Pulping processes
AssigneeCargill, Incorporated
InventorsBrent A. Hawkins, Fred Martin
Life of this patent
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Abstract
A pulping process comprises using a high concentration of anthraquinone (AQ). The pulping process is capable of providing a pulp having low Kappa number with unexpectedly high strength. The pulping process can use wood or non-wood fibers (e.g., bagasse and corn stover) to provide pulp having good papermaking quality. The method for pulping a fiber comprising cooking a first mixture comprising the fibers, water, an alkali, and a delignification selectivity enhancing chemical for a cooking time and at a cooking condition sufficient to form a first pulp having a desired Kappa number of about 15 or less, and strength parameters that are sufficient for papermaking, where the starting material prior to cooking has a Kappa number of 60 or greater.
Claims27
A method for pulping a fiber comprising:
- providing a first mixture comprising the reaction products of:
- a fiber from a non-wood fiber source,
- water,
- anthraquinone, or derivative thereof, having concentration of about 0.1% by weight or greater of the dry fiber, and
- an alkali,
- wherein the first mixture has a liquid to dry fiber ratio from about 4 to about 10, and an initial Kappa number of about 60 or greater;
- and
- reacting the first mixture for a cooking time and at a cooking condition sufficient to form a second mixture having a Kappa number of about 15 or less, a tensile of at least about 5.50 km, and/or a burst index of at least about 3.00 kPa·m2/g.
A method for pulping a fiber comprising:
- providing a first mixture comprising the reaction products of:
- a fiber from a wood fiber source,
- water,
- anthraquinone or derivative thereof, having a concentration of about 0.1% by weight or greater of the dry fiber, and
- an alkali,
- wherein the first mixture has a liquid to dry fiber ratio from about 4 to about 10, and an initial Kappa number of about 60 or greater;
- and
- reacting the first mixture for a cooking time and at a cooking condition sufficient to form a second mixture having a Kappa number of about 15 or less, a tensile of at least about 5.50 km, and/or a burst index of at least about 3.00 kPa·m2/g.
Dependencies are inferred from the claim text.