Method and apparatus for the production of a blank for a structural product, and blank so produced

摘要

Procedure for the fabrication of a blank for a structural product, such as a blank for a structural board, from material (1) comprising longer (L) and shorter (S) particles and possibly also particles (F) smaller than these. The particles are mixed with a binding agent and possible additives and then passed into at least one blank former, from where the particles are brought onto a base (10). Longer particles (L) are brought onto the base (10) to form a first surface layer, onto which is brought at least one layer of smaller particles (F, S), and onto this layer is again brought a layer of longer particles (L) to form a second surface layer, the smallest particles (F) being so brought onto the base that they mainly end up in at least one middle layer in the cross-section of the blank while the amount of smallest particles (F) diminishes towards the surface layers as seen in the cross-section of the blank. The invention also relates to an apparatus implementing the procedure and to a blank for a structural product. <IMAGE>