voxeljet AG

Possibilities for functional prototypes, small series and volume production

For 3D functional parts manufactured in PA12, PP, TPU, PEBA and EVA based polymers; the voxeljet High Speed Sintering (HSS) process opens up new dimensions in product development in every respect. With industry leading productivity, surface quality, and precise shape and edge definition, we offer an alternative to injection molding quality. Our large and high-speed 3D polymer printers drive efficiency and output for economical operation. Laser-free high-speed polymer sintering is an exciting alternative to injection molding, even in the production of small components or functional parts with complex geometries.

Polymer High Speed Sintering is a 3D printing process in which powder material applied in thin layers is selectively wetted with an ink and fused by means of energy input. The coater applies hair-thin layers of powder material (e.g. PA12 or TPU) to the heated building platform, which is then selectively wetted by the inkjet print head with an infrared-absorbing ink. By irradiating the layer with infrared light, the ink-dyed parts of the component fuse together, while the uncolored powder remains loose. These steps are repeated until the component is assembled. In practice, several components are usually produced in a single job box to achieve maximum production efficiency. Finally, the entire installation space is cooled in a controlled manner. After the printing process, the printed components are freed from unbound printing material and prepared for further processing. voxeljet materials are resource-friendly and, depending on the material, unbound powder residues can be fed back into the production cycle.

Grayscale for variable object properties

voxeljet High Speed Sintering (HSS) is similar to the laser sintering of polyamides and other polymers - only without a laser. Polymer sintering combines the advantages of this technique with higher production speed, material variety and optimum surface quality. It is the first system to combine the greyscale and dithering processes with unique possibilities to partially influence the material properties in grid structures and solid material. Our unique greyscale process enables the material properties of the part to be varied in all three dimensions. This can be the partial change of mechanical strength, elasticity, or material density in the product, such as, for example, to optimize the ergonomics, weight and center of gravity of a product to a previously unattainable extent.

The grey value, greyscale or grey level indicates the amount of ink printed into the powder. Depending on the material used, up to six different grey levels can be printed into the powder material. The inkjet printheads are controlled via bitmaps. Since the printhead controls the amount of infrared-absorbing ink in the HSS process, the drop size of the absorber and thus the grey value per volume can be changed. Furthermore, the grayscale can be combined with dithering (simulation of actually non-existent intermediate steps via certain pixel arrangements / rasterizations). This allows even finer adjustment of the absorption coefficient, the energy input and thus the effective temperature of the powder material, which has a further influence on the material properties.

The young technology of 3D printing expert voxeljet has great potential for a variaty of industries. Material diversity, resource conservation, lightweight construction, customisation and performance enhancement for end customers are just a few of the potential benefits.