Research on novel solid conveying theory of grooved feed extruders

摘要

Grooved feed extruders are widely accepted in present plastics process industry. However,enormous shear heat and huge pressure gradient in solid conveying zone can not be solved and many researchers thought grooved feed extruder can not make positive conveying in solid conveying zone.Double-flight driving theory, one novel solid conveying theory, was proposed based on the model of arc plates in solid conveying zone. The key idea is to avoid circumferential shear to the solid plug and translate from friction drag conveying to positive conveying in solid conveying zone. Through motion analysis and force analysis of the solid plug, one can find that the driving forces from screw flank and feeding sleeve flank are the reason of the motion of solid plug. Friction forces between solid plug and screw surface or feeding sleeve surface are both resistance forces. Furthermore, the boundary condition avoiding circumferential shear to the solid plug can be decided by the determination coefficient k.