TY - CHAP A1 - Felis, Simeon A1 - Mottok, Jürgen A1 - Bauer, B. A1 - Kohlert, Dieter A1 - Jantz, D. A1 - Laumer, M. T1 - FBI3 – Fehlereinspeisung auf Hardware-Ebene T2 - 3. Landshuter Symposium Mikrosystemtechnik, Tagungsband, 13. und 14. März 2012, Hochschule Landshut Y1 - 2012 SP - 119 EP - 127 ER - TY - JOUR A1 - Heinl, M. A1 - Laumer, Tobias A1 - Bayer, F. A1 - Hausotte, Tino T1 - Temperature-dependent optical material properties of polymer powders regarding in-situ measurement techniques in additive manufacturing JF - Polymer Testing N2 - Due to the growing number of applications for Additive Manufacturing (AM), an increasing need for enhanced quality control methods exists. Here optical measurement techniques are often used for in-situ monitoring in AM. There is a great potential to standardize and improve applications of optical measurement devices in accordance to the increasing requirements of measuring tasks. Beside the optical material qualifications, especially process-oriented changes in optical effects are of great relevance for in-situ evaluations. The optical modifications may be attributed to aggregate specific phase transitions coming along with variable emitted wavelengths. A measuring setup with two integrations spheres and a heated process chamber have been developed to analyze the optical interactions of laser radiation and visual illumination with the powder. The process oriented analysis for selective laser sintering lead to improved operating conditions in the field of in-situ measurements in combination with an accurate evaluation of the absorption ratio of the examined powder. Y1 - 2018 U6 - https://doi.org/10.1016/j.polymertesting.2018.09.016 VL - 71 IS - October SP - 378 EP - 383 PB - Elsevier ER - TY - JOUR A1 - Launhardt, M. A1 - Wörz, A. A1 - Loderer, A. A1 - Laumer, Tobias A1 - Drummer, Dietmar A1 - Hausotte, Tino A1 - Schmidt, Michael T1 - Detecting surface roughness on SLS parts with various measuring techniques JF - Polymer Testing N2 - Selective Laser Sintering (SLS) is an additive manufacturing technique whereby a laser melts polymer powder layer by layer to generate three-dimensional parts. It enables the fabrication of parts with high degrees of complexity, nearly no geometrical restrictions, and without the necessity of a tool or a mold. Due to the orientation in the building space, the processing parameters, and the powder properties, the resulting parts possess an increased surface roughness. In comparison to other manufacturing techniques, e.g. injection molding, the surface roughness of SLS parts results from partially melted powder particles on the surface layer. The actual surface roughness must thus be characterized with respect to the part's eventual application. At the moment, there is no knowledge regarding which measuring technique is most suitable for detecting and quantifying SLS parts' surface roughness. The scope of this paper is to compare tactile profile measurement methods, as established in industry, to optical measurement techniques such as Focus Variation, Fringe Projection Technique (FPT), and Confocal Laser Scanning Microscope (CLSM). The advantages and disadvantages of each method are presented and, additionally, the effect of tactile measurement on a part's surface is investigated. KW - Selective Laser Sintering (SLS) KW - PA12 KW - Surface roughness KW - Measuring technique Y1 - 2016 SN - 0142-9418 U6 - https://doi.org/10.1016/j.polymertesting.2016.05.022 SN - 1873-2348 VL - 53 SP - 217 EP - 226 PB - Elsevier CY - Amsterdam ER -