TY - CONF A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - Behaviour of rubber seals at low temperatures - results of component tests - N2 - 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. T2 - Jahrestagung Kerntechnik 2013 CY - Berlin, Germany DA - 14.05.2013 PY - 2013 SP - 1 EP - 6 AN - OPUS4-28574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Stark, Wolfgang A1 - Bohmeyer, W. ED - Karbhari, V.M. T1 - Non-destructive evaluation (NDE) of composites: using ultrasound to monitor the curing of composites N2 - Typical composite materials for lightweight construction consist of a fibre (glass or carbon) reinforced thermosetting matrix. The impregnation of the fabric is made with liquid resin – usually epoxy resin or unsaturated polyester resin are used. The main processing methods are resin transfer moulding (RTM) and prepreg technology often used in combination with autoclave curing. After shaping, the resin must be cured. The final properties of the produced parts depend on the curing degree and the final glass transition temperature. Analytical methods and the use of ultrasound for online cure monitoring in the manufacturing process are introduced. Examples for the application of ultrasonic cure monitoring for the production of composite parts for traffic systems are also covered. KW - Epoxy KW - DSC KW - DMA KW - Kinetic KW - Autoclave KW - Curing KW - Glass transition KW - Curing behaviour KW - Curing degree KW - Rheology KW - Differential scanning calorimetry KW - Dynamic mechanical analysis KW - Sound velocity KW - Sound damping KW - Resin transfer moulding KW - RTM KW - Prepreg PY - 2013 SN - 978-0-85709-344-8 SN - 978-0-85709-355-4 DO - https://doi.org/10.1533/9780857093554.1.136 SN - 2052-5281 SN - 2052-529X N1 - Serientitel: Woodhead publishing sereies in composites science and engineering – Series title: Woodhead publishing sereies in composites science and engineering VL - 43 IS - Part 1 / Chapter 7 SP - 136 EP - 181 PB - Woodhead Publishing Ltd CY - Cambridge, UK AN - OPUS4-28848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Stark, Wolfgang T1 - Investigating low temperature properties of rubber seals N2 - 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. T2 - WM2013 Conference CY - Phoenix, Arizona, USA DA - 24.02.2013 PY - 2013 SN - 978-0-9836186-2-1 SP - 1 EP - 12 CY - Phoenix, Arizona, USA AN - OPUS4-28853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Stark, Wolfgang A1 - Völzke, Holger T1 - Investigation of elastomer seal behavior for transport and storage packages N2 - 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. T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 18.08.2013 PY - 2013 SP - Paper 227, 1 EP - 8 PB - Omnipress AN - OPUS4-30377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - Low temperature - For a seal this depends on the applied material T2 - DKT 2012 - German Rubber Conference CY - Nuremberg, Germany DA - 2012-07-02 PY - 2012 IS - 10-2330_5-L-1530 SP - 1 EP - 4 PB - Deutsche Kautschuk-Gesellschaft CY - Frankfurt am Main AN - OPUS4-26190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - Material behaviour of static seals at low temperatures T2 - 17th ISC - International sealing conference CY - Stuttgart, Germany DA - 2012-09-13 PY - 2012 SN - 978-3-00-039198-9 IS - A 16 SP - 295 EP - 300 CY - Frankfurt/M. AN - OPUS4-26524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Stark, Wolfgang T1 - Low temperature properties of rubber seals - results of component tests T2 - 10th Fall rubber colloquium CY - Hannover, Germany DA - 2012-11-07 PY - 2012 SN - 978-3-9814076-1-7 IS - khk2012_jaunich.pdf SP - 1 EP - 8 AN - OPUS4-26995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Schulz, Sebastian A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - Characterization of the low temperature behaviour of rubber sealing materials N2 - 