US 12,234,605 B2
Light weight linerboard for corrugated board
Seppo Lampainen, Lahti (FI); Janne Myllykangas, Kaarenkylä (FI); Petri Paakkanen, Vantaa (FI); Atso Laakso, Varkaus (FI); and Kaj Backfolk, Lappeenranta (FI)
Assigned to Stora Enso OYJ, Helsinki (FI)
Appl. No. 17/757,602
Filed by Stora Enso OYJ, Helsinki (FI)
PCT Filed Dec. 11, 2020, PCT No. PCT/IB2020/061801
§ 371(c)(1), (2) Date Jun. 17, 2022,
PCT Pub. No. WO2021/124040, PCT Pub. Date Jun. 24, 2021.
Claims priority of application No. 1951507-1 (SE), filed on Dec. 19, 2019.
Prior Publication US 2023/0019391 A1, Jan. 19, 2023
Int. Cl. D21F 11/12 (2006.01); B32B 3/28 (2006.01); B32B 7/12 (2006.01); B32B 29/00 (2006.01); B32B 29/08 (2006.01); D21F 1/02 (2006.01); D21F 3/02 (2006.01); D21F 11/04 (2006.01)
CPC D21F 11/12 (2013.01) [B32B 3/28 (2013.01); B32B 7/12 (2013.01); B32B 29/005 (2013.01); B32B 29/08 (2013.01); D21F 1/02 (2013.01); D21F 3/0218 (2013.01); D21F 11/04 (2013.01); B32B 2250/26 (2013.01); B32B 2262/062 (2013.01); B32B 2307/538 (2013.01); B32B 2307/718 (2013.01); B32B 2307/72 (2013.01); B32B 2307/75 (2013.01)] 22 Claims
 
1. A method to produce a linerboard, which method comprises the steps of:
forming a top ply, comprising a first layer, by supplying a first furnish onto a first forming fabric of a paperboard machine, wherein the first furnish is ejected from a first headbox,
forming a two-layered ply, comprising a second layer and a third layer, by supplying a second and a third furnish onto a second forming fabric, wherein the second and third furnish is ejected from a multi-layer headbox,
couching said top ply and said two-layered ply together so that said second layer is arranged between said first layer and said third layer, thereby forming a multi-ply web,
dewatering and drying said multi-ply web, and,
calendering of the multi-ply web in a calender section comprising at least one nip formed between a heated calender roll and a backing roll or a belt, wherein the nip provides a highest line-load in the calender section and wherein said highest line-load is less than 50 kN/m,
wherein the first and third furnish exhibit a first Schopper Riegler value (SR-value) according to ISO 5267-1 of between 22-80 and the second furnish exhibits a second Schopper Riegler value (SR-value) according to ISO 5267-1 of less than 30, and wherein the first SR-value is at least 2 units higher than the second SR-value.