Preparation,Structure And Properties Of DLP Type Photosensitive 3D Printing Resin For Precision Casting

3D printing technology is called an important part of "the third industrial revolution",because of its advantages of directly producing parts with any shapes from computer graphics data without machining or mould,greatly shortening product development cycle,and improving production efficiency.Digital light processing(DLP)-type light curing printing technology has the advantages of fast molding speed and high precision,which is suitable for printing precise casting components with small sizes(e.g.,personalized and little jewelry).However,3D printer and the raw material market of light curing resin are currently monopolized by foreign market,resulting in its high manufacturing cost.Therefore,the purpose of this paper was to develop a DLP-type 3D printing and precise casting light curing resin with excellent comprehensive performance and affordable price,which could be applied to jewelry.Moreover,its formula and related technology were also studies.The main contents were as follows:(1)The epoxy acrylate resin E51 with high surface hardness and low price was chosen as raw material.It was modified using polyethylene glycol 200 and then was esterified with acrylic acid to obtain modified epoxy acrylate resin.Besides,its technological conditions were also investigated.The results showed that the modified epoxy acrylate resin prepared by optimized modification and esterification process conditions had low viscosity and good stability.Furthermore,its viscosity,appearance and color had no prominent change after being kept for 3 months.(2)The modified epoxy acrylate resin,epoxy acrylate resin,polyethylene wax paste,di-tropylene glycol diacrylate(TPGDA,active diluent monomer),2,4,6-trimethylbenzoyl-trimethylphosphine oxide(TPO,photo-initiator)were used as raw materials to prepare the DLP-type light-curing 3D printing materials.Then,the sample strips and triangular pendant models were printed by 3D printers.Their structures and properties were studied.The results showed that the formula of the DLP-type 3D printing material with the optimal comprehensive performance was obtained.In addition,the flexibility of the sample strip was improved by adding modified epoxy acrylate resin,and the shrinkage rate and surface roughness could be reduced by properly adding wax auxiliary.The triangular pendant model could be quickly,completely and accurately printed out by prepared DLP-type 3D printing material.(3)The DLP-type light-curing 3D printing materials were prepared by using three active monomers(difunctional polyurethane acrylate(PUA),trihydroxymethyl propane triacrylate(TMPTA)and trihydroxymethyl propane triacrylate(TMP9EOTA)),epoxy acrylate resin,polytetrafluoroethylene-modified polyvinyl wax powder,dipentaerythritol hexacrylate monomer(DPHA),TPGDA(active diluent monomer),and TPO(photo-initiator).Then,the sample strips and diamond ring models were printed by 3D printers.Their structures and properties were studied.The results showed that the formula of the DLP-type 3D printing material with the optimal comprehensive performance was got.Besides,the softening and toughening modification effect of PUA was favorable,and the viscosity was effectively reduced by blending PUA and TMP0 EOTA.By properly adding wax,the shrinkage rate was reduced and the notch impact strength was improved,while the ash rate was not adversely affected.The diamond ring model could be quickly,completely and accurately printed out by prepared DLP-type 3D printing materials.