Americanmachinist 2457 Tt0400png00000002299

Roll form curved shapes

Dec. 1, 2004
A new method of roll forming steel sections promises substantial cost reductions in the fabrication of vehicle parts compared to conventional techniques. The Monroe process uses high-precision computer control and infinitely adjustable rollers to fabricat

The Monroe roll-forming method produces parts with curved sides, conical shapes, and profiles with varying cross-sections.

A new method of roll forming steel sections promises substantial cost reductions in the fabrication of vehicle parts compared to conventional techniques. The Monroe process uses high-precision computer control and infinitely adjustable rollers to fabricate curved sides, conical shapes, and variable profiles.

Developed by the Swedish company Ortic, together with Bemo of Germany, the Monroe method is currently used to construct customdesigned roofing and cladding sections for projects such as the new Milan Fair. But it appears to be making its way into automotive applications as well.

The automotive industry has been using roll forming for many years to manufacture straight sections. "Generally speaking, roll forming is an efficient and economical way of making sections at high production rates," says Lars Ingvarsson, CEO and owner of Ortic AB. "Its limitation has been that traditional roll-forming machines have fixed rollers. The difference with the Monroe machine is that we use rollers that are infinitely adjustable in various directions. This means we can produce parts that would have been quite unthinkable for roll forming in the past."

Such parts may include the A and B pillars of vehicle cabins, which are often of curved shape. The Monroe method would also be suitable for many curved impactprotection bars. These components being made of extra-high and ultrahigh strength steel is not a problem, but actually an advantage, according to Ingvarsson.

"Roll forming is a near-optimal method of working high-strength steels, and the vehicle industry has a lot to gain from the Monroe method," he comments.

Although the process runs at high speeds, it shapes sheet steel relatively gently and gradually. This lessens the risk of cracks and other defects, while delivering tighter bending radii than possible with other methods.