摘要 |
A fibreboard (4) formed by dry forming of a fibrous tissue (2) in a forming box (6) with subsequent heat treatment in an oven, wherein the fibres are selected from synthetic fibres, natural fibres or a mixture thereof, and wherein the fibreboard (4) is provided with rupture zones (30). The inventio n also relates to a forming box (6) for use in the manufacture of fibreboards (4), wherein the forming box (6) is arranged above a forming wire (14) which extends across a vacuum box (20). The object of the invention is to introduc e rupture zones (30) in fibreboards (4) which are formed directly in the formi ng process, and that the gap (36) of the rupture zone is formed without the use of cutting tools. Hereby, fibreboards (4) can easily be adapted in width and length without the use of tools, while separation of the fibreboard (4) provides a regular rupture face ensuring that no thermal bridge is created a t joints. The forming box (6) may be provided with vertical partitions (12) longitudinally of the forming wire (4) and sets of vertical partitions (13) transversely to the forming wire (14). The purpose of the partitions (12, 13 ) is to enable production of fibreboards (4) with incorporated rupture zones (30) or fibreboards (4) in independent webs/sections (58, 60). |