Journal of offshore mechanics and Arctic engineering, May 5, 2017
The application of thin-film coatings is a method to protect armatures, accessories, and control ... more The application of thin-film coatings is a method to protect armatures, accessories, and control elements on offshore facilities against corrosion and mechanical damages. The performance of a dual-layer thin-film (30 μm) coating system under simulated Arctic offshore exposure was investigated. The coating system consisted of polyamide-based primer and molybdenum-disulfide (MoS2)/polytetrafluoroethylene (PTFE)—modified topcoat. The investigations involved the following tests: accelerated corrosion protection/aging tests, coating adhesion tests, scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) inspections, static contact angle measurements, specific surface energy measurements, hoarfrost accretion, and abrasion resistance tests. The test conditions were adapted to Arctic offshore conditions. Effects of accelerated offshore aging on surface morphology, surface chemistry, and hoarfrost accretion were also investigated.
MP MATERIALPRUEFUNG - MP MATERIALS TESTING, Feb 1, 2022
Polyethylene is a very common liner material for type IV pressure vessels due to its good toughne... more Polyethylene is a very common liner material for type IV pressure vessels due to its good toughness and easy processing. The property profile of the polymer can be improved by cross-linking thereby changing the nature of the polymer from thermoplastic toward more elastomeric. For this purpose, polyethylene is modified either chemically, using peroxide or silane, or physically by radiation. In the present work, a cross-linkable polyethylene grade that can be processed by rotational molding was peroxide cross-linked under variation of temperature and time. Subsequently, the material was characterized by differential scanning calorimetry, tensile tests, notched bar impact tests and permeation measurements. Two of the altogether six parameter combinations investigated did not lead to successful cross-linking resulting in very poor toughness. Stiffness, strength and permeation barrier properties, however, were much better than those of the other series due to higher crystallinity. Mechanical, physical and chemical properties changed significantly by successful cross-linking. The impact strength could be improved by a factor of more than 10. At the same time, significant losses in stiffness, strength and permeation barrier properties had to be accepted. Peroxide induced randomly distributed formation of cross-links above the melting point interfered with formation of crystalline regions upon cooling.
Abstract The abrasive wear performance of six organic offshore coating systems is investigated at... more Abstract The abrasive wear performance of six organic offshore coating systems is investigated at two temperature levels (0 °C and 20 °C) with a rotating wheel abrasion tester. The relationship between exposure time (in terms of number of revolutions) and coating thickness reduction follows a linear relationship: Δ h = C 1 · n R + C 2 . The reverse of the progress parameter (1/ C 1 ) is defined as abrasion resistance. This parameter is found to be sensitive to the testing temperature; it decreases for most of the coatings for the lower temperature. Combined SEM/EDX analyses reveal a number of material removal modes. The separation and pull-off of filler/pigment particles contribute notably to the material abrasion on all coating systems at the two temperature levels. Type, distribution and hardness of filler materials are important design parameters. A model of Bello and Wood (2005) [33] for filled polyamides is adapted and extended in order to systematically register different material removal modes. Image analysis is applied to quantify filler particle distribution and size.
Journal of offshore mechanics and Arctic engineering, Jul 29, 2016
Six organic coating systems were investigated according to their corrosion protection performance... more Six organic coating systems were investigated according to their corrosion protection performance under simulated Arctic offshore conditions. The investigations involved accelerated aging, coating adhesion measurements, and dynamic mechanical analysis (DMA). The test conditions were adapted to Arctic offshore conditions, which mainly covered temperature shocks between −20 and −60 °C, chloride exposure, dry–wet cycles, and ultraviolet (UV) radiation. Corrosion protection capability dropped for all coatings if temperature decreased from −20 °C to −60 °C. Two types of coatings could be classified according to their response to the corrosive load: temperature-sensitive coatings and insensitive coatings. Adhesive effects (interface between coating system and substrate) were found to be marginal only at low temperatures and did not affect the response of the coatings to the corrosive load. Cohesive effects (mechanical properties of free polymer films) could be identified in terms of a very high storage modulus and changes in the loss modulus for a temperature-sensitive coating at −60 °C.
