| 摘要 |
<p>In a process for producing mouldings, in particular particle boards, at leas t one binding agent is mixed with a least one fine-particle basic material extruded at high temperature and pressure. The basic material has, or is brought to, a total content of 6 to 25 wt.%. It is extruded, together with at least one biopolymer, preferably a binding agent containing starch which can be con- vented to molten and/or gel form at least at the extrusion temperature and pressure, and the fine-particle material. Immediately after extrusion, the pressure is relieved by spontaneous expansion. The devi ce for implementing the process comprises extrusion machines (2,20) for starting components in lump form. These machines have an extrusion nozzle (26,260) and an upstream pro- cessing region (204) where the basic material to be processed is partially pressure relieved by internal partial expansion. The ex- truded mouldings have a compact surface and a basic material in which particles of a fine-particle fibrous material are distribut- ed throughout a matrix containing numerous minute voids. The fraction of starch-containing matrix is equal to 5 to 85 wt.%.</p> |
