The Danish software company Create it Real from Aalborg (Denmark) entered into a development partnership with AIM3D to integrate the Voxelfill process as a plug-in into the system technology of the ExAM 255 and ExAM 510. The slicing software solution SlicEx, which is based on Create it Real’s Real Vision Slicer, will enable future users to make optimum use of AIM3D’s patented Voxelfill technology to overcome inhomogeneous strengths and to achieve selective densities of 3D components made of metals, plastics, fiber-filled plastics, and ceramics.
AIM3D’s Voxelfill process overcomes inhomogeneous strengths by making use of a cross-layer filling strategy. The layer-based 3D build-up processes currently used in 3D printers often exhibit inhomogeneous strength values. With the now patented Voxelfill process, AIM3D is taking a new approach that overcomes inhomogeneous strengths and achieves defined selective densities in the component. With Create it Real’s new slicing software solution SlicEx, users are given the opportunity to exploit the potential of Voxelfill in the construction of 3D components. As a premiere, both companies will demonstrate the SlicEx 3D printer software and the Voxelfill plug-in at Formnext 2023 in Frankfurt.
Advantages for users of the Voxelfill technology
With the SlicEx plug-in, users of the AIM3D systems ExAM 255 and ExAM 510 will benefit from comprehensive access to the 3D component-building process with Voxelfill. Furthermore, their input and feedback on the subject of slicers can be passed on via AIM3D directly to the developer Create it Real in order to further optimize the process.
“With the development of Voxelfill, the user now has the possibility to use the unique new process of Voxelfill to improve the Z-strength and the printing speed. However, these modules are currently still under development,” said Clemens Lieberwirth, CTO at AIM3D.
Voxelfill principle overcomes inhomogeneous strength properties
In additive manufacturing of polymers, components have inhomogeneous strength properties due to the layer-based build process. This manifests itself primarily in the form of tensile and flexural strength shortcomings, as well as very brittle behaviour along the Z axis. In contrast, the strengths achieved along the X and Y axes with some processes are already close to the strengths possible with conventional injection molding. AIM3D has already demonstrated this with the processing of fiber-filled components based on PA6 GF30 material. The phenomenon of inhomogeneous strength properties must be resolved in order to enable a wide applicability of 3D-printed components. By using the 3D extrusion technology of the CEM process, AIM3D has developed a Voxelfill strategy that overcomes these limitations and increases the cost effectiveness of the CEM process. Voxelfill can also be used for multi-material components and is suitable for constructing 3D components using plastics, metals and ceramics.
The two-stage Voxelfill process at a glance
With the Voxelfill approach, components are no longer created exclusively in layers (i.e. 2.5D), but use cross-layer filling with so-called voxels as volume areas. To do this, the component contour is first created as usual as the basic structure using one or more webs of the extruded material. A lattice pattern is created inside the component, which defines the boundaries of the volume elements to be filled, similar to cavities. This structure of the voxels to be filled resembles the honeycomb in a beehive.
The Voxelfill strategy now comprises two process stages:
- Generation of a lattice structure: The CEM system repeats this structure up to a defined height of the volume elements, then at this point the previously created cavities (voxels) are filled by injecting thermoplastic material with the extruder.
- Filling phase of the voxels: Now the second, even more important component of this 3D printing strategy is deployed. When the volume areas are filled, this does not include filling all voxels in one plane. This would again result in a Z direction weakness directly in the “seam” plane. By shifting the volume elements halfway up the voxel, a kind of “brick-like bond” is created in the component, resulting in the yield line being offset. This results in an enormous increase in strength and also improves the elasticity of the components in the Z direction. In addition, the introduced volume elements greatly reduce the printing time for fully filled components and thus significantly increases the cost-effectiveness of the CEM process.
A look at the potential of Voxelfill
Variations of the Voxelfill strategy with the CEM process enable the use of various materials: hybrid multi-material solutions with different Voxelfill materials and different materials for the contour/structure of the inner walls become possible. This way, the material properties can be “customized.” Defined component weight, damping properties, elasticity or changes to the center of gravity can be tailored to the application. By selectively filling only certain volume chambers (selective densities), component properties could be influenced in a targeted manner on the basis of FE simulations. With Voxelfill, it is possible to only fill the areas of a component that are absolutely necessary for the flow of forces. As a result, from the outside these components purely look like conventional parts, and can also benefit from applying finishing processes.
At the same time, however, the 3D printing process is carried out with reduced material and weight, right up to realizing lightweight components. Especially when deploying fiber-reinforced materials, the use of Voxelfill offers an additional option for specifically aligning the fibres in the component to enhance mechanical properties. In the flat plane, the CEM process already offers very good options for controlling the orientation of the fibres. With the Voxelfill strategy, this affects the contour and the inner walls of the component. By injecting the material into the volume chambers (filling the voxels), the 3D component also receives fibers that are aligned in the Z axis, thereby further improving mechanical properties.
“Of course, the Voxelfill process is particularly suitable for 3D printing of plastics and fibre-filled plastics, but it is also suitable for 3D printing of metal and ceramic components using the CEM process. In general, there are advantages due to the higher build speed and cross-layer filling,” said Clemens Lieberwirth, CTO at AIM3D.
Create It Real