| 摘要 |
<p>A method and apparatus for the extrusion processing of wood particles and fibrous material is provided which uses an extruder (20) having an axially rotatable flighted screw (96) to subject the material to impregnation by a chemical treating agent by constricting the fibers, concentrating the agent in the material, and then permitting the material to expand in a sponge-like manner to absorb additional treating agent. The impregnation is accomplished within impregnation zones (A, B, C) along the extruder and defined by structure within a groove (106, 108) on the flighted screw (96). A plurality of chemical injection ports (56) may be circumferentially spaced around the barrel (26) of the extruder to ensure thorough and even chemical distribution through the material to be treated. In the process hereof, the material may be exposed to a first agent in a preconditioner (208) and thereafter exposed to a second, complementary agent in the extruder (20).</p> |
