The Design Of Fused Deposition Modeling Rapid Prototyping Machine And The Study On It's Theory

Fused Deposition Modeling has great value not only in science, but also in the industrial application. The technology has been thoroughly analyzed in the aspects of principle, material, conditions of no spilth in feeding section, the erection of the melted modeling and the design principle of FDM machine.Based on the study of polymer performance, the special performance that used in the FDM. The flow principles of melted polymer in the die and heated tube were investigated. The relationship between the needed driven force and the main flow parameters, such as flow rate, structure parameters of the liquefier, were educed, which theoretically promoted the design of the new die and heated tube system.Though the conditions of no spilth in feeding section, the boundary velocity of the feeding polymer wire has been found out; The melted modeling in the melting process is erected, which is the theoretical bases for the design of heated tube. Applied with the finite element analysis, the changing rule of the interphase boundary is educed, which is the bases in the choice of heating power and the temperature of the inner face.Based on the preceding study, the FDM machine is designed. The key problem is focused on the feeding section and the extrusion of the melted polymer wire. The separation between the filament drive set and thefilament extrusion mechanism has solved the problems of bigger filament extrusion head. The friction driving force and the best angle of the flute on the friction wheel when the friction driving force is in the max are made out. The analysis of fluid flow in filament extrusion is made, the connection between drive power and parameters of the flow path in varies flow paths which are in series combination and the connection between parameters of respective flow path and pressure difference are analysed. The control system of the filament extrusion head is designed adaptive with the structure.