US 12,331,463 B2
Multi-ply paper products having a first stratified base sheet and a second stratified base sheet
Peter G. Anderson, De Pere, WI (US); Frank D. Harper, Neenah, WI (US); and Nathan E. Capps, Appleton, WI (US)
Assigned to GPCP IP HOLDINGS LLC
Filed by GPCP IP Holdings LLC, Atlanta, GA (US)
Filed on Aug. 29, 2023, as Appl. No. 18/457,432.
Application 17/321,705 is a division of application No. 16/257,349, filed on Jan. 25, 2019, granted, now 11,035,078, issued on Jun. 15, 2021.
Application 18/457,432 is a continuation of application No. 17/321,705, filed on May 17, 2021, granted, now 11,781,270.
Claims priority of provisional application 62/639,559, filed on Mar. 7, 2018.
Prior Publication US 2023/0407566 A1, Dec. 21, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. D21H 21/20 (2006.01); D21F 3/02 (2006.01); D21F 11/00 (2006.01); D21F 11/14 (2006.01); D21H 27/00 (2006.01)
CPC D21F 11/145 (2013.01) [D21F 3/02 (2013.01); D21F 11/006 (2013.01); D21H 21/20 (2013.01); D21H 27/005 (2013.01)] 61 Claims
OG exemplary drawing
 
1. A multi-ply paper product comprising:
a first ply including a first stratified base sheet, the first stratified base sheet having at least two layers, one of the at least two layers being an inner layer, and another of the at least two layers being an outer layer comprising papermaking fibers, at least about eighty percent of the papermaking fibers in the outer layer being softwood fibers, the softwood fibers of the outer layer having (i) a weight-weighted average fiber length between about two and seven tenths millimeters and about three millimeters and (ii) a coarseness of about sixteen milligrams per one hundred meters or lower, the outer layer including a wet strength resin and the inner layer being substantially free of the wet strength resin; and
a second ply including a second stratified base sheet, the second stratified base sheet having at least two layers, one of the at least two layers being an inner layer, and another of the at least two layers being an outer layer comprising papermaking fibers, at least about eighty percent of the papermaking fibers in the outer layer being softwood fibers, the softwood fibers of the outer layer having (i) a weight-weighted average fiber length between about two and seven tenths millimeters and about three millimeters and (ii) a coarseness of about sixteen milligrams per one hundred meters or lower, the outer layer including a wet strength resin and the inner layer being substantially free of the wet strength resin,
wherein the first ply and the second ply are arranged such that the inner layer of the first ply is adjacent to the inner layer of the second ply and the inner layer of the first ply is attached to the inner layer of the second ply.