Introduction
Binder jetting is one of the 7 3d printing processes, depicted in the standard DIN EN ISO/ASTM. In addition to vat photo polymerisation (VPP), material extrusion (MEX) and material jetting (MJT), binder jetting is used to produce ceramic parts as well.
Binder Jetting at WZR
Since 2004 WZR is working on the field of binder jetting of ceramics and during that time we experienced eight different binder jetting machines. We started with a in that time highly modern machine of the manufacturer ZCorp, which is now part of 3D-Systems. We used the smaller model Z310 for eight years. Of the bigger model Z510 we bought five machines in total, from which two machines are still in use. For these machines, we developed, tested and sintered many different mixtures. Since 2008 we sell 3d printed parts made of Al2O3 printed on our ZCorp printers.
Since 2008 we deal with the development and usage of particle filled inks, which are oriented on the powder bed. We expect a high green strength, good imaging precision and also higher densities and strengths after sintering. Our first binder jetting machine to print these inks used a single nozzle so in order to place ink on a space of 50×50 mm² it needed five minutes. The next printer used a multi nozzle printhead, which was able to print with 1000 nozzles in parallel. Therefore it was possible to shorten the printing time drastically. In the next development step we were able to print water based inks. By using these we were able to reach a green strength of 8 MPa. All of these binder jetting machines are prototypes developed for us. The huge advantage is visible in the freedom to change all of the machine’s parameters. A disadvantage lies in the missing warranty and spare parts supply.
Concr3de
In May 2021 we met concr3de and began to work with their printers. First tests with our powder and ink were successful, even without major changings to the machine. All further tests were successful, which was the reason that we decided to buy an Armadillo White.
Description Armadillo White
The Armadillo-White has a build space of 370x290x250 mm³. The printhead is able to print particle filled inks. Additionally, there is an infrared heater built in the machine to instantly dry the ink. As further upgrade we bought a smaller building space to also test smaller amounts of ink (ca. 1 litre) as well.
Our experience within the first 10 weeks
After the delivery of the printer, Ion Martinez, Technical Sales Engineer from concr3de briefed us.
Here, all functions of the printer were tested and explained.
The first step is filling the printer with powder and ink:
The setting of the printing parameters (traverse movement, roller speed, infrared parameter, amount of ink printed, number of coatings) is an optimizing procedure consuming a lot of time.
In the following video the heat input by the infrared lamp is visible:
To optimize the printer’s parameters, we usually print test bars. By optimizing the parameters, the flatness of the surface increases and the printed image gets sharper.
After printing, the part moves out of the building space and gets dried at temperatures of about 195°C.
After drying, the bars get removed from the powder bed and are afterwards available for further tests.
Our first conclusion at this stage is, that the printer is very reliable. The software is very intuitive to use and is generally stable. Our first powders can be laid down in layers with thicknesses between 50 µm and 100 µm. A water based particle ink can be printed reliably, the ink circulation system works with our particle ink and the cleaning of the printhead is working effectively. We learned, that we need to keep attention on the filters in the ink system.
So far, we continuously used the same ink and 95% of the time we used the same powder mixture.
The remaining 5% of the time we used a second powder and the small print bed. We are happy to approve our first impression, that the feature is a clever solution to minimize powder consumption. When using the smaller powder bed, we still need to further optimize the parameters, to get an even surface.
Summary
To summarize the last 10 weeks: We used the printer every day and we are really happy with it.
