Board with improved compression strength
AssigneeStora Enso OYJ
InventorsIsto Heiskanen, Seppo Lampainen, Jukka Kankkunen
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Abstract
A corrugated fiberboard comprising cellulosic fibers, wherein said corrugated fiberboard has at least one of a geometrical tensile index in the range of from 32 to 65 Nm/g, a fracture toughness index in the range of from 4 to 24 Jm/kg, and a ring crush index in the range of from 5 to 10 Nm/g5 measured at relative humidity of 85% RH; wherein the cellulosic fibers comprises a mixture of less refined fibers having a Schopper-Riegler (SR) value in the range of 15 to 28 and microfibrillated cellulose fibers, wherein mixture comprises said microfibrillated cellulose in a range of from 1% to 5% by weight of the dry content of the cellulosic fibers.
Claims9
A corrugated fiberboard, comprising cellulosic fibers, wherein said corrugated fiberboard has at least one of a geometrical tensile index in the range of from 32 to 65 Nm/g, a fracture toughness index in the range of from 14 to 24 Jm/kg, and a ring crush index in the range of from 5 to 10 Nm/g measured at relative humidity of 85% RH;
- wherein
- the cellulosic fibers comprise a mixture of fibers having a Schopper-Riegler (SR) value in the range of 15 to 28 and microfibrillated cellulose fibers, wherein the mixture comprises said microfibrillated cellulose in a range of from 1% to 5% by weight of the dry content of the cellulosic fibers, wherein the corrugated fiberboard comprises a hydrophobic sizing additive, and wherein the corrugated fiberboard comprises a fluting and a liner.
A method of manufacturing a corrugated fiberboard comprising cellulosic fibers, wherein the corrugated fiberboard comprises a fluting and a liner, wherein the corrugated fiberboard has at least one of a geometrical tensile index in the range of from 32 to 65 Nm/g, a fracture toughness index in the range of from 14 to 24 Jm/kg, and a ring crush index in the range of from 5 to 10 Nm/g measured at relative humidity of 85% RH, and wherein the corrugated fiberboard is produced from a base pulp
- wherein
- the base pulp comprises cellulosic fibers having a Schopper-Riegler value in the range of 15 to 28,
- and wherein said method comprises the steps of
- providing a furnish comprising said base pulp;
- adding a microfibrillated cellulose solution to said furnish, wherein the content of the microfibrillated cellulose is in the range of 1% to 5% by weight of the dry content of the cellulosic fibers;
- and
- adding a hydrophobic sizing additive in a wet end process.
Dependencies are inferred from the claim text.