@article{24241, abstract = {{For gas phase nanoparticle production, hot wall reactors are widely used. In this article, we will describe the fundamental design considerations for a hot wall reactor system able to produce oxide nanoparticles. The system is outstanding in its ability to produce mostly spherical nanoparticles at particle sizes of up to 100 nm and even larger at mass outputs in the order of grams per hour by being able to rapidly quench the aerosol. While high production rates or larger particle sizes are already easily obtained with hot wall reactors, it is very challenging to produce these spherical particles at high mass rates. We will show in this research that the temperature and the particle number concentration are the major aspects influencing the particle morphology at the end of the process. Investigation on the performance of the setup shows good control over the temperature and the particle production stability. A representative particle characterization using SEM and scanning mobility particle sizer showed that particles are mostly spherical, while the particle size distribution had a geometric standard deviation close to 1.5. In addition to the aspects mentioned above, a possibility to manipulate the aggregation downstream of the reactor is to be presented as well. We found that applying electrical charges to the aerosol particles (in opposite polarity) can significantly foster aggregation.}}, author = {{Rasche, David B. and Tigges, Lena and Schmid, Hans-Joachim}}, journal = {{Review of Scientific Instruments}}, pages = {{055104}}, publisher = {{AIP Publishing}}, title = {{{An Apparatus to Synthesize Ceramic Nanoparticles with a Precisely Adjusted Temperature History and a Significant Mass Output}}}, doi = {{10.1063/1.5133438}}, volume = {{91}}, year = {{2020}}, } @inproceedings{22182, author = {{Kummert, Christina and Diekmann, Wolfgang and Tews, Katrin and Schmid, Hans-Joachim}}, booktitle = {{29th Annual International Solid Freeform Fabrication Symposium}}, pages = {{735--744}}, title = {{{Influence of Part Microstructure on Mechanicl Properties of PA6X Laser Sintered Specimens}}}, doi = {{http://utw10945.utweb.utexas.edu/sites/default/files/2019/063%20Influence%20of%20Part%20Microstructure%20on%20Mechanical%20Pro.pdf}}, volume = {{29}}, year = {{2020}}, } @inproceedings{25062, author = {{Tischendorf, Ricardo and Schmid, Hans-Joachim and Bieber, M. and Reddemann , M. and Kneer, R. and Fröde, F. and Grenga, T. and Pitsch, H.}}, location = {{Duisburg}}, publisher = {{4th International Symposium Gas‐Phase Synthesis of Functional Nanomaterials}}, title = {{{Influence of differing nozzle configurations on the final particle characteristics and particle structure evolution in spray flames}}}, year = {{2020}}, } @article{21949, abstract = {{This paper presents the results of an interlaboratory study of the rheological properties of cement paste and ultrasound gel as reference substance. The goal was to quantify the comparability and reproducibility of measurements of the Bingham parameters yield stress and plastic viscosity when measured on one specific paste composition and one particular ultrasound gel in different laboratories using different rheometers and measurement geometries. The procedures for both in preparing the cement paste and carrying out the rheological measurements on cement paste and ultrasound gel were carefully defined for all of the study’s participants. Different conversion schemes for comparing the results obtained with the different measurement setups are presented here and critically discussed. The procedure proposed in this paper ensured a reasonable comparability of the results with a coefficient of variation for the yield stress of 27% and for the plastic viscosity of 24%, despite the individual measurement series’ having been performed in different labs with different rheometers and measurement geometries.}}, author = {{Haist, Michael and Link, Julian and Nicia, David and Leinitz, Sarah and Baumert, Christian and von Bronk, Tabea and Cotardo, Dario and Eslami Pirharati, Mahmoud and Fataei, Shirin and Garrecht, Harald and Gehlen, Christoph and Hauschildt, Inga and Ivanova, Irina and Jesinghausen, Steffen and Klein, Christopher and Krauss, Hans-W. and Lohaus, Ludger and Lowke, Dirk and Mazanec, Oliver and Pawelczyk, Sebastian and Pott, Ursula and Radebe, Nonkululeko W. and Riedmiller, Joachim Jürgen and Schmid, Hans-Joachim and Schmidt, Wolfram and Secrieru, Egor and Stephan, Dietmar and Thiedeitz, Mareike and Wilhelm, Manfred and Mechtcherine, Viktor}}, issn = {{1359-5997}}, journal = {{Materials and Structures}}, keywords = {{Rheology, Wall Slip, Slip, apparent slip, suspension, cement, concrete}}, title = {{{Interlaboratory study on rheological properties of cement pastes and reference substances: comparability of measurements performed with different rheometers and measurement geometries}}}, doi = {{10.1617/s11527-020-01477-w}}, year = {{2020}}, } @article{21948, abstract = {{Since suspensions (e.g., in food, cement, or cosmetics industries) tend to show wall slip, the application of structured measuring surfaces in rheometers is widespread. Usually, for parallel-plate geometries, the tip-to-tip distance is used for calculation of absolute rheological values, which implies that there is no flow behind this distance. However, several studies show that this is not true. Therefore, the measuring gap needs to be corrected by adding the effective gap extension δ to the prescribed gap height H in order to obtain absolute rheological properties. In this paper, we determine the effective gap extension δ for different structures and fluids (Newtonian, shear thinning, and model suspensions that can be adjusted to the behavior of real fluids) and compare the corrected values to reference data. We observe that for Newtonian fluids a gap- and material-independent correction function can be derived for every measuring system, which is also applicable to suspensions, but not to shear thinning fluids. Since this relation appears to be mainly dependent on the characteristics of flow behaviour, we show that the calibration of structured measuring systems is possible with Newtonian fluids and then can be transferred to suspensions up to a certain particle content.}}, author = {{Pawelczyk, Sebastian and Kniepkamp, Marieluise and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, issn = {{1996-1944}}, journal = {{Materials}}, keywords = {{wall slip prevention, effective gap height, parallel-plate system, structured surfaces, model suspensions, cement paste, fresh concrete}}, title = {{{Absolute Rheological Measurements of Model Suspensions: Influence and Correction of Wall Slip Prevention Measures}}}, doi = {{10.3390/ma13020467}}, year = {{2020}}, } @techreport{24628, author = {{Menge, Dennis and Walter, Rolf and Schmid, Hans-Joachim and Breuer, Ulf Paul}}, pages = {{77}}, title = {{{FVA-Nr. 813 I - Generative Verfahren zur Herstellung von Polymerbauteilen}}}, volume = {{1338}}, year = {{2019}}, } @inbook{26098, abstract = {{Since, in the presence of humidity the inter-particle processes are dominated by capillary forces, a fundamental understanding of the water adsorption and the capillary bridge formation is very important. However, the adsorbed water structure and thus the capillary bridge formation is influenced by various parameters like the particle morphology (e.g. particle size, roughness) as well as the surface chemistry (surface energy, adsorbate structure) and therefore needs to be analyzed on a submicroscopic or even molecular basis. A multi-scale approach ranging from experiments on an individual particle level (AFM and liquid bridge simulation) and investigations on small particle ensembles (combined QCM-D/FTIR) up to macroscopic description of bulk behavior is presented in this chapter. In this context, the combined in situ QCM-D/FTIR experiments are bridging the gap between experiments on an individual particle level and macroscopic bulk behavior. Variation of surface chemistry by means of adsorption of functional organic molecules allows for the correlation of macroscopic particle behavior to nanoscopic effects like the presence and structure of adsorbate layers as well as the formation of capillary bridges while keeping the disperse properties constant. Besides extensive experimental work, simulations of capillary bridges formed by condensation from humid air are presented. It is clearly shown that well known approximations which have been introduced for micron-sized particles are not valid any more for nano-scaled particles. The forces between nanoparticles by static liquid bridges and their dependency on particle size, contact angle, humidity and interparticle distance are discussed in detail. Furthermore, capillary forces during separation of particles are studied thoroughly and a constitutive law based on a contact stiffness allows the transfer to DEM simulations of wet powders. Finally, it is demonstrated by comparison to Molecular Dynamics simulations, that the used continuum approach to simulate capillary bridges might even be used down to particle sizes of a few nanometers, if some additional effects are considered correctly.