Sequential application of layers, comprising nanocellulose, onto the surface of paper or paperboard substrates

Abstract

Methods of sequentially applying nanocellulose(s) onto the surface of paper and paperboard substrates, paper or paperboard prepared using said methods, and systems for producing paper or paperboard having sequentially applied nanocellulose(s).

1 - 164 . canceled 
     
     
         165 . A method of sequentially applying a plurality of nanocellulose-containing compositions onto the surface of a paper or paperboard substrate, the method comprising:
 applying a first layer of a first nanocellulose-containing composition to the top of a consolidating base sheet after the consolidating base sheet leaves a headbox of a paper machine, thereby forming a consolidating substrate; and   applying a second layer of a second nanocellulose-containing composition to the top of the consolidating substrate,   wherein the first nanocellulose-containing composition comprises first nanocellulose having a first Fines B% by fibre analyzer, the second nanocellulose-containing composition comprises second nanocellulose having a second Fines B% by fibre analyzer, and the first Fines B% by fibre analyzer is lower than the second Fines B% by fibre analyzer.   
     
     
         166 . The method according to  claim 165 , wherein:
 the first layer of the first nanocellulose-containing composition is applied using a first slotted applicator; and   the second layer of the second nanocellulose-containing composition is applied using a second slotted applicator.   
     
     
         167 . The method according to  claim 166 , wherein the first slotted applicator is a slot coater. 
     
     
         168 . The method of according to  claim 167 , wherein the second slotted applicator is a slot coater. 
     
     
         169 . The method according to  claim 165 , wherein the first layer of the first nanocellulose-containing composition, and the second layer of the second nanocellulose-containing composition are both applied via spraying. 
     
     
         170 . The method according to  claim 165 , wherein:
 the first layer of the first nanocellulose-containing composition is applied using a slotted applicator; and   the second layer of the second nanocellulose-containing composition is applied via spraying.   
     
     
         171 . The method according to  claim 170 , wherein the slotted applicator is a slot coater. 
     
     
         172 . The method according to  claim 165 , wherein applying the second layer of the second nanocellulose-containing composition causes the consolidating substrate to have a heptane vapor transmission rate of about 0 g m −2  day −1  to about 2,500 g m −2  day −1 . 
     
     
         173 . The method according to  claim 165 , wherein the first nanocellulose-containing composition comprises nanofibrillated cellulose, microfibrillated cellulose, or a combination thereof. 
     
     
         174 . The method according to  claim 165 , wherein the first nanocellulose-containing composition comprises nanocellulose in a range of about 0.2 wt % to about 6 wt % based on the total weight of the first nanocellulose-containing composition. 
     
     
         175 . The method according to  claim 165 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose containing composition comprises one or more inorganic particulate material. 
     
     
         176 . The method according to  claim 175 , wherein:
 the first nanocellulose-containing composition comprises the one or more inorganic particulate material; and   the second nanocellulose-containing composition is free of inorganic particulate material.   
     
     
         177 . The method according to  claim 175 , wherein the one or more inorganic particulate material comprise bentonite, alkaline earth metal carbonate, alkaline earth metal sulphate, dolomite, gypsum, hydrous kandite clay, anhydrous calcined kandite clay, talc, mica, perlite, diatomaceous earth, magnesium hydroxide, aluminum trihydrate, or a combination thereof. 
     
     
         178 . The method according to  claim 165 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose containing composition comprises one or more starches. 
     
     
         179 . The method according to  claim 165 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose containing composition comprises one or more sizing agents. 
     
     
         180 . The method according to  claim 165 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose containing composition comprises one or more polyacrylamides. 
     
     
         181 . The method according to  claim 165 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose containing composition comprises one or more copolymers. 
     
     
         182 . The method according to  claim 165 , wherein the mean size of the first nanocellulose and or second nanocellulose is from 5 μm to 500 μm. 
     
     
         183 . A paper or paperboard prepared using the method according to  claim 165 . 
     
     
         184 . A method of manufacturing a multi-ply paper or paperboard product, the method comprising:
 (a) providing a consolidating base sheet of pulp following a headbox of a paper or paperboard machine;   (b) applying a first layer of a first nanocellulose-containing composition to the top of the consolidating base sheet to form a first consolidating substrate;   (c) applying a second layer of a second nanocellulose-containing composition to the top of the first consolidating substrate to form a second consolidating substrate; and   (c) dewatering the second consolidating substrate to produce the multi-ply paper or paperboard product,   
       wherein:
 (i) the first layer of the first nanocellulose-containing composition is applied to the consolidating base sheet in an amount ranging from about 0.1 g/m 2  to about 20 g/m 2 ; 
 (ii) the second layer of the second nanocellulose-containing composition is applied to the first consolidating substrate in an amount ranging from about 1 g/m 2  to about 20 g/m 2 ; and 
 (iii) wherein the first nanocellulose-containing composition comprises first nanocellulose having a first Fines B% by fibre analyzer, the second nanocellulose-containing composition comprises second nanocellulose having a second Fines B% by fibre analyzer, and the first Fines B% by fibre analyzer is lower than the second Fines B% by fibre analyzer. 
 
