Process for producing increased bulk pulp fibers, pulp fibers obtained, and products incorporating same

Patent metadata

Field	Value
Publication number	US-10280559-B2
Application number	US-201715793239-A
Country	US
Kind code	B2
Filing date	Oct 25, 2017
Priority date	Nov 1, 2016
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

Processes for pulping raw pulp material, such as wood chips, to provide pulp fibers having increased bulk, as well as bleaching the resulting pulp fibers to provide bleached pulp fibers having increased bulk. These pulp fibers and bleached pulp fibers may be incorporated into or used various products, such as multi-ply coated paperboards, fluff pulp, etc.

First claim

What is claimed is:

1. A composition comprising one or more of: softwood pulp fibers having an ISO brightness of at least about 60 and a coarseness in the range of from about 15 to about 45 mg/100 m. of fiber; or hardwood pulp fibers having an ISO brightness of at least about 80 and a coarseness in the range of from about 5 to about 20 mg/100 m. of fiber, the pulp fibers comprising:
for softwood pulp fibers:
from about 15 to about 27% by weight acid-insoluble lignin;
from about 20 to about 25% by weight hemicellulose;
from about 40 to about 50% by weight cellulose; and
about 0.4% or less by weight extractives; or

for hardwood pulp fibers:
from about 8 to about 20% by weight acid-insoluble lignin;
from about 15 to about 25% by weight hemicellulose;
from about 47 to about 58% by weight cellulose; and

from about 0.01 to about 0.08% by weight extractives.

2. The composition of claim 1 , wherein the softwood pulp fibers are unbleached and comprise: from about 23 to about 27% by weight of acid-insoluble lignin; from about 20 to about 23% by weight of hemicellulose; from about 40 to about 50% by weight (of cellulose; and about 0.25% or less by weight extractives.

3. The composition of claim 1 , wherein the softwood pulp fibers are bleached and comprise: from about 15 to about 20% by weight of acid-insoluble lignin; from about 22 to about 25% by weight of hemicellulose; from about 46 to about 50% by weight of cellulose; and about 0.01% or less by weight of the extractives.

4. The composition of claim 1 , wherein the softwood pulp fibers have an ISO brightness of from about 60 to about 68.

5. The composition of claim 4 , wherein the softwood pulp fibers have an ISO brightness of from about 60 to about 64.

6. The composition of claim 1 , wherein the hardwood pulp fibers are unbleached and comprise: from about 15 to about 20% by weight of acid-insoluble lignin; from about 15 to about 25% by weight of hemicellulose; from about 47 to about 52% by weight of cellulose; and from about 0.05 to about 0.08% by weight of extractives.

7. The composition of claim 1 , wherein the hardwood pulp fibers are bleached and comprise: from about 8 to about 12% by weight of acid-insoluble lignin; from about 15 to about 25% by weight of hemicellulose; from about 54 to about 58% by weight of cellulose; and from about 0.01 to about 0.04% by weight of extractives.

8. The composition of claim 1 , wherein the hardwood pulp fibers have an ISO brightness of from about 80 to about 90.

9. The composition of claim 8 , wherein the hardwood pulp fibers have an ISO brightness of from about 84 to about 88.

10. The composition of claim 1 , wherein the softwood pulp fibers have a coarseness in the range of from about 32 to about 42, and wherein the hardwood pulp fibers have a coarseness in the range of from about 15 to about 18.

11. The composition of claim 1 in the form of a fluff pulp.

12. The composition of claim 11 , wherein the fluff pulp has an absorption capacity of at least about 8 g/g for a 0.9% saline solution.

13. The composition of claim 11 , wherein the fluff pulp has a shred quality of about 5% or less Nits by weight.

14. The composition of claim 11 , wherein the fluff pulp has an absorption time of at least about 8 seconds for a 0.9% saline solution.

15. The composition of claim 11 , wherein the fluff pulp has a shred energy of at least about 150 kj/kg.

16. The composition of claim 11 , wherein the fluff pulp comprises from about 90 to about 100% by weight softwood pulp fibers.