}}, author = {{Schmid, Hans-Joachim and Grundmeier, Guido and Dörmann, Michael and Orive, Alejandro González and de los Arcos, Teresa and Torun, Boray}}, booktitle = {{Particles in Contact}}, title = {{{Understanding and Manipulation of Nanoparticle Contact Forces by Capillary Bridges}}}, doi = {{10.1007/978-3-030-15899-6_2}}, year = {{2019}}, } @inproceedings{22198, abstract = {{Zuverlässige, wiederholbare Bauteileigenschaften sind unabdingbar um das Herstellungsverfahren Polymer Lasersintern im industriellen Prozess-Portfolio vieler Firmen aufnehmen zu können. Einige Unternehmen und Institute haben sich daher in jüngster Zeit mit dem Thema der reproduzierbaren Bauteileigenschaften beschäftigt. Mit der hier vorgestellten und angewandten Methodik wird nicht nur der Prozessablauf vom Bauteil bis zu Nachbearbeitung betrachtet, sondern auch die Maschinenperformance in einem Ringversuch und über einen längeren Zeitraum geprüft. Rückgrat dieser Untersuchung bildet hierbei der aus der Six Sigma Lehre stammende DMAIC (Define - Measure - Analyse - Improve - Control) Verbesserungszyklus. Hierfür wird ein Standard-Prozess definiert. Diesem folgend werden die für die Industrie oder den Anwender interessanten Messungen aufgenommen und analysiert. Anschließend wird der Prozess sowie die Messmethodik optimiert und auch Kontrollmethoden definiert. Für die Anwendung der entwickelten Methodik wird exemplarisch der Maschinentyp EOS P396 mit PA2200 untersucht. Daten für die Bestimmung der Mechanik, der Optik und der Haptik sowie für die Dimensionen und die Bauteildichte werden als Qualitätskriterium aufgenommen und über einen längeren Zeitraum analysiert. Weiteres Ziel ist es, den Messaufwand zu reduzieren und die Qualitätssicherung im Serienbtrieb zu gewährleisten.}}, author = {{Klippstein, Sven Helge and Schmid, Hans-Joachim}}, booktitle = {{Proceedings of the 16th Rapid.Tech Conference}}, title = {{{Methodik zur Qualifizierung des Lasersinter Prozesses für die Serienfertigung}}}, doi = {{10.3139/9783446462441.025}}, year = {{2019}}, } @inproceedings{24515, author = {{Tischendorf, Ricardo and Bieber, M. and Kneer, R. and Schmid, Hans-Joachim}}, keywords = {{FSP, nanoparticle synthesis, in situ measurements}}, location = {{Nürnberg}}, publisher = {{PARTEC 2019 International Congress on Particle Technology}}, title = {{{Representative Sample Extraction from Spray Flames for SMPS and HR-TEM Measurements}}}, year = {{2019}}, } @inproceedings{22202, abstract = {{Structural parts for aviation have very high demands on the development and production process. Therefore, the entire process must be considered in order to produce high-quality AM metal parts. In this case study, a conventional part was selected to be optimized for AM. The process presented includes component selection, design improvement with a novel approach for topology optimization based on the AMendate algorithm as basis of MSC Apex Generative Design,component production on a SLM 250 HL and post-processing including heat treatment and surface smoothing. With the topology optimization a weight reduction of ~60 % could be realized, whereby the stress distribution is more homogeneous. Furthermore, the challenges of support optimization and post-processing have to be addressed, in order to produce competitive parts.}}, author = {{Klippstein, Sven Helge and Duchting, Anne and Reiher, Thomas and Hengsbach, F. and Menge, Dennis and Schmid, Hans-Joachim}}, booktitle = {{30th Annual International Solid Freeform Fabrication Symposium}}, pages = {{1932--1945}}, title = {{{Devolopment, Production and post-processing of a topology optimized aircraft bracket }}}, volume = {{30}}, year = {{2019}}, } @article{22541, abstract = {{Monodisperse micron-sized silica particle monolayers deposited onto plasma-grown SiOx-ultra-thin films have been used as reference systems to investigate wetting, water adsorption and capillary bridge formation as a function of silica surface functionalization. 1H,1H, 2H,2H perfluorooctyltriethoxysil (FOTS) monolayers, have been deposited on the respective surfaces by means of chemical vapor deposition resulting in macroscopically low energy surfaces. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) reflection absorption spectroscopy confirmed the monolayer formation. Water adsorption isotherms were studied by a combination of in-situ FTIR reflection spectroscopy and quartz crystal microbalance (QCM) while macroscopic wetting was analysed by contact angle measurements. The comparative data evaluation indicates that the macroscopic wetting behaviour was changed as expected, however, that water nanodroplets formed both at intrinsic defects of the FOTS monolayer and at the FOTS/SiOx interface. Capillary bridges of liquid water are dominantly formed in the confined particle contact areas and between surface asperities on the particles. The comparison of wetting, adsorption and capillary bridge formation shows that the hydrophobization of porous materials by organosilane monolayers leads to the formation of morphology dependent nanoscopic defects that act as sites for preferential capillary bridge formation.