Research On Recoating Technology Of Stereolithography Rapid Prototyping

Stereolithography (SL) is the most widely used Rapid Prototyping technique all over the world, which plays an important role in the product design and evaluation, function test and product showing, etc. In several years recently SL have been developing very quickly in China, but its technology used is far from advanced ones in foreign countries. Recoating technology is one of the most important technologies of SL, which make great effect in improvement of SL stability, efficiency, precision. So this paper covers a comprehensive theoretical study, and developed new recoating system in HRPL.Through researching into recoating technology adopted in SL apparatus presently, this paper designed and developed a new type recoating system used vac-sorb pump, which included design of resin vac-sorb recoating device and overflow liquid level controlling device. A recoating blade that could keep resin inside was brought forward, which have a good action in improvement of coat quality and efficiency. Peristaltic pump was applied in overflow liquid level controlling device, which achieved fine control of flow ratio. Processing parameter was optimized in some way, recoating type was chose according to the part characteristics, and blade action was self adapting controlled. For the adoption of scanning method used different layer thick according to different region, the precision and efficiency is enhanced in evidence.Resin level detection & control technique is one of the very important technologies of recoating, which plays a critical role in the reliability, efficiency and accuracy of coating. A method which used the reflection of laser to detect and control the resin level is put forward, which made use of the Position Sensitive Detector (PSD) and based on the elements of laser triangular surveying. Based on the level detection method, Auto conditioning the resin level through elevation and subsidence of resin tank is put forward, which is basic of development of a new generation SL apparatus and processing.