In a process for producing bleached mechanical woodpulp, said process comprising the steps of a) delaminating comparatively large particles of wood, which have optionally been pretreated with chemicals and/or water, into modified particles of wood, b) grinding the modified particles of wood from a) in one or more refiners, c) optionally treating the stalk obtained in step b) with oxidative or reductive bleaching agents, a composition Z is present during step a) and/or step b), said composition Z comprising one or more of the following components (Z1) to (Z3): a salt of dithionous acid H.sub.2S.sub.2O.sub.4 (Z1), a dithionous acid or dithionous acid derivative generator compound (Z2), a salt of sulfurous acid (sulfite) plus sodium tetraborohydride (Z3) and also optionally additives (Z4).

In a process for producing bleached mechanical woodpulp, said process comprising the steps of a) delaminating comparatively large particles of wood, which have optionally been pretreated with chemicals and/or water, into modified particles of wood, b) grinding the modified particles of wood from a) in one or more refiners, c) optionally treating the stalk obtained in step b) with oxidative or reductive bleaching agents, a composition Z is present during step a) and/or step b), said composition Z comprising one or more of the following components (Z1) to (Z3): a salt of dithionous acid H.sub.2S.sub.2O.sub.4 (Z1), a dithionous acid or dithionous acid derivative generator compound (Z2), a salt of sulfurous acid (sulfite) plus sodium tetraborohydride (Z3) and also optionally additives (Z4).

A method and an arrangement for generating process steam at a chemical pulp mill. Water is heated by subjecting it to an indirect heat exchange contact with steam in a heat exchanger. The water is heated with live steam produced in a steam boiler for generating process steam, whereby the live steam is condensed and the generated condensate is recovered. The process steam is subjected to a direct heat exchange contact with a material for heating the material. The water used for process steam production is obtained from secondary condensates, purified waste water and/or raw water. Process steam can be used in the treatment of cellulosic fibrous material, such as chips.

Methods for preparing aqueous suspensions comprising microfibrillated cellulose, and optionally inorganic particulate material, with increased tensile properties, and methods for selecting a fibrous substrate comprising cellulose for preparation of microfibrillated cellulose having increased tensile properties.

Methods for preparing aqueous suspensions comprising microfibrillated cellulose, and optionally inorganic particulate material, with increased tensile properties, and methods for selecting a fibrous substrate comprising cellulose for preparation of microfibrillated cellulose having increased tensile properties.

A center plate for a rotor in a pulp refiner has a surface provided with at least one feeding wing for directing lignocellulose-containing material towards a periphery. The feeding wing is an elongated protrusion arranged such that its second end is arranged further away from a center of the center plate than a first end and also is displaced relative to the first end in a direction opposite to a direction of rotation of the rotor. The center plate is also provided with at least one counter-feeding wing for directing steam flowing along the surface towards the center of the center plate. The counter-feeding wing is an elongated protrusion arranged such that a second end of the counter-feeding wing is arranged further away from the center of the center plate than a first end and closer to the center of the center plate than the first end.

A center plate for a rotor in a pulp refiner has a surface provided with at least one feeding wing for directing lignocellulose-containing material towards a periphery. The feeding wing is an elongated protrusion arranged such that its second end is arranged further away from a center of the center plate than a first end and also is displaced relative to the first end in a direction opposite to a direction of rotation of the rotor. The center plate is also provided with at least one counter-feeding wing for directing steam flowing along the surface towards the center of the center plate. The counter-feeding wing is an elongated protrusion arranged such that a second end of the counter-feeding wing is arranged further away from the center of the center plate than a first end and closer to the center of the center plate than the first end.

The present invention relates to pulp molded products including seaweed by-products and methods for producing the same. According to the methods of the present invention, pulp molded products including seaweed by-products are produced using apple pomace and/or green tea pomace. The presence of seaweed as a biodegradable and eco-friendly material and the addition of apple pomace and/or green tea pomace allow the pulp molded products to have natural antibacterial and anti-insect functions.

The present invention relates to pulp molded products including seaweed by-products and methods for producing the same. According to the methods of the present invention, pulp molded products including seaweed by-products are produced using apple pomace and/or green tea pomace. The presence of seaweed as a biodegradable and eco-friendly material and the addition of apple pomace and/or green tea pomace allow the pulp molded products to have natural antibacterial and anti-insect functions.

In a method for producing nanofibrillar cellulose, cellulose based fibre material, in which internal bonds in cellulose fibres have been weakened by preliminary modification of cellulose, is subjected to disintegration treatment in form of pulp comprising fibres and liquid. The fibre material is supplied at a consistency higher than 10 wt-%, preferably at least 15 wt-%, to a disintegration treatment where fibrils are detached from the fibre material by joint effect of repeated impacts to the fibre material by fast moving successive elements and the weakened internal bonds of the cellulose fibres. The nanofibrillar cellulose is withdrawn from the disintegration treatment at dry matter which is equal or higher than the consistency of the fibre material.

In the disintegration treatment, the fibre material is supplied through several counter-rotating rotors (R1, R2, R3 . . . ) outwards in the radial direction with respect to the rotation axis (RA) of the rotors in such a way that the material is repeatedly subjected to shear and impact forces by the effect of the blades (1) of the different counter-rotating rotors.