Claims
- 1. A process for producing paper materials with improved wet strength, comprising:(a) preparing a suspension of unbleached or semi-bleached chemical or semichemical pulp or pulp from recycled fibres; (b) treating the pulp with a laccase and a mediator; (c) de-watering the treated pulp in a paper making machine to remove process water and produce a paper sheet, and; (d) heat-drying the paper sheet at a temperature of 150° C. or above to produce a heat treated paper of increased wet strength.
- 2. The process of claim 1, wherein the mediator is 10-phenothia-zine-propionic acid (PPT) or 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonate (ABTS).
- 3. The process of claim 1, wherein at least a part of the process water from step (c) is recycled, and step (a) comprises dilution of the pulp with the recycled process water.
- 4. The process of claim 1, wherein the laccase is derived from Polyporus pinsitus.
- 5. The process of claim 1, wherein the laccase is present in an amount of 10-10,000 PODU per gram of dry matter or 0.001-1000 LACU per gram of dry matter.
- 6. The process of claim 1, wherein the enzyme treatment is performed on a pulp having a consistency of 0.5-25%, a pH of 4-10, and a temperature of 20-90° C.
- 7. The process of claim 1, wherein the laccase treatment is carried out at atmospheric pressure.
- 8. The process of claim 1, wherein the pulp is unbleached or semi-bleached kraft pulp, neutral sulfite semichemical pulp, or recycled pulp from old corrugated containers.
- 9. The process of claim 8, wherein the recycled pulp from old corrugated containers is an unbleached kraft pulp.
- 10. A process for producing corrugated paperboard or corrugated containers, comprising producing linerboard and/or corrugated linerboard by the process of claim 1, and combining linerboard and corrugated linerboard to produce the corrugated paperboard or container.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1999 00611 |
May 1999 |
DK |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. 119 of U.S. provisional application No. 60/133,894 filed May 12, 1999 and Danish application no. PA 1999 00611 filed May 6, 1999, the contents of which are fully incorporated herein by reference.
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Entry |
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Provisional Applications (1)
|
Number |
Date |
Country |
|
60/133894 |
May 1999 |
US |