@article{DzaficMaiwaldHierl, author = {Dzafic, Adelisa and Maiwald, Frederik and Hierl, Stefan}, title = {Messung der Schmelzefließgeschwindigkeit beim Laser-Durchstrahlschweißen von Kunststoffen}, series = {Werkstoffe in der Fertigung}, volume = {57}, journal = {Werkstoffe in der Fertigung}, number = {3}, publisher = {HW-Verl.}, address = {Mering}, issn = {0939-2629}, pages = {31 -- 33}, subject = {Laserdurchstrahlschweissen}, language = {de} } @misc{MaiwaldDzaficHierl, author = {Maiwald, Frederik and Dzafic, Adelisa and Hierl, Stefan}, title = {Messung der Schmelzefließgeschwindigkeit beim Laser-Durchstrahlschweißen von Kunststoffen}, series = {Laser in der Elektronikproduktion \& Feinwerktechnik - LEF 2021, Erlangen, 22.04.2021}, journal = {Laser in der Elektronikproduktion \& Feinwerktechnik - LEF 2021, Erlangen, 22.04.2021}, subject = {Laserdurchstrahlschweissen}, language = {de} } @techreport{Hierl, author = {Hierl, Stefan}, title = {Forschungsschwerpunkte im Labor Lasermaterialbearbeitung}, series = {Forschungsbericht 2017}, journal = {Forschungsbericht 2017}, editor = {Baier, Wolfgang}, organization = {Ostbayerische Technische Hochschule Regensburg}, pages = {56 -- 57}, abstract = {Durch das Laserkunststoffschweißen k{\"o}nnen sowohl filigrane N{\"a}hte in der Mikrotechnik als auchtragf{\"a}hige Verbindungen f{\"u}r Strukturbauteile hergestellt werden. In der Automotiv- oder der Medizintechnik-Industrie ist diese F{\"u}getechnologie mittlerweile etabliert, jedoch sind die Anwen-dungsm{\"o}glichkeiten bei Weitem noch nicht ausgesch{\"o}pft. In k{\"u}rzlich gestarteten Forschungsprojekten mit regionalen Industrieunternehmen und internationalen Forschungspartnern werden im Labor Lasermaterialbearbeitung weitere Potenziale gehoben.}, subject = {Laserschweissen}, language = {de} } @article{MaiwaldEnglmaierHierl, author = {Maiwald, Frederik and Englmaier, Stephan and Hierl, Stefan}, title = {Online pyrometry for weld seam localization in absorber-free laser transmission welding of transparent polymers}, series = {Journal of Laser Micro/Nanoengineering}, volume = {Vol. 16}, journal = {Journal of Laser Micro/Nanoengineering}, number = {1}, publisher = {Japan Laser Processing Society}, issn = {1880-0688}, doi = {10.2961/jlmn.2021.01.2002}, pages = {8 -- 13}, abstract = {Production of optical and medical devices makes high demands on cleanliness, precision, visual appearance and reliability. Advantages of laser transmission welding - contactless input of energy, high precision, no adhesives and no particle formation - can be fully exploited for this use. For absorber-free welding, lasers emitting in the polymers' intrinsic absorption spectrum between 1.6 μm and 2 μm are used. Focusing the laser beam with high NA provides large intensity gradients inside the specimen and enables selective fusing of the joining zone without affecting the surface. Since a molten upper surface leads to visible and palpable irregularities and causes warpage, the verticalexpansion of the weld seam is crucial. To meet the high quality and reliability required in the medical and optical industry, online monitoring of the seam is necessary. The aim of this work is the localization and evaluation of the weld seam using pyrometry. First, the emitted thermal radiation is computed, enabling signal analysis regarding origin and spectrum. Thus, assessment of measurement spectrum and forecast of the signal in dependence on seam shape and position is possible. Finally, welding tests with Topas 8007-04 are performed at 200 mm/s feed rate and monitored with 100 kHz. The comparison of tracked data with thin-cuts demonstrates that weld seam localization by pyrometry is possible, enabling online assessment of the process.}, subject = {Laserdurchstrahlschweissen}, language = {en} } @article{MaiwaldHierl, author = {Maiwald, Frederik and Hierl, Stefan}, title = {Pyrometerbasierte Prozess{\"u}berwachung beim Laserkunststoffschweißen}, series = {Photonik}, journal = {Photonik}, number = {52}, publisher = {AT-Fachverl.}, address = {Fellbach}, pages = {22 -- 25}, subject = {Laserschweissen}, language = {de} } @article{Lorenz, author = {Lorenz, Bj{\"o}rn}, title = {Cardboard Engineering 2.0}, series = {Zeitschrift f{\"u}r wirtschaftlichen Fabrikbetrieb : ZWF}, volume = {109}, journal = {Zeitschrift f{\"u}r wirtschaftlichen Fabrikbetrieb : ZWF}, number = {1/2}, publisher = {De Gruyter}, address = {Berlin}, doi = {10.3139/104.111083}, pages = {26 -- 28}, abstract = {Das Material Karton ist in heutigen Fertigungen f{\"u}r die schnelle Umsetzung von Ideen aus einem Kaizen-Prozess ein g{\"a}ngiger Werkstoff. Die Vorgehensweise wird auch als Cardboard Engineering bezeichnet. Aber die Entwicklung geht weiter. Die immer weiter verbreiteten 3D-Drucktechnologien erm{\"o}glichen die schnelle Generierung von Vorrichtungen, die deutlich h{\"o}here Anforderungen hinsichtlich Pr{\"a}zision, Robustheit und Komplexit{\"a}t erf{\"u}llen.}, language = {de} } @inproceedings{MaiwaldEnglmaierHierl, author = {Maiwald, Frederik and Englmaier, Stephan and Hierl, Stefan}, title = {Online pyrometry for weld seam localization in absorber-free laser transmission welding of transparent polymers}, series = {21st International Symposium on Laser Precision Microfabrication: Dresden, 26.06.2020}, booktitle = {21st International Symposium on Laser Precision Microfabrication: Dresden, 26.06.2020}, abstract = {Optical and medical devices made of transparent polymers are gaining popularity because of its cost advantages. The manufacturing technology must be able to meet the high demands of these applications. Advantages of laser transmission welding - contactless input of energy, precision, no adhesives and no particle formation - can be exploited here. For absorber-free welding, lasers emitting in the polymers' intrinsic absorption spectrum are used. Focusing the laser beam with high NA enables selective fusing of the joining zone. Since a molten upper surface leads to visible and palpable irregularities, the lateral expansion of the weld seam is monitored in this work. Welding tests with 1 mm thick plates of COC are performed and monitored by pyrometry. Distances between seam and surface measured in thin cuts and are compared with the pyrometer signal. This shows that the localization of the weld seam is possible and proper and faulty parts can be distinguished by pyrometry.}, subject = {Laserdurchstrahlschweissen}, language = {en} }