GARNWICKELHÜLSEN

摘要

A multi-grade spirally wound paperboard winding core of enhanced resistance to inside diameter deformation includes a plurality of structural paperboard layers having at least two predetermined densities including a lower density and a higher density wherein the lower density is at least about 3% less than the higher 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 lower density paperboard and the inwardly and outwardly located structural paperboard layer are formed from higher density paperboard.