Sonoco Development Incorporated

Sonoco Products Company

Yiming Wang

Terry D Gerhardt

Lawrence E Renck

David E Rhodes

Glenda J Cahill

Yanping Qiu

Wim Van De Camp

John F Auten

Patrick Trevanion

Richard Skiff

Monica McCarthy

Charles G Johnson

Winding cores for elastically stretched or shrinkable materials are designed to significantly reduce the amount of roll strain energy developed during winding. This is accomplished by building into the core an energy-absorbing zone that can be collapsed by a substantial amount and in a relatively controlled fashion over a substantial period of time under the influence of a continued radially inward pressure exerted by the roll of wound material. The energy-absorbing zone is formed by one or more collapsible layers having repeated atomic regions projecting out of a plane of the sheet and each defining a plurality of normal vectors in different sub-regions of the atomic region, wherein the normal vectors, when projected onto the two-dimensional plane of the sheet, are in a plurality of different directions in the plane.

Winding cores for material rolls having high roll strain energy, and method for making same

Composite paperboard container constructions, providing optimized axial crush strength, and related properties, are formed of one, two, or three structural paperboard plies that are arranged to form a layered body wall having a cross-section of the construction in the ordered structure, high compression strength paperboard layer&bsol;low compression strength paperboard layer&bsol;high compression strength paperboard layer. Preferably, the container body is formed of one or two structural plies and at least one structural ply is a multiple layer paperboard having both high compression strength and low compression strength paperboard layers.

Composite paperboard containers of optimized axial strength construction

The invention provides multi-grade spirally wound paperboard tubes of enhanced flat crush strength construction. The multi-grade spirally wound paperboard tubes of the invention include a plurality of structural paperboard plies having at least two predetermined densities including a lower density and a higher density wherein the higher density is at least about 3% greater than the lower density. The cylindrical bodywall is defined in radial cross section by at least one centrally located paperboard layer disposed between at least one radially inwardly located structural paperboard layer and at least one radially outwardly located structural paperboard layer. The centrally located paperboard layer is formed from the higher density paperboard and the inwardly and outwardly located structural paperboard layers are formed from lower density paperboard.

Enhanced crush strength construction multi-grade paperboard tubes

Growing community of inventors

Middleton, WI, United States of America

Yiming Wang