Sonoco Products Company

James R Martin

John F Whitehead

George E Lennon

Wim Van De Camp

Arnold B Floyd, Jr

Troy W Johnson, Jr

Robert D Bacon, Jr

Charles D Anderson

Honor S Bonds

A concrete column forming tube and method of making same for receiving poured concrete column therein to produce a concrete column is characterized by a smooth inside coated surface in the forming tube to eliminate spiral seam lines and other undesirable characteristics on the outside surface of the formed concrete column. The tube is formed from spirally-wound plies of paper adhered together and has a centrifugally-cast epoxy resin coating sprayed onto the inside surface of the spirally-wound tube while the tube is rotating to produce a smooth inside coated surface on the forming tube.

Concrete column forming tube having a smooth inside coated surface

A single-ply wound paperboard tube is disclosed as is its forming method. The method comprises applying an adhesive to a paperboard ply having relatively thin longitudinal edges and a relatively thick central portion therebetween, then spirally winding the ply about a mandrel in edge-overlapping relation. Preferably, the thinned edges and the thick central portion of the ply share a common face, and the ply is preferably steam-conditioned to raise its temperature and its moisture content prior to the application of the adhesive.

Single-ply paperboard tube and method of forming same

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Hartsville, SC, United States of America

James R Martin