New 3D Print Head Enables Variable Web Widths

2023 Author : Hannah Pearcy | [email protected] . Last modified: 2023-05-24 11:12

The importance of additive manufacturing in industrial production increases with the possible functions of the 3D printer. Despite constant further developments, it has so far not been possible to apply plastic webs of different widths within a printed component. Previous approaches by the industry have not been resounding.

Replaceable nozzles on the extruder are time-consuming, and the 3D printer must also be recalibrated after each nozzle change . Printers with multiple nozzles cause undesirable dripping and smearing of the material. All previous attempts to develop a 3D printer with different nozzle diameters have proven to be relatively complicated and expensive.

Prof. Dr.-Ing. Michael Koch from the Faculty of Mechanical Engineering and Supply Technology at the Technical University of Nuremberg has achieved a breakthrough here: it enables plastic webs of different widths to be printed in one process step . In his research project "Innovative Extruder Concept for Fast and Efficient Additive Production", or "IvExAP" for short, he is developing a prototype of a print head for additive manufacturing at the Institute for Chemistry, Material and Product Development at TH Nuremberg.

Seminar tip

The 3D printing seminar in direct digital production conveys the technology, suitability and requirements of 3D printing and gives the participants an overview of the developments, possibilities and limits.

Resolution vs. Print speed

In melt layering, the most common method of additive manufacturing, the printer builds the workpiece in layers from a meltable plastic. The print head, a so-called extruder, heats the plastic and applies it to the workpiece in right-angled paths. The layers bond together and the material then hardens immediately.

Fine nozzles with a nozzle bore of 0.1 to 0.4 mm represent the smallest details. However, this requires a longer printing time . Coarse nozzles with a diameter of 0.5 to 2 mm work at a higher printing speed , but the details are lost due to the larger layer thickness. The industry could theoretically resolve this contradiction between resolution and printing speed with a nozzle that can extrude a plastic thread of different thickness. “Technically, however, this is not that easy, which is why I and my team are researching a new option, a plastic thread or strand with different diameters in the range of 0.2 to 1 mm,”explains Prof. Michael Koch.

Oval and rectangular nozzle opening

So far, the 3D printers only have a round nozzle bore. In their project, Prof. Koch and his team are developing an oval and a rectangular nozzle opening. This so-called elongated hole is easy to set up and works with the existing standard extruders - as a result, it also works stably in daily use. In order to be able to use the different nozzle openings in all directions, the complete extruder or at least the nozzle should be rotatable .

Depending on the angular position, printing is then carried out with the narrow side, the wide side or an intermediate position. “This gives us plastic webs of different thicknesses at a constant printing speed. We can print both large areas and small details in one step without stopping the printer,”says Prof. Koch.

The further development of the extruder by the research team makes the 3D printing process significantly more efficient and faster . The low costs should also enable small and medium-sized companies to use the future-oriented technology of additive manufacturing.

Book tip

The book Additive Manufacturing describes the basics and practice-oriented methods for the use of additive manufacturing in industry. The book is aimed at designers and developers to support the successful implementation of additive processes in their companies.