Flexural Modulus of Lasersintered PA 2200

Abstract

With the evolving of rapid manufacturing methods, new fields of application become feasible. Selective Laser Sintering (SLS), an additive process, allows the production of medical devices made out of PA 2200, a biocompatible plastic powder. Due to the fast production cycle, medical robots or devices can be highly customised. However, those new production methods force the engineer to design robots and mechanisms adapted for this process. In particular the use of compliant structures is necessary if small mechanisms are to be created. Creating laparoscopic grippers out of flexible hinges revealed that there are properties unknown for the particular material used. Lasersintered PA 2200 parts seem to have a flexural modulus, which varies with their thickness and build orientation during the production process. This paper investigates those phenomenons with three-point loading tests. A dependency could be found and has been characterised for five orientations allowing the engineer to estimate the flexural modulus of lasersintered PA 2200 parts according to their thickness.