[article]
Titre : |
Powder coating advances for edge corrosion protection |
Type de document : |
texte imprimé |
Auteurs : |
Kathryn Shaffer, Auteur ; John Schneider, Auteur ; Holli Gonder, Auteur ; Cassandra Allen, Auteur ; Shawn Flegm, Auteur ; Lan Deng, Auteur ; Brian Woodworth, Auteur ; Susan Miller, Auteur |
Année de publication : |
2019 |
Langues : |
Américain (ame) |
Catégories : |
Anticorrosifs Anticorrosion Bordures Essais de brouillard salin Métaux -- Revêtements protecteurs Poudres métalliques Revêtement poudre -- Additifs:Peinture poudre -- Additifs Revêtements organiques Revêtements poudre:Peinture poudre
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Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Sharp edge coverage is a huge challenge for the coatings industry. The lack of coverage on sharp edges can compromise a coating’s performance. One of the major failures is rust/corrosion resulting from these exposed edges. Several approaches exist as solutions, both from the manufacturing standpoint and from a coatings/technical perspective. A well-known strategy in manufacturing involves the rounding off of sharp edges on parts prior to coating application. However, this adds significant cost from the manufacturing side. From the coatings standpoint, two-coat systems are the standard for many customers, but this requires two separate oven bakes, adding complexity to the process. This under layer doesn’t always apply at appropriate thicknesses that result in any true protection of those areas. Dry-on-dry approaches remove the double-bake complexity, but the performance hasn’t been found to be a match to the two-bake process. Furthermore, the difficulty in applying dry-on-dry technology makes it a less attractive choice. It is evident that innovation opportunities exist in improving on high-edge coverage.
Our team has developed a new, one-coat, direct-to-pretreated metal powder innovation which exceeds the corrosion protection performance of current technologies. This paper provides an overview of our approach toward the development of this new product. |
Note de contenu : |
- The Challenge of Edge Protection
- Getting the Powder to the Edges
- Keeping the Powder at the Edge
- Fig. 1 : Maximizing powder coverage at the edges is a challenge for both liquid and powder thermoset systems. Pull-back of paint during the cure cycle further exposes these sharp edges
- Fig. 2 : Increased viscosity of high-edge formulation (orange dots) improves the ability of the coating to remain on the edge during the cure cycle
- Fig. 3 : Salt spray results for a standard powder formulation and one modified for edge-protection. Significant performance improvement is evident in the high-edge formulation
- Fig. 4 : 40 Cycles CCT (SAEJ2334) of a high-edge powder formulation along with our standard powder control on laser-cut iron phosphate pretreated hot-rolled steel
- Fig. 5 : 1000 hour salt spray data on actual powder line-applied parts. Even on a large application line, the improvement in edge film build is greatly improved based on this long-range test data
- Fig. 6 : The SEM images shown here portray a 40% increase in sharp edge coverage for our high-edge formulation versus the standard powder production control part
- Fig. 7 : These SEM images demonstrate the high-edge formulation’s ability to cover even highly ragged, burred edges
- Fig. 8 : Shown is an example of line coated parts at a customer trial, this time over primer, another great example for our high-edge powder and its ability to overcome transfer efficiency and flow issues and build film
- Fig. 9 : Shown is an example of line coated parts at a customer trial, this time over primer, another great example for our high-edge powder and its ability to overcome transfer efficiency and flow issues and build film |
En ligne : |
https://www.coatingsworld.com/issues/2019-05-01/view_technical-papers/powder-coa [...] |
Format de la ressource électronique : |
Html |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32511 |
in COATINGS WORLD > Vol. 24, N° 5 (05/2019)
[article]
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