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Predicting in-service weatherability of automotive coatings : A new approach / David R. Bauer in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 69, N° 864 (01/1997)
[article]
Titre : Predicting in-service weatherability of automotive coatings : A new approach Type de document : texte imprimé Auteurs : David R. Bauer, Auteur Année de publication : 1997 Article en page(s) : p. 85-96 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Automobiles -- Revêtements:Automobiles -- Peinture
Délaminage
Durée de vie (Ingénierie)
Photodétérioration
Résistance aux conditions climatiquesIndex. décimale : 667.9 Revêtements et enduits Résumé : The prediction of long-term weatherability of coatings has always been a difficult task. This task has been made significantly more difficult by the recent, rapid changes in coatings technology. Conventional weathering protocols which rely on observation of appearance changes after outdoor or laboratory exposures have not always been successful in anticipating in-service failures. This paper discusses the reason for this and describes a new approach for estimating in-service weatherability in coatings. The formalism begins by identifying specific failure modes and developing time-to-failure models which are based on fundamental studies of the chemistry and physics of failure. The statistical variation of the key material, process, and exposure parameters in the failure model are described in terms of distribution functions. Since photooxidation plays a critical role in most weathering issues, a specific distribution function for exposure harshness is estimated that can be used to describe the variation in photooxidation rate under actual in-service conditions. By combining a specific failure model with in-service variations in the key parameters, it is possible to estimate in-service failure rates as a function of material and processing variables, thus, allowing for improved risk assessment of any proposed material or processing change. The formalism also provides clearer direction in the design and use of specific laboratory and outdoor exposures in predicting performance. The method is illustrated by deriving distributions of time-to-failure based on two different hypothetical mechanisms of photo-induced coating delamination. Note de contenu : - ESTIMATION OF AN EXPOSURE DISTRIBUTION FUNCTION
- DEVELOPMENT OF MODELS OF TIME-TO-FAILURE : Constant UV light transmission - Determination resulting from loss of UVAPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18077
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 69, N° 864 (01/1997) . - p. 85-96[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003533 - Périodique Bibliothèque principale Documentaires Disponible Preventing and solving delamination during multilayer pipeline girth weld coating application / Alan Kehr in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 31, N° 2 (02/2014)
[article]
Titre : Preventing and solving delamination during multilayer pipeline girth weld coating application Type de document : texte imprimé Auteurs : Alan Kehr, Auteur Année de publication : 2014 Article en page(s) : p. 42-49 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Délaminage
Epoxydes
Pipelines -- Entretien et réparations
Pipelines -- Revêtements protecteurs
Polyéthylène
PolyoléfinesUne polyoléfine, parfois appelée polyalcène, désigne un polymère aliphatique saturé, synthétique, issu de la polymérisation d'une oléfine (aussi appelée un alcène) telle l'éthylène et ses dérivés.
La formule générale est -(CH2-CRR')n-, où R et R' peuvent être l'atome d'hydrogène (H) ou les radicaux alkyle apolaires CH3, CH2-CH3, CH2-CH(CH3)2. Il existe aussi des mousses isolantes souples faites à partir de polyoléfine (pour l'isolation thermique de tuyaux plastiques par exemple).
PRESENTATION : Les polyoléfines forment la plus importante famille de matières plastiques, avec quatre représentants (PP, HDPE, LDPE, LLDPE) parmi les plastiques de grande consommation. La consommation mondiale de ces quatre polymères est évaluée à plus de 60 millions de tonnes en 20001.
Seul un petit nombre de polyoléfines a atteint le niveau industriel :
les polyoléfines thermoplastiques semi-cristallines : polyéthylène (PE), polypropylène (PP), polyméthylpentène (PMP), polybutène-1 (PB-1) ;
les polyoléfines élastomères : polyisobutylène (PIB), éthylène-propylène (EPR ou EPM) et éthylène-propylène-diène monomère (EPDM).
PROPRIETES : En raison de leur nature paraffinique, les polyoléfines sont hydrophobes et possèdent en général une grande inertie chimique (aux solvants, acides, bases, etc.). Ces matériaux ont donc une qualité alimentaire. Le collage est très difficile (la surface est particulièrement inerte, des traitements de surface spéciaux sont nécessaires).