}}, author = {{Giner, Ignacio and Torun, Boray and Han, Yan and Duderija, Belma and Meinderink, Dennis and Orive, Alejandro González and de los Arcos de Pedro, Maria Teresa and Weinberger, Christian and Tiemann, Michael and Schmid, Hans-Joachim and Grundmeier, Guido}}, issn = {{0169-4332}}, journal = {{Applied Surface Science}}, pages = {{873--879}}, title = {{{Water adsorption and capillary bridge formation on silica micro-particle layers modified with perfluorinated organosilane monolayers}}}, doi = {{10.1016/j.apsusc.2018.12.221}}, year = {{2019}}, } @article{26103, abstract = {{Pore-scale filtration simulations require high spatio-temporal resolutions and significant computational effort, hence, keeping the domain size to a minimum is desirable. Previous studies have considered domains based on Brinkman length, or are limited by computing power, and little information is available for conditions involving high fluid saturation – typical of steady state mist filtration. In this study, simulations are performed to characterize the effect of domain size on pressure drop, residual saturation, liquid film thickness and interfacial area concentration, using virtual nonwoven and foam filters with similar micro-structural properties. Further, experiments using micro-CT are performed to validate the present computational simulations. It is found that two phase flow through filters are more sensitive to local geometric variations or mesh resolution in the porous media than single phase flow. Statistical uncertainties in the steady state quantities of less than +-10% can be expected to cope with the increase in computing power required for practical mesh sizes. A computational domain size of about 50–100xd (where d is the strut or fibre diameter) was found to be required for CFD for the operating conditions considered.}}, author = {{Abishek, S. and King, A.J.C. and Schuler, J. and Kasper, G. and Schmid, Hans-Joachim and Mullins, B.J.}}, issn = {{1383-5866}}, journal = {{Separation and Purification Technology}}, pages = {{344--352}}, title = {{{Representative domain size for the simulation of coalescence filtration in nonwoven and foam media}}}, doi = {{10.1016/j.seppur.2018.06.051}}, year = {{2018}}, } @inproceedings{22183, abstract = {{Function integration is a key issue for an efficient and economic usage of Additive Manufacturing. An efficient heat transfer by topology optimized structures is a rarely considered approach which will be outlined with an exemplary electronic housing which has been newly designed. A commercial projector unit, whose electrical components in total produce 38 W, shall be integrated in the closed housing and passively cooled by natural convection. Topology optimized structures shall be generated in the inner part of the housing to transfer the heat homogenously from the projector components to the housing wall while simultaneously minimizing the mass. At the outside of the housing walls, lattice and rib structures are applied to increase the effective surface for heat transfer by natural convection and radiation. Furthermore, the housing geometry is optimized regarding a minimization of support structures to reduce the post-processing effort. Finally, the housing shall be built of AlSi10Mg by SLM.}}, author = {{Menge, Dennis and Delfs, Patrick and Töws, Marcel and Schmid, Hans-Joachim}}, booktitle = {{29th Annual International Solid Freeform Fabrication Symposium}}, pages = {{687--697}}, title = {{{Topology Optimized Heat Transfer Using the Example of an Electronic Housing}}}, volume = {{29}}, year = {{2018}}, } @article{22196, abstract = {{The influence of selective laser sintering (SLS) parameters on PA12 part properties is well known, but research on other materials is rare. One alternative material is a thermoplastic elastomer (TPE) called PrimePart ST that is more elastic and shows a distinct SLS processing behavior. It undergoes a three-dimensional temperature distribution during the SLS process within the TPE part cake. To examine this further, a temperature measurement system that allows temperature measurements inside the part cake is applied to TPE in the present work. Position-dependent temperature histories are directly correlated with the color and mechanical properties of built parts and are in very good agreement with artificial heat treatment in a furnace. Furthermore, it is clearly shown that the yellowish discoloration of parts in different intensities is not only temperature dependent but also influenced by the residual oxygen content in the process atmosphere. Nevertheless, the discoloration has no influence on the mechanical part properties.