Influence of roller characteristics on powder layer applying in additive technologies

In the study and analysis of additive technologies, special attention is paid to increasing the productivity and quality of printed products. However, to improve the 3D printing productivity, it is impossible to increase simply the speed of the squeegee without changing its shape or type. In this case, the quality of the powder layer may suffer, which will lead to a deterioration in the qualities of the final part. To study the effect of roller characteristics on the powder layer deposition, a series of computer simulations of simulation models was carried out. The effect of roller characteristics on the powder layer applying, was assessed, for roller diameters of 30, 50, 70, 100, 150, 200, 250, 300 mm. The simulation was carried out with three application methods: by a rotating and non-rotating roller, as well as by a rotating roller with additional powder feed. It was determined that when applying a layer with a rotating roller with additional powder feed, it is possible to achieve constancy of the forces acting on the roller. This can positively affect the homogeneity of the applied layer. The application of a layer by a rotating roller with additional powder feed is most suitable for 3D printers with a large print area. This method allows avoiding the movement of a large mass of powder over the previous layer, which positively influences the quality of the final part. The study revealed the influence of roller characteristics on the deposition of a powder layer. In particular, with an increase in the roller diameter from 30 to 300 mm, the peak force value also increases. With an increase in the roller diameter by 7.9 %, the powder layer density also increases. It was found that the non-rotating roller is affected by the greatest force, and the forces acting on the rotating rollers differ slightly. A rotating roller, without adding powder, creates the densest layer and allows achieving a powder layer compaction of 5.35 %.