| 摘要 |
<p>A process and apparatus for extrusion of a mixture of vegetable bits with a binder, particularly wood chips with a weather-resistant binder, comprising precompressing in a compression chamber of an extrusion press the mixture by a compression stroke transverse to the extrusion axis, the compression stroke being delivered by at least one precompression piston, wherein the improvement comprises mixing the mixture prior to precompression with elongated bits which will be acted on by an orienting influence in a known way so that the elongated bits are deposited substantially parallel to the extrusion axis, and performing the precompression of the outer layers of the mixture with a reduced precompression ratio so that the bits oriented prior to precompression remain fixed in position during the subsequent extrusion stroke. Preferably the elongated bits in the mixture are oriented by free fall of the mixture through a plurality of upright, thin-walled bars of approximately equal height positioned above the compression chamber during filling of the extrusion apparatus by a mechanical hopper moving to and fro over the bars continuously. The bars may be vibrated and the hopper moved intermittently instead of continuously as an alternative.</p> |
