Abstract: An improved, low cost, energy efficient extrusion device and method for processing of cellulose, hemicellulose, and like fiber-bearing materials is described which includes a pretreatment extrusion zone and a reaction extrusion zone separated by a pressure sensitive variable die. The method hereof includes the steps of extruding cellulosic material through the pretreatment zone at an elevated pressure and temperature, passing the material into the reaction zone where it is mixed with an acid and is processed at a lower pressure and temperature than in the pretreatment zone, and extruding the material through a final extrusion die. The surging and blowing usually experienced with extrusion of fibrous material is drastically reduced by the unique construction of the extruder die members. The cellulosic material may be hydrolyzed to simple sugars in accordance with the method and apparatus hereof with a minimum of acid degradation of the extrusion equipment.

Abstract: An extruder for processing wood particles, shavings or sawdust is particularly useful for the production of a refined product exhibiting a large number of separated, individual fibers each of a relatively long length as is desirable in the production of a fiber core for a composite particle board. The extrusion apparatus comprises an elongated barrel and a flighted screw rotatable within the barrel, with the final downstream section of the screw being of a configuration to sequentially present three processing zones each having a compression region, a restricted region and a decompression region. The three processing zones of the final screw section cooperate with a compression region and restricted region formed in the final head section to choke the advancement of wood materials through the extruder sufficiently to enable satisfactory processing of the same without the use of a final die or restricted orifice disposed on the outlet of the extruder barrel.

Abstract: An improved, low cost, energy efficient extrusion device and method for processing of cellulose, hemicellulose, and like fiber-bearing materials is described which includes a pretreatment extrusion zone and a reaction extrusion zone separated by a pressure sensitive variable die. The method hereof includes the steps of extruding cellulosic material through the pretreatment zone at an elevated pressure and temperature, passing the material into the reaction zone where it is mixed with an acid and is processed at a lower pressure and temperature than in the pretreatment zone, and extruding the material through a final extrusion die. The surging and blowing usually experienced with extrusion of fibrous material is drastically reduced by the unique construction of the extruder die members. The cellulosic material may be hydrolyzed to simple sugars in accordance with the method and apparatus hereof with a minimum of acid degradation of the extrusion equipment.