A paper or paperboard product having at least one layer containing high yield cellulose and a method for its manufacture

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. 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.