Research On The Fabrication Of Personalized 3D Prosthesis Based On SPPC

Nowadays the development of traditional manufacture benefits from the rapid development of 3D printing. Especially the rise of rapid tooling based on 3D printing has witnessed its widely application in all industries, such as auto parts manufacturing, bio-fabrication, bionic medicine and multi-functional materials. With the expiration of key patents of FDM 3D printing and the prosperous progress of 3D printing open source project, desktop FDM 3D printer is rather stabile and easy to be modified, making it popular among DIY amateurs. Compared to industrial grade 3D printer, desktop FDM 3D printer is lower in precision, higher in surface roughness and less available materials. However, it is much cheaper and easier to manipulate. A rapid tooling manufacturing method based on desktop FDM 3D printer is proposed in this paper. The rapid mold is polished to eliminate the stair case on the surface. And its surface roughness has been quantitative researched to obtain the best polish technological parameters of different structural molds, which is quite important in promoting the surface quality of the final models. This technical has been widely used in human prosthesis, medical simulator and so on, expanding the application fields of desktop 3D printer.First of all, the process of SPPC based on desktop 3D printer is clarified:building model—design mold—printing—post processing—casting—demoulding. For those molds with complicated structure which is impossible to fabricate by just one mold, part fabrication is necessary, and upper and lower molds are designed and printed, then sealed by bolts before casting.Then the extruding filament process of FDM printer is modeled and analyzed. According to the definition of surface roughness, the relationship functions among the surface roughness, the curve of filament section and the angle of rapid mold surface are built up. The polishing surface roughness is quantitative analyzed with the help of surface roughness tester. The polishing universal rules are summarized and the optimal polishing parameters are obtained. As the result shows, the surface roughness of the polished rapid mold surface can be as smooth as 1μm, which is equally smooth as the finish machining in traditional processing method.Based on the techniques discussed above, the personalized customization of silicone prosthesis comes true with the combination of rapid tooling and silicone mold casting. As desktop FDM 3D printer is low cost and easily manipulated, the stair case on the rapid mold can be eliminated by acetone vapor, personalized silicone prosthesis with smoothed surface can be fabricated in low cost and short time. Everybody can fabricate their prosthesis at home or in the hospital.Meanwhile, the SPPC method can also been applied to the fabrication of medical bionic simulator. "With the help of personalized simulator, the intern doctor can improve their learning efficiency and grasp the surgical techniques in short time. What’s more, based on the bionic simulator of the patient, doctor can make up the individual operation plan before surgery, which will raise the surgical success rate efficiently.