Rolling with fewer passes

Working principle:

Two Umlauf Bridles – one arranged ahead and one behind the rolling stand – achieve the perfect ratio between tension and compression.

Benefits:

Fewer passes

• Rolling under high back-tension makes higher reductions per pass possible. This results in fewer passes, less frequent recoiling and reduces the handling effort otherwise needed.

Excellent leveling result, minimal residual stresses

• High strip back-tension makes for higher flow of material in the roll gap and increases the specific contact pressure of the rolls. This achieves higher reduction rates. Consequently, the number of passes can be reduced.
• The fact that the high back-tension is uniformly applied over the width of the strip facilitates the flow of material in the roll gap. Residual stresses are reduced. Thus, already during rolling Umlauf Bridles work as continuous stretch-levelers.

Ideal strip shape

• The shorter side edge of the strip is automatically subjected to a higher strip tension. This supports equalization of the microstructural fibers and corrects camber in the process.

Precise strip guidance

• Keeps the running strip in position with an accuracy of + / - 1 mm.

Minimal head and tail loss

• As Umlauf Bridles are arranged very close to the roll gap, head and tail loss is reduced to a minimum.
• After the last pass, the strip is directly fed to the next downstream process (no recoiling required)