Novel recoating process with dynamic optimized blade speed

In order to improve the recoating quality of piston recoating system and resolve the problem that resin layer thickness increases with the height of object during building process in high-resolution stereolithography system, a novel recoating process whose blade speed is dynamically optimized during building process is proposed. Experiments are carried out to investigate the influence of blade speed and object height on the thickness of resin layer. The mathematical model describing the relationship of recoating layer thickness with object height and blade speed is established with response surfaces methodology. Based on the mathematical model, blade speed is dynamically optimized according to the object height during building process, and then uniformity resin layers can be obtained. Verifying experiment results show that compared with current recoating process, the novel recoating process reduces the difference between maximum and minimum thickness of resin layer from 27 μm to 6.9 μm. Experiment results also indicate that the problem that the thickness of resin layer which increases with the height of objects is resolved, and the uniform resin layers have been obtained. As a result, fabricating accuracy of microstructures in building direction is improved. The methodology of the novel recoating process can be applied to current stereolithography system as a solution to the problem that the thickness of resin layer increases with the height of objects when fabricating objects with trapped volume, therefore the new recoating process has important significance for stereolithography system to improve building accuracy.