Design of a Powder Removal Device for DirectMetal Laser Sintered Parts
Precision ADM is a global engineering and manufacturing solutions provider that produces a variety of metallic 3-D printed parts for various sectors including the medical sector. The production of such parts involves sequentially sintering thin layers of metallic powder until a part is built. Upon completion of the printing process, the part is encompassed in loose powder and must be subjected to a post-print powder removal process. Precision ADM’s current post-print powder removal process is time-consuming, labour-intensive, lacks repeatability, and exposes employees to safety risks. To address these issues, Precision ADM has commissioned a design project to a student engineering team through the University of Manitoba’s IDEA Program. The project was completed over the course of a 4-month semester. The goal of this design project was to design a device that improves the client’s post-print powder removal process, an important step in the production of 3-D printed metallic parts. After parts are printed, they are first vacuum cleaned to remove the loose encompassing powder but some powder remains within the tight spaces and voids of the part. This powder must be completely removed for parts to meet the medical industry’s stringent regulations. The proposed solution to this challenge is a fully automated device with three modes of powder removal: gravity-assisted powder removal, vibration and impact, and blow-off air cleaning. The device rotates the build-plate about two rotational axes, allowing gravity to pull powder out of part voids at virtually any spatial orientation. Continuous vibration and forceful impacts are delivered to the parts by two vibration motors and a pneumatic impactor, respectively. Blow-off air cleaning is accomplished using an industrial air knife attached to a linear actuator. Automation and control of these systems is achieved via a PLC system and compatible sensors, switches and valves. Powder removal takes place in a sealed enclosure that is connected to a powder collection-and-recovery system. The device also features a blow-out panel which allows for excess pressure to be released from the enclosure into an adjoining vent in case of a powder explosion. The design of this vent is provided as a mitigation and is...