Cependant, ils sont sensibles à l'action des UV, et résistent très peu à l'inflammation car leur indice limite d'oxygène est faible (exemple : ILO ~ 17 pour le polyéthylène).
Leur densité est très faible [0,83 (cas du PMP) < d < 0,95] : ils flottent dans l'eau.
Ils sont opaques, sauf le PMP (transparent).
Polypropylène
Revêtements multicouches
TuyauterieIndex. décimale : 667.9 Revêtements et enduits Résumé : Fusion-bonded epoxy (FBE) and three-layer polyolefin (3LPO—polyethylene or polypropylene) are the most common externat coating systems for new pipelines. Multilayer coatings using polypropylene (MLPP) can be several inches thick, protect from corrosion, and provide thermal insulation. Both FBE and multilar polyolefin coatings have long tracé records of successful use, but there are occasional issues that must be addressed as part of the pipe installation process. One of these issues is delamination between the FBE and the steel in the girth weld area of coated pipes.
The primary audiences for this article are pipeline owners, coating applicators, and inspectors. What can happen is that an issue like this is discovered and it appears to be new and not understood. Hundreds of thousands of dollars are then spent on studies, and millions are lost in delays while the issue is sorted out. An understanding of the phenomenon and a solution allows the project to move ahead. Even better, preventive measures are taken, and the issue does not happen.Note de contenu : - Multilayer coatings : end-of-pipe adhesion issues
- Adhesion loss mechanisms
- Adhesion loss prevention
- Adhesion loss solution - Cut back to well-adhered coatingPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21661
in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL) > Vol. 31, N° 2 (02/2014) . - p. 42-49[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 16091 - Périodique Bibliothèque principale Documentaires Disponible Reduction of cathodic delamination rates of anticorrosive coatings using free radical scavengers in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 7, N° 6 (11/2010)
[article]
Titre : Reduction of cathodic delamination rates of anticorrosive coatings using free radical scavengers Type de document : texte imprimé Année de publication : 2010 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Acier -- Laminage
Adhésion
Antioxydants
Délaminage
Epoxydes
Revêtements -- Corrosion
Revêtements protecteursIndex. décimale : 667.9 Revêtements et enduits Résumé : Cathodic delamination is one of the major modes of failure for anticorrosive coatings subjected to a physical damage and immersed in seawater. The cause of cathodic delamination has been reported to be the result of a chemical attack at the coating–steel interface by free radicals and peroxides formed as intermediates in the cathodic reaction during the corrosion process. In this study, antioxidants (i.e., free radical scavengers and peroxide decomposers) have been incorporated into various generic types of coatings to investigate the effect of antioxidants on the rate of cathodic delamination of epoxy coatings on cold rolled steel. The addition of <5 wt% free radical scavengers to epoxy coatings improved the resistance toward cathodic delamination by up to 50% during seawater immersion, while peroxide decomposers had a limited effect. Testing using substrates prepared from stainless steel, copper, aluminum, galvanized steel, and brass also showed a reduction in the rate of cathodic delamination when the coating was modified with a free radical scavenger. The protective mechanism of free radical scavengers investigated for the primers are similar to that of antioxidants used for protection against photochemical degradation by UV-radiation of top coatings. Both substrate corrosion and degradation of a coating exposed to UV-radiation lead to the formation of free radicals as reactive intermediates. DOI : 10.1007/s11998-010-9267-0 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-010-9267-0.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10405
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 7, N° 6 (11/2010)[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 012672 - Périodique Bibliothèque principale Documentaires Disponible A security barrier's compromised corrosion protection / Jay Helsel in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 35, N° 10 (10/2018)
[article]
Titre : A security barrier's compromised corrosion protection Type de document : texte imprimé Auteurs : Jay Helsel, Auteur Année de publication : 2018 Article en page(s) : p. 11-13 Langues : Américain (ame) Catégories : Délaminage
Expertises
Métaux -- Revêtements protecteurs
Polyéthylène basse densité
Revêtements -- Analyse
Revêtements -- DéfautsIndex. décimale : 667.9 Revêtements et enduits Résumé : A new perimeter security barrier was installed at an electrical power station in the rural, mid-Atlantic U.S. Installed over several weeks in the late fall, the barrier was construted from thin galvanized sheet panels, approximately 6 feet by 8 feet in size, that were formed into a corrugated shape and then shop-coated. The formed shape had horizontally angled bends across the sheet (near the top and bottom) and multiple vent openings.
