a second. The necessary pressure is applied by means of powerful hydraulic cylinders at the four corners of the machine. The result is that an absolutely constant leveling gap is achieved at all times - even when cross-sections change. Even difficult flame-cut parts are flat and strainless within a couple of minutes.