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. T2 - Technomer 2011 - 22. Fachtagung über Verarbeitung und Anwendung von Polymeren CY - Chemnitz, Deutschland DA - 10.11.2011 PY - 2011 SN - 978-3-939382-10-2 IS - Kap. 3.7 SP - 1 EP - 4 AN - OPUS4-24971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias A1 - von der Ehe, Kerstin A1 - Wolff, Dietmar A1 - Völzke, Holger A1 - Stark, Wolfgang T1 - Understanding low temperature properties of elastomer seals N2 - 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. KW - Sealing material KW - Elastomer KW - Compression set KW - Dynamic mechanical analysis KW - Low temperature behaviour PY - 2011 DO - https://doi.org/10.1179/1746510911Y.0000000004 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 22 IS - 2 SP - 83 EP - 88 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-24015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - Low temperature properties of rubber seals T2 - 9th Fall rubber colloquium CY - Hannover, Germany DA - 2010-11-03 KW - Dichtungen KW - Elastomere KW - Tieftemperaturverhalten PY - 2010 SN - 978-3-9814076-0-0 SP - 175 EP - 178 AN - OPUS4-22331 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stark, Wolfgang T1 - Development of quality assurance for insulating materials PY - 2010 UR - https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwjyyejZ7tvKAhXBVxoKHeV0Dr4QFgghMAA&url=https%3A%2F%2Fwww.kunststoffe.de%2Fen%2F_storage%2Fasset%2F590842%2Fstorage%2Fmaster%2Ffile%2F6128237%2Fdownload%2FDevelopment%2520of%2520Quality%2520Assurance%2520for%2520Insulating%2520Materials.pdf&usg=AFQjCNGMbKTaYDrHEdGuZ2IB_7zQCrTVkw SN - 1862-4243 VL - 100 IS - 2 SP - 6 EP - 9 PB - Hanser CY - München AN - OPUS4-20936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frübing, P. A1 - Wang, F. A1 - Günter, C. A1 - Gerhard, R. A1 - Wegener, M. A1 - Jaunich, Matthias A1 - Stark, Wolfgang T1 - Relation between dielectric and mechanical losses in ferroelectric poly(vinylidene fluoride - hexafluoropropylene) films N2 - 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. T2 - 10th IEEE International conference on solid dielectrics (ICSD) CY - Potsdam, Germany DA - 2010-07-04 KW - Poly(vinylidene(fluoride - hexafluoropropylene) KW - P(VDF-HFP) KW - Ferroelectric polymer KW - Dielectric relaxation KW - Dynamic mechanical analysis KW - Uniaxial stretching PY - 2010 SN - 978-1-4244-7945-0 DO - https://doi.org/10.1109/ICSD.2010.5567936 SP - 1 EP - 4(?) AN - OPUS4-23421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - von der Ehe, Kerstin A1 - Wolff, Dietmar A1 - Völzke, Holger A1 - Stark, Wolfgang T1 - Understanding the low temperature properties of rubber seals N2 - 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. T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - Dichtungen KW - Elastomere KW - Tieftemperaturverhalten PY - 2010 SP - 1 EP - 7 (Session T41 / Paper 169) AN - OPUS4-23887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - Properties of elastomeric seals at low temperature T2 - International rubber conference (IRC 2009) CY - Nürnberg, Germany DA - 2009-06-29 PY - 2009 IS - Poster 23 SP - 1 EP - 3 AN - OPUS4-19611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoster, B. A1 - Jaunich, Matthias A1 - Stark, Wolfgang T1 - Monitoring of the vulcanisation process by ultrasound during injection moulding N2 - 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. KW - Ultrasonic KW - Sound velocity KW - Vulcanisation KW - On-line monitoring KW - Injection moulding PY - 2009 UR - https://www.ndt.net/search/docs.php3?id=8042 SN - 1435-4934 VL - 14 IS - 9 SP - 1 EP - 9 PB - NDT.net CY - Kirchwald AN - OPUS4-19858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stark, Wolfgang T1 - Characterizing the flow-cure behaviour of thermoset plastics using thermoanalytical and ultrasonic methods N2 - The prospects of modern thermoanalytical methods