Paperboard tube structures with one or more cut-and-folded plies

Abstract

There is provided a paperboard tube structure with an intermediate ply having cut-and-folded tabs to increase the effective thickness of the intermediate ply. The paperboard tube includes a plurality of paperboard plies wrapped one atop another about an axis with the intermediate ply positioned between an interior paperboard ply and an exterior paperboard ply. A plurality of cut-and-folded tabs are each created by a nonlinear incision in the intermediate ply that extends from a first endpoint to a second endpoint thereby creating a folding axis along a line from the first endpoint to the second endpoint. The tab is folded about the folding axis to overlie a region of the intermediate ply adjacent the folding axis. The tabs increase the effective thickness of the wall of the paperboard tube. Therefore, the bending stiffness of the paperboard tube is increased compared to a tube without cut-and-folded tabs or the tube requires less paperboard ply material to maintain an approximately equal bending stiffness as a tube without cut-and-folded tabs.