A system and method of forming a molded pulp product that involves separately collecting, from a paper-making process, waste water containing short fibers at a first fiber consistency, waste water as dilution water containing fibers at a second fiber consistency that is lower than the first fiber consistency, and water containing long fibers, the long fibers having a length that is greater than a length of the short fibers, blending the waste water containing short fibers and the water containing long fibers to obtain a pulp slurry, and molding the pulp slurry into a molded pulp product at a pulp molding machine. In an embodiment, filtrate removed during the molding of the molded pulp product has a BOD measurement that is 95% less than a BOD measurement of the pulp slurry, where the BOD measurements are obtained using the EPA 405.1, SM5210B Test Method.

A method for producing an aqueous copolymer solution, which comprises dissolving a copolymer of (meth)acrylamide and at least 1 mol-% cationic monomers, calculated from total amount of monomers in the dissolving water having calcium hardness of at least mg/l, expressed as Ca.sup.2+, and adding acid comprising monoprotic organic acid and/or mineral acid to the dissolving water and/or the aqueous solution of the copolymer in an amount sufficient to provide the aqueous solution of the copolymer with a pH of equal to or less than 4.5. The invention also relates to uses of the obtained polymer solutions in manufacturing of paper, board or the like or in treatment of sludge or water.

A method of making a paper product can comprise making one or more sheets at least by, for each of the sheet(s), forming a web from one or more furnishes that comprise fibers dispersed in water. The fibers of the furnish(es) can comprise a plurality of first fibers that are hardwood fibers and a plurality of second fibers that include softwood fibers and surface enhanced pulp fibers (SEPF), the SEPF having a length weighted average fiber length of at least 0.20 mm. The method can comprise at least partially dewatering the web to form the sheet. The sheet(s) can be laminated and/or embossed such that a total dry tensile strength of the paper product is less than or equal to 90% of the sum of the total dry tensile strength(s) of the sheet(s).

A sheet forming binder includes a first powder and a second powder having a larger volume average particle size than the first powder. The proportion of the first powder is 10.0% by mass or more relative to the total mass of the first powder and the second powder.

The invention relates to a fire retardant paper comprising reinforcing fibre, a fire retardant material and a binder system, wherein the binder system comprises a first organic binder and a second organic binder, wherein the first organic binder has a lower glass transition temperature than the second organic binder.

The present invention relates to a process wherein microfibrillated cellulose (MFC) is mixed with at least two retention aids, selected from a cationic or amphoteric polymer and a microparticle or nanoparticle as a pre-mix before dosing it to the stock in a process for manufacture of a fiber based product.

A surface treatment composition for paper, board or other fibrous webs. The composition of the invention comprises particles which comprise an active material and a supporting material. The active material comprises a salt of a multivalent metal, such as a divalent or trivalent metal. In accordance with the invention, the supporting material is adapted to release the active material from the particles when subjected to heat and/or pressure and/or a change in pH. Consequently, the active material's adverse effects on the rheology of the composition are avoided while its desired effects on the surface characteristics are retained or enhanced.

This method for treating the surface of paper and/or one of the layers thereof, comprises the following successive steps: i) Supplying an aqueous suspension S of polysaccharide; ii) Supplying an aqueous dispersion D comprising (a) particles of at least one anionic water-swellable polymer P and (b) at least one compound selected from a mineral salt, an organic salt, an organic dispersing polymer and the mixtures thereof; iii) Mixing the suspension S and the dispersion D to obtain a mixture M; iv) Applying the mixture M to the surface of the paper and/or to at least one of the layers thereof.

The invention relates to the field of dispersing agents for an aqueous composition, in particular for dispersing a mineral material in the form of particles. The dispersing agent according to the invention comprises a dispersing polymer combined with an osidic derivative or a derivative of saccharide origin. The invention also relates to an aqueous composition comprising said dispersing agent and a mineral material in the form of particles, and to the use of said agent or composition.

This method for treating the surface of paper and/or one of the layers thereof, comprises the following successive steps: i) Supplying an aqueous suspension S of polysaccharide; ii) Supplying an aqueous dispersion D comprising (a) particles of at least one anionic water-swellable polymer P and (b) at least one compound selected from a mineral salt, an organic salt, an organic dispersing polymer and the mixtures thereof; iii) Mixing the suspension S and the dispersion D to obtain a mixture M; iv) Applying the mixture M to the surface of the paper and/or to at least one of the layers thereof.