Abstract: A method is disclosed for producing a multilayer paperboard product, as well as an assembly suited for implementing the method and a paperboard manufactured according to the method, whereby the paperboard is made from at least two, advantageously three layers (4, 5, 6) bonded to each other by gluing, and the material of the middle layer (5) is subjected to mechanical working in a dry state (8) so as to deform the material prior to gluing through pressing thereon desired pattern that is raised from the surface of the material (5). The layers (4, 5, 6) are bonded to each other in a single step (7). The method is capable of providing a strong paperboard that uses less fiber than prior-art paperboards of equal thickness and strength.

Abstract: The present invention is directed to a method for the manufacture of corrugated board and to a method for gluing a fluting medium to a liner by means of hot-melt adhesives using curtain coating technique. By means of this method it is possible to manufacture corrugated board consisting of one or more corrugated layers of board and one or more layers of liner, joined to each other.

Abstract: A method for manufacturing a board product made up of at least two layers, and a multilayer board product. According to the method, the board webs (4, 5, 6) forming the layers are bonded together by gluing. According to the invention, at least one of the webs is treated mechanically by compression so that in the web surface there form permanent deformations projecting from the web surface, and the layers are glued together by using a starch-based adhesive, which is applied at a solids content over 45% to the layers to be bonded. The adhesive having a high solids content dries and bonds rapidly to the surfaces to be joined, even without additional heating. Since the adhesive contains little or no water, no after-bending or flattening of the middle layer occurs in the bond.

Abstract: A method is disclosed method for manufacturing a cardboard product comprised of at least two layers, the method comprising the step of bonding the separate webs of paper or cardboard by an adhesive into a combination product. At least one of the webs is worked mechanically by embossing so that the permanent deformations appear projecting outwardly from at least one surface of said at least one web to a height not making the web thickness to exceed 3 mm. The method is further applicable to the manufacture of a cellulosic-fiber-containing cardboard or paper product for manufacturing a multilayer cardboard grade comprising at least two adhesively bonded layers, whereby the product is worked mechanically so as to make permanent three-dimensional deformations on the product material to a height not making the product thickness to exceed 3 mm.

Abstract: A method is disclosed for producing a multilayer paperboard product, as well as an assembly suited for implementing the method and a paperboard manufactured according to the method, whereby the paperboard is made from at least two, advantageously three layers (4, 5, 6) bonded to each other by gluing, and the material of the middle layer (5) is subjected to mechanical working in a dry state (8) so as to deform the material prior to gluing through pressing thereon desired pattern that is raised from the surface of the material (5). The layers (4, 5, 6) are bonded to each other in a single step (7). The method is capable of providing a strong paperboard that uses less fiber than prior-art paperboards of equal thickness and strength.