EXTRUDING METHOD FOR VOLATILIZATION AND SCREW TYPE EXTRUSION MACHINE FOR VOLATILIZATION

摘要

In a method for extruding a polymer composition for volatilization which comprises supplying the polymer composition containing a polymer and volatile components to a screw type extrusion machine equipped with a cylinder having a supply port and an outlet for a polymer and an outlet for volatile components and a screw being rotatably supported within the cylinder at the supply for a polymer, and discharging volatile components from the outlet therefor, while withdrawing the polymer from the outlet therefor, an improvement wherein said supply port for a polymer has an opening area of its nozzle satisfying the formula (1): phi : polymer content based on weight (kg) of polymer composition [-] ( phi is represented as 0.50 when the polymer content is 50 %); Q: rate of supply of polymer [m<3>/min]; S: area of opening of nozzle [m<2>]; H: depth of flute of screw [m]; N: spindle speed of screw [min<-1>] ; D: diameter of screw [m] is disclosed. The improvement results in efficiently removing volatile materials while avoiding vent-up.