3D Printing of abrasive Materials
FDD enables the 3D printing of highly filled and highly viscous pastes like ceramic
Before using the FDD dosing unit, Unfold worked with a classic time pressure system in their 3D printers. Here it comes to different flow behaviors due to various reasons. These include inhomogeneous mixed materials or the decreasing quantities in cartridges. Therefore the dosing volumes are difficult to control in a time pressure system even if the inlet pressure is constant. It needs a trained person to regulate the time pressure system manually while printing in order to compensate the fluctuations of the dosed volume and to avoid defect in the printed parts. Unfold improved the 3D printing of ceramics fundamentally and stabilized the process by installing ViscoTec dosing units and printing with this FDD process. The advantage is the volumetric conveying technology working with the endless piston principle. The dosed volume per revolution and per time unit is exact defined, regardless of material properties such as viscosity or particle size of the solids. “With the volumetric system from ViscoTec we don’t need to recalibrate all 3D printing parameters when we change the material”, explains Dries Verbruggen from Unfold. The material flow is 100 % controlled by the 3D printer software and electronics and not by material properties. Therefore additional costs for manually readjust can be saved.
An important feature of ViscoTec‘s dispenser technology is the ability of dosing highly filled, abrasive media very precisely with low wearing. The wear of components by sharp solid share is a big problem for many types of pumps. The ViscoTec endless piston principle based on the progressive cavity technology conveys abrasive solids in its carrier medium through chambers between a rotor (steel) and a stator (elastomer) with a low pulsation rate – for gentle product and pump handling.
By the use of the FDD technology, the design studio Unfold could handle ceramics with a solids content of up to 80 % with grain sizes up to 63 µm and a viscosity of about 250,000 mPas in a 3D printer. The resulted artwork show new forms that have been produced with a precise, repeatable process with a very low error rate.
ViscoTec Pumpen- u. Dosiertechnik GmbH
ViscoTec Pumpen- u. Dosiertechnik GmbH primarily deals with systems required for conveying, dosing, applying, filling and emptying medium to high-viscosity fluids. The technological leader headquarter is in Töging a. Inn (Bavaria). Furthermore ViscoTec has subsidiaries in the USA, in China and in Singapore and employs almost 120 people worldwide. Numerous sales partners all over the world complete the international distribution network. Next to technically sophisticated solutions to even the most complicated application, ViscoTec is the single point of contact to deliver all components for a complete system: from emptying to preparing and to dosing. This guarantees successful interaction of all components. All fluids showing a viscosity of up to 7.000.000 mPas can be conveyed and dosed almost pulsation-free and with extremely low shear. ViscoTec offers comprehensive consulting for every application and, if required, extensive tests will be carried out in close cooperation with the customer. The dosing pumps and systems are perfectly adapted to their respective application whether it is the food sector, the automotive industry, the aerospace field, the medical technology, the pharmaceutical industry and many other branches.