AIM3D Validates Voxelfill Strategy for Overcoming Inhomogeneous Strengths in 3D Components

AIM3D says it has succeeded in demonstrating the advantages of its patented Voxelfill cross-layer filling process for overcoming inhomogeneous strength issues in 3D components. The material qualification testing indicates many benefits of creating components with AIM3D’s Voxelfill printing strategy along with the composite extrusion modeling (CEM) process, which uses standard pellets rather than the more expensive filaments required by other platforms.

The company’s strength tests have shown that the process can overcome inhomogeneous strengths of 3D components in the X, Y and Z axes, and thus comes close to conventional processes such as injection molding. The Voxelfill process testing indicates an 80 to 100% tensile strength in the printing direction. 

Voxelfill is a combination of injection molding and 3D extrusion printing based on the CEM process. The company says Voxelfill achieves almost isotropic material properties in all directions, as well as enabling higher productivity and an orientation of fibers along the Z-direction. With Voxelfill, AIM3D now achieves 80% tensile strength compared to the mold-bound injection molding process and therefore enables the technical application of 3D printed parts made from certified pellets. The potential target is to achieve even 100% tensile strength.

“This makes Voxelfill a game changer with respect to the mechanical strengths of 3D components,” says Clemens Lieberwirth, AIM3D CTO. “With Voxelfill, the user now has the unique possibility to improve the Z-strength and the printing speed.”

AIM3D has previously successfully demonstrated success with the processing of both fiber-filled (composite) components based on PA6 GF30 material and pure thermoplastics such as Ultem 9085. The material qualification testing of Sabic’s Ultem 9085 resin granulate for its ExAM 510 3D printer using its CEM process with standard pellets showed a variety of benefits compared to using filament 3D printers. The advantages include lower material costs, faster build speeds, improved reproducibility and high tensile strengths. 

“We now believe more than ever in our CEM technology and the established team at AIM3D. 3D pellet printers offer the unique option of very cost-effectively mapping the properties of conventionally manufactured components with an additive manufacturing strategy,” Lieberwirth says. “With the Voxelfill strategy, 3D printing now approaches the mechanical strengths of conventional injection molding.”

The company has focused on granular 3D pellet printers — used instead of fused deposition modeling (FDM) 3D printers which require more expensive filaments — for making components of metals, plastics, fiber-filled plastics (composites) and ceramics. The lower material costs for pellets and use of reclaimed material straight from the mill help form the basis for the cost-effectiveness of the company’s additive manufacturing (AM) production strategy.

AIM3D is continuing to further develop its 3D pellet printing with CEM processing because 3D buildup processes currently used in 3D printers often exhibit inhomogeneous strength values. This manifests itself primarily in the form of tensile and flexural strength shortcomings, as well as very brittle behavior along the Z-axis. In contrast, strengths achieved along the X and Y axes with some processes are already close to the strengths possible with conventional injection molding. The company says this problem of inhomogeneous strength properties needs to be resolved to enable a wider applicability of 3D printed components.

With the Voxelfill process, AIM3D is taking an approach that overcomes these inhomogeneous strengths while also achieving defined selective densities in the component by making use of a cross-layer filling strategy.  The component weight, damping properties, elasticity or changes to the center of gravity can be 3D tailored to the application. By selectively filling only certain volume chambers (selective densities), the component properties can be influenced in a targeted manner on the basis of finite element analysis (FEA) simulations. 

Voxelfill makes it 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 look like conventional parts, and can also benefit from applying conventional finishing processes. In addition, the 3D printing process is carried out with less material, resulting in components of a reduced weight, right up to lightweight components.

When using fiber-reinforced materials, Voxelfill offers the additional option to specifically align the fibers in the component to enhance the mechanical properties. In the horizontal plane, the CEM process already offers good options for controlling the orientation of the fibers. With the Voxelfill strategy, this affects the contour and 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 along the Z-axis, thereby further improving the mechanical properties.

“Of course, the Voxelfill process is particularly suitable for 3D printing plastics and fiber-filled plastics, but it is also suitable for the 3D printing of metal and ceramic components using the CEM process,” Lieberwirth adds. “In general, the main advantages are a higher build speed and cross-layer filling.”

The company also says that Voxelfill can now be licensed to users of other 3D printing processes for material extrusion in accordance with EP 4100235-B1.