Three-dimension Print Molding Technology Based On DLP

3D printing technology is mainly used in aerospace industry,food industry,automobile industry,medical industry and so on.In recent years,dental 3D printing in the medical industry has become popular,so this paper selected for dental 3D rapid prototyping technology to research.Commonly used in dental 3D printing rapid prototyping technology mainly has the following four:FDM technology,SLA technology,PolyJet technology and DLP technology.FDM technology has the disadvantage of low precision molding,forming speed is slow,the printer structure of high precision,the nozzle temperature requirements are high,in addition,the printing material needs to melt in the nozzle,will produce irritating odor gas;SLA technology has the disadvantage of needing for a dedicated experimental environment,after needing for secondary curing and other post-processing,laser tube life is short(3000 hours or so,expensive),forming a long time,the use of raw materials is limited;The shortcomings of PolyJet technology are the high cost of supplies,which is very demanding on the structural accuracy of the printer.The DLP technology is a high-resolution DLP projector to cure the liquid photopolymer,each time curing a level,the stepper motor to drive the slider down a distance until the complete three-dimensional objects.Compared with the former three molding technologies,DLP technology is the greatest advantage of forming fast,high precision.The former three molding techniques are taken from point to line,then to the surface,and finally to the three-dimensional objects,and DLP technology is directly into a face,and then to three-dimensional objects,so the molding speed.For DLP technology,the higher the resolution of the projector,the higher the molding accuracy.Although the molding technology can be used less printed materials,but for the application in the dental,the current MED610 this print material is sufficient to meet the needs,so the impact is not large.Through the comparison of the above four molding techniques,this paper chooses the DLP technology with high forming speed and high precision to realize the 3D printing of objects such as dentures,dental molds and braces.The 3D printer based on DLP molding technology is mainly composed of DLP projection system,printer server,steppeing motor control system,stepping motor kit and forming kit.The DLP projection system based on DLP projector to improve,through the HDMI interface to connect to the printer server,for the transmission of 3D model image information,so that it projected onto the molding platform to solidify the liquid print material molding;print server is based on raspberry and the other parts of the printer work to complete the print task;stepper motor control system is based on the Arduino Mega2560 platform to build,through the USB platform,which is the core part of the design system for the client access to upload 3D print files and control the other components of the printer work to complete the print task.The stepper motor is composed of three parts:stepper motor,screw and guide rail,mainly when the signal of the stepping motor drive system is received,the molding platform is driven by the molding machine.The stepping motor is used to control the movement of the stepping motor.The molding kit includes a molding platform and a molding groove for placing a 3D printing object and a liquid printing material.The stepping motor control system,the stepping motor kit and the molding kit together form a mechanical system of the printer.In order to improve the molding accuracy and molding speed,this paper is based on the DLP projector to build a verification platform,the specific steps are as follows:First,the projector's optical system to optimize the light source and the projection lens coincides with the projection surface edge illumination closer to the central light intensity,to improve molding accuracy;Second,the design of trapezoidal optical integrator,enhanced UV light energy,shorten the curing time,to improve molding speed.The results show that compared with the modified optical system,DLP print accuracy(0.05mm)to high and print speed(0.013mm/s)to be fast.Through the final experimental results show that the study of this fast molding,high precision,simple structure,low cost of the 3D printer can be used in the dental aspects.