Sonoco Development Incorporated

Mike Drummond

Alan D Williams

Ray Adams

Gerald Gainey

A tubular composite container includes a paperboard body ply wrapped into a tubular shape, and a polymer film liner ply wrapped into a tubular shape and adhered to the inner surface of the body ply. The liner ply has a circumferential length when unwrapped and flat that is less than that of the body ply so that the liner ply is substantially uncompressed circumferentially. A strip of polymer film liner material is wrapped onto a mandrel and overlapping edge portions of the liner strip are heat sealed together by first preheating the liner strip to a temperature below the sealing temperature of the heat seal material on the edge portions of the liner strip, and then further heating the overlap region of the liner strip to at least the sealing temperature to cause heat sealing of the edge portions. A paperboard strip is coated on an inner surface with adhesive and is then wrapped about the liner and adhered thereto. The outer surface of the liner strip is surface treated by corona discharge or flame treatment prior to being wrapped on the mandrel to improve adhesion to the paperboard, and the liner strip tension is maintained less than about 1 pound per inch of width to prevent liner stretching as the liner strip is advanced to and wrapped about the mandrel. The preheating of the liner strip is performed by a heated section of the mandrel over which the liner strip passes. The overlap region is locally heated by an infrared heater.

Tubular composite containers having unsupported film liners and methods and apparatus for making same

A tubular composite container includes a paperboard body ply wrapped into a tubular shape, and a polymer film liner ply wrapped into a tubular shape and adhered to the inner surface of the body ply. The liner strip includes a heat seal layer facing the body ply that is formed of a heat-sealable material, and the inner surface of the liner ply that contacts the mandrel is formed of a hard polymer material whose melting temperature is substantially higher than the sealing temperature at which the heat-sealable material softens and seals to itself. One edge portion of the liner ply is folded inward toward the mandrel, the liner ply is wrapped onto the mandrel such that the folded edge portion overlaps an opposite edge portion of the liner ply, and the heat seal layer on the folded edge portion is heat sealed to the opposite edge portion.

Growing community of inventors

Laurinburg, NC, United States of America

Mike Drummond