HPC for improved efficiency on standard machine tools by using new fluid-driven spindles

Part of: Seliger, Günther (Ed.): Innovative solutions : proceedings / 11th Global Conference on Sustainable Manufacturing, Berlin, Germany, 23rd - 25th September, 2013. - Berlin: Universitätsverlag der TU Berlin, 2013. - ISBN 978-3-7983-2609-5 (online). - http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-40276. - pp. 241-246.The use of fluid-driven spindles is well known for machining various components, but not in real metal cutting. Machining of larger precision components as prototypes, tools and dies requires the use of relatively large machine tools and high-performance spindles. Usually these are mechanical spindles with relatively high power, displaying a rather low maximum speed of approximately 15,000 rpm. However, in semi-finishing and finishing with HPC conditions and in micro machining, the required rotation speeds are higher and the required power is lower. This paper presents sustainability and efficiency using fluid-driven spindles for HPC on standard machine tools with small tool diameters and rotation speeds of up to 90,000 rpm using air and 30,000 rpm using the coolant flow. The fluid-driven spindle leads to a significant widening of the application range of larger machine tools and to an improvement of productivity by higher efficiency and faster tool- and spindle change, respectively

MIPAS IMK/IAA Carbon Tetrachloride (CCl4) Retrieval and First Comparison With Other Instruments

MIPAS thermal limb emission measurements were used to derive vertically resolved profiles of carbon tetrachloride (CCl4). Level-1b data versions MIPAS/5.02 to MIPAS/5.06 were converted into volume mixing ratio profiles using the level-2 processor developed at Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Cientificas (CSIC), Instituto de Astrofisica de Andalucia (IAA). Consideration of peroxyacetyl nitrate (PAN) as an interfering species, which is jointly retrieved, and CO2 line mixing is crucial for reliable retrievals. Parts of the CO2 Q-branch region that overlap with the CCl4 signature were omitted, since large residuals were still found even though line mixing was considered in the forward model. However, the omitted spectral region could be narrowed noticeably when line mixing was accounted for. A new CCl4 spectro-scopic data set leads to slightly smaller CCl4 volume mixing ratios. In general, latitude-altitude cross sections show the expected CCl4 features with highest values of around 90 pptv at altitudes at and below the tropical tropopause and values decreasing with altitude and latitude due to stratospheric decomposition. Other patterns, such as subsidence in the polar vortex during winter and early spring, are also visible in the distributions. The decline in CCl4 abundance during the MI-PAS Envisat measurement period (July 2002 to April 2012) is clearly reflected in the altitude-latitude cross section of trends estimated from the entire retrieved data set

On the improved stability of the version 7 MIPAS ozone record

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) was an infrared limb emission spectrometer on the Envisat platform. From 2002 to 2012, it performed pole-to-pole measurements during day and night, producing more than 1000 profiles per day. The European Space Agency (ESA) recently released the new version 7 of Level 1B MIPAS spectra, in which a new set of time-dependent correction coefficients for the nonlinearity in the detector response functions was implemented. This change is expected to reduce the long-term drift of the MIPAS Level 2 data. We evaluate the long-term stability of ozone Level 2 data retrieved from MIPAS v7 Level 1B spectra with the IMK/IAA scientific level 2 processor. For this, we compare MIPAS data with ozone measurements from the Microwave Limb Sounder (MLS) instrument on NASA\u27s Aura satellite, ozonesondes and ground-based lidar instruments. The ozonesondes and lidars alone do not allow us to conclude with enough significance that the new version is more stable than the previous one, but a clear improvement in long-term stability is observed in the satellite-data-based drift analysis. The results of ozonesondes, lidars and satellite drift analysis are consistent: all indicate that the drifts of the new version are less negative/more positive nearly everywhere above 15km. The 10-year MIPAS ozone trends calculated from the old and the new data versions are compared. The new trends are closer to old drift-corrected trends than the old uncorrected trends were. From this, we conclude that the nonlinearity correction performed on Level 1B data is an improvement. These results indicate that MIPAS data are now even more suited for trend studies, alone or as part of a merged data record

Technologieentwicklung zur Herstellung präziser mikrofluidischer Systemkomponenten

