	US 11,732,411 B2
	Paper filler composition
John Claude Husband, St. Austell (GB); Per Svending, Kungalv (SE); David Robert Skuse, Truro (GB); and Tafadzwa Motsi, Par (GB)
Assigned to FiberLean Technologies Limited, Par (GB)
Filed by FiberLean Technologies Limited, Par (GB)
Filed on Oct. 1, 2021, as Appl. No. 17/492,036.
Application 17/492,036 is a continuation of application No. 16/117,582, filed on Aug. 30, 2018, granted, now 11,162,219.
Application 16/117,582 is a continuation of application No. 14/843,516, filed on Sep. 2, 2015, granted, now 10,100,464.
Application 14/843,516 is a continuation of application No. 12/994,356, granted, now 9,127,405, issued on Sep. 8, 2015, previously published as PCT/GB2010/000982, filed on May 17, 2010.
Claims priority of application No. 0908401 (GB), filed on May 15, 2009.
Prior Publication US 2022/0018068 A1, Jan. 20, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. D21C 9/00 (2006.01); D21H 11/18 (2006.01); D21H 11/20 (2006.01); D21H 15/02 (2006.01); D21D 1/20 (2006.01); D21H 19/38 (2006.01); D21B 1/32 (2006.01); D21B 1/30 (2006.01); D21H 11/04 (2006.01)

CPC D21C 9/007 (2013.01) [D21B 1/30 (2013.01); D21B 1/32 (2013.01); D21C 9/001 (2013.01); D21D 1/20 (2013.01); D21H 5/1236 (2013.01); D21H 11/04 (2013.01); D21H 11/18 (2013.01); D21H 11/20 (2013.01); D21H 19/38 (2013.01); D21H 19/385 (2013.01)]

22 Claims

1. A method for preparing an aqueous suspension comprising microfibrillated cellulose, the method comprising a step of microfibrillating a fibrous substrate comprising cellulose in an aqueous environment by grinding in the presence of a grinding medium, which is to be removed after completion of grinding and wherein the grinding is carried out in the absence of added grindable inorganic particulate material, wherein the microfibrillated cellulose has a fibre steepness of from about 20 to about 50 and the grinding is performed in a tower mill or a screened grinder, and wherein the grinding medium is present in an amount of at least about 10% by volume of the aqueous environment, wherein the fibrous substrate comprises cellulose having a Canadian Standard freeness equal to or less than 450 cm³and wherein the fibrous substrate comprising cellulose is a recycled pulp, or a papermill broke, or a papermill waste stream, or waste from a papermill, or a combination thereof.