     
     
         185 . The method according to  claim 184 , wherein the pulp comprises recycled pulp, papermill broke, paper streams rich in mineral fillers, cellulosic materials from a papermill, chemical pulp, thermomechanical pulp, chemi-thermomechanical pulp, mechanical pulp, or a combination thereof. 
     
     
         186 . The method according to  claim 184 , wherein:
 the first layer of the first nanocellulose-containing composition is applied using a first slotted applicator; and   the second layer of the second nanocellulose-containing composition is applied using a second slotted applicator.   
     
     
         187 . The method according to  claim 186 , wherein the first slotted applicator is a slot coater. 
     
     
         188 . The method of according to  claim 186 , wherein the second slotted applicator is a slot coater. 
     
     
         189 . The method according to  claim 184 , wherein the first layer of the first nanocellulose-containing composition, and the second layer of the second nanocellulose containing composition are both applied via spraying. 
     
     
         190 . The method according to  claim 184 , wherein:
 the first layer of the first nanocellulose-containing composition is applied using a slotted applicator; and   the second layer of the second nanocellulose-containing composition is applied via spraying.   
     
     
         191 . The method according to  claim 190 , wherein the slotted applicator is a slot coater. 
     
     
         192 . The method according  claim 184 , wherein applying the second layer of the second nanocellulose-containing composition causes the second consolidating substrate to have a heptane vapor transmission rate of about 0 g m −2  day −1  to about 2,500 g m −2  day −1 . 
     
     
         193 . The method according to  claim 184 , wherein the first nanocellulose-containing composition comprises first nanocellulose produced from hardwood pulp, softwood pulp, wheat straw pulp, bamboo, bagasse, virgin fiber, chemical pulp, chemithermomechanical pulp, mechanical pulp, thermomechanical pulp, kraft pulp, bleached long fibre kraft pulp, eucalyptus pulp, spruce pulp, pine pulp, beech pulp, hemp pulp, acacia cotton pulp, recycled pulp, papermill broke, paper stream, paper steam rich in mineral fillers, or a combination thereof. 
     
     
         194 . The method according  claim 184 , wherein the first nanocellulose-containing composition comprises nanofibrillated cellulose, microfibrillated cellulose, or a combination thereof. 
     
     
         195 . The method according to  claim 184 , wherein the first nanocellulose-containing composition comprises first nanocellulose in a range of about 0.2 wt % to about 6 wt % based on the total weight of the first nanocellulose-containing composition. 
     
     
         196 . The method according to  claim 184 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose-containing composition comprises one or more inorganic particulate material. 
     
     
         197 . The method according to  claim 196 , wherein:
 the first nanocellulose-containing composition comprises the one or more inorganic particulate material; and   the second nanocellulose-containing composition is free of inorganic particulate material.   
     
     
         198 . The method according to  claim 196 , wherein the one or more inorganic particulate material comprises bentonite, alkaline earth metal carbonate, alkaline earth metal sulphate, dolomite, gypsum, hydrous kandite clay, anhydrous calcined kandite clay, talc, mica, perlite, diatomaceous earth, magnesium hydroxide, aluminum trihydrate, or a combination thereof. 
     
     
         199 . The method according to  claim 184 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose containing composition comprises one or more starches. 
     
     
         200 . The method according to  claim 184 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose-containing composition comprises one or more sizing agents. 
     
     
         201 . The method according to  claim 184 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose-containing composition comprises one or more polyacrylamides. 
     
     
         202 . The method according to  claim 184 , wherein at least one of the first nanocellulose-containing composition and the second-nanocellulose containing composition comprises one or more copolymers. 
     
     
         203 . The method according to  claim 184 , further comprising applying one or more additional layers to the top of the dewatered second consolidating substrate, wherein the one or more additional layers optionally comprise one or more of a barrier layer, a wax layer, and a silicon layer. 
     
     
         204 . The method according to  claim 184 , further comprising applying an additional layer to the top of the dewatered second consolidating substrate, wherein the additional layer consists essentially of inorganic particulate material and microfibrillated cellulose. 
     
     
         205 . The method according to  claim 204 , wherein the inorganic particulate material comprises calcium carbonate, ground calcium carbonate, precipitated calcium carbonate, magnesium carbonate, dolomite, gypsum, an anhydrous kandite clay, kaolin, perlite, bentonite, diatomaceous earth, wollastonite, talc, magnesium hydroxide, titanium dioxide, or aluminium trihydrate, or a combination thereof. 
     
     
         206 . The method according to  claim 184 , wherein the mean size of the first nanocellulose and/or the second nanocellulose is from 5 μm to 500 μm. 
     
