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US 8,916,024 B2Granted
Method and system for producing market pulp and products thereof
AssigneeBuckman Laboratories International, Inc.
InventorsWeiping Ban, Philip M. Hoekstra, Michael R. Elsey
Life of this patent
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Abstract
Methods and systems are provided for producing market pulp which include treatment of pulp with diverse ionic compounds before pulp drying. Cationically and anionically charged compounds can be used to treat pulp before pulp drying to improve pulp dewatering performance and efficiency in the production of market pulp. Market pulp products containing the treatment compounds are also described.
Claims19
A method for producing market pulp, comprising:
- forming cellulosic particulates into pulp;
- adding at least one cationic polymer and at least one anionic polymer to said pulp to provide treated pulp effective to form a polyelectrolyte complex in said treated pulp;
- mechanically dewatering said treated pulp to provide mechanically dewatered pulp;
- and
- thermally drying said mechanically dewatered pulp to form market pulp,
- wherein the amount of complex formed is effective for increasing obtained free drainage to a value which is from about 60% to about 200% greater than free drainage value obtained with using the cationic polymer individually in the pulp.
3 more elements
A method for producing market pulp, comprising:
- forming cellulosic particulates into pulp;
- adding at least one cationic polymer and at least one anionic polymer to said pulp to provide treated pulp effective to form a polyelectrolyte complex in said treated pulp;
- mechanically dewatering said treated pulp to provide mechanically dewatered pulp;
- thermally drying said mechanically dewatered pulp to form market pulp;
- wherein an amount of polyelectrolyte complex formed in said pulp is effective to provide at least one of the following:
- (i) increased pulp free drainage (g/60 sec) to a value which is at least three times greater than free drainage value obtained without the complex formed/present in the pulp;
- (ii) increased pulp free drainage to a value which is at least about 50% greater than free drainage value obtained with using the cationic polymer individually in the pulp without the anionic polymer;
- (iii) increased pulp free drainage to a value which is at least about 10% greater than a free drainage value calculated as a sum of the free drainage increases obtained from using the anionic polymer and cationic polymer separately and individually in the pulp;
- and
- (iv) reducing pulp water retention value (WRV) to a value which is at least about 10% less than WRV obtained with using the cationic polymer individually in the pulp without the anionic polymer.
7 more elements
A method for producing market pulp, comprising:
- forming cellulosic particulates into pulp;
- adding at least one cationic polymer and at least one anionic polymer to said pulp to provide treated pulp effective to form a polyelectrolyte complex in said treated pulp;
- mechanically dewatering said treated pulp to provide mechanically dewatered pulp;
- thermally drying said mechanically dewatered pulp to form market pulp;
- wherein the cationic polymer comprises a combination of a cationic polyamine having a weight average molecular weight of no greater than about 500,000 daltons or both, with a copolymer containing acrylamide with a cationic monomer having a weight average molecular weight greater than 500,000 daltons;
- and
- wherein an amount of polyelectrolyte complex formed in said pulp is effective to provide increased pulp free drainage of at least about 10% greater than a sum of the free drainage increases obtained from using the cationic polymers separately and individually in the pulp in sequential additions before the anionic polymer.
4 more elements
Dependencies are inferred from the claim text.