for characterisation of flow, curing and final mechanical behaviour of moulding compounds were demonstrated. Using urea resin moulding compounds from different manufacturers the possibilities of the various techniques could be shown. With comparatively low effort, fundamental information can be gained before production process had been started. On this basis it is possible to make appropriate material selection at an early point in the process chain. On the basis of thermoanalytical data an incoming goods inspection can be established. Also it is easy to control the compliance with the conditions of delivery. In some cases it could also be helpful to have stored analysis data especially when problems appear in manufacturing process or unexpected part damages occur With the ultrasound measuring system it is possible to transfer the findings from the analytical methods directly to the processes in the mould. The application of ultrasound provides Dynamic Mechanical Analysis in the mould. Beside quality assurance ultrasound can also be used for process optimisation, especially for reduction of cycle time. In an advanced form ultrasound information can be used as a basis for improved machine control based on material state. The ultrasound measuring system developed by ISK Iserlohn and BAM can be obtained from the ISK. T2 - 5. Internationale Duroplasttagung / International Thermoset Conference CY - Iserlohn, Germany DA - 2008-11-20 KW - Differential Scanning Calorimetry KW - Dynamic Mechanical Analysis KW - Ultrasound KW - Urea rsin KW - Moulding compound KW - Incoming goods inspection KW - Process optimization PY - 2008 IS - Duro08_GB_08 SP - 1 EP - 8 AN - OPUS4-18586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stark, Wolfgang A1 - Bartusch, Jürgen A1 - Döring, Joachim A1 - Mc Hugh, Jarlath T1 - Making cure visible: monitoring the crosslinking process using integrated ultrasound sensors N2 - A special ultrasonic measuring system was developed to monitor the cross-linking process, enabling interaction with the manufacturing process in order to optimise part quality and reduce cycle times. KW - Thermoset KW - Ultrasound sensors KW - Mould KW - Rtm KW - Gelation KW - Vitrification PY - 2008 SN - 1639-965X IS - 38 SP - 64 EP - 66 PB - JEC CY - Paris AN - OPUS4-18610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Hoster, B. T1 - In-situ vulcanization monitoring by ultrasonic wave propagation T2 - 8. Kautschuk-Herbst-Kolloquium CY - Hannover, Deutschland DA - 2008-11-26 KW - Vulcanization KW - Cure monitoring KW - Ultrasound PY - 2008 SP - 133 AN - OPUS4-18574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stark, Wolfgang A1 - Goering, Harald A1 - Bayerl, H. A1 - Hoster, B. T1 - Post-annealing of thermosets T2 - 4th International Thermoset Conference CY - Iserlohn, Germany DA - 2006-11-16 PY - 2006 AN - OPUS4-13801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stark, Wolfgang A1 - Fritsch, Sebastian A1 - Kelm, Jürgen T1 - Vulcanization Monitoring in the Mould by Means of Ultrasound T2 - German Rubber Conference 2006 CY - Nuremberg, Germany DA - 2006-07-03 KW - Vulkanisation KW - Ultraschall KW - Prozesskontrolle KW - Rheologie PY - 2006 SP - 189 EP - 193 PB - Deutsche Kautschuk-Gesellschaft CY - Frankfurt am Main AN - OPUS4-13082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mc Hugh, Jarlath A1 - Döring, Joachim A1 - Stark, Wolfgang A1 - Guey, J. L. T1 - Relationship between the Mechanical and Ultrasound Properties of Polymer Materials T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - Ultrasound KW - DMA KW - Epoxy KW - Modulus KW - tan delta KW - High temperature PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 9(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-14065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stark, Wolfgang A1 - Fengler, Petra T1 - Investigation of curing