	US 11,926,128 B2
	Light weight linerboard for corrugated board
Seppo Lampainen, Lahti (FI); Frank Peng, Hammarö (SE); Atso Laakso, Varkaus (FI); and Ari-Pekka Määttänen, Espoo (FI)
Assigned to Stora Enso OYJ, Helsinki (FI)
Appl. No. 17/256,058
Filed by Stora Enso OYJ, Helsinki (FI)
PCT Filed Jun. 25, 2019, PCT No. PCT/IB2019/055349 § 371(c)(1), (2) Date Dec. 24, 2020, PCT Pub. No. WO2020/003128, PCT Pub. Date Jan. 2, 2020.
Claims priority of application No. 1850798-8 (SE), filed on Jun. 27, 2018.
Prior Publication US 2021/0268783 A1, Sep. 2, 2021
Int. Cl. B32B 29/08 (2006.01); B32B 7/05 (2019.01); B32B 29/00 (2006.01); D21H 11/02 (2006.01); D21H 11/04 (2006.01); D21H 11/08 (2006.01); D21H 11/10 (2006.01); D21H 11/18 (2006.01); D21H 17/28 (2006.01); D21H 17/42 (2006.01); D21H 17/44 (2006.01); D21H 27/30 (2006.01); D21H 27/40 (2006.01)

CPC B32B 29/08 (2013.01) [B32B 7/05 (2019.01); B32B 29/005 (2013.01); D21H 1/02 (2013.01); D21H 11/02 (2013.01); D21H 11/04 (2013.01); D21H 11/08 (2013.01); D21H 11/10 (2013.01); D21H 11/18 (2013.01); D21H 17/28 (2013.01); D21H 17/42 (2013.01); D21H 17/44 (2013.01); D21H 27/40 (2013.01); B32B 2250/26 (2013.01); B32B 2307/546 (2013.01); B32B 2307/718 (2013.01); B32B 2307/72 (2013.01)]

10 Claims

1. A corrugated board comprising:

a corrugated medium, and

a linerboard, wherein the linerboard has a grammage between 80 to 150 gsm and wherein the linerboard comprises:

a first ply, wherein said first ply comprises 20-80 wt % CTMP from wood fibers and 80-20 wt % chemical pulp, all percentages calculated on a total fiber weight of said first ply, and

wherein the CTMP exhibits a bulk according to ISO 534:2005 of at least 2.5 cm³/g,

wherein the CTMP has a freeness according to ISO 5267-2 of at least 300 ml, and,

wherein said first ply has a density according to ISO 534 of below 690 kg/m³,

a second ply, wherein the second ply comprises 100 wt % kraft pulp calculated on a total fiber weight of said second ply,

a third ply, wherein the third ply comprises 30-70 wt % CTMP and 30-70 wt % kraft pulp calculated on a total fiber weight of said third ply, and

wherein said second ply forms a top ply, said first ply forms a middle ply, and said third ply forms a back ply.