3D printing software optimises properties of plastic components

3D printers are a flexible way to produce components; now, researchers at Technische Universität Kaiserslautern (TUK) are using this technology to optimise the printing result for plastics. The researchers have developed software that can adjust parameters such as temperature and printing speed during printing. Temperature differences between the individual layers, which can occur during production, can negatively affect the properties of the plastic. The researchers are striving to overcome these problems with their software.

In 3D printing, a component is printed layer by layer along a specified path. This technique allows companies to produce their goods without much effort. However, various parameters such as temperature, printing speed, printing direction, layer height and geometry of the component can influence the printing result.

Researchers at the Institute for Composite Materials, led by Professor Dr-Ing Alois K. Schlarb at TUK, are working on 3D printing technologies to optimise the properties of the printed products. Miaozi Huang, a research assistant at the Institute, said that once a layer is printed, it cools down — when the next layer is applied on top of it, it has a higher temperature than the one underneath, and the layer underneath heats up again. “This contact temperature or local temperature between the printed part and the part to be printed influences the quality of the seam or the weld,” Huang said. This can affect the properties of the product — in the finished component, this is a weak spot, especially if the local temperature was not high enough when the seams were created.

To solve this issue, engineers from Kaiserslautern have developed a software which during printing ensures that various constants such as the temperature of the print nozzle or the printing speed can be flexibly changed, depending on the shape of the component and the plastic used.

“The aim of our technology is to optimally exploit the material properties. Similar processes do not yet exist,” said Alexander Schlicher, who is involved in implementing the concepts at the Institute. With the software, researchers can flexibly change the parameters for each individual movement of the printing process.

Researchers have tested the new procedure in the laboratory; two samples, one printed with conventional software, the other with the new technique, differ in their structure, as observed under the microscope. “There is also a difference in the properties, especially in the tensile strength across the direction of printing. This method allows the weak points in the printed products to be eliminated,” Huang said. For example, with this method it is possible to keep the contact temperatures between two strands in the optimal range for the respective moulded part geometry.

Such optimisations are important, for example, for increasing the service life of a component. The method used by the team from Kaiserslautern is designed to allow weak points in the plastic to be avoided.

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