Method of manufacturing pulp and articles made therefrom

• US 20070193706A1
• Filed: 02/21/2006
• Published: 08/23/2007
• Est. Priority Date: 02/21/2006
• Status: Active Grant

• Current Assignee: Packaging Corporation of America
• Original Assignee: Packaging Corporation of America
• Inventors: Sethy, Anil, Kirov, Ventzislav, Sorensen, Bryan
• Granted Patent: US 7,771,565 B2
• Time in Patent Office: Days
• US Class Current: 162/28
• CPC Class Codes: D21B 1/16 in the presence of chemical agents
• CPC Class Codes: D21C 1/02 with water or steam
• CPC Class Codes: D21C 11/0007 Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for volatile compounds obtained by decomposition of spent liquors in order to regenerate them D21C11/125; compounds obtained by fractionating the liquors in order to regenerate them D21C11/0042
• CPC Class Codes: D21C 3/02 with inorganic bases or alkaline reacting compounds, e.g. sulfate processes

Abstract

A method of making pulp adapted to be used in forming corrugating medium is disclosed. The method comprises cooking woodchips in a first liquor in the absence of an alkali addition. The method further comprises mechanically fiberizing the woodchips to form a pulp. The method further comprises separating hydrolyzate from the pulp. The method further comprises treating the pulp with a second liquor, the second liquor including at least one alkali. The method further comprises refining the pulp.

Claims

1. A method of making pulp adapted to be used in forming corrugating medium, the method comprising the acts of:

cooking woodchips in a first liquor in the absence of an alkali addition;

mechanically fiberizing the woodchips to form a pulp;

separating hydrolyzate from the pulp;

treating the pulp with a second liquor, the second liquor including at least one alkali; and

refining the pulp.

2. The method of claim 1, wherein the ratio of the first liquor to woodchips is from about 1.5:

1 to about 6;

1.

3. The method of claim 2, wherein the first liquor has a temperature ranging from about 320°

F. to about 370°

F. and the woodchips are cooked in the first liquor for about 5 to about 45 minutes.

4. The method of claim 1, wherein the act of cooking the woodchips in the first liquor is conducted in a batch digester or a continuous digester.

5. The method of claim 1, wherein the act of mechanically fiberizing the woodchips is conducted in a mechanical defibrator at a consistency of about 25% to about 35%.

6. The method of claim 5, wherein the mechanical defibrator is operated at a temperature ranging from about 150°

F. to about 350°

F.

7. The method of claim 1, wherein the act of separating hydrolyzate from the pulp is conducted in an extraction press/impress refiner, a drum washer, a chemiwasher, or a continuous digester with displacement washing.

8. The method of claim 7, wherein the act of separating the hydrolyzate from the pulp is generally conducted at a temperature ranging from about 100°

F. to about 210°

F.

9. The method of claim 1, wherein the hydrolyzate is used to produce a biogas comprising methane, acetic acid, ethanol, xylitol, natural polymers, or combinations thereof.

10. The method of claim 1, wherein the at least one alkali in the second liquor includes sodium hydroxide, sodium carbonate, a similarly acting alkali, or a combination thereof.

11. The method of claim 1, wherein the act of treating the pulp with a second liquor is conducted in a low to high density tower or a pulp storage vessel at a consistency of about 5% to about 20%.

12. The method of claim 11, wherein the temperature of the second liquor ranges from about 100°

F. to about 210°

F. and wherein the pulp is treated with the second liquor for about 1 hour to about 4 hours.

13. The method of claim 12, wherein the second liquor includes a chemical charge of from about 0.5% to about 2% expressed as sodium oxide on a bone dry wood basis.

14. The method of claim 1, wherein the act of treating the pulp with a second liquor is conducted in a digester/impregnator fed at a consistency of about 30% to about 55%.

15. The method of claim 14, wherein the temperature of the second liquor ranges from about 210°

F. to about 370°

F. and wherein the pulp is treated with the second liquor for about 1 minute to about 15 minutes.

16. The method of claim 15, wherein the second liquor includes a chemical charge of from about 2% to about 4% expressed as sodium oxide on a bone dry wood basis.

17. The method of claim 16 further comprising, prior to the act of refining the pulp, washing the pulp in an extraction press, drum washer, chemiwasher, or continuous digester with displacement washing.

18. The method of claim 1, wherein the act of refining the pulp is conducted at a temperature ranging from about 100°

F. to about 210°

F. and a consistency of about 3% to about 6%.

19. The method of claim 1, wherein the act of refining the pulp includes obtaining a freeness suitable for corrugating medium ranging from between about 350 ml to about 500 ml.

20. The method of claim 1 further comprising, prior to the act of cooking woodchips in a first liquor, presteaming the woodchips.

21. The method of claim 1 further comprising prior to the act of cooking woodchips in a first liquor, washing the woodchips.

22. A method of making pulp adapted to be used in forming corrugating medium, the method comprising the acts of:

cooking woodchips in a first liquor in the absence of an alkali addition;

mechanically fiberizing the woodchips to form a pulp;

separating hydrolyzate from the pulp;

treating the hydrolyzate to remove at least one byproduct;

treating the pulp with a second liquor, the second liquor including at least one alkali; and

refining the pulp.

23. The method of claim 22, wherein the at least one byproduct includes acetic acid.

24. The method of claim 23, wherein the at least one byproduct includes organics.

25. The method of claim 24 further comprising using the organics to produce methane, ethanol, xylitol, natural polymers, or combinations thereof.

26. A method of manufacturing a corrugating medium, the method comprising the acts of:

cooking woodchips in a first liquor in the absence of an alkali addition;

mechanically fiberizing the woodchips to form a pulp;

separating hydrolyzate from the pulp;

treating the pulp with a second liquor, the second liquor including at least one alkali;

refining and deshiving the pulp;

blending the pulp with recycled fibers to form a blended pulp; and

sending the blended pulp to a papermachine to form a corrugating medium.

27. The method of claim 26, wherein the recycled fibers include old corrugating containers, double-lined kraft clippings, or combinations thereof.

28. A method of manufacturing a corrugated board, the method comprising the acts of:

cooking woodchips in a first liquor in the absence of an alkali addition;

mechanically fiberizing the woodchips to form a pulp;

separating hydrolyzate from the pulp;

treating the pulp with a second liquor, the second liquor including at least one alkali;

refining and deshiving the pulp;

blending the pulp with recycled fibers to form a blended pulp;

sending the blended pulp to a papermachine to form a corrugating medium; and

coupling the corrugating medium between a first outer ply and a second outer ply of linerboard to form a corrugated board.

29. The method of claim 28, wherein the recycled fibers include old corrugating containers, double-lined kraft clippings, or combinations thereof.

30. The method of claim 28 further comprising folding the corrugated board, thereby forming at least a portion of a cardboard container.