The present disclosure relates to producing paper or paperboard having improved stiffness and strength, compared to the conventional paperboard at the same basis weight. It also discloses a method of wood pulping having a significantly increased yield and providing fiber pulps with enhanced properties such as strength and stiffness. Wood chips are chemically pulped to a high kappa number, providing a rejects component and an accepts component. The rejects component is subjected to a substantially mechanical pulping process, optionally in a presence of bleaching agent, prior to blending back into the accepts component. The resulting fiber blend is washed, optionally bleached, and subjected to a papermaking process to provide paper or paperboard with enhanced strength and stiffness at low basis weight.

The present invention includes a method of manufacturing a sack paper having a Gurley porosity (ISO 5636-5) of less than 25 s, comprising the steps of: a) mixing an unbleached pulp with a bleached pulp to obtain a pulp mixture in such proportions that the dry weight ratio of unbleached pulp to bleached pulp in the pulp mixture is between 7:1 and 1:1; and b) forming the sack paper from said pulp mixture, wherein starch is added in an amount of 1-7 kg/ton paper.

A method of wood pulping having a significantly increased yield is disclosed. Wood chips are chemically pulped to a high kappa number, providing a first accepts component and a first rejects component. The first rejects component is subjected to a high consistency pulping process such as a substantially mechanical pulping process to generate a second accepts component and a second rejects component. The first accepts component may be used in the production of saturating kraft paper with excellent saturability and resin pick up. The second accepts may be used as a second fiber source in the production of multiply linerboard and unbleached paperboard with enhanced stiffness, strength, and smoothness. Alternatively, the first accepts component may be blended with the second accepts component to produce fiber blends, which may be used in a production of paper-based products having enhanced strength and stiffness at low basis weight.

A method of wood pulping having a significantly increased yield is disclosed. Wood chips are chemically pulped to a high kappa number, providing a first accepts component and a first rejects component. The first rejects component is subjected to a high consistency pulping process such as a substantially mechanical pulping process to generate a second accepts component and a second rejects component. The first accepts component may be used in the production of saturating kraft paper with excellent saturability and resin pick up. The second accepts may be used as a second fiber source in the production of multiply linerboard and unbleached paperboard with enhanced stiffness, strength, and smoothness. Alternatively, the first accepts component may be blended with the second accepts component to produce fiber blends, which may be used in a production of paper-based products having enhanced strength and stiffness at low basis weight.

The present invention relates to compositions for use in an aqueous pulp bleaching process, comprising one or more alkaline earth metal oxides and/or one or more alkaline earth metal hydroxides; one or more alkaline earth metal salts; and optionally, one or more pitch control additives. Methods and kits for the formation of said compositions, are also part of the invention, as is the use of said compositions, methods and kits.

An omnibus process of pulping and bleaching lignocellulosic materials in which a charge of a lignocellulosic material is biopulped and/or water extracted prior to pulping and bleaching. The lignocellulosic material may be mechanically pulped and bleached in the presence of an enzyme that breaks lignin-carbohydrate complexes.

An omnibus process of pulping and bleaching lignocellulosic materials in which a charge of a lignocellulosic material is biopulped and/or water extracted prior to pulping and bleaching. The lignocellulosic material may be mechanically pulped and bleached in the presence of an enzyme that breaks lignin-carbohydrate complexes.

A system and method of manufacturing a feedstock for producing paper fiber from fruit of a plant may include providing a by-product source inclusive of fiber from the edible fruit after a process for removing a majority of the edible fruit is used to produce a food. One or more treatment processes to brighten the fruit by-product may be performed. The feedstock may be produced from the brightened fruit by-product.

A system and method of manufacturing a feedstock for producing paper fiber from fruit of a plant may include providing a by-product source inclusive of fiber from the edible fruit after a process for removing a majority of the edible fruit is used to produce a food. One or more treatment processes to brighten the fruit by-product may be performed. The feedstock may be produced from the brightened fruit by-product.

Processes disclosed are capable of converting biomass into high-crystallinity nanocellulose with low mechanical energy input. In some variations, the process includes fractionating biomass with sulfur dioxide or a sulfite compound and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; and mechanically treating the cellulose-rich solids to form nanofibrils and/or nanocrystals. The total mechanical energy may be less than 500 kilowatt-hours per ton. The crystallinity of the nanocellulose material may be 80% or higher, translating into good reinforcing properties for composites. The nanocellulose material may include nanofibrillated cellulose, nanocrystalline cellulose, or both. In some embodiments, the nanocellulose material is hydrophobic via deposition of some lignin onto the cellulose surface. Optionally, sugars derived from amorphous cellulose and hemicellulose may be separately fermented, such as to monomers for various polymers. These polymers may be combined with the nanocellulose to form completely renewable composites.