Micro-droplet jetting 3D printing typically uses low-viscosity material, but in a study entitled “Research and Development of a 3D Jet Printer for High-Viscosity Molten Liquids,” a group of researchers investigates using the technology for high-viscosity liquids. Micro-droplet jetting manufacture, or MDJM, is based on discrete deposition technology, which “sprays liquid through a 3D printing device, controls the trajectory of the droplet ejection via the motion platform, accurately sprays the droplet at a specified position, and gradually accumulates into a three-dimensional model.”
The technology is used in biomedical manufacturing, three-dimensional microstructure manufacturing, microelectronics, micro-spacecraft and more. In the paper, the researchers develop a jet 3D printer consisting of a piezoelectric stack, drive frame, lever, heat insulation, heat sink, heater, needle and nozzle. A device for ejecting high-viscosity fluid is designed by analyzing the injection principle of the fluid.
“Initially, the cooling mechanism is designed to overcome the defect that the piezoelectric stacks cannot operate in high-temperature conditions,” the researchers state. “Thereafter, the mathematical model of the liquid velocity in the nozzle is derived, and the factors influencing injection are verified by Fluent.”
The needle velocity of the 3D printer was tested by a laser micrometer, and the relationship between voltage difference and the needle velocity was also obtained.
“The experimental results matched the theoretical model well, showing that the voltage difference, needle radius, nozzle diameter, and taper angle are closely related to the injection performance of the 3D jet printer,” the researchers state. “By using a needle with a radius of 0.4 mm, a nozzle with a diameter of 50 μm, a taper angle of 90°, a supply pressure of 0.05 Mpa, and a voltage difference of 98 V, a molten liquid with a viscosity of 8000 cps can be ejected with a minimum average diameter of 275 μm, and the variation of the droplet diameter is within ±3.8%.”
Several experiments were run on the influencing factors of injection, such as the voltage difference, the needle radius, the nozzle diameter and the nozzle taper angle. The researchers came to the following conclusions:
- The defect that the piezoelectric stacks cannot operate in high-temperature conditions can be solved by a specially designed cooling mechanism
- The velocity of the needle is positively correlated with the voltage difference of the piezoelectric stacks
- Through simulation analysis and experimental research, the ejection capacity of the jet printer is positively correlated with the velocity and the radius of the needle and negatively correlated with the diameter and taper angle of the nozzle
- Through experimental comparison, by using a needle with a radius of 0.4 mm, a nozzle with a diameter of 50 μm, a taper angle of 90°, a supply pressure of 0.05 Mpa, and a voltage difference of 98 V, a molten liquid with a viscosity of 8000 cps can be sprayed with the minimum average droplet diameter of 275 μm, and the variation of the droplet diameter was within ±3.8%
For this study, the researchers used a type of polyurethane. In future studies, the researchers conclude, the focus should be on the effect of other high-viscosity molten liquids that have not been used for jetting in 3D printing before. This could potentially open up new applications for the technology.
Authors of the paper include Yang Yang, Shoudong Gu, Jianfang Liu, Hongyu Tian and Qingqing Lv.
Discuss this and other 3D printing topics at 3DPrintBoard.com or share your thoughts below.
Subscribe to Our Email Newsletter
Stay up-to-date on all the latest news from the 3D printing industry and receive information and offers from third party vendors.
You May Also Like
Biden Admin Announces Flurry of Reshoring Actions, Including Council on Supply Chain Resilience
Yesterday, I posted about the over $6 billion in new funding for US advanced manufacturing related to batteries and semiconductor packaging announced by the Biden administration to be awarded in...
Biden Admin Announces Over $6 Billion in Funding for Battery and Chip Advanced Manufacturing in November
In a development that has become routine for the Biden administration, the White House announced a total of more than $6 billion in new funding opportunities for advanced manufacturing applications...
America Makes and NCDMM Funding Now Tops $729M for American 3D Printing and Beyond
In a significant move to advance the U.S. manufacturing sector, the National Center for Defense Manufacturing and Machining (NCDMM) and America Makes have recently announced substantial ceiling increases on their...
US Army Reserve Test 3D Printed Explosives
In October 2023, US Army Reserve Soldiers assigned to the 102nd Training Division (Maneuver Support) attended a two-week Combat Engineer Reclassification Course at Fort Leonard Wood in Missouri, where they...
Upload your 3D Models and get them printed quickly and efficiently.