Abstract: A method of producing a paper or paperboard product having at least one ply comprising high yield pulp (HYP), comprising the steps of: —providing a furnish comprising at least 50% of high yield pulp (HYP) of a total pulp content in said furnish, said high yield pulp being produced with a wood yield above 85%; —dewatering the furnish to form a moist web and pressing said moist web to a dry solids content of at least 40-70%; and —densifying the moist web to a density above 600 kg/m3 in a press nip of a paper machine at a temperature above a softening temperature of water-saturated lignin comprised in said high yield pulp to provide a paper or paperboard product, containing at least 30% high yield pulp (HYP) of a total pulp content of said product.

Abstract: A method of producing a paper or paperboard product having at least one ply comprising high yield pulp (HYP), comprising the steps of: —providing a furnish comprising at least 50% of high yield pulp (HYP) of a total pulp content in said furnish, said high yield pulp being produced with a wood yield above 85%; —dewatering the furnish to form a moist web and pressing said moist web to a dry solids content of at least 40-70%; and —densifying the moist web to a density above 600 kg/m3 in a press nip of a paper machine at a temperature above a softening temperature of water-saturated lignin comprised in said high yield pulp to provide a paper or paperboard product, containing at least 30% high yield pulp (HYP) of a total pulp content of said product.

Abstract: This patent application describes a method to produce wood chips with the intention of reducing the energy consumption in the subsequent process steps for pulp production. With the present method wood chipping is done in a wood chipper where the chipping tool (3) has an angle ? (4) within the interval of 75° to 105° between the fibre direction of the log and the side of the tool which faces the chip (2). Angles in this interval will cause an axially directed compression of the chip which will cause a cracking of the wood during chipping.

Abstract: The content of ray cells in cellulose pulp causes problems and therefore these ray cells should be removed from the cellulose pulp to improve the pulp quality. The present invention makes this possible and comprises a method wherein at first an advancing pulp suspension is screened or vortex cleaned, (3) leading to the formation of an accept pulp fraction (4) and a reject pulp fraction (5) and that the reject pulp fraction is cleaned and divided, and that accepted material (pulp fibres and valuable fine material) is brought to further treatment and/or use.

Abstract: There is a need for a cheaper method of producing bleached TMP and CTMP without impairing the properties of the pulp.