Integrated flattening allows hole punching without sheet metal distortion

TRUMPF® has introduced a new integrated flattening concept, available on the TruPunch 5000 punching machine and the TruMatic 7000 punch/laser combination machine.

The process allows punching of a large number of holes in thin sheet metal without distorting the panel. Opposing stresses are introduced to keep the sheet metal panels flat, thereby eliminating an additional step to even out the material.

To help the sheet metal maintain its flatness, the convex die works in tandem with a stripper featuring a recess and special coating. The convex die presses the sheet metal against the stripper from underneath, which overbends the material. The concave stripper counteracts by pressing the material raised by the convex die back downward at the edge of the die. The overbending creates counterstresses that offset the compressive and tensile stresses caused by the punching process. In this way, the sheet metal is flat when it leaves the machine.