17. The composition of claim 16 , wherein the fluff pulp has an absorption capacity of from about 8 to about 10 g/g for a 0.9% saline solution.

18. The composition of claim 16 , wherein the fluff pulp has an absorption capacity of from about 8.5 to about 9.5 g/g for a 0.9% saline solution.

19. The composition of claim 16 , wherein the fluff pulp has a shred quality of about 5% or less Nits by weight.

20. The composition of claim 16 , wherein the fluff pulp has a shred quality of about 2% or less Nits by weight.

21. The composition of claim 16 , wherein the fluff pulp has an absorption time of from about 8 to about 20 seconds for a 0.9% saline solution.

22. The composition of claim 16 , wherein the fluff pulp has an absorption time of from about 9 to about 15 seconds for a 0.9% saline solution.

23. The composition of claim 16 , wherein the fluff pulp has a shred energy of from about 150 to about 250 kj/kg.

24. The composition of claim 16 , wherein the fluff pulp has a shred energy of from about 160 to about 200 kj/kg.

25. A process for preparing pulp fibers, the process comprising the following steps:
(a) cooking raw wood material comprising one or more of softwoods or hardwoods in an aqueous cooking liquor comprising from about 8 to about 12% sodium sulfite at a temperature in the range of from about 150° to about 200° C. for at least about 30 minutes to provide cooked wood material; and
(b) comminuting the cooked wood material of step (a) using a fiberization energy of at least about 50 kj/kg to provide pulp fibers in a yield of from about 50 to about 85% and having:
for softwood pulp fibers, an ISO brightness of at least about 60 and a coarseness in the range of from about 15 to about 45 mg/100 m., the softwood pulp fibers comprising:
from about 23 to about 27% by weight acid-insoluble lignin;
from about 20 to about 23% by weight hemicellulose;
from about 40 to about 45% by weight cellulose; and
about 0.4% or less by weight extractives; or

for hardwood pulp fibers, an ISO brightness of at least about 80 and a coarseness in the range of from about 5 to about 20 mg/100 m., the hardwood pulp fibers comprising:
from about 15 to about 20% by weight acid-insoluble lignin;
from about 15 to about 25% by weight hemicellulose;
from about 47 to about 52% by weight cellulose; and
about 0.05 to about 0.08% by weight extractives.

26. The process of claim 25 , wherein the raw wood material comprises wood chips.

27. The process of claim 25 , wherein the fiberization energy used in step (b) is at least about 150 kj/kg.

28. The process of claim 27 , wherein the fiberization energy used in step (b) in the range of from about 150 to about 250 kj/kg.

29. The process of claim 28 , wherein the fiberization energy used in step (b) in the range of from about 160 to about 200 kj/kg.

30. The process of claim 25 , wherein step (a) is carried out at a temperature in the range of from about 160° to about 180° C.

31. The process of claim 30 , wherein step (a) is carried out for from about 30 to about 90 minutes.

32. The process of claim 25 , wherein the softwood pulp fibers of step (b) have a coarseness in the range of from about 32 to about 42, and wherein the hardwood pulp fibers of step (b) have a coarseness in the range of from about 15 to about 18.

33. A process for preparing bleached pulp fibers, the process comprising the following steps:
(a) cooking raw wood material comprising one or more of softwoods or hardwoods in an aqueous cooking liquor comprising from about 8 to about 12% sodium sulfite at a temperature in the range of from about 150° to about 200° C. for at least about 30 minutes to provide cooked wood material;
(b) comminuting the cooked wood material of step (a) using a fiberization energy of

Assignees

• Int Paper Co

Inventors

• Goyal Gopal

Classifications

• D21C9/00

  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 title

• D21C3/06 Primary

  sulfur dioxide; sulfurous acid; bisulfites {sulfites} · CPC title

• D21H19/48

  Diolefins, e.g. butadiene; Aromatic vinyl monomers, e.g. styrene; Polymerisable unsaturated acids or derivatives thereof, e.g. acrylic acid · CPC title

• D21C3/12 Primary

  sodium bisulfite · CPC title

• D21C9/163

  with peroxides · CPC title