As customers demand faster build speeds from additive manufacturing, vendors have developed interesting and innovative new ways to deliver that speed. Check out these recent developments in making parts fast.
Multimaterial multinozzle 3D (MM3D) printing
Multimaterial Multinozzle 3D (MM3D) printing was developed at Harvard’s Wyss Institute for Biologically Inspired Engineering and John A. Paulson School of Engineering and Applied Sciences (SEAS). This technique uses high-speed pressure valves to achieve rapid, continuous, and seamless switching between up to eight different printing materials, enabling the creation of complex shapes in a fraction of the time currently required using printheads that range from a single nozzle to large multi-nozzle arrays.
The MM3D printheads are manufactured using 3D printing, enabling their rapid customization and facilitating adoption by others. Each nozzle can switch materials up to 50 times per second, which is faster than the eye can see, or about as fast as a hummingbird beats its wings.
The key to MM3D printing’s speedy ink-switching is a series of Y-shaped junctions inside the printhead where multiple ink channels come together at a single output nozzle. The shape of the nozzle, the printing pressure, and the ink viscosity are precisely calculated and tuned so that when pressure is applied to one of the “arms” of the junction, the ink that flows down through that arm does not cause the static ink in the other arm to flow backwards, which prevents the inks from mixing and preserves the quality of the printed object. By operating the printheads using a bank of fast pneumatic valves, this one-way flow behavior allows the rapid assembly of multimaterial filaments that flow continuously out from each nozzle, and enables the construction of a 3D multi-material part. The length of the ink channels can be adjusted to account for materials that have different viscosities and yield stresses, and thus flow more quickly or slowly than other inks.