IP Library Granted Patent US 9,487,916
Granted Patent B2
US 9,487,916 · App. 13/919,167 · Granted Nov 8, 2016

Method of improving dewatering efficiency, increasing sheet wet web strength, increasing sheet wet strength and enhancing filler retention in papermaking

Inventors: Yulin Zhao (Shanghai, CN); Jun Li (Hubei, CN); Qing Long Rao (Shanghai, CN); Stephen Ashton (Saint Charles, IL); Weiguo Cheng (Naperville, IL); Aleksandar Todorovic (Helsinki, FI); Alan Smith (Sandbach, GB)
Assignee: NALCO Company
D21H17/74D21C3/02D21C5/00D21C5/025D21H17/675D21H17/69D21H21/10D21H21/20Y02W30/648
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Quick Facts
Patent No.
US 9,487,916
App. No.
13/919,167
Granted
Nov 8, 2016
Kind
B2
Abstract

The invention provides a method of improving dewatering efficiency, increasing sheet wet web strength, increasing sheet wet strength and enhancing filler retention in a papermaking process The method improves the efficiency of drainage aids or wet web strength aids or wet strength aid by coating at least some of the filler particles with a material that prevents the filler materials form adhering to a those additives. The drainage additive or wet web strength additive or wet strength aid holds the cellulose fibers together tightly and is not wasted on the filler particles.

Claims (44)

1. A method of papermaking, the method comprising the steps of:

treating filler particles in a container with a composition of matter in the absence of cellulose fiber stock by

contacting the filler particles with a rotating admixing apparatus having a distribution head rotating at a rotational speed of 1800 to 3000 rpm while the filler particles are in the container,

combining the treated filler particles with the cellulose fiber stock thereby forming a combination,

treating the combination with at least one wet strength aid or wet web strength additive or drainage additive, and

forming a paper mat from the combination,

wherein the filler particles are selected from precipitated calcium carbonate, ground calcium carbonate, and any combination thereof, the cellulose fiber stock comprises a plurality of cellulose fibers and water, and the composition of matter enhances the performance of the wet strength aid or wet web strength additive or drainage additive in the paper mat,

the distribution head is rotated by a drive, the distribution head is arranged in the container containing a slurry of the filler particles, and the distribution head is associated with a rotational plane, and the distribution head has, along a circumference thereof, which surrounds a rotational axis, distributed outlets from which the composition is passed into the container bearing a slurry of filler particles and mixing blades, characterized in that the outlets are formed as openings and the mixing blades are formed as strips extending transverse to the rotational plane and having a length equal at least half of an inner diameter of the container;

and the composition is dispersed by the distribution head to the filler particles.

2. The method of claim 1 in which the paper mat is formed by removing some of the water from the combination.

3. The method of claim 1 in which at least some of the calcium carbonate is in one form selected from the list consisting of: undispersed calcium carbonate, dispersed slurry calcium carbonate, chalk, and any combination thereof.

4. The method of claim 1 in which at least a portion of the calcium carbonate is in a dispersed slurry calcium carbonate form, the dispersed slurry calcium carbonate further comprising at least one item selected from: polyacrylic acid polymer dispersants, sodium polyphosphate dispersants, Kaolin clay slurry, and any combination thereof.

5. The method of claim 1 in which the blend of filler particles is 50% ground calcium carbonate and 50% precipitated calcium carbonate.

6. The method of claim 1 in which the composition of matter is a coagulant.

7. The method of claim 1 in which the composition of matter is a coagulant selected from the list consisting of: inorganic coagulants, organic coagulants, condensation polymerization coagulants, and any combination thereof.

8. The method of claim 1 in which the composition of matter is a coagulant having a molecular weight range of between 200 and 1,000,000.

9. The method of claim 1 in which the composition of matter is a coagulant selected from the list consisting of: alum, sodium aluminate, polyaluminum chlorides, aluminum chlorohydroxide, aluminum hydroxide chloride, polyaluminum hydroxychloride, sulfated polyaluminum chlorides, polyaluminum silica sulfate, ferric sulfate, ferric chloride, epichlorohydrin-dimethylamine (EPI-DMA), EPI-DMA ammonia crosslinked polymers, polymers of ethylene dichloride and ammonia, polymers of ethylene dichloride, polymers of dimethylamine, condensation polymers of multifunctional diethylenetriamine, condensation polymers of multifunctional tetraethylenepentamine, condensation polymers of multifunctional hexamethylenediamine condensation polymers of multifunctional ethylenedichloride, melamine polymers, formaldehyde resin polymers, cationically charged vinyl addition polymers, and any combination thereof.