The primary surface preparation in the shop consisted of a degreasing process using an acidic solution. The galvanized sheet was then powder coated in a fluidized bed process with a low-density polyethylene (LDPE) coating material. Field touch-up was accomplished using an acrylic primer/finish coating.
The following spring, coating failure was first reported in the form of delamination from the galvanized substrate. The failure grew worse as the year progressed, and the facility owner contracted with an independent coating consulting firm to investigate the premature failure.Note de contenu : - Site visit
- Laboratory analysis
- Fig. 1 : The glossy black coating had delaminated from the underlying galvanized metal sheetingPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31899
in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL) > Vol. 35, N° 10 (10/2018) . - p. 11-13[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 20309 - Périodique Bibliothèque principale Documentaires Disponible Statistical modeling of coating lifetimes in disparate environments / Mark E. Nichols in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 12, N° 1 (01/2015)
[article]
Titre : Statistical modeling of coating lifetimes in disparate environments Type de document : texte imprimé Auteurs : Mark E. Nichols, Auteur ; Jacqueline Frey, Auteur Année de publication : 2015 Article en page(s) : p. 49-61 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse des défaillances (fiabilité)
Automobiles -- Revêtements:Automobiles -- Peinture
Délaminage
Durée de vie (Ingénierie)
Etudes comparatives
Revêtements -- Détérioration:Peinture -- Détérioration
Revêtements -- Effets du climat
Revêtements -- Fissuration:Peinture -- FissurationIndex. décimale : 667.9 Revêtements et enduits Résumé : The effect of environmental loads on the propensity for failure of automotive coating systems was evaluated for both the United States and China. Population weighted climate distribution functions were created for both nations and applied to various failure modes including yellowing or color change, gloss loss, delamination, and cracking. The effect of process variability on specific failure modes was captured through the use of minimum and maximum film builds measured on vehicles produced in a commercial automotive assembly plant. The U.S. was shown to be a significantly harsher environment for most failure modes driven by UV radiation and high temperatures. China was shown to be a harsher environment for failure modes driven by liquid water and cold temperatures. The use of these models allowed for the prediction of regional failure rates given the time to failure of a coating of known thickness in a different location. Note de contenu : - DATA COLLECTION
- FAILURE MODELS : UV radiation-induced failures - UV and temperature-induced failures - UV-induced failure with thickness dependent absorption - UV plus thickness-induced cracking induced failure - Gloss loss failures - Denver cracking failures - DISCUSSION : Effect of coating thickness distribution - Other failure modes - Implications for weathering exposureDOI : 10.1007/s11998-014-9624-5 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-014-9624-5.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=23206
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 12, N° 1 (01/2015) . - p. 49-61[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 16952 - Périodique Bibliothèque principale Documentaires Disponible The case of the mysterious hailstones / E. Bud Senkowski in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 30, N° 2 (02/2013)
PermalinkThe compromised propane tank coating / Jayson L. Helsel in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 30, N° 11 (11/2013)
PermalinkThe effect of polyurethane curing conditions on the delamination of pressure sensitive films / B. W. Ludwig in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 66, N° 839 (12/1994)
PermalinkThe missing piece / Chrissy Stewart in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 34, N° 12 (12/2017)
PermalinkThermographic detection of corrosion delamination / Peter Meinlschmidt in EUROPEAN COATINGS JOURNAL (ECJ), N° 03/01 (03/2001)
PermalinkTroubled bridge over salt water / Michael O. Woodward in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 34, N° 10 (10/2017)
PermalinkPermalinkWhen a good idea goes bad / Rick A. Huntley in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 30, N° 3 (03/2013)
PermalinkZinc-rich primer and UHP waterjetting in severe marine environments / Philippe Le Calvé in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 34, N° 3 (03/2017)
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