The present invention relates to a paper or paperboard substrate having barrier properties, which substrate comprises a single or multiply structure with e.g. a top ply, a middle ply and a bottom ply, wherein at least one of said top ply and said bottom ply is provided with a high-density bio-barrier layer, and wherein said top or bottom ply provided with the high-density bio-barrier layer and said top or bottom ply not provided with the high-density bio-barrier layer have both been subjected to grafting with a fatty acid halide.

Methods of making a paper or board product comprising a top ply slurry comprising microfibrillated cellulose and, optionally, one or more inorganic particulate material, applied to a forming web of paper through an applicator comprising a channel terminating in a slot, wherein the slot is in fluid communication with a flexible blade suitable to form a top ply on top of the forming web of paper at the wet end of the paper machine and applicators for practicing such methods.

Methods of making a paper or board product comprising a top ply slurry comprising microfibrillated cellulose and, optionally, one or more inorganic particulate material, applied to a forming web of paper through an applicator comprising a channel terminating in a slot, wherein the slot is in fluid communication with a flexible blade suitable to form a top ply on top of the forming web of paper at the wet end of the paper machine and applicators for practicing such methods.

Processes disclosed are capable of converting biomass into high-crystallinity, hydrophobic cellulose. In some variations, the process includes fractionating biomass with an acid (such as sulfur dioxide), a solvent (such as ethanol), and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; and depositing lignin onto cellulose fibers to produce lignin-coated cellulose materials (such as dissolving pulp). The crystallinity of the cellulose material may be 80% or higher, translating into good reinforcing properties for composites. 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 hydrophobic cellulose to form completely renewable composites.

The present invention is directed to products, such as paper and paperboard products, comprising a substrate containing cellulose and top ply comprising microfibrillated cellulose and inorganic particulate, to methods of making such paper and paperboard products, and associated uses of such paper and paperboard products. The microfibrillated cellulose and inorganic particulate material are applied at the stage when the wet substrate is in the process of being formed on the wire of a papermaking machine, thereby avoiding the additional cost of more extensive equipment and machinery as well as in separate drying of a coating. The microfibrillated cellulose facilitates the application of inorganic particulate onto the surface of a wet paper or paperboard substrate when applied thusly, by trapping the inorganic particulate on the surface of the substrate and by giving the composite sufficient strength and a suitable pore structure to make it suitable for printing and other end-use demands.

The present invention is directed to products, such as paper and paperboard products, comprising a substrate containing cellulose and top ply comprising microfibrillated cellulose and inorganic particulate, to methods of making such paper and paperboard products, and associated uses of such paper and paperboard products. The microfibrillated cellulose and inorganic particulate material are applied at the stage when the wet substrate is in the process of being formed on the wire of a papermaking machine, thereby avoiding the additional cost of more extensive equipment and machinery as well as in separate drying of a coating. The microfibrillated cellulose facilitates the application of inorganic particulate onto the surface of a wet paper or paperboard substrate when applied thusly, by trapping the inorganic particulate on the surface of the substrate and by giving the composite sufficient strength and a suitable pore structure to make it suitable for printing and other end-use demands.

A method for manufacturing an injection molding material includes: an imparting step of imparting a water-soluble high molecular weight material to a cellulose raw material; a defibrating step of defibrating the cellulose raw material to which the water-soluble high molecular weight material is imparted to form a defibrated material; and a mixing step of mixing the defibrated material with a starch in a gas atmosphere.

The invention discloses a paperboard comprising a base ply, a top ply, and an intermediate layer disposed in-between the at least one base ply and the top ply. The intermediate layer comprises pigment and microfibrillated cellulose (MFC). The application of an intermediate layer comprising pigment and MFC in-between the base ply and the top ply gives rise to improved optical properties of the paperboard, even when using an uncoated top ply having a low grammage. This makes it possible to reduce the grammage of top ply and still obtain good optical properties.

The invention discloses a paperboard comprising a base ply, a top ply, and an intermediate layer disposed in-between the at least one base ply and the top ply. The intermediate layer comprises pigment and microfibrillated cellulose (MFC). The application of an intermediate layer comprising pigment and MFC in-between the base ply and the top ply gives rise to improved optical properties of the paperboard, even when using an uncoated top ply having a low grammage. This makes it possible to reduce the grammage of top ply and still obtain good optical properties.

The present invention relates to a method for preparing a surface-treated fibrous material comprising nanocellulose, in which a fibrous material is surface treated with an organic acid or salt thereof. Fibrous materials as such are also provided. The present technology allows improved Water Vapor Transmission Rates (WVTR) for the fibrous material, while operating on an industrial scale.