<p>Mit verschiedenen Industriepartnern und dem Fraunhofer AGP wurde ein Fertigungsverfahren... more <p>Mit verschiedenen Industriepartnern und dem Fraunhofer AGP wurde ein Fertigungsverfahren zur Herstellung von Stabtragwerken aus faserverstärktem Kunststoff (FVK) entwickelt. Es erlaubt, beliebige Tragwerksstrukturen als ein integrales und besonders leichtes Bauteil direkt aus den Halbzeugen Roving und Matrixharz ressourceneffizient sowie kostengünstig herzustellen. Das Verfahren ist weitgehend automatisierbar. Zu den Produktbeispielen zählen unter anderem Masten, Brückenstrukturen und Rotorblätter von Windkraftanlagen. </p> <p>&amp;nbsp;</p> <p>Fraunhofer AGP has developed a process for manufacturing fibre-reinforced plastic (FRP) rod frameworks. The semi-finished products roving and resin are used to manufacture almost a random number of spatial structures as an integral and very lightweight component in a resource-efficient way at low cost. Large parts of the process can be automated. Product examples are masts, bridge structures and wind turbine blades.</p>
Schiffe sind wie eine eigene kleine Stadt, in der Rohrleitungen für verschiedene Medien wie Frisc... more Schiffe sind wie eine eigene kleine Stadt, in der Rohrleitungen für verschiedene Medien wie Frisch-, Grauund Kühlwasser sowie Kraftstoff benötigt werden. Je nach Anwendungsfall variieren die Materialien und Abmessungen der auf Schiffen verbauten metallischen Rohrleitungen (Bild 1). Das derzeit überwiegend eingesetzte Verfahren zum Fügen von Rohrleitungen ist das Schweißen. Es stellt vor dem Auftrag von Korrosionsschutzbeschichtungen das optimale Fügeverfahren dar. Nach dem Beschichten ist das Schweißen jedoch mit einigen Problemen verbunden. Zum einen ist es nicht möglich, auf Korrosionsschutzbeschichtungen zu schweißen. Soll trotzdem geschweißt werden, erfordert dies ein vorheriges Entschichten. Zum anderen muss die beschichtete Umgebung vor den Einflüssen des Schweißens (Temperatureintrag, Funkenflug, Rauchgase, usw.) geschützt werden, um Beschichtungsschäden zu vermeiden, die Korrosionsprobleme zur Folge haben können. Der gesamte Prozess ist zeitund kostenintensiv. Hinzu kommt eine mangelnde Ressourceneffizienz aufgrund des wiederholten Beschichtens der geschweißten Verbindungen. Aus dieser Problematik entstand die Forderung nach einem wärmearmen Fügeverfahren für Rohrleitungen, das nach dem Beschichten angewendet werden kann. Da mechanische Lösungen wie Rohrkupplungen nicht wartungsfrei sind und Verfahren wie das Kaltlöten derzeit noch nicht problemlos anwendbar sind, wurde im Rahmen des von der Arbeitsgemeinschaft industrieller Forschungsvereinigungen „Otto von Guericke“ (AiF) geförderten Forschungsprojektes „Klebtechnisches Fügen von Rohrleitungen im Schiffbau“ eine klebtechnische Lösung entwickelt. Der erste Teil dieser vierteiligen Serie beschäftigt sich mit der Auswahl einer Oberflächenvorbehandlung sowie mit der Ermittlung thermischer Abminderungsfaktoren. Der Folgebeitrag in der Novemberausgabe wird auf die Fes-
Journal of offshore mechanics and Arctic engineering, May 5, 2017
The application of thin-film coatings is a method to protect armatures, accessories, and control ... more The application of thin-film coatings is a method to protect armatures, accessories, and control elements on offshore facilities against corrosion and mechanical damages. The performance of a dual-layer thin-film (30 μm) coating system under simulated Arctic offshore exposure was investigated. The coating system consisted of polyamide-based primer and molybdenum-disulfide (MoS2)/polytetrafluoroethylene (PTFE)—modified topcoat. The investigations involved the following tests: accelerated corrosion protection/aging tests, coating adhesion tests, scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) inspections, static contact angle measurements, specific surface energy measurements, hoarfrost accretion, and abrasion resistance tests. The test conditions were adapted to Arctic offshore conditions. Effects of accelerated offshore aging on surface morphology, surface chemistry, and hoarfrost accretion were also investigated.
MP MATERIALPRUEFUNG - MP MATERIALS TESTING, Feb 1, 2022
Polyethylene is a very common liner material for type IV pressure vessels due to its good toughne... more Polyethylene is a very common liner material for type IV pressure vessels due to its good toughness and easy processing. The property profile of the polymer can be improved by cross-linking thereby changing the nature of the polymer from thermoplastic toward more elastomeric. For this purpose, polyethylene is modified either chemically, using peroxide or silane, or physically by radiation. In the present work, a cross-linkable polyethylene grade that can be processed by rotational molding was peroxide cross-linked under variation of temperature and time. Subsequently, the material was characterized by differential scanning calorimetry, tensile tests, notched bar impact tests and permeation measurements. Two of the altogether six parameter combinations investigated did not lead to successful cross-linking resulting in very poor toughness. Stiffness, strength and permeation barrier properties, however, were much better than those of the other series due to higher crystallinity. Mechanical, physical and chemical properties changed significantly by successful cross-linking. The impact strength could be improved by a factor of more than 10. At the same time, significant losses in stiffness, strength and permeation barrier properties had to be accepted. Peroxide induced randomly distributed formation of cross-links above the melting point interfered with formation of crystalline regions upon cooling.