10. The method of claim 1 in which the composition of matter is an AcAm/DADMAC copolymer.

11. The method of claim 1 in which the drainage additive or wet web strength additive or wet strength aid is one selected from the list of: glyoxylated Acrylamide/DADMAC copolymer, poly-vinylamine, poly-vinylamide, poly-diallylamine, and any combination thereof.

12. The method of claim 1 in which the ratio of drainage additive or wet web strength additive or wet strength aid relative to the solid portion of the paper mat is 0.3 to 5 kg of strength additive per ton of paper mat.

13. The method of claim 1 in which at least some of the filler particles are GCC.

14. The method of claim 1 in which none of the filler particles are PCC.

15. The method of claim 1 in which the paper mat has a solid portion and the filler particles in the paper mat comprise more than 50% of the combined mass of the solid portion of the paper mat.

16. The method of claim 1 in which the drainage additive or wet web strength additive or wet strength aid and the composition of matter carry the same charge.

17. The method of claim 1 in which the blend of filler particles further comprises one item selected from the list consisting of: organic pigment, inorganic pigment, clay, talc, titanium dioxide, alumina trihydrate, barium sulfate, magnesium hydroxide, and any combination thereof.

18. A method of papermaking comprising the use of filler, the method comprising the steps of:

treating filler particles in a container with a composition of matter in the absence of cellulose fiber stock by

contacting the filler particles with a rotating admixing apparatus while the filler particles are in the container,

combining the treated filler particles with the cellulose fiber stock thereby forming a combination,

treating the combination with at least one dry strength aid, and

forming a paper mat from the combination,

wherein at least 10% of the filler particles are in a dispersed slurry calcium carbonate form,

the cellulose fiber stock comprises a plurality of cellulose fibers and water, and

the composition of matter enhances the performance of the dry strength aid in the paper mat

the rotating admixing apparatus having a distribution head, the distribution head rotated by a drive at a rotational speed of 1800 to 3000 rpm, the distribution head is arranged in the container containing a slurry of the filler particles, and the distribution head is associated with a rotational plane, and the distribution head has, along a circumference thereof, which surrounds a rotational axis, distributed outlets from which the composition is passed into the container bearing a slurry of filler particles and mixing blades, characterized in that the outlets are formed as openings and the mixing blades are formed as strips extending transverse to the rotational plane and having a length equal at least half of an inner diameter of the container;

and the composition is dispersed by the distribution head to the filler particles.

19. A method of increasing the interactions between a drainage additive or wet web strength additive or wet strength aid and cellulose fibers mixed with filler particles, the method comprising the steps of:

pre-treating filler particles in a container with a composition of matter in the absence of cellulose fiber stock, the composition delivered by a rotating admixing apparatus,

combining the pre-treated filler particles with cellulose fibers to form a combination, and

treating the combination with at least one drainage additive or wet web strength additive or wet strength aid,

wherein the filler particles are selected from the list consisting of precipitated calcium carbonate, ground calcium carbonate, and any combination thereof, and

the composition of matter inhibits the drainage additive or the wet web strength additive or wet strength aid from adhering to the filler particles,

the rotating admixing apparatus having a distribution head, the distribution head rotated by a drive at a rotational speed of 1800 to 3000 rpm, the distribution head is arranged in the container containing a slurry of the filler particles, and the distribution head is associated with a rotational plane, and the distribution head has, along a circumference thereof, which surrounds a rotational axis, distributed outlets from which the composition is passed into the container bearing a slurry of filler particles and mixing blades, characterized in that the outlets are formed as openings and the mixing blades are formed as strips extending transverse to the rotational plane and having a length equal at least half of an inner diameter of the container;

and the composition is dispersed by the distribution head to the filler particles.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 28, 2017
From: NALCO COMPANY LLC
To: ECOLAB USA INC.
Reel/Frame 043133/0876 →
CHANGE OF NAME Recorded Jun 21, 2017
From: NALCO COMPANY
To: NALCO COMPANY LLC
Reel/Frame 042939/0891 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 30, 2014
From: ZHAO, YULIN; LI, JUN; RAO, QING LONG; ASHTON, STEPHEN; CHENG, WEIGUO; TODOROVIC, ALEKSANDAR; SMITH, ALAN
To: NALCO COMPANY
Reel/Frame 033211/0505 →
Continuity (4)
Continuation 12323976 · Nov 26, 2008
Continuation In Part 13449888 · Apr 18, 2012
Continuation In Part 11854044 · Sep 12, 2007
Related Publication 20130299110A1 · Nov 14, 2013