Patent ID: 8297027

Claim:
A panel, comprising: an elongated sheet of molded fiberboard material of corrugated shape having opposite first and second faces and opposite side edges, each face having a plurality of alternating, longitudinally extending ribs and grooves extending along the length of the sheet, the ribs on the first face each having a first peak and the ribs on the second face each having a second peak facing in the opposite direction to the first peaks; the sheet having at least one slotted portion which has a plurality of spaced slits, each slit extending lengthwise across at least a plurality of the first peaks and being cut through part of the ribs of the first face including the first peaks to a depth less than the depth of the grooves in the first face and terminating short of the second peaks of the second face; the panel being formed into at least one curve at said one, slotted portion with the slotted, first face of the sheet facing inward; and the slits are closed at the first peaks of the ribs on the inwardly curved first face of the sheet.