Abstract The abrasive wear performance of six organic offshore coating systems is investigated at... more Abstract The abrasive wear performance of six organic offshore coating systems is investigated at two temperature levels (0 °C and 20 °C) with a rotating wheel abrasion tester. The relationship between exposure time (in terms of number of revolutions) and coating thickness reduction follows a linear relationship: Δ h = C 1 · n R + C 2 . The reverse of the progress parameter (1/ C 1 ) is defined as abrasion resistance. This parameter is found to be sensitive to the testing temperature; it decreases for most of the coatings for the lower temperature. Combined SEM/EDX analyses reveal a number of material removal modes. The separation and pull-off of filler/pigment particles contribute notably to the material abrasion on all coating systems at the two temperature levels. Type, distribution and hardness of filler materials are important design parameters. A model of Bello and Wood (2005) [33] for filled polyamides is adapted and extended in order to systematically register different material removal modes. Image analysis is applied to quantify filler particle distribution and size.
Journal of offshore mechanics and Arctic engineering, Jul 29, 2016
Six organic coating systems were investigated according to their corrosion protection performance... more Six organic coating systems were investigated according to their corrosion protection performance under simulated Arctic offshore conditions. The investigations involved accelerated aging, coating adhesion measurements, and dynamic mechanical analysis (DMA). The test conditions were adapted to Arctic offshore conditions, which mainly covered temperature shocks between −20 and −60 °C, chloride exposure, dry–wet cycles, and ultraviolet (UV) radiation. Corrosion protection capability dropped for all coatings if temperature decreased from −20 °C to −60 °C. Two types of coatings could be classified according to their response to the corrosive load: temperature-sensitive coatings and insensitive coatings. Adhesive effects (interface between coating system and substrate) were found to be marginal only at low temperatures and did not affect the response of the coatings to the corrosive load. Cohesive effects (mechanical properties of free polymer films) could be identified in terms of a very high storage modulus and changes in the loss modulus for a temperature-sensitive coating at −60 °C.
<p>Mit verschiedenen Industriepartnern und dem Fraunhofer AGP wurde ein Fertigungsverfahren... more <p>Mit verschiedenen Industriepartnern und dem Fraunhofer AGP wurde ein Fertigungsverfahren zur Herstellung von Stabtragwerken aus faserverstärktem Kunststoff (FVK) entwickelt. Es erlaubt, beliebige Tragwerksstrukturen als ein integrales und besonders leichtes Bauteil direkt aus den Halbzeugen Roving und Matrixharz ressourceneffizient sowie kostengünstig herzustellen. Das Verfahren ist weitgehend automatisierbar. Zu den Produktbeispielen zählen unter anderem Masten, Brückenstrukturen und Rotorblätter von Windkraftanlagen. </p> <p>&amp;nbsp;</p> <p>Fraunhofer AGP has developed a process for manufacturing fibre-reinforced plastic (FRP) rod frameworks. The semi-finished products roving and resin are used to manufacture almost a random number of spatial structures as an integral and very lightweight component in a resource-efficient way at low cost. Large parts of the process can be automated. Product examples are masts, bridge structures and wind turbine blades.</p>
Schiffe sind wie eine eigene kleine Stadt, in der Rohrleitungen für verschiedene Medien wie Frisc... more Schiffe sind wie eine eigene kleine Stadt, in der Rohrleitungen für verschiedene Medien wie Frisch-, Grauund Kühlwasser sowie Kraftstoff benötigt werden. Je nach Anwendungsfall variieren die Materialien und Abmessungen der auf Schiffen verbauten metallischen Rohrleitungen (Bild 1). Das derzeit überwiegend eingesetzte Verfahren zum Fügen von Rohrleitungen ist das Schweißen. Es stellt vor dem Auftrag von Korrosionsschutzbeschichtungen das optimale Fügeverfahren dar. Nach dem Beschichten ist das Schweißen jedoch mit einigen Problemen verbunden. Zum einen ist es nicht möglich, auf Korrosionsschutzbeschichtungen zu schweißen. Soll trotzdem geschweißt werden, erfordert dies ein vorheriges Entschichten. Zum anderen muss die beschichtete Umgebung vor den Einflüssen des Schweißens (Temperatureintrag, Funkenflug, Rauchgase, usw.) geschützt werden, um Beschichtungsschäden zu vermeiden, die Korrosionsprobleme zur Folge haben können. Der gesamte Prozess ist zeitund kostenintensiv. Hinzu kommt eine mangelnde Ressourceneffizienz aufgrund des wiederholten Beschichtens der geschweißten Verbindungen. Aus dieser Problematik entstand die Forderung nach einem wärmearmen Fügeverfahren für Rohrleitungen, das nach dem Beschichten angewendet werden kann. Da mechanische Lösungen wie Rohrkupplungen nicht wartungsfrei sind und Verfahren wie das Kaltlöten derzeit noch nicht problemlos anwendbar sind, wurde im Rahmen des von der Arbeitsgemeinschaft industrieller Forschungsvereinigungen „Otto von Guericke“ (AiF) geförderten Forschungsprojektes „Klebtechnisches Fügen von Rohrleitungen im Schiffbau“ eine klebtechnische Lösung entwickelt. Der erste Teil dieser vierteiligen Serie beschäftigt sich mit der Auswahl einer Oberflächenvorbehandlung sowie mit der Ermittlung thermischer Abminderungsfaktoren. Der Folgebeitrag in der Novemberausgabe wird auf die Fes-
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