PROCESSES FOR IMPROVING HIGH ASPECT RATIO CELLULOSE FILAMENT BLENDS

• US 20190316293A1
• Filed: 04/12/2019
• Published: 10/17/2019
• Est. Priority Date: 04/12/2018
• Status: Active Grant

• Current Assignee: Mercer International Incorporated
• Original Assignee: Mercer International Incorporated
• Inventors: Ziegenbein, Tobias
• Granted Patent: US 11,352,747 B2
• Time in Patent Office: Days
• CPC Class Codes: D01C 1/00 Treatment of vegetable material
• CPC Class Codes: D01F 2/00 Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
• CPC Class Codes: D01G 5/00 Separating, e.g. sorting, fibres separating fibres of differing lengths in silk-dressing machines D01G17/00; in combing machines D01G19/00
• CPC Class Codes: D10B 2201/00 Cellulose-based fibres, e.g. vegetable fibres
• CPC Class Codes: D21C 5/00 Other processes for obtaining cellulose, e.g. cooking cotton linters obtaining fibres for spinning D01C; Processes characterised by the choice of cellulose-containing starting materials
• CPC Class Codes: D21C 9/00 After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere polysaccharides, derivatives thereof C08B; paper-making D21B - D21H
• CPC Class Codes: D21D 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: D21H 11/16 modified by a particular after-treatment
• CPC Class Codes: D21H 11/18 Highly hydrated, swollen or fibrillatable fibres

Abstract

A process for improving high aspect ratio cellulose filament blends comprising the steps of: a) providing a blend of cellulose nano-filaments or blend of cellulose micro-filaments; b) diluting the blend of cellulose nano-filaments or the blend of cellulose micro-filaments to a target consistency; c) fractionating the diluted blend of cellulose nano-filaments or the diluted blend of cellulose micro-filaments from the step c); and, d) collecting the fraction of the diluted blend of cellulose nano-filaments or the diluted blend of cellulose micro-filaments from the step c) having an average length of greater than at least about 25 μm.

Claims

1. A process for improving high aspect ratio cellulose filament blends comprising the steps of:

a) providing a blend of cellulose nano-filaments or blend of cellulose micro-filaments;

b) diluting said blend of cellulose nano-filaments or said blend of cellulose micro-filaments to a target consistency;

c) fractionating said diluted blend of cellulose nano-filaments or said diluted blend of cellulose micro-filaments into, at least, a high-solids fraction and a low-solids fraction; and

,

d) collecting said fraction of said diluted blend of cellulose nano-filaments or said diluted blend of cellulose micro-filaments having an average length of greater than at least about 25 μ

m.

2. The process for improving high aspect ratio filament blends of claim 1 wherein the diluting of said blend of cellulose nano-filaments or said blend of cellulose micro-filaments of step b is done with water.

3. The process for improving high aspect ratio filament blends of claim 1 wherein the diluting step of step b) dilutes the blend of cellulose nano-filaments or said blend of cellulose micro-filaments to a target consistency of less than 4%.

4. The process for improving high aspect ratio filament blends of claim 1 wherein the diluting step of step b) dilutes the blend of cellulose nano-filaments or said blend of cellulose micro-filaments to a target consistency of less than 3%.

5. The process for improving high aspect ratio filament blends of claim 1 wherein the fractionation step of step c) comprises centrifuging said diluted blend of cellulose nano-filaments or said diluted blend of cellulose micro-filaments from said step b);

and, the collecting step of step d) comprises decanting said low-solids fraction from said diluted and centrifuged blend of cellulose nano-filaments or said diluted and centrifuged blend of cellulose micro-filaments leaving the high-solids fraction for collection.

6. The process for improving high aspect ratio filament blends of claim 2 wherein the water of the dilution step b) has a pH of greater than about 7.

7. The process for improving high aspect ratio filament blends of claim 6 wherein the water of the diluting step b) has a pH of greater than about 8.

8. The process for improving high aspect ratio filament blends of claim 7 wherein the water of the diluting step b) has a pH of greater than about 9.

9. The process for improving high aspect ratio filament blends of claim 1 wherein the diluting step b), the fractionating step c), and the collecting step d) are performed sequentially.

10. The process for improving high aspect ratio filament blends of claim 9 wherein the sequential steps b), c) and d) are repeated at least twice.

11. The process for improving high aspect ratio filament blends of claim 10 wherein the sequential steps b), c) and d) are repeated at least three times.

12. The process of claim 1 wherein the collecting step d) collects said high-solids fraction of said diluted blend of cellulose nano-filaments or said diluted blend of cellulose micro-filaments having an average length of greater than at least about 50 μ

m.

13. The process of claim 1 wherein the collecting step d) collects said fraction of said diluted blend of cellulose nano-filaments or said diluted blend of cellulose micro-filaments having a average length of greater than at least about 100 μ

m.

14. The process of claim 1 wherein the collecting step d) collects said fraction of said diluted blend of cellulose nano-filaments or said diluted blend of cellulose micro-filaments having an average aspect ratio of greater than at least about 50.

15. The process of claim 1 wherein the collecting step d) collects said fraction of said diluted blend of cellulose nano-filaments or said diluted blend of cellulose micro-filaments having an average aspect ratio of greater than at least about 100.

16. The process of claim 1 wherein the collecting step d) collects said fraction of said diluted blend of cellulose nano-filaments or said diluted blend of cellulose micro-filaments having a average aspect ratio of greater than at least about 200.

17. The process of claim 2 wherein the water of the diluting step is initially reduced to a pH of less than about 6 and then raised to a pH of greater than about 9.

18. The process of claim 2 wherein the water of the diluting step is initially reduced to a pH of less than about 5 and then raised to a pH of greater than about 9.