Modification Of 3D Printing Materials Photosensitive Resin

3D printing photosensitive resin has the characteristics of high forming precisi-on,fast processing speed and excellent mechanical properties.It has been widely ap-plied in many fields such as automobile manufacturing industry,casting industry an-d medical industry.Due to the shrinkage rate,gel content,viscosity,curing time and hardness,the quality of the printed products can be affected.Therefore,it is of great significance to study the technological formulation of high quality photosensitive re-sin.Bisphenol F epoxy acrylate prepolymer was prepared by using Bisphenol F epoxy resin and acrylic acid as raw materials,followed by mixing with diluent TPGDA and photoinitator BDK at the ratio of 70%:26%:4%to produce photosensitive bisphenol F resin.Its Shrinkage ratio and gel content were studied to for the optimum synthesis process.The orthogonal experiment results showed that,at 100℃,with 1.0%tetramethyl ammonium chloride as the catalyst,0.1%bisphenol as polymerization inhibitor and the mass ratio of 1:0.8 between epoxy resin and acrylic acid,bisphenol F photosensitive resin’s shrinkage ratio was 5.05%after 4 hours’ reaction,which was 30%lower than Bisphenol A epoxy resin.The gel content was 92.25%,which was 3%higher than Bisphenol A epoxy resin.The curing time was 13s,which was 28%lower than Bisphenol A epoxy resin.Meanwhile,the sensitivity to UV light and sensitivity and absorption capacity to UV were also improved.It can be used for 3D printing.The experiment showed that,when using bisphenol F epoxy acrylate resin as prepolymer,tripropylene glycol diacrylate(TPGDA)as diluents and(2,4,6-Trimethylbenzoyl)diphenyl-phosphine oxide(TPO)as photoinitiator with the mass ratio of 70%:26%:4%,the photo sensitive resin was well dispersed when 5%(mass ratio)thermochromatic material was added.The final viscosity of photosensitive resin was 458 mPa s,and the gel content was 90.65%.the final printing product shrinkage was 4.34%,the curing time was 13s and had reversible color change at 140℃ to used in passive without chip temperature label.Observing under microscope,there is good suspension also homogeneous dispersion in photosensitive resin,when mass ratio of the addition of graphene oxide is 0.1%.The final viscosity of photo sensitive resin was 468 mPa s,shrinkage ratio was 4.14%,and the gel content was 89.65%.the curing time was 13s.Tension strength is 21.65 MPa,and pencil handness 5H to satisfy the request of 3D printing.Compared with the ordinary photosensitive resin,hardness increases the hardness level four,tension enhanced 30%.There was something flaw during printing of configured existence of gap if printing complexed structure buckling deformation in printing plate structure,there was an analysis about flaw according to experiment.