Study On Soft Nylon Used In 3D Printing And Soft PUA UV-curing Resin

Most of 3D printing materials are hard and the application of its printing specimens in the textile and clothing proofing and other areas which have a higher demand of soft is limited.Therefore,the research of the application of soft materials in 3D printing is necessary.In this paper,the preparation process and printing process of soft nylon 3D printing wire in fused deposition modeling were optimized.Then the synthesis process of the PUA prepolymer resin in UV-curing was studied.Finally,the UV-curing resin formulation was discussed and the UVcuring properties of the resin were studied.Firstly,the 3D printing wire was fabricated from the soft material PA12/3533 by twinscrew extruder and then the printing process was studied by the desktop melt-deposited 3D printer.Both these wire-making process and printing process were studied.The results show that,the processing temperature range of material PA12/3533 is wider before it reaches the decomposition temperature,which is suitable for extrusion and printing,and also the processing temperature and extrusion rate have a very important influence on the experiment.In the preparation process of PA12/3533 soft 3D printing wire,the wire will be affected by the selfweight and will fall down naturally when the extrusion temperature is high,so that it can not be drafted.And also when the extrusion temperature is low,the melt viscosity is large,the flow resistance is large,so that the wire can not be squeezed out.To improve the screw speed and feed speed appropriately is beneficial for the stable extrusion of the wire.For the soft material PA12/3533,the optimum extrusion parameters of 3D printing wire are as follows,the four zone temperature are set to 180 ?,185 ?,190 ?,195 ?,the screw speed is 35 r/min,the feeding speed is 20 r/min.In the 3D printing process of PA12/3533 soft wire,the moving speed should not too fast,the layer hight and the print temperature should not too high,otherwise the mechanical properties printing specimens is poor.For PA12/3533 soft wire,the optimum 3D printing parameters are,moving speed 40 mm/s,layer height 0.10 mm,printing temperature 200 ?.On the basis of the above optimization process,we also explored the application of soft material PA12/3533 in textile and clothing proofing and industrial production,and the printing dress and wheel model under this process has a good modeling style and flexibility.Secondly,the PUA prepolymer resin,which is an important component of the UV-curing resin,was synthesized combining with the molecular structure design,and its synthesis process was studied.The results show that,to increase the first step reaction temperature and to decrease the second step reaction temperature appropriately and add proper addition of catalyst and polymerization inhibitor can shorten the reaction time,improve the reaction efficiency and reduce the double bond loss.The optimum reaction conditions are as follows,first step reaction temperature 65 ?,reaction time 3 h,catalyst DBTDL content 0.10 %,second step reaction temperature 55 ?,reaction time 4 h,catalyst content 0.15 %,polymerization inhibitor HQ content 0.20 %.The PUA prepolymer resin synthesized in this condition has generated the polyurethane segment structure.Finally,A kind of soft UV-curing PUA resin was prepared and the effect of the kind and content of the photoinitiator and diluent on the mechanical properties of the UV-curing specimens were studied.The results show that,the UV-curing resin prepared in this experiment is soft and has good mechanical properties.The type and content of the photoinitiator have a great influence on the curing speed of the resin.The type and content of the diluent mainly affect the mechanical properties of the resin after the UV-curing.In this experiment,the UV-curing time is the shortest when the content of TPO is 3 %.And when the content of diluent 2-EHA is 10 %,the UV-curing resin has the best mechanical properties.The UV-curing PUA resin prepared according to this formula has been irradiated with a 405 nm laser(power of 1 W)can be fast curing and the interlaminar bonding force and softness of curing specimen is good,which is expected to be further developed into a soft UV-curing 3D printing resin.