Patent ID: 6645593
Filing Date: 2003-11-11
Classification: B27N,E04B,Y02A,Y10T

Abstract:
A fibreboard formed of a fibrous tissue by dry forming in a forming box and with subsequent fixing of fibres by heat treatment in an oven, the fibres are selected from synthetic fibres, natural fibres or a mixture thereof, the fibreboard is comprised of at least one layer of said fibres, the thickness of the fibreboard and the density are adaptable, and the fibreboard has rupture zones perpendicular to the surface of the fibreboard, the rupture zones extend in at least one direction, the rupture zones are comprised of a rupture zone gap having a height of between 10% and 100% of the thickness of the fiberboard, the forming of the fibreboard of a fibrous tissue by dry forming directly provides rupture zones which do not have through-going fibres in the gap of the rupture zone, thereby forming a rupture zone gap without the use of cutting tools, the rupture zone gap further including two sides being bonded to each other to close the gap.