Multiply containerboard for use in corrugated board
AssigneeStora Enso OYJ
InventorsIsto Heiskanen, Jukka Kankkunen
Life of this patent
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Abstract
The present invention relates to a multiply containerboard for use in corrugated board, said multiply containerboard comprising: a first outer ply, a second outer ply, and at least one intermediate ply sandwiched between the first and second outer ply, wherein said first and second outer ply comprise at least 70 wt % neutral sulfite semi chemical (NSSC) pulp based on dry weight, and wherein said intermediate ply comprises at least 30 wt % unbleached kraft pulp based on dry weight and at least one cellulose based strength enhancement agent, and wherein said intermediate ply comprises less than 30 wt % NSSC pulp based on dry weight.
Claims15
A corrugated board comprising:
- a multiply containerboard as a fluting, a liner, or both, wherein the multiply containerboard comprises:
- a first outer ply,
- a second outer ply, and
- at least one intermediate ply sandwiched between the first outer ply and the second outer ply, wherein said first outer ply and the second outer ply each comprise at least 70 wt % neutral sulfite semi chemical (NSSC) pulp based on a dry weight of the first outer ply or the second outer ply, respectively, and
- wherein said at least one intermediate ply comprises at least 30 wt % unbleached kraft pulp, based on a dry weight of the at least one intermediate ply, and at least one cellulose based strength enhancement agent, and
- wherein said at least one intermediate ply comprises less than 30 wt % NSSC pulp based on the dry weight of the at least one intermediate ply.
A method for manufacturing a corrugated board having a multiply containerboard, the method comprising the steps of:
- a) forming a first web layer from a first pulp suspension and dewatering said first web layer to obtain a first outer ply;
- b) forming a second web layer from a second pulp suspension and dewatering said second web layer to obtain an intermediate ply on the first outer ply;
- c) forming a third web layer from a third pulp suspension and dewatering said third web layer to obtain a second outer ply on the intermediate ply and thereby form a multiply containerboard,
- wherein said first pulp suspension and the third pulp suspension each comprise at least 70 wt % neutral sulfite semi chemical (NSSC) pulp based on a dry weight of the first pulp suspension or the third pulp suspension, respectively, and
- wherein said second pulp suspension comprises at least 30 wt % unbleached kraft pulp, based on a dry weight of the second pulp suspension, and at least one cellulose based strength enhancement agent, and
- wherein said second pulp suspension comprises less than 30 wt % NSSC pulp based on the dry weight based on a dry weight of the second pulp suspension;
- and,
- d) providing the multiply containerboard as a fluting, a liner, or both for a corrugated board.
Dependencies are inferred from the claim text.