Claims
- 1. A fiber pulp for a generally streak and scratch-free blade-coated paper from a furnish having at least 10% by weight of said fiber pulp produced from recycled paper substantially comprised of recycled corrugated containers, said fiber pulp containing less than about 20 ppm per unit area of solid, non-fibrous contaminants of a size greater than 0.05 mm.sup.2, said fiber pulp being produced from said recycled paper by a method comprising the steps of:
- a) combining a quantity of paper substantially comprised of corrugated containers to be recycled, containing lignin, cellulosic fibers and solid non-fibrous contaminants, with an aqueous liquid to form a slurry containing about 9-15% by weight solids and agitating said slurry in a low shear mixer at a temperature of less than 65.6.degree. C. for a time sufficient to separate said lignin and cellulosic fibers from said solid contaminants without significantly degrading said solid contaminants, and then sequentially;
- b) removing from said slurry gross contaminants of a size in a range greater than about 5 mm.sup.2 by passing said slurry through holes of a predetermined diameter;
- c) removing from said slurry contaminants having a specific gravity in a range greater than 1;
- d) removing from said slurry intermediate contaminants having a size in a range greater than about 2 to 3 mm.sup.2 by passing said slurry through holes of a predetermined size;
- e) removing sand from said slurry;
- f) removing from said slurry fine contaminants of a size in a range at least about 0.15 mm.sup.2, by passing said slurry through elongated slots of a predetermined width;
- g) removing from said slurry by centrifugal means contaminants having a specific gravity less than 1;
- h) dewatering said slurry to form a wet, friable pulp having a moisture content of about 30-60%;
- i) digesting said pulp in a cooking liquor for a time and at a temperature sufficient to hydrolyze a substantial portion of said lignin remaining in intimate association with said cellulosic fibers wherein said digesting takes place at a target temperature in a range of 121.degree. -150.degree. C.; and
- j) separating said digested pulp from spent cooking liquor.
- 2. A paper for a streak and scratch-free blade-coated paper, which paper is produced from a furnish having at least 10% by weight of fiber pulp produced from recycled paper substantially comprised of recycled corrugated containers, said paper having less than about 20 ppm per unit area solid, non-fibrous contaminants of size greater than 0.05 mm.sup.2, and said fiber pulp being produced from said recycled paper by a method comprising the steps of:
- a) combining a quantity of paper substantially comprised of corrugated containers to be recycled, containing lignin, cellulosic fibers and solid non-fibrous contaminants, with an aqueous liquid to form a slurry containing about 9-15% by weight solids and agitating said slurry in a low shear mixer at a temperature of less than 65.6.degree. C. for a time sufficient to separate said lignin and cellulosic fibers from said solid contaminants without significantly degrading said solid contaminants, and then sequentially:
- b) removing from said slurry gross contaminants of a size in a range greater than about 5 mm.sup.2 by passing said slurry through holes of a predetermined diameter:
- c) removing from said slurry contaminants having a specific gravity in a range greater than 1;
- d) removing from said slurry intermediate contaminants having a size in a range greater than about 2 to 3 mm.sup.2 by passing said slurry through holes of a predetermined size;
- e) removing sand from said slurry;
- f) removing from said slurry fine contaminants of a size in a range at least about 0.15 mm.sup.2, by passing said slurry through elongated slots of a predetermined width;
- g) removing from said slurry by centrifugal means contaminants having a specific gravity less than 1;
- h) dewatering said slurry to form a wet, friable pulp having a moisture content of about 30-60%;
- i) digesting said pulp in a cooking liquor for a time and at a temperature sufficient to hydrolyze a substantial portion of said lignin remaining in intimate association with said cellulosic fibers wherein said digesting takes place at a target temperature in a range of 121.degree.-150.degree. C.;
- j) separating said digested pulp from spent cooking liquor; and
- k) preparing paper from said separated pulp.
- 3. The paper of claim 2, containing less than 10 ppm solid contaminants.
- 4. The paper of claim 2, containing at least 20% recycled paper.
- 5. The paper of claim 2 which is a bleached paper.
Parent Case Info
This is a continuation of application Ser. No. 08/216,448 filed on Mar. 23, 1994, now abandoned, which is a divisional of application Ser. No. 08/021,662, filed Mar. 9, 1993, now abandoned, which is a continuation-in-part of application Ser. No. 07/862,996, filed Apr. 6, 1992, now abandoned.
US Referenced Citations (3)
Non-Patent Literature Citations (2)
Entry |
Kanazawa "Recovery of Unbleached Kraft Pulp from AOCC . . . Bleached Kraft Pulp" Nov. 1988. |
Aikawa et al "Processing OCC, Deinking, Approach Flow Screening" World Pulp & Paper Technology 1990, pp. 102-105. |
Divisions (1)
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Number |
Date |
Country |
Parent |
21662 |
Mar 1993 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
216448 |
Mar 1994 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
862996 |
Apr 1992 |
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