of epoxy resin composite materials by dynamic mechanical analysis (DMA) T2 - Polydays 2006 CY - Berlin, Germany DA - 2006-10-04 PY - 2006 AN - OPUS4-13447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stark, Wolfgang A1 - Goering, Harald A1 - Seeger, Stefan A1 - Jaunich, Matthias T1 - Correlation between degree of cure and fracture behaviour of electro installation parts made from urea formaldehyde resin T2 - Polydays 2006 CY - Berlin, Germany DA - 2006-10-04 PY - 2006 AN - OPUS4-13500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Simone A1 - Goering, Harald A1 - Stark, Wolfgang A1 - Bayerl, H. A1 - Brinkmann, P. T1 - Thermo Analytical Investigations of Phenol Moulding Compound Curing - Potential for Post-Cure Optimisation T2 - 3rd International Thermoset Conference CY - Iserlohn, Germany DA - 2005-04-21 KW - Post curing KW - High pressure DSC KW - DMA KW - Reaction kinetic KW - Phenolic resin PY - 2005 SP - 219 EP - 225 PB - Fachhochschule Südwestfalen - Hochschule für Technik und Wirtschaft CY - Iserlohn AN - OPUS4-7453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Straet, T. A1 - Bayerl, H. A1 - Stark, Wolfgang A1 - Döring, Joachim A1 - Kürten, Ch. T1 - Ultrasonic Measurements on Thermoset Moulding Compounds KW - Ultraschall KW - Fertigungskontrolle KW - Schallgeschwindigkeit KW - Vernetzungsreaktion KW - Qualitätssicherung PY - 2005 SN - 0945-0084 VL - 95 IS - 7 SP - 1 EP - 5 PB - Hanser CY - München AN - OPUS4-10304 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mc Hugh, Jarlath A1 - Döring, Joachim A1 - Bartusch, Jürgen A1 - Stark, Wolfgang T1 - Making Cure Visible T2 - Aerospace Testing Expo 2005 - Europe, April 5-7, 2005, Hamburg CY - Hamburg, Deutschland DA - 2005-04-05 PY - 2005 SP - 4 pages PB - UKIP Media & Events CY - Dorking AN - OPUS4-7379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fengler, Petra A1 - Stark, Wolfgang A1 - Döring, Joachim A1 - Mc Hugh, Jarlath T1 - Coupling of hidden ultrasound sensors to a moulding tool N2 - Ultrasound on-line NDT methods have been demonstrated as a useful tool for monitoring the curing reaction of thermosets. In order to achieve this ultrasound sensors are incorporated into compression, injection and RTM (resin transfer) mould. For many commercial products imprints or any surface markings upon the moulded product are undesirable. Due to its physical properties ultrasound has a large advantage over other techniques for similar applications. The sound wave can pass through the wall of the mould and direct contact with the moulded part is not required. In this particular case one fundamental problem is a good coupling of the sensors to the mould wall. Several mediums came into question but because of the high technical (e. g. temperature and long time stability) and practical demands, it was decided that dry (non-fluid) coupling would be the most promising candidate. A handful of coupling foils suitable also at high temperatures and for long time application under industrial conditions were tested and are presented in this paper. KW - Sensors KW - Ultrasound KW - Mould wall coupling KW - Thermoset manufacturing PY - 2004 UR - http://www.ndt.net/article/v09n03/stark/stark.htm SN - 1435-4934 VL - 9 IS - 3 SP - 1 EP - 10 PB - NDT.net CY - Kirchwald AN - OPUS4-3316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mc Hugh, Jarlath A1 - Döring, Joachim A1 - Stark, Wolfgang A1 - Erhard, Anton T1 - Characterisation of epoxy materials used in the development of ultrasound arrays T2 - 16th World Conference on Nondestructive Testing CY - Montreal, Canada DA - 2004-08-30 PY - 2004 UR - http://www.ndt.net/article/wcndt2004/pdf/materials_characterization/616_mchugh.pdf SP - 8 pages PB - International Committee for Non-Destructive Testing CY - Montreal AN - OPUS4-5215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Stark, Wolfgang A1 - Döring, Joachim A1 - Kelm, Jürgen A1 - Fritsch, Sebastian ED - Green, R. E. ED - Djordjevic, B. B. ED - Hentschel, M. P. T1 - Rubber processing monitored by ultrasound T2 - 11th International Symposium on Nondestructive Characterization of Materials CY - Berlin, Germany DA - 2002-06-24 PY - 2003 SN - 3-540-40154-7 SP - 659 EP - 664 PB - Springer CY - Berlin AN - OPUS4-2769 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mc Hugh, Jarlath A1 - Stark, Wolfgang A1 - Döring, Joachim ED - Green, R. E. ED - Djordjevic, B. B. ED - Hentschel, M. P. T1 - Evaluation of the cure behaviour of epoxy resin using rheometric and ultrasonic techniques T2 - 11th International Symposium on Nondestructive Characterization of Materials CY - Berlin, Germany DA - 2002-06-24 PY - 2003 SN - 3-540-40154-7 SP - 651 EP - 658 PB - Springer CY - Berlin AN - OPUS4-2772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stark, Wolfgang T1 - Dielektric Process Monitoring of Thermosetting Resins T2 - DEA-Seminar, Achema-Messe CY - Frankfurt am Main, Germany DA - 2003-05-22 PY - 2003 AN - OPUS4-4071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stark, Wolfgang A1 - Döring, Joachim A1 - Goering, Harald A1 - Mc Hugh, Jarlath A1 - Opfermann, J. A1 - Knappe, S. T1 - The RTM-Process and the Problems with Gelation, Vitrification and Degree of Curing T2 - 6th Internationale AVK-Tv Conference CY - Baden-Baden, Germany DA - 2003-09-07 PY - 2003 AN - OPUS4-4072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Gorokhovatsky, Y.A. A1 - Krüger, Simone A1 - Brademann-Jock, Kerstin A1 - Stark, Wolfgang A1 - Temnov, Dmitri A1 - Kuvshinova, Oksana A1 - Goldade, V.A. ED - Fleming, R. J. T1 - Thermally stimulated luminescence in LDPE fibers T2 - 11th International Symposium on Electrets (ISE 11) CY - Melbourne, Australia DA - 2002-10-01 PY - 2002 SN - 0-7803-7560-2 SP - 138 EP - 140 PB - IEEE Service Center CY - Piscataway, NJ AN - OPUS4-1654 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Döring, Joachim A1 - Stark, Wolfgang T1 - Ultrasonic Production Control N2 - Ultrasound waves penetrate solid objects without damaging them. Their fields of application range from the imaging of internal organs in medicine, to interior testing of mechanical and chemical engineering components. However, ultrasonic systems can also be used to visualise the way the mechanical properties of reactive resins change during processing in the mould. PY - 2001 SN - 0945-0084 VL - 91 IS - 1 SP - 35 EP - 36 PB - Hanser CY - München AN - OPUS4-2135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stark, Wolfgang A1 - Döring, Joachim A1 - Walentowski, Heinz-Ulrich T1 - Crosslinking Instead of Glassy Transition N2 - In processing fibre-reinforced composites, the curing reaction can be significantly retarded if the temperature and reaction time are not optimally set. In such situations, complete curing is sometimes impossible under practically relevant conditions. It is difficult for processors to recognize or detect incomplete curing. The equilibrium glass transition temperature plays an important role in complete curing in the production process. PY - 2000 SN - 0945-0084 VL - 90 IS - 4 SP - 33 EP - 35 PB - Hanser CY - München AN - OPUS4-822 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Döring, Joachim A1 - Stark, Wolfgang A1 - Bartusch, Jürgen A1 - Mc Hugh, Jarlath T1 - Contribution to ultrasound cure control for composite manufacturing N2 - The curing conditions play an important role in the quality assurance of composite products. Especially as composite materials are widely used in high tech areas so that they are required to fulfil high quality Standards. Some problems which occur during curing, for instance undercuring, can hardly be detected using Standard NDT investigations, mainly because they are manifested only at high temperatures, particularly close to glass-rubber-transition. On-line