}}, author = {{Kummert, Christina and Josupeit, Stefan and Schmid, Hans-Joachim}}, journal = {{Journal of Minerals, Metals and Materials Society}}, number = {{3}}, pages = {{425--430}}, publisher = {{Springer}}, title = {{{Thermoplastic Elastomer Part Color as Function of Temperature Histories and Oxygen Atmosphere During Selective Laser Sinterung}}}, doi = {{10.1007/s11837-017-2658-2}}, volume = {{70}}, year = {{2018}}, } @misc{29824, abstract = {{ Zusammenfassung: Bei einem Verfahren und einer Vor- richtung zur Bestimmung von Nanopartikeleigenschaften ei- nes nanopartikelbeladenen Aerosols (17), mit einer Test- kammer (1) zur Bestimmung der Nanopartikeleigenschaften des Aerosols (17), wobei die Testkammer (1) einen Aero- soleinlass (9) zum Einleiten des Aerosols (17) und ein Hül- lenluftstromeinlass (10) zur Einleitung eines Hüllenluftstroms (16) aufweist, die Oberseite (2) und die Unterseite (3) der Testkammer (1) jeweils eine flächige Elektrode (4, 5) auf- weist, so dass zwei im Abstand zueinander angeordnete Elektroden (4, 5) bereitstehen, zwischen denen ein elektri- sches Feld (6) erzeugbar ist, soll ein kompaktes Messgerät für die Vermessung der Eigenschaften von Aerosolnanopar- tikeln zur Verfügung gestellt werden, bei dem es ermöglicht wird, im selben Gerät die zweidimensionale Verteilung be- züglich des aerodynamischen und des volumenäquivalen- ten Durchmessers zu bestimmen, wodurch eine Lösung ge- schaffen wird, die es ermöglicht Aussagen über die Größe, die Masse, die Form und die geometrische Struktur einer Partikel zu treffen. Dies wird dadurch erreicht, dass der Inhalt der Testkammer (1) in Rotation versetzt wird, wobei die Ro- tationsachse (18) parallel zum elektrischen Feld (6) verläuft.}}, author = {{Schmid, Hans-Joachim and Rasche, David}}, title = {{{Bestimmung von Nanopartikeleigenschaften eines Aerosols}}}, year = {{2018}}, } @inbook{26104, abstract = {{Selective Laser Sintering (SLS) is an Additive Manufacturing technology, which allows the production of functional polymer parts. Conventionally mainly Nylon 12 (PA 12), Polyamide 11 (PA 11), glass- or aluminum filled materials enable rapid prototyping during the product development process. Those materials do not always meet the requirements for direct production of functional parts by laser sintering. For Direct Manufacturing of functional parts out of required materials and in high quality, the laser sintering process and the material palette needs to be further developed. During this research a laser sintering test equipment for material qualification has been built up. The forthcomings are an optimized software solution, an innovative optical system, an alternative powder coating system and an improved temperature control. The functionality of the test equipment is proved with the standard material PA2200 and two new laser-sintering-materials, Nylon 6 (PA 6) and Polyamide 613 (PA 613), are investigated. The process parameters are derived and mechanical properties are determined by tensile tests.}}, author = {{Lohn, Johannes and Schmid, Hans-Joachim}}, booktitle = {{Rapid.Tech – International Trade Show & Conference for Additive Manufacturing}}, title = {{{Aufbau einer Lasersinter-Versuchsanlage und Verarbeitung neuer Materialien am Beispiel von Polyamid 6 und Polyamid 613}}}, doi = {{10.3139/9783446454606.023}}, year = {{2017}}, } @article{26106, abstract = {{We study the variation of the adhesion forces between wet TiO2 nanoparticles as a function of their size and the ambient relative humidity. Combining all-atom molecular dynamics and capillary simulations we demonstrate that the linear scaling of the interparticle forces with the particle diameter, well established for microscopic and macroscopic particles, can be extended down to diameters of a few nm. At this size scale, however, the molecular nature of the water adsorbates dictates the adhesion forces both via solvation effects and influencing parameters of analytical capillary models such as the equilibrium particle–particle separation distance and the water/particle contact angle. Moreover, the water surface tension becomes considerably larger than the macroscopic bulk value due to combined effects of thin-film confinement and tight curvature, in a way that strongly depends on humidity and particle size. Taking these effects into proper account, classical capillary equations can be used to predict the interparticle forces even of the smallest particles considered here (4 nm), although the circular approximation fails to reproduce the distance at which the water meniscus breaks. Finally, the transition between the dominating effects at the nanoscopic scale and conventional capillary theory valid at microscopic size scales can be only rationalized if the presence of roughness asperities on the surface of the large particles is explicitly taken into account.