| The continuous development of 3D printing technology has changed the concept and mode of traditional manufacturing,and has become a representative subversion technology in the manufacturing industry,and has gradually been applied in many fields such as national defense,aerospace,machinery manufacturing,transportation and biomedicine.At present,3D printing technology is divided into selective laser sintering,selective laser melting,fused deposition molding,stereolithography,polymer jet technology,etc.according to different molding processes,among which stereolithography has its advantages in high-precision printing.The share of the above is constantly increasing.At present,domestic research on stereolithography mainly focuses on hardware technology.There are relatively few researches on consumables with excellent performance.Most of the commercial resin materials come from imports and the price is high,which limits the development of domestic 3D printing.In view of this,based on the 3D printing system based on digital light processing(DLP)technology developed by our research group,we developed the photosensitive resin with excellent performance in the 405nm band and applied it to the DLP-3D printing system.The main work of this paper is as follows:(1)The physical properties of the radical type photosensitive resin were studied and analyzed.We chose aliphatic urethane acrylate as the oligomer,and tripropylene glycol diacrylate(TPGDA)and trimethylolpropane triacrylate(TMPTA)were mixed in 3:2 to make thinner,{double(2,4),6-trimethylbenzoyl)phenylphosphine oxide}(819 is also called BAPO)as a photoinitiator,through experimental comparison,determined the best material ratio of 405nm band applied to DLP-3D printing system(60:40:3),a volume shrinkage of 8.5%and a viscosity of 232 mPa · s of a radical type photosensitive resin were obtained.(2)The physical properties of the cationic photosensitive resin were analyzed.Although the common cationic initiator is less in the 405 nm band,the corresponding cationic photosensitive resin is not used in the DLP-3D technology,but the cationic photosensitive resin has a small volume shrinkage,so it has a good application prospect.Through experimental comparison,we selected bisphenol A modified epoxy acrylate as oligomer,ethoxylated trimethylolpropane triacrylate(TMPE03TA)as diluent,bis[2,6-difluoro-3-(1H)-pyrrolyl-1)phenyl]titanocene(784)as an initiator,according to the optimum ratio of 60:40:3,finally obtained a cationic light-sensitive film with a volume shrinkage of 2.25%and a viscosity of 742 mPa · s in the 405 nm band.Resin.(3)The free radical and cationic mixed photosensitive resin was studied and analyzed.The bisphenol a type modified epoxy acrylate and the aliphatic urethane acrylate are mixed as an oligomer in a ratio of 1:1,(TPGDA)and(TMPE03TA)are mixed in a ratio of 3:2 to prepare a diluent,and 819 and 784 are photoinitiator.As the initiator,a photosensitive resin with the volume shrinkage ratio of 2.6%and a viscosity of 249 mPa·s was obtained in accordance with the final ratio of 59:41:3.At the same time,we added nano-inorganic to improve the mechanical properties of the resin and perform DLP-3D printing tests.By comparison,we found that the performance of mixed resin is competitive with the imported resin in the viscosity hardness parameter,and is superior to the imported resin in volume shrinkage.It is the photosensitive resin with the best comprehensive performance in this paper. |
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