eure monitoring has the outstanding advantage that it can monitor the material parameters even at the highest temperatures possible. In recent years eure monitoring with ultrasonic methods has become more populär. In comparison to dielectric methods mechanical parameters are measured directly. The quantities to be measured are the velocity and the attenuation of the sound wave. On this basis the storage and loss modulus can be calculated. Depending on the form of excitation with longitudinal or transversal waves these moduli are referred to as long wave or shear modulus. Well developed Computer based technology and sensor materials are available in the non-destructive testing (NDT) market. The measuring equipment employed a commercial NDT System, which worked computer-aided. With a special Software the demands of automatic Operation under industrial conditions was accomplished. This measurement equipment was tested on composites. Its structure, performance and some practical results will be presented in the following paper. T2 - 15th World Conference on Non-Destructive Testing (WCNDT) CY - Roma, Italy DA - 15.10.2000 PY - 2000 UR - http://www.ndt.net/article/wcndt00/papers/idn482/idn482.htm SN - 1435-4934 VL - 5 IS - 11 PB - NDT.net CY - Kirchwald AN - OPUS4-2136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Sturm, Heinz A1 - Schulz, Eckhard A1 - Stark, Wolfgang A1 - Bovtun, V. A1 - Friedrich, Jörg Florian ED - Olefjord, I. ED - Nyborg, L. ED - Briggs, D. T1 - Techniques for surface composition analysis with scanning force microscopy (SFM) using electrical surface properties T2 - 7th European Conference on Applications of Surface and Interface Analysis CY - Göteborg, Sweden DA - 1997-06-16 PY - 1997 SN - 0-471-97827-2 SP - 579 EP - 582 PB - Wiley CY - Chichester AN - OPUS4-6854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schulz, Eckhard A1 - Sturm, Heinz A1 - Stark, Wolfgang A1 - Bovtun, V. ED - Xia, Z. T1 - Determination of electric properties of heterogeneous systems using the contact and noncontact scanning force microscopy (SFM) N2 - With an extended contact and non-contact mode scanning force microscope samples with different heterogeneous electrical properties can be characterized. The contact mode method allows the determination of local electric conductivities of heterogeneous systems at the sample surfaces. An interpretation of this behaviour can be obtained in combination with other SFM modes such as topography, friction and compliance used simultaneously. The non-contact mode SFM allows to get more information about the local surface charge of heterogeneous samples. In this paper two new SFM approaches will be discussed on examples of carbon-fibre reinforced, organic and ceramic materials T2 - 9th International Symposium on Electrets (ISE 9) CY - Shanghai, China DA - 1996-09-25 PY - 1996 SN - 0-7803-2695-4 DO - https://doi.org/10.1109/ISE.1996.578094 SP - 334 EP - 339 PB - IEEE Service Center CY - Piscataway, NJ AN - OPUS4-6852 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Sturm, Heinz A1 - Stark, Wolfgang A1 - Bovtun, V. A1 - Schulz, Eckhard ED - Xia, Z. T1 - Methods for simultaneous measurements of topography and local electrical properties using scanning force microscopy N2 - Two different approaches to investigate the local complex conductivity and the surface charge with Scanning Force Microscopy (SFM) techniques are presented. It is shown that the measurement of local electrical properties with SFM leads to interesting information about the composition of electrically heterogeneous surfaces T2 - 9th International Symposium on Electrets (ISE 9) CY - Shanghai, China DA - 1996-09-25 PY - 1996 SN - 0-7803-2695-4 DO - https://doi.org/10.1109/ISE.1996.578073 SP - 223 EP - 228 PB - IEEE Service Center CY - Piscataway, NJ AN - OPUS4-6851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -