Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-26106 Zeitschriftenartikel Buchholz, Uwe; Jaunich, Matthias; Stark, Wolfgang; Habel, Wolfgang; Petersson, B.A.T. Acoustic data of cross linked polyethylene (XLPE) and cured liquid silicone rubber (LSR) by means of ultrasonic and low frequency DMTA Partial discharges may cause damage to electrical insulation of high voltage equipment. They initiate elastic waves in the insulating material, e.g. in the stress cone of an outdoor termination. Localisation of the origin of such elastic waves can help to predict serious damaging processes in the electrical insulation. In order to measure and evaluate the wave propagation effects in typical multilayered elastomeric structures, knowledge of the material properties is required. The propagating velocity and the attenuation of longitudinal waves are important parameters. Values for these quantities found in the literature were not appropriate. Therefore, for cross-linked polyethylene (XLPE) and cured liquid silicone rubber (LSR), the longitudinal wave velocity and the attenuation were evaluated in the temperature interval from -20°C to 50°C and in the frequency range from 200 kHz to 600 kHz using a two-sample ultrasound technique. The loss factor was determined from these measured quantities. Additionally, low frequency Dynamic Mechanical Thermal Analysis (DMTA) was applied to investigate LSR and XLPE in a temperature interval between -100 and 50°C and to check qualitatively the ultrasound data. New York, NY Institute of Electrical and Electronics Engineers 2012 IEEE transactions on dielectrics and electrical insulation 19 2 558 566 10.1109/TDEI.2012.6180250 2016-02-19 OPUS4-23421 Beitrag zu einem Tagungsband Frübing, P.; Wang, F.; Günter, C.; Gerhard, R.; Wegener, M.; Jaunich, Matthias; Stark, Wolfgang Relation between dielectric and mechanical losses in ferroelectric poly(vinylidene fluoride - hexafluoropropylene) films The temperature dependences of dielectric permittivity and elastic modulus of poly(vinylidene fluoride - hexafluoropropylene) (P(VDF-HFP)) are compared and explained by use of structural data obtained by differential scanning calorimetry and X-ray analysis. Special emphasis is put on the effect of uniaxial stretching which renders the polymer ferroelectric. It is shown that dielectric and mechanical relaxations at the glass transition (aa relaxation) are closely related and not significantly affected by stretching. It is further confirmed that stretching destroys the non-polar spherulitic crystalline structure and produces relatively small-sized polar crystallites. This manifests in the disappearence of the so-called ac relaxation which is associated to molecular motions within the spherulitic crystalline lamellae. However, there are discrepancies between dielectric and mechanical losses above the glass transition which point towards a still not described structural transition. Institute of Electrical and Electronics Engineers (IEEE) 2010 10th IEEE International conference on solid dielectrics (ICSD) 978-1-4244-7945-0 10th IEEE International conference on solid dielectrics (ICSD) Potsdam, Germany 2010-07-04 2010-07-09 1 4(?) 10.1109/ICSD.2010.5567936 2016-02-19 OPUS4-19858 Zeitschriftenartikel Hoster, B.; Jaunich, Matthias; Stark, Wolfgang Monitoring of the vulcanisation process by ultrasound during injection moulding Today rubber is due to its unique property profile one of the most important materials for the production of bearings, dampers or also tires and tubes. In the production of rubber goods a chemical cross-linking reaction (vulcanisation) generates the final material properties. This process takes place during the shape giving of the rubber compound in the mould and can proceed for several minutes. The cross-linking process is influenced by the mixture of the basic polymer, the cross-linking agent, the influence of catalysts and inhibitors and especially the processing conditions. The quality of every ingredient, the reproducibility of the mixing ratio, the homogeneity of the mixture and the accurateness in temperature control can have a direct influence on the cross linking reaction. To control the quality of a rubber compound and verify the processing conditions in industry moving die rheometers, named curemeter, are involved in the production process. Starting from our experience in cure monitoring of thermosetting materials by measuring ultrasound velocity in the mould we extended the measuring principle to rubber vulcanisation monitoring. After first investigations using a compression mould we dealt here with on-line monitoring of vulcanisation in an injection moulding process which is one of the most used techniques in rubber industry. Kirchwald NDT.net 2009 The e-journal of nondestructive testing & ultrasonics 14 9 1 9 2016-02-19 OPUS4-29661 Beitrag zu einem Sammelband Jaunich, Matthias; Probst, Ulrich; Schulz, Sebastian; Wolff, Dietmar; Stark, Wolfgang Berger, K.-F.; Kiefer, S. Elastomere - Untersuchung des Tieftemperaturverhaltens im Dichtungseinsatz Aufgrund ihrer einfachen und zuverlässigen Anwendung werden Elastomere für viele Dichtungsaufgaben eingesetzt. In vielen Anwendungsbereichen, wie z.B. Verkehr, Luftfahrt und Verfahrenstechnik, können während des Einsatzes tiefe Temperaturen auftreten, bei denen die Funktionsfähigkeit der Dichtung erhalten bleiben muss. Daher ist die Untersuchung des Verhaltens von Elastomerdichtungen bei tiefen Temperaturen wichtig, um ihren Temperatureinsatzbereich nach unten abzugrenzen und dadurch einen verlässlichen Betrieb zu sichern. Ziel dieser Arbeit ist es, den sicheren Einschluss von gefährlichen Gütern unter verschiedenen Umgebungsbedingungen und über lange Zeiten zu ermöglichen bzw. die Materialauswahl entsprechend zu steuern. Mannheim ISGATEC GmbH 2013 Dichtungstechnik Jahrbuch 2014 978-3-9811509-7-1 82 91 2016-02-20 OPUS4-24971 Beitrag zu einem Tagungsband Jaunich, Matthias; Schulz, Sebastian; Stark, Wolfgang; Wolff, Dietmar Characterization of the low temperature behaviour of rubber sealing materials Rubbers are often used for seal applications due to their special material properties and easy use. In many applications the material is exposed to low temperatures during Operation. Therefore it is important to know the material behavior at low temperatures to determine the temperature ränge that allows a Safe Operation of the seal, e.g. in storage and transport Containers for radioactive materials. The seal function of an elastomer is limited in temperature by the rubber-glass transition during which the material properties change from rubber-like to stiff and glass-like. For a given application this correlation is not trivial and therefore needs an in-depth investigation under consideration of the physical properties and the application conditions. In this work different analytical methods are used to characterize the material behavior at low temperature in the ränge of the glass-rubber-transition and are compared with the quality of Operation of a component which is here defined by the detected leakage rate. 2011 Technomer 2011 - 22. Fachtagung über Verarbeitung und Anwendung von Polymeren 978-3-939382-10-2 Technomer 2011 - 22. Fachtagung über Verarbeitung und Anwendung von Polymeren Chemnitz, Deutschland 10.11.2011 12.11.2011 Kap. 3.7 1 4 2016-02-19 OPUS4-19959 Zeitschriftenartikel Jaunich, Matthias; Stark, Wolfgang Monitoring the vulcanization of rubber with ultrasound: Influence of material thickness and temperature In consideration of the influence of the curing reaction on the material properties of elastomers, it is very important to control the vulcanization process properly. As shown previously [1], the effects of the vulcanization reaction of an elastomer can be monitored by use of ultrasonic sound waves. This technique has to a certain degree a high similarity to the standard curemeter test according to ISO 6502 but can be applied also inside a production tool. So far, the method was only applied to the vulcanization of one compound at a given temperature and sample thickness. This is now complemented with measurements on another compound system at different temperatures and sample thicknesses. The expected effects of temperature and thickness on the curing behaviour were found by use of the ultrasound online control. Amsterdam [u.a.] Elsevier Science 2009 Polymer testing 28 8 901 906 10.1016/j.polymertesting.2009.08.006 2016-02-19 OPUS4-20566 Zeitschriftenartikel Jaunich, Matthias; Stark, Wolfgang Einfluss der Härtung auf die Materialeigenschaften eines Harnstoffharzes Über die in der Technik weit verbreitete typisierte Harnstoffformmasse UF 131.5, ein Aminoplast, wird berichtet, dass sie im Zuge der thermisch aktivierten Vernetzungsreaktion wegen "Überhärtung" mangelhafte Eigenschaften annimmt. Zur Verifizierung dieses Effektes werden mithilfe der Ultraschall-Prozesskontrolle gezielt Proben unterschiedlicher Aushärtegrade hergestellt. Sie werden mit verschiedenen Methoden, wie der "Kochprobe" und der Thermoanalyse, charakterisiert und auf ihre Materialeigenschaften untersucht. Dabei zeigt sich ein deutlicher Einfluss der Härtezeit auf die Glasübergangstemperatur der Formmasse. In den mechanischen Eigenschaften ist eine Veränderung allerdings nur in der Schlagzähigkeit festzustellen, die sich mit steigender Härtezeit sogar wesentlich verbessert. München Hanser Bundesanstalt für Materialforschung und -prüfung 2009 MP materials testing 51 11-12 828 834 2016-02-19 OPUS4-18574 Beitrag zu einem Tagungsband Jaunich, Matthias; Stark, Wolfgang; Hoster, B. In-situ vulcanization monitoring by ultrasonic wave propagation Deutsches Institut für Kautschuktechnologie e.V. 2008 8. Kautschuk-Herbst-Kolloquium, 26.- 28.11.2008, Hannover (Proceedings) 8. Kautschuk-Herbst-Kolloquium Hannover, Deutschland 2008-11-26 2008-11-28 133 2016-02-19 OPUS4-18674 Zeitschriftenartikel Jaunich, Matthias; Stark, Wolfgang; Hoster, B. Monitoring the vulcanization of elastomers: Comparison of curemeter and ultrasonic online control The vulcanization of elastomeric materials has a high impact on the properties of the final product. Therefore, it is important to monitor and control this crosslinking process. A common technique to attain the necessary curing time is the use of a curemeter in accordance with ISO 6502 in order to determine the time for full cure of a sample with a standardized geometry. Based on this result and a lot of practical experience, the required curing time for a given product geometry is estimated. Within the scope of this work, a new analysis technique will be compared with the standard procedure. The ultrasonic online control employs ultrasound waves to measure the changes in material properties caused by vulcanization. For this study, a natural rubber compound with a conventional curing system was investigated by both techniques. It was found that the results of the ultrasonic technique show good agreement with the results of the curemeter. Amsterdam [u.a.] Elsevier Science 2009 Polymer testing 28 1 84 88 10.1016/j.polymertesting.2008.11.005 2016-02-19 OPUS4-26190 Beitrag zu einem Tagungsband Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Low temperature - For a seal this depends on the applied material Frankfurt am Main Deutsche Kautschuk-Gesellschaft 2012 DKT 2012 - German Rubber Conference DKT 2012 - German Rubber Conference Nuremberg, Germany 2012-07-02 2012-07-05 10-2330_5-L-1530 1 4 2016-02-19 OPUS4-28574 Beitrag zu einem Tagungsband Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Behaviour of rubber seals at low temperatures - results of component tests - The investigation of low temperature properties of elastomeric sealing materials by means of thermo-analytical methods is a sound way to get information about the glass transition process. The breakdown temperature of the sealing function of O-ring seals was measured in a component test setup depending on material and degree of compression. An in depth explanation of the observed component tests behaviour is currently in preparation. It requires the results of thermo-analytical methods and measurements as the compression set (not shown here). With that, a model was developed to describe the correlation between physical material parameters and observed component behaviour. Kerntechnische Gesellschaft e.V. (KTG) 2013 Jahrestagung Kerntechnik 2013 (Proceedings) Jahrestagung Kerntechnik 2013 Berlin, Germany 14.05.2013 16.05.2013 1 6 2016-02-20 OPUS4-29616 Beitrag zu einem Tagungsband Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Druckverformungsrest bei tiefen Temperaturen Für Elastomenwerkstoffe im Allgemeinen und im Bereich der Dichtungstechnik im Besonderen ist der Druckverformungsrest eine wichtige Kenngröße zur Beurteilung der Eignung eines Werkstoffs bzw. der Funktion eines Bauteils. Er ermöglicht eine Einschätzung des zeitabhängigen Rückstellverhaltens eines Werkstoffs nach Deformation. Dieses ist für Dichtungen von besonderer Bedeutung, da der Test deren Einbauzustand nachstellt. Oft wird er, bei der Prüfung unter erhöhten Temperaturen, zur Beurteilung des Alterungsverhaltens verwendet und kann anhand eines definierten Versagenskriteriums zur Lebensdauerabschätzung eingesetzt werden. Bei tiefen Temperaturen dient er dazu, die limitierende Einsatztemperatur zu bestimmen. Dabei spielt eine Alterung im eigentlichen Sinne nur eine untergeordnete Rolle, wohl aber physikalische Effekte wie Tieftemperaturkristallisation und Glasübergang. Diese Effekte sind weit weniger durch lange Lagerzeiten beeinflusst als die eigentliche Alterung. Die Versuchsdurchführung unterscheidet sich je nach angewandter Norm und kann einen deutlichen Einfluss auf den Druckverformungsrest haben. Alle standardisierten Methoden sind aufgrund der langen Lagerzeiten relativ langwierig und erfordern das regelmäßige Eingreifen durch den Prüfer. Zusätzlich sehen einige Methoden nur die Bestimmung eines einzelnen Wertes nach einer definierten Zeit vor. Um die Messungen zu beschleunigen wurde eine Methode entwickelt, die automatisch die erforderlichen Messungen bei mehreren Temperaturen durchführt. Dazu wird ein Prüfgerät der Dynamisch Mechanischen Analyse verwendet, das kontinuierlich die Deformation während eines frei programmierbaren Temperaturzyklus misst, wodurch eine sehr große Datenmenge verfügbar ist. Ein Vergleich der neuen Methode mit den Ergebnissen des nach ISO 815 genormten Messprinzips ergibt eine gute Übereinstimmung. Ergebnisse der neuen Methode werden vorgestellt und die Vorzüge der kontinuierlichen Datenerfassung, z.B. für die Materialauswahl, diskutiert. Die vorgestellten Ergebnisse beziehen sich zum großen Teil auf die in beschriebenen Untersuchungen und Ergebnisse. Technische Universität Chemnitz 2013 Technomer 2013 - 23. Fachtagung über Verarbeitung und Anwendung von Polymeren 978-3-939382-11-9 Technomer 2013 - 23. Fachtagung über Verarbeitung und Anwendung von Polymeren Chemnitz, Germany 14.11.2013 15.11.2013 Kapitel V 3.4 1 8 2016-02-20 OPUS4-22331 Beitrag zu einem Sammelband Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Low temperature properties of rubber seals Deutsches Institut für Kautschuktechnologie e.V. 2010 9th Fall rubber colloquium 978-3-9814076-0-0 9th Fall rubber colloquium Hannover, Germany 2010-11-03 2010-11-05 175 178 2016-02-19 OPUS4-26524 Beitrag zu einem Tagungsband Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Material behaviour of static seals at low temperatures Frankfurt/M. VDMA Fluidtechnik 2012 17th ISC - International sealing conference 978-3-00-039198-9 17th ISC - International sealing conference Stuttgart, Germany 2012-09-13 2012-09-14 A 16 295 300 2016-02-19 OPUS4-26538 Zeitschriftenartikel Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Comparison of low temperature properties of different elastomer materials investigated by a new method for compression set measurement The method for the determination of compression set values with a Dynamic Mechanical Analysis (DMA) setup at low temperatures, which was presented previously, allows a much faster and readily automated procedure than the standardized compression set test according to ISO 815-2. This method is applied to a series of different elastomeric materials that are commonly used for sealing applications. The results of the compression set test are compared with results from thermal analysis to allow an in depth comparison of the material behaviour at low temperatures. Furthermore, a comparison between two EPDM materials is presented. These materials show very similar properties determined by thermo analytical methods such as Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) but differ clearly in their compression set behaviour. This comparison shows the importance and value of information of the compression set test in addition to thermal analysis to judge the behaviour of sealing materials and confirms the relevance of the new compression set test method for the investigation of low temperature properties of elastomers. Amsterdam [u.a.] Elsevier Science 2012 Polymer testing 31 8 987 992 10.1016/j.polymertesting.2012.07.016 2016-02-19 OPUS4-31572 Zeitschriftenartikel Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Druckverformungsrest bei tiefen Temperaturen Der Druckverformungsrest (DVR) stellt insbesondere für Dichtungsanwendungen eine wichtige Kenngröße zur Beurteilung der Eignung eines Elastomers dar. Er ermöglicht die Einschätzung des zeitabhängigen Rückstellverhaltens eines Werkstoffs nach Deformation. Neben der Prüfung bei erhöhten Temperaturen, zur Beurteilung des Alterungsverhaltens, lässt sich bei der Durchführung bei tiefen Temperaturen die limitierende Einsatztemperatur bestimmen. Die Versuchsdurchführung unterscheidet sich je nach angewandter Norm und kann einen deutlichen Einfluss auf den DVR-Wert haben. Um bei tiefen Temperaturen eine schnelle Aussage zu gestatten, ist eine im Vergleich zu genormten Methoden deutlich schneller durchzuführende, automatisierte Methode entwickelt und mit Standardmethoden verglichen worden. Durch kontinuierliche Messung des Druckverformungsrests kann die Kinetik der Materialrückstellung betrachtet und dadurch ein effizienter Materialvergleich und eine effiziente Materialauswahl ermöglicht werden. Compression set (CS) is especially for sealing applications an important parameter for material selection. It allows an assessment of the time dependent recovery after deformation. In addition to testing at elevated temperatures which aims at the evaluation of the ageing behaviour, testing at low temperatures permits the determination of the low working temperature limit. The test procedure varies depending on the applied standard and can show a significant effect on the CS value. In order to allow a quick statement regarding low temperatures an automated procedure being significantly faster realisable in relation to the standardised methods has been developed and compared with standard procedures. Continuous measurement of the compression set allows evaluating the recovery kinetics and therefore an efficient comparison and selection of materials. Ratingen Gupta 2014 GAK: Gummi, Fasern, Kunststoffe 67 8 487 491 2016-02-20 OPUS4-19611 Beitrag zu einem Tagungsband Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Properties of elastomeric seals at low temperature Deutsche Kautschuk-Gesellschaft e.V. 2009 International rubber conference 2009 International rubber conference (IRC 2009) Nürnberg, Germany 2009-06-29 2009-07-02 Poster 23 1 3 2016-02-19 OPUS4-20386 Beitrag zu einem Sammelband Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Messung des Tieftemperaturverhaltens von Elastomer-Dichtungen Technische Universität Chemnitz 2009 TECHNOMER 2009 - 21. Fachtagung über Verarbeitung und Anwendung von Polymeren 978-3-939382-09-6 TECHNOMER 2009 - 21. Fachtagung über Verarbeitung und Anwendung von Polymeren Chemnitz, Deutschland 2009-11-12 2009-11-14 ETV7 1 9 2016-02-19 OPUS4-21914 Zeitschriftenartikel Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar A new method to evaluate the low temperature function of rubber sealing materials A new method for the evaluation of the low temperature properties of rubber materials is presented. The method emulates the standardized compression set measurement, which is frequently used for sealing materials, but can be performed within a considerably shorter time. The results are compared with the standard test and found to be qualitatively the same. Slight differences are discussed on the basis of the differences in the measurement procedures. Further data evaluation is done by fitting functions to describe the material behaviour. Amsterdam [u.a.] Elsevier Science 2010 Polymer testing 29 7 815 823 10.1016/j.polymertesting.2010.07.006 2016-02-19 OPUS4-23422 Zeitschriftenartikel Jaunich, Matthias; Stark, Wolfgang; Wolff, Dietmar Low temperature properties of rubber seals Rubber is widely used as sealing material in various applications. In many fields the sealing function at low temperatures is necessary. Therefore the understanding of failure mechanisms is of high importance. Rubbers are normally used above their glass-rubber transition region but the minimum working temperature limit is not defined precisely. Therefore the lower operation temperature limit of rubber seals should be determined in dependence of the material properties. The results of Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) are combined with the results of the standardized compression set according to ISO 815 respectively a modified test using the DMA equipment. Heidelberg Hüthig Deutsche Kautschuk-Gesellschaft 2011 Kautschuk, Gummi, Kunststoffe (KGK) 03 52 55 2016-02-19 OPUS4-23887 Beitrag zu einem Tagungsband Jaunich, Matthias; von der Ehe, Kerstin; Wolff, Dietmar; Völzke, Holger; Stark, Wolfgang Understanding the low temperature properties of rubber seals Rubbers are widely used as main sealing materials for containers for low and intermediate level radioactive waste and as additional component to metal seals in spent fuel and high active waste containers. The save encapsulation of the radioactive container inventory has to be guaranteed according to legislation and appropriate guidelines for long term storage periods as well as down to temperatures of -40 °C during transport. Therefore the understanding of failure mechanisms that lead to leakage at low temperatures is of high importance. It is known that the material properties of rubbers are strongly temperature dependent. At low temperatures this is caused by the rubber-glass transition (abbr. glass transition). During continuous cooling the material changes from rubber-like entropy-elastic to stiff energy-elastic behaviour, that allows nearly no strain or retraction, due to the glass transition. Hence rubbers are normally used above their glass transition but the minimum working temperature limit is not defined precisely, what can cause problems during application. Therefore the lower operation temperature limit of rubber seals should be determined in dependence of the material properties. The results of Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) are combined with the results of standardized measurements as the compression set according to ISO 815. To reduce the test time of the standard tests a faster technique was developed. Additionally, the breakdown temperature of the sealing function of complete O-ring seals is measured in a component test setup to compare it with the results of the other tests. The experimental setup is capable of measuring the leakage rate at low temperatures by the pressure rise method. A fluorocarbon rubber (FKM) was selected for this investigation as it is often used for radioactive waste containers. Some materials (seals and test sheets) were purchased from a commercial seal producer and some materials were compounded and cured at BAM in form of rubber sheets. PATRAM 2010 PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials (Proceedings) PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials London, UK 2010-10-03 2010-10-08 1 7 (Session T41 / Paper 169) 2016-02-19 OPUS4-24015 Zeitschriftenartikel Jaunich, Matthias; von der Ehe, Kerstin; Wolff, Dietmar; Völzke, Holger; Stark, Wolfgang Understanding low temperature properties of elastomer seals Elastomers are widely used as the main sealing materials for containers for low and intermediate level radioactive waste and as an additional component to metal seals in spent fuel and high active waste containers. The safe encapsulation of the radioactive container inventory has to be guaranteed according to regulation and appropriate guidelines for long term storage periods as well as for temperatures as low as -40°C during transport. Therefore, the understanding of failure mechanisms that lead to leakage at low temperatures is of high importance. It is known that the material properties of elastomers are strongly temperature dependent. At low temperatures, this is caused by the rubber-glass transition (abbreviated: glass transition). During continuous cooling, the material changes from a rubber-like entropy elastic to a stiff energy elastic behaviour, which allows nearly no strain or retraction. Hence, rubbers are normally used above their glass transition, but the minimum working temperature limit is not defined precisely; this can cause problems during the above noted applications. Therefore, the lower operation temperature limit of elastomer seals must be determined in dependence of the material properties. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) are combined with standardised measurements to determine the compression set according to ISO 815. To reduce the test time of the standard tests, a faster technique than normally used was developed. Additionally, the breakdown temperature of the sealing function of complete O ring seals was measured in a component test set-up to compare it with the results of the other tests. The experimental set-up is capable of measuring the leakage rate at low temperatures by the pressure rise method. A fluorocarbon rubber (FKM) was selected for this investigation as it is often used for radioactive waste containers. The materials (seals and test sheets) were purchased from a commercial seal producer. Ashford Ramtrans Publ. 2011 Packaging, transport, storage & security of radioactive materials (RAMTRANS) 22 2 83 88 10.1179/1746510911Y.0000000004 2016-02-19 OPUS4-29221 Beitrag zu einem Tagungsband Jaunich, Matthias; Wolff, Dietmar; Stark, Wolfgang Riedl, A. Was passiert bei tiefen Temperaturen? - Dichtungsverhalten im Bereich des Glasübergangs Elastomere werden vielfach als Dichtungsmaterial für verschiedene Anwendungen eingesetzt. In vielen Bereichen ist die Funktion der Dichtung auch bei tiefen Temperaturen erforderlich. Daher ist das Verständnis des Versagensmechanismus von großer Bedeutung. Normalerweise werden Elastomere oberhalb ihres Glass-Gummi Umwandlungsbereiches eingesetzt, wobei die minimale Einsatztemperatur nicht exakt definiert ist. Daher ist es sinnvoll, diese untere Temperatureinsatzgrenze in Abhängigkeit von den Materialeigenschaften zu bestimmen. Hierfür werden die Ergebnisse der thermischen Analyse mit den Resultaten des Druckverformungsrests aus einer abgewandelten Messung mit der Dynamisch Mechanischen Analyse (DMA) kombiniert. Weiterhin werden Ergebnisse von Bauteilversuchen vorgestellt und diskutiert. Die vorgestellten Untersuchungen wurden zum großen Teil auf Untersuchungen im Rahmen der Dissertation von M. Jaunich durchgeführt. Vulkan 2013 XVIII. Dichtungskolloquium - Sichere und zuverlässige Dichtverbindungen 978-3-8027-2216-5 XVIII. Dichtungskolloquium - Sichere und zuverlässige Dichtverbindungen Rheine, Germany 25.09.2013 26.09.2013 51 58 2016-02-20 OPUS4-21272 Beitrag zu einem Tagungsband Jaunich, Matthias; Wolff, Dietmar; Stark, Wolfgang Tieftemperaturverhalten von Elastomerdichtungen - Eigenschaftsbestimmung für den Einsatz in Transport- und Lagerbehältern für radioaktive Stoffe Die Messung des dynamischen Speichermoduls mit der Dynamisch-Mechanischen-Analyse ermöglicht einen schnellen Überblick über das temperaturabhängige Verhalten von elastomeren Dichtungsmaterialien. Ein direkter Rückschluss von der so ermittelten Glasübergangstemperatur Tg auf die Versagenstemperatur einer Dichtung ist aber ohne zusätzliche Messungen bisher nicht möglich. Mit den Ergebnissen des Druckverformungsrestes DVR und des DVRDMA ist eine ge-nauere Beschreibung der Tieftemperatureigenschaften und dadurch der Funktion von elastomeren Dichtungsmaterialien möglich. Messungen ergeben beispielsweise, dass sich das EPDM bei einer Temperatur von -40 °C laut der Dynamisch Mechanischen Analyse noch im gummielastischen Bereich befindet. Die DVRDMA-Werte zeigen eine Rückstellung um mehr als 40 % der Ausgangsdeformation in wenigen Minuten. Mit derart detailliert bestimmten Eigenschaften lassen sich Rückschlüsse auf einsatzspezifische Anforderungen wie z. B. die Dichtwirkung in Abhängigkeit von Betriebstemperatur und mechanischer Belastungsgeschwindigkeit ziehen, so dass je nach Einsatzbedingungen für die Dichtungen eine geeignete Materialauswahl getrof-fen werden kann. Berlin Kerntechnische Gesellschaft e.V. (KTG) 2010 Jahrestagung Kerntechnik 2010 (Proceedings) Jahrestagung Kerntechnik 2010 Berlin, Deutschland 2010-05-04 2010-05-06 Sektion 5 / 503 1 4 2016-02-19 OPUS4-26995 Beitrag zu einem Tagungsband Jaunich, Matthias; Wolff, Dietmar; Stark, Wolfgang Low temperature properties of rubber seals - results of component tests Deutsches Institut für Kautschuktechnologie e.V. 2012 10th Fall rubber colloquium (Proceedings) 978-3-9814076-1-7 10th Fall rubber colloquium Hannover, Germany 2012-11-07 2012-11-09 khk2012_jaunich.pdf 1 8 2016-02-19 OPUS4-28853 Beitrag zu einem Tagungsband Jaunich, Matthias; Wolff, Dietmar; Stark, Wolfgang Investigating low temperature properties of rubber seals To achieve the required tightness levels of Containers for low and intermediate level radioactive wastes rubbers are widely applied as main sealing materials. The save encapsulation of the radioactive Container contents has to be guaranteed according to legislation and appropriate guidelines for long storage periods as well as down to temperatures of-40 °C during transportation. Therefore the understanding of failure mechanisms that lead to leakage at low temperatures is of high importance. It is known that the material properties of rubbers are strongly influenced by temperature. At low temperatures this is caused by the rubber-glass transition (abbr. glass transition). During continuous cooling the material changes from rubber-like entropy-elastic to stiff energy-elastic behaviour, that allows nearly no strain or retraction. Therefore, rubbers are normally used above their glass transition but the minimum working temperature limit is not defrned precisely, what can cause problems during application. The temperature ränge where full functionality is possible is strongly dependent on the application conditions and the material. For this investigation mainly ethylene propylene diene (EPDM) and fluorocarbon rubbers (FKM) were selected as they are often used for radioactive waste Containers. Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) are typically used for the determination of the temperature ränge of the glass transition process. The standardized compression set measurement according to ISO 815 is common for investigation of rubber sealing materials as the test simulates the seal behaviour after release. To reduce the test time of the Standard tests a faster technique giving the same information was developed. Additionally, the breakdown temperature of the sealing function of complete O-ring seals is measured in a component test Setup to compare it with the results of the other tests. The experimental Setup is capable of measuring the leakage rate at low temperatures by the pressure rise method. A model was developed that allows calculating the minimum working temperature limit of a seal by combining the results of the applied methods. Phoenix, Arizona, USA 2013 WM2013 Conference (Proceedings) 978-0-9836186-2-1 WM2013 Conference Phoenix, Arizona, USA 24.02.2013 28.02.2013 1 12 2016-02-20 OPUS4-28894 Zeitschriftenartikel Jaunich, Matthias; Wolff, Dietmar; Stark, Wolfgang Low temperature properties of rubber seals - Results of component tests - Rubbers are widely used as sealing material in various applications. In many fieldsthefunction of seal materials at lowtemperatures is required. Therefore the understanding of faiiure mechanisms that lead to leakage at low temperatures is of high importance. Therefore the lower Operation temperature limit of rubber seals should be determined in dependence of the material properties. The results of Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) are combined with results of standardized measurements as the compression set according to ISO 815. To reduce the test time of the Standard tests a faster and more efficient technique was developed and