Zhongyun He

Development and research of vacuum coating system in SL

Purpose – The purpose of this paper is to show how to precisely control the liquid resin coating thickness in stereolithography (SL).Design/methodology/approach – A vacuum adsorption coating equipment and technology are developed to precisely control the liquid resin coating thickness in SL. Dual‐electrode device is used, so adsorption can be precisely controlled and the electrode polarization can be avoided.Findings – It turns out that the apparatus can control coating thickness effectively, and thickness uniformity is increased remarkably, which induces the standard deviation thickness decrease from 0.00547 to 0.00243 mm, and efficiency of rapid prototyping production increase by 53 percent.Originality/value – The paper demonstrates that the apparatus can control coating thickness effectively.

A detection and control method of resin liquid‐level of stereolithography apparatus

Purpose – The purpose of this paper is to detect and control the liquid‐level of stereolithography apparatus precisely.Design/methodology/approach – A brightness‐variable laser source is adopted to remove the computational error of divider and a closed‐loop circuit is set to measure the terminal voltage directly proportional to the output current of photosensitive devices. It employs a sinking‐block device to control the liquid‐level.Findings – The precise calibration result of this detecting device indicates that the resolution of the liquid‐level detection can reach ±1.5 μm.Originality/value – This sinking‐block style liquid‐level control device can allow for the liquid‐level wave reduced from ±45 to ±15 μm.