Die Miniaturisierung von mikrofluidischen Systemen und Funktionselementen stellt, bedingt durch steigende Anforderungen hinsichtlich Funktionalität und Funktionsdichte, hohe Anforderungen an die eingesetzten Fertigungsverfahren. Das Heißprägen von Mikrostrukturelementen stellt ein kostengünstiges und effektives Verfahren mit hoher Abbildungsqualität dar, welches es ermöglicht die benötigten Mikrostrukturen in unterschiedlichste Materialen wie Kunststoff, Glas und Metall in hohen Stückzahlen abzuformen. Dabei werden an die benötigten metallischen oder keramischen Abformwerkzeuge besondere Anforderungen gestellt. Von entscheidender Bedeutung ist dabei die Oberflächenqualität und die Genauigkeit der Mikrofluidikstrukturen um einen gleichmäßigen und definierten Fluidfluss zu gewährleisten. Geeignete Verfahren zur Herstellung solcher hochpräzisen Prägewerkzeuge sind unter anderem das Mikrofräsen und die Lasermikrostrukturierung sowie die Kombination beider Verfahren

Associations between factors influencing engineering design communication

Abstract not available

Tool System for UV induced micro moulding of biomedical disposables

A new approach for the generation of double-sided microstructured polymer films is presented based on injection-molding of urethane- and epoxy-based acrylates that are polymerized by irradiation with ultraviolet light (395 nm). Compared to hot embossing, this offers not only working under ambient conditions, but also a reduction of cycle time as well as flexibility regarding adjustment of the mechanical and/or chemical properties of the resulting polyacrylate film. A setup, consisting of the mold with the microstructured insert and two LED lamps emitting UV-light moved by a controllable stepper motor and a computer-based controller, was installed and successfully used for the fabrication of double-sided microstructured polyacrylate films.Therefore a new and innovative tool system for 2-component UV induced micro moulding of biomedical disposables was developed. The geometrical dimensions of the microstructures (e.g. fins, channels, sharp edges and slopes) require different technologies to machine the tool inserts. Therefore micromilling and μ-laserablation technologies were used in combination attached by laser polishing operations in special areas. A highly precise, complex designed tool system with mechanically moveable areas is needed to fill the tool with the 2 various chemical compositions. The paper presents the tool concept and explains the investigated surface treatment options

Criteria for selecting design process modelling approaches

Process models are among the principal artefacts used for managing design projects. However, the selection of effective modelling approaches can be difficult for design project managers, given that a plethora of tools exists for various modelling purposes. In addition to date no systematic approach for the assessment and selection of process modelling approaches is available to practitioners. This paper presents the development of criteria for benchmarking and selecting different process modelling tools. The results are based on three elements. (1) In a four-hour workshop undertaken by the Design Process SIG of the Design Society, bringing together around 20 international researchers and practitioners in design process modelling, an initial set of 58 criteria were brainstormed and consolidated during the workshop and in follow-up meetings. (2) The consolidated criteria were then compared with literature. The finalised criteria list was then validated by external experts in industry (3). The resulting list of 12 criteria provides a sound basis for practitioners to support a systematic selection of process modelling approaches. Further, it lays the foundation of a benchmarking tool, which is subject to future work

Vom Prototypen in die massenproduktionstaugliche Fertigung - neue Konzepte zur Erzeugung mikrostrukturierter Oberflächen: Poster präsentiert auf der Fachtagung "VAKUUM & PLASMA", V2019, 8. - 10. Oktober 2019, Dresden

Die Adaptionsfähigkeit von technologisch anspruchsvollen Produktionsprozessen an extrem variierende Chargengrößen, kurze Produktlebens- und Entwicklungszyklen ist ausschlaggebend für einen wirtschaftlichen Erfolg und stellt die Wandlungsfähigkeit entsprechender Wertschöpfungsketten vor große Herausforderungen. Am Beispiel mikrostrukturierter Oberflächen für mikrofluidische Systemkomponenten werden Lösungsansätze und Perspektiven für den Bereich Lab-on-a-Chip Systeme vorgestellt, die auch in andere Industriezweige übertragbar sind