applied. In addition the breakdown temperature of the sealing function of O-ring seals at lowtemperatures is measured in a component test Setup in dependence of the material and the degree of compression. Heidelberg Hüthig Deutsche Kautschuk-Gesellschaft 2013 Kautschuk, Gummi, Kunststoffe (KGK) 66 7-8 26 30 2016-02-20 OPUS4-30377 Beitrag zu einem Tagungsband Jaunich, Matthias; Wolff, Dietmar; Stark, Wolfgang; Völzke, Holger Investigation of elastomer seal behavior for transport and storage packages Rubbers are widely used as main sealing materials for containers for low and intermediate level radioactive waste and as additional component to metal seals in spent fuel and high active waste containers. According to appropriate guidelines and regulations safe enclosure of the radioactive container contents has to be guaranteed for long storage periods as well as down to temperatures of -40 °C for transportation. Therefore the understanding of seal behavior is of high importance. In this paper we focus on the behavior of elastomer seals at low temperatures with regard to poten-tial decrease of leak-tightness. In addition, changes in material properties due to aging effects over long periods of time and their influence on the seal performance is investigated. It is known that material properties of rubbers are strongly temperature dependent. At low tempera-tures this is caused by the rubber-glass transition (abbr. glass transition). During continuous cool-ing, the material changes from rubber-like entropy-elastic to stiff energy-elastic behavior, that al-lows nearly no strain or retraction due to the glass transition. Hence rubbers are normally used above their glass transition but the minimum working temperature limit is not defined precisely. Aging of elastomer seals is important, as possible dynamic loads may have to be considered during the whole interim storage period (so far approved in Germany for up to 40 years) and for transporta-tion after storage. For the investigations, fluorocarbon (FKM) and ethylene-propylene-diene (EPDM) rubbers were selected as they are often used in radioactive waste containers. Some materials were purchased from a commercial seal producer and some materials were compounded and cured at BAM. The elastom-ers where studied by several thermo-analytical methods and compression set to characterize the material behavior at low temperatures. Additionally component tests were performed to determine the breakdown temperature of the sealing function of complete elastomer O-rings. Omnipress Institute of Nuclear Materials Management (INMM) 2013 PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials (Proceedings) PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials San Francisco, CA, USA 18.08.2013 23.08.2013 Paper 227, 1 8 2016-02-20 OPUS4-23206 Zeitschriftenartikel Stark, Wolfgang; Jaunich, Matthias Investigation of ethylene/vinyl acetate copolymer (EVA) by thermal analysis DSC and DMA Two types of commercially applied Ethylene/Vinyl Acetate Copolymers (EVA) for encapsulation of photovoltaic modules were investigated by the thermal analysis methods of Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) in the temperature range from -150 °C to 200 °C. Glass transition, crystal melting and cross-linking were analyzed. The aims of the investigations were to gain more information for incoming goods control and to get information about the whole temperature dependent material properties in the investigated temperature range, starting at very low temperatures up to the crosslinking temperature region. Amsterdam [u.a.] Elsevier Ltd. 2011 Polymer testing 30 2 236 242 10.1016/j.polymertesting.2010.12.003 2016-02-19 OPUS4-24168 Zeitschriftenartikel Stark, Wolfgang; Jaunich, Matthias Thermoanalytische Charakterisierung von Ethylen-Vinylacetat-Copolymer (EVA) für Photovoltaikmodule Das Ziel der Untersuchungen war mit Hilfe von DSC und DMA EVA-Folien im Anlieferungszustand hinsichtlich der Lage der Glasübergangstemperatur, des Schmelzverhaltens und der Temperaturabhängigkeit der Vernetzungsreaktion zu charakterisieren. Auf dieser Basis sollte die Lieferstabilität im Sinne einer Wareneingangskontrolle auf eine messtechnische Basis gestellt werden. In einem 2. Schritt sollte die vernetzte Folie dahingehend charakterisiert werden, ob infolge der Vernetzung eine Änderung der Netzsch 2011 OnSet 8 3 5 2016-02-19 OPUS4-26291 Zeitschriftenartikel Stark, Wolfgang; Jaunich, Matthias; Bohmeyer, W.; Lange, K. Investigation of the crosslinking behaviour of ehtylene vinyl acetate (EVA) for solar cell encapsulation by rheology and ultrasound EVA is a widely used material for the encapsulation of photovoltaic modules. It melts at elevated temperatures, and seals the module before it is crosslinked at temperatures above 130 °C by a peroxide-initiated crosslinking reaction. EVA has good optical properties necessary for application in solar modules. For process optimization and quality management, a method for the quick and reliable characterization of EVA crosslinking behaviour is of great value. Here, the practicability of ultrasound for online crosslinking monitoring is demonstrated. A sound velocity increase of about 8 m/s during the crosslinking reaction is found. The ultrasound results are compared with rheometer measurements performed with a curemeter typically used for the investigation of rubber crosslinking. Amsterdam [u.a.] Elsevier Science 2012 Polymer testing 31 7 904 908 10.1016/j.polymertesting.2012.07.004 2016-02-19 OPUS4-32325 Zeitschriftenartikel Stark, Wolfgang; Jaunich, Matthias; Mc Hugh, Jarlath Dynamic mechanical analysis (DMA) of epoxy carbon-fibre prepregs partially cured in a discontinued autoclave analogue process Epoxy carbon-fibre prepreg, Hexcel Type 6376 HTS, was investigated using Dynamic Mechanical Analysis (DMA). The DMA characteristic parameters are storage modulus E', loss modulus E' and loss factor tanδ. These parameters are ideally suited to observe the vitrification, referred to as glass transition, resulting from the cross-linking reaction. Detection of the cure state may also be achieved by determining the momentary glass transition temperature of partially cured samples. The consequent use of a multi-frequency measuring regime was used to derive the apparent activation energy for the glass transition process. Different temperature programs were also applied to monitor the curing process directly, as well as to investigate the different states of incomplete cure reached in preceding curing steps. The intention was to provide better understanding of the consequences of an interrupted autoclave curing process and to use DMA to detect the cure state achieved. With DMA, the continuation of an incomplete curing process also can be monitored. DMA measurements up to 300 °C showed, furthermore, that the final glass transition temperature was reduced by thermal degradation at high temperatures. Amsterdam [u.a.] Elsevier Science 2015 Polymer testing 41 140 148 10.1016/j.polymertesting.2014.11.004 2016-02-20 OPUS4-29067 Zeitschriftenartikel Stark, Wolfgang; Jaunich, Matthias; McHugh, J. Cure state detection for pre-cured carbon-fibre epoxy prepreg (CFC) using temperature-modulated differential scanning calorimetry (TMDSC) Carbon-fibre prepregs have found widespread use in lightweight applications. They are based on a carbon-fibre fabric impregnated with reactive epoxy resin. Prepreg materials are generally pre-cured so that they have a higher molecular weight than typical resins in order to reduce resin flow, which facilitates storage and later processing properties. The measurements were carried out using commercially available materials and follow the published DMA investigations of the same material. TMDSC was used to find the correlation between curing conditions, the degree of cure and glass transition temperature. TMDSC has the advantage over standard DSC that it enables better determination of the glass transition temperature, which is often accompanied by an exothermic curing reaction, and thus overshadowed. The influence of the amplitude of temperature modulation was tested in preliminary experiments. For non-cured material a glass transition temperature of approximately 0 °C was determined; whereas for the totally cured material it was approximately 230 °C. The changes in degree of cure, temperature of actual glass transition and post-reaction are given as a function of curing time at 180 °C. The correlation between actual glass transition temperature and degree of cure is derived. Amsterdam [u.a.] Elsevier Science 2013 Polymer Testing 32 7 1261 1272 10.1016/j.polymertesting.2013.07.007 2016-02-20 OPUS4-29479 Zeitschriftenartikel Stark, Wolfgang; Jaunich, Matthias; McHugh, J. Carbon-fibre epoxy prepreg (CFC) curing in an autoclave analogue process controlled by dynamic mechanical analysis (DMA) Carbon fibre prepregs have found widespread application in lightweight constructions. They are based on a carbon-fibre fabric impregnated with reactive epoxy resin. DMA measurements under temperature conditions similar to an autoclave programme were carried out using commercially available prepreg material with a high glass transition temperature. The characteristic of the temperature programme was a dynamic heating segment at 1.5 K/min followed by a longer isothermal segment at 180 °C. The courses of the storage modulus E', loss modulus E'' and tanδ were recorded. The measuring frequency was varied between 1 Hz and 33.3 Hz. Gelation and vitrification are assigned. The influence of the measuring frequency on the time to vitrification and the correlation with DSC are discussed. The reaction does not end even after 10 h curing at 180 °C, which is interpreted as the slow cessation of the reaction caused by vitrification. Amsterdam [u.a.] Elsevier Science 2013 Polymer Testing 32 8 1487 1494 10.1016/j.polymertesting.2013.09.014 2016-02-20 OPUS4-28530 Beitrag zu einem Tagungsband Wolff, Dietmar; Jaunich, Matthias; Stark, Wolfgang Investigating the performance of rubber seals at low temperatures Rubbers are widely used as main sealing materials for Containers for low and intermediate level radioactive waste and as additional component to metal seals in spent fuel and high active waste containers. The save enclosure of the radioactive container inventory has to be guaranteed according to legislation and appropriate guidelines for long term storage periods as well as down to temperatures of -40 °C for transportation. Therefore the understanding of failure mechanisms that lead to leakage at low temperatures is necessary to ensure a proper material choice which is certainly also influenced by additional factors as e.g. the aging behavior. Omnipress American nuclear society (ANS) 2013 IHLRWM 2013 - 14th International high-level radioactive waste management conference (Proceedings) 978-1-62748-644-6 14th International high-level radioactive waste management conference Albuquerque, New Mexico, USA 28.04.2013 02.05.2013 1 7(Paper # 6888) 2016-02-20