US 12,168,852 B2
Process and system for increasing the solids content of microfibrillated cellulose
Hans Henrik Øvrebø, Sarpsborg (NO); and Seid Ali Moosavi Far, Sarpsborg (NO)
Assigned to Borregaard AS, Sarpsborg (NO)
Appl. No. 17/311,667
Filed by Borregaard AS, Sarpsborg (NO)
PCT Filed Dec. 19, 2019, PCT No. PCT/EP2019/086200
§ 371(c)(1), (2) Date Jun. 7, 2021,
PCT Pub. No. WO2020/127658, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 18214966 (EP), filed on Dec. 20, 2018.
Prior Publication US 2023/0160145 A1, May 25, 2023
Int. Cl. D21H 11/18 (2006.01); D21C 9/18 (2006.01)
CPC D21H 11/18 (2013.01) [D21C 9/18 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A process for at least partial removal of solvent from a suspension comprising microfibrillated cellulose, wherein solids content of the microfibrillated cellulose increases, during said at least partial removal of solvent, from a first solids content of microfibrillated cellulose in a range of from 0.1% weight by weight (“w/w”) to 6% w/w up to a second solids content of microfibrillated cellulose of 5% w/w or above, wherein the second solids content is higher than the first solids content, wherein said process comprises at least the following steps:
(i) providing microfibrillated cellulose in a solvent wherein the solids content of microfibrillated cellulose is in a range of 0.1% weight by weight (“w/w”)−6% w/w; and
(ii) applying said microfibrillated cellulose from step (i) onto an at least partly apertured substrate as a layer and subjecting the microfibrillated cellulose, while applied onto said apertured substrate, to a vacuum that is a pressure that is reduced vis-a-vis a respective ambient pressure, wherein the layer of microfibrillated cellulose is applied to a top side of the at least partly apertured substrate and the vacuum is applied to the layer from underneath the at least partly apertured substrate, and
(iii) rotating at least one segment of the at least partly apertured substrate at least once by 360 degrees, thereby removing microfibrillated cellulose of an increased solids content from the apertured substrate,
wherein a thickness of the layer of microfibrillated cellulose, after step (ii), is in a range of from 1 mm to 200 mm.