| abstract |
A method for manufacturing a multi-layered paperboard, which comprises at least two fibrous layers, in which method at least one layer of the multi- layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form comprising anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to the fibre stock from which at least one of the fibrous layers joined together is formed. |