A method for controlling a fiber fractionation system for fractionating an input material into a long fraction (LF) stream comprising LF fibers and a short fraction (SF) stream comprising SF fibers includes measuring an average LF fiber length at one or more locations post-fractionation, and maintaining the average LF fiber length within a target variability range by automatically altering a rotational speed of a rotor of the fiber fractionation system.

A method for controlling a fiber fractionation system for fractionating an input material into a long fraction (LF) stream comprising LF fibers and a short fraction (SF) stream comprising SF fibers includes measuring an average LF fiber length at one or more locations post-fractionation, and maintaining the average LF fiber length within a target variability range by automatically altering a rotational speed of a rotor of the fiber fractionation system.

The invention relates to a method for producing particles of mineral material comprising grinding of at least one mineral material in the presence of water. The grinding according to the invention is carried out in the presence of at least one polymer obtained by a radical polymerization reaction of a partial sodium salt of itaconic acid and partial decarboxylation of the polymer obtained followed by partial or total neutralization of the decarboxylated polymer. The invention also relates to an aqueous composition comprising particles of ground mineral material and such a polymer, in particular a mass-loading composition for the production of paper or a paper-coating-colour composition.

The invention relates to a method for producing particles of mineral material comprising grinding of at least one mineral material in the presence of water. The grinding according to the invention is carried out in the presence of at least one polymer obtained by a radical polymerization reaction of a partial sodium salt of itaconic acid and partial decarboxylation of the polymer obtained followed by partial or total neutralization of the decarboxylated polymer. The invention also relates to an aqueous composition comprising particles of ground mineral material and such a polymer, in particular a mass-loading composition for the production of paper or a paper-coating-colour composition.

A fiber blend includes a first amount of wood pulp fibers refined in an amount of at least about 150 kWh per metric ton of gross refining energy, and a second amount of wood pulp fibers refined in an amount of at most about 10 kWh per metric ton of gross refining energy.

A sanitary tissue product may comprise a first layer comprising eucalyptus fibers and a second layer comprising eucalyptus fibers and softwood fibers. The eucalyptus fibers in the second layer may have at least 24% more vessel elements than the eucalyptus fibers in the first layer.

A sanitary tissue product may comprise a first layer comprising eucalyptus fibers and a second layer comprising eucalyptus fibers and softwood fibers. The eucalyptus fibers in the second layer may have at least 24% more vessel elements than the eucalyptus fibers in the first layer.

The invention relates to a wrapping paper for a smoking article, said wrapping paper comprising long-fibre pulp, short-fibre pulp, and inorganic filler, wherein: at least a portion of the long-fibre pulp is ground and the ground long-fibre pulp constitutes at least 15% and at most 70% of the mass of the wrapping paper, at least a portion of the short-fibre pulp is ground and the ground short-fibre pulp constitutes at least 5% and at most 80% of the mass of the wrapping paper, and the ground short-fibre pulp has a freeness value of at least 20? SR and at most 60? SR; the short-fibre pulp as a whole constitutes at least 10% and at most 80% of the mass of the wrapping paper, at least 5% and at most 45% of the mass of the wrapping paper is constituted by one or more inorganic fillers; the mass per unit area of the wrapping paper is at least 15 g/m.sup.2 and at most 45 g/m.sup.2; the diffusion capacity of the wrapping paper is at least 0.05 cm/s and at most 0.5 cm/s; and the standard deviation of the diffusion capacity of the wrapping paper is at most 0.05 cm/s. The invention also relates to an associated manufacturing method and to a smoking article making use of said wrapping paper.

The invention relates to a process and an apparatus for producing a molded fiber article. The process comprises the steps of dissolving fibrous materials in water to form a fibrous material suspension in a pulper, removing moisture from the fibrous material suspension by pressing to form a molded fiber article in a mold and/or drying the molded fiber article by supplying heat, demolding the molded fiber article from the mold. The process is characterized by the feature whereby, in mold drying of the molded fiber article in the mold, a moisture content of the molded fiber article of not more than 10% by weight or not more than 7.5% by weight or not more than 5% by weight is achieved.

A process for manufacturing a web material is disclosed. The process generally provides the steps of: a. providing a pulp material comprising fibers and vessels; b. separating said vessels from said fibers in said pulp material to form a slurry having at least about 7 percent less vessels per meter than said pulp material; and c. processing said slurry to form said web material.