     
         207 . A paper or paperboard manufactured according to  claim 184 . 
     
     
         208 . The paper or paperboard according to  claim 207 , wherein the paper or paperboard comprises a base layer having a grammage ranging from about 25 g/m 2  to about 500 g/m 2   
     
     
         209 . A system for producing a paper or paperboard, the system comprising:
 a headbox ( 102 ) configured to output a consolidating base sheet ( 104 );   a first means for applying a first layer of a first nanocellulose-containing composition to the top of the consolidating base sheet to form a first consolidating substrate;   a second means for applying a second layer of a second nanocellulose-containing composition to the top of the first consolidating substrate to form a second consolidating substrate; and   a couch roll ( 128 ) configured to receive the second consolidating substrate,   wherein the first nanocellulose-containing composition comprises first nanocellulose having a first Fines B% by fibre analyzer, the second nanocellulose-containing composition comprises second nanocellulose having a second Fines B% by fibre analyzer, and the first Fines B% by fibre analyzer is lower than the second Fines B% by fibre analyzer.   
     
     
         210 . The system according to  claim 209 , wherein:
 the first means is a first slotted applicator; and   the second means is a second slotted applicator.   
     
     
         211 . The system according to  claim 210 , wherein the first slotted applicator and/or the second slotted applicator is a slot coater. 
     
     
         212 .
 the first means is a first spray boom ( 114   a ); and   the second means is a second spray boom ( 114   b ).   
     
     
         213 . The system according to  claim 209 , wherein:
 the first means is a slotted applicator ( 110 ); and   the second means is a spray boom ( 114 ).   
     
     
         214 . The system according to  claim 213 , wherein the slotted applicator is a slot coater. 
     
     
         215 . The system according to  claim 209 , wherein the second consolidating substrate has a heptane vapor transmission rate of about 0 g m −2  day −1  to about 2,500 g m −2  day −1 . 
     
     
         216 . The system according to  claim 209 , wherein the first nanocellulose-containing composition comprises at least about 0.2 wt % first nanocellulose based on the total weight of the first nanocellulose-containing composition. 
     
     
         217 . The system according to  claim 209 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose-containing composition comprises one or more inorganic particulate material. 
     
     
         218 . The system according to  claim 209 , wherein:
 the first nanocellulose-containing composition comprises the one or more inorganic particulate material; and   the second nanocellulose-containing composition is free of inorganic particulate material.   
     
     
         219 . The system according to  claim 217 , wherein the one or more inorganic particulate material comprises bentonite, alkaline earth metal carbonate, alkaline earth metal sulphate, dolomite, gypsum, hydrous kandite clay, anhydrous calcined kandite clay, talc, mica, perlite, diatomaceous earth, magnesium hydroxide, aluminum trihydrate, or a combination thereof. 
     
     
         220 . The system according to  claim 209 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose containing composition comprises one or more starches. 
     
     
         221 . The system according to  claim 209 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose-containing composition comprises one or more sizing agents. 
     
     
         222 . The system according to  claim 209 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose-containing composition comprises one or more polyacrylamides. 
     
     
         223 . The system according to  claim 209 , wherein at least one of the first nanocellulose-containing composition and the second nanocellulose containing composition comprises one or more copolymers. 
     
     
         224 . The system according to  claim 209 , wherein the mean size of the first nanocellulose and or second nanocellulose is from 5 μm to 500 μm. 
     
     
         225 . The system according to  claim 209 , wherein the nanocellulose is microfibrillated cellulose. 
     
     
         226 . The system according to  claim 225 , wherein the microfibrillated cellulose has a fibre length (Lc(w) ISO) of less than about 0.7 mm less than about 0.6 mm, less than about 0.5 mm, less than about 0.4 mm, less than about 0.3 mm, less than about 0.2 mm, or less than about 0.1 mm as measured by a fiber image analyzer. 
     
     
         227 . The method according to  claim 165 , wherein the nanocellulose is microfibrillated cellulose. 
     
     
         228 . The method according to  claim 227 , wherein the microfibrillated cellulose has a fibre length (Lc(w) ISO) of less than about 0.7 mm less than about 0.6 mm, less than about 0.5 mm, less than about 0.4 mm, less than about 0.3 mm, less than about 0.2 mm, or less than about 0.1 mm as measured by a fiber image analyzer. 
     
     
         229 . The method according to  claim 184 , wherein the nanocellulose is microfibrillated cellulose. 
     
     
         230 . The method according to  claim 229 , wherein the microfibrillated cellulose has a fibre length (Lc(w) ISO) of less than about 0.7 mm less than about 0.6 mm, less than about 0.5 mm, less than about 0.4 mm, less than about 0.3 mm, less than about 0.2 mm, or less than about 0.1 mm as measured by a fiber image analyzer.