In the single-screw extruder a vibration force field was applied to the solids conveying process by the axial vibration of the screw and a novel concept of the solids conveying process being strengthened with the vibration force field was brought forward.A mathematical model that described the solids conveying process with the vibration force field was established and the approximate analytical solutions of the pressure and velocity of the solids conveying along the screw channel were obtained.When the amplitude of the axial vibration of the screw was zero

the new solids conveying theory presented in this paper could describe the conventional solids conveying process

namely

the conventional solids conveying process was the special case of the one being strengthened with the vibration force field.In the new theory

if the screw has no axial vibration the solids conveying pressure is the same as that of the Darnell and Mol theory

but the density and velocity of solids conveying along the screw channel are variable

which has modified the Darnell and Mol theory in which the density and velocity of the solids conveying along the screw channel are considered invariable.The theoretical results reveal that the axial vibration of the screw can increase the average pressure of solids conveying

decrease the channel length of the solids conveying section and increase the solids conveying angle.In the self-developed experimental extruder with transparent barrel

the successive visualization experimental results proved that the axial vibration of the screw indeed shortened the channel length needed for solids compressing and conveying.