| 摘要 |
To harden extruded strands of vegetable fragments and particles and a bonding agent, from an extrusion press, it is pushed through a rigid preheating zone and/or a reactor (3) if available, and then carried through a bonding section (5) which gives a bonded edge zone. The material then passes through a an evaporation zone (7) where the water contained in the material is heated abruptly. The extruded strand is heated to a suitable gelling temperature for the bonding agent, in a range of 80-100 deg C, using generally dry or superheated steam or hot water or water vapor at a temperature of 105-200 deg C. The bonding agent is thoroughly hardened in a following channel where reheating either evaporates the condensed water within the material and/or the water is evaporated again and total or partial vacuum is generated within the material so that the water evaporation temperature within the extruded strand is lower than the temperature of the strand and/or the water. |
