Single-ply paperboard tube and method of forming same

A method of producing a paperboard tube comprising the steps of:

• providing a continuous paperboard ply defined in transverse cross-section by first and second relatively thin longitudinal edge portions and a relatively thick central portion disposed therebetween, each of said relatively thin edge portions each having a predetermined uniform width and a substantially constant thickness, said relatively thick central portion having a predetermined uniform width substantially greater than said edge portion width and a substantially constant thickness that is greater than said edge portion thickness;
• applying a longitudinally continuous permanent adhesive layer to a first face of said first edge portion of said paperboard ply, said adhesive layer being of nonuniform thickness in the transverse direction such that said layer is thicker in portions thereof closer to the central portion of said ply than in portions of said layer closer to the longitudinal edge of the ply;
• and
• spirally winding said paperboard ply onto a mandrel in edge overlapping relation so that a second face of the second edge portion of the ply overlaps the adhesive layer on the first face of the first edge portion of the ply, thereby forming a permanently bonded, continuous paperboard tube.

A method of producing a paperboard tube comprising the steps of:

• heating a continuous paperboard ply defined in transverse cross-section by first and second relatively thin longitudinal edge portions and a relatively thick central portion disposed therebetween, each of said edge portions having a predetermined uniform width and a substantially constant thickness, said central portion having a predetermined uniform width substantially greater than said width of edge portions and a substantially constant thickness that is greater than said edge portion thickness, said heating of said ply being conducted under conditions sufficient to raise the temperature of the paperboard ply to at least about 125 degrees Fahrenheit;
• applying a permanent adhesive layer to a first face of the first edge portion of said paperboard ply;
• and
• spirally winding said paperboard ply onto a mandrel in edge overlapping relation so that a second face of the second edge portion of said paperboard ply contacts the adhesive coated face of the first edge portion of said ply, thereby forming a permanently bonded, continuous paperboard tube.

A method of producing a single layer, self-supporting paperboard tube comprising the steps of:

• providing a continuous paperboard ply defined in transverse cross-section by a relatively thick central portion disposed between first and second relatively thin longitudinal edge portions, each of the relatively thin longitudinal edge portions having a predetermined uniform width and a substantially constant thickness, and the width of the thick central portion being substantially greater than that of the relatively thin edge portions of the ply, the thin edge portions of the ply each having a first face that is coplanar with the first face of the other edge portion and a second face that is substantially co-planar with one face of the relatively thick central portion of the ply;
• applying a permanent adhesive layer to said first face of the first edge portion of the paperboard ply;
• and
• spirally winding said ply in edge overlapping relation onto a mandrel so that the second face of the second edge of the ply is overlapped onto the adhesive coated first face of the first edge portion of tile ply, thereby forming a permanently bonded, continuous paperboard tube.