Patent ID: 11299853

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.