}}, author = {{Laube, Jens and Dörmann, Michael and Schmid, Hans-Joachim and Mädler, Lutz and Colombi Ciacchi, Lucio}}, issn = {{1932-7447}}, journal = {{The Journal of Physical Chemistry C}}, pages = {{15294--15303}}, title = {{{Dependencies of the Adhesion Forces between TiO2 Nanoparticles on Size and Ambient Humidity}}}, doi = {{10.1021/acs.jpcc.7b05655}}, year = {{2017}}, } @article{26107, abstract = {{Capillary forces are very important considering the handling of powders as they, in general, exceed other adhesion forces. These capillary forces are dependent on several different parameters. Especially the distance between the particles is an important parameter. For example, in moving bulk solids a large variety of distances between particles will occur. Therefore, the distance-dependence of capillary bridges was investigated with a numerical simulation method, assuming thermodynamic equilibrium which is attained very fast for small particles. This method uses the Kelvin equation and the Young-Laplace equation to calculate numerically the shape of the capillary bridge without any assumption regarding the shape. The force is eventually derived from the meniscus shape. The distance becomes extremely important when the capillary liquid bridge between two surfaces is only determined by capillary condensation depending on relative humidity. Only a slight increase of the distance within the fraction of a nanometer changes the behaviour of the capillary force significantly. Furthermore, the influence of the force on the separation of particles will be presented. The force decreases almost linearly with increasing distance for a wide range of distances and consequently, a contact stiffness for capillary bridges could be derived. These results may e.g. be used in DEM models. Also, the maximum separation distance of capillary bridges in thermodynamic equilibrium and the correlation with the according bridge volume was investigated. As two limiting cases for capillary bridges at varying distances one can assume either a constant curvature, i.e. infinitely fast attainment of equilibrium, or a constant volume, i.e. infinitely slow attainment of equilibrium. Therefore, a comparison of these two possibilities will be presented and discussed as well.}}, author = {{Dörmann, Michael and Schmid, Hans-Joachim}}, issn = {{0032-5910}}, journal = {{Powder Technology}}, pages = {{175--183}}, title = {{{Distance-dependency of capillary bridges in thermodynamic equilibrium}}}, doi = {{10.1016/j.powtec.2017.01.012}}, year = {{2017}}, } @inbook{23759, author = {{Menge, Dennis and Josupeit, Stefan and Delfs, Patrick and Schmid, Hans-Joachim}}, booktitle = {{Additive Fertigung von Bauteilen und Strukturen}}, editor = {{Richard, Hans Albert and Schramm, Britta and Zipsner, Thomas}}, isbn = {{9783658177799}}, pages = {{105--120}}, publisher = {{Springer Vieweg}}, title = {{{Herstellbarkeit und mechanische Charakterisierung von lasergesinterten Gitterstrukturen}}}, doi = {{10.1007/978-3-658-17780-5}}, year = {{2017}}, } @article{22195, abstract = {{Polymer laser sintering (LS) is an important additive manufacturing (AM) technology. Individual and complex parts are directly produced from CAD data without the need of specific tools. The raw material is a polymer powder, which is deposited layerwise and melted selectively with a laser. Built parts are embedded in residual unmolten powder, the so-called part cake, which undergoes thermal ageing effects due to the exposure to high temperatures for long times during the manufacturing process. Hence, the recyclability of the unmolten powder is limited. This article focuses on a fundamental analysis of the ageing kinetics dependent on time, temperature, and oxygen content in the gas atmosphere. A model is developed and applied to measured, position-dependent process temperature histories to successfully predict the ageing distribution within a part cake. The results can be used to optimize the thermal process management in LS and to develop new efficient powder recycling methods. }}, author = {{Josupeit, Stefan and Schmid, Hans-Joachim}}, journal = {{Journal of Applied Polymer Science}}, number = {{42}}, publisher = {{Wiley}}, title = {{{Experimental analysis and modeling of local ageing effects during laser sintering of polyamide 12 in regard to individual thermal histories}}}, doi = {{10.1002/app.45435}}, volume = {{134}}, year = {{2017}}, }