Contribution to a better FBE selection for 3 layer polyolefin coatings
Abstract
Recent case studies reported large scale disbondments of three-layer polyolefin (3-LPE) coatings, which could favour corrosion beneath the coating and lead to possible major damage. Therefore, it is necessary to better investigate the adhesion strength of fusion-bonded epoxy (FBE) primer to steel taking into account the water diffusing through the topcoat within the lifetime of pipeline. A methodology was developed to examine the adhesion of sublayers to steel under wet exposure: peel tests were carried out on pipe rings industrially coated with FBE and adhesive layers only, aged in vapour to simulate the water ingress through the topcoat. This methodology could be included in selection or pre-qualification tests. 1 BACKGROUND Among the two great families of external coatings of pipelines-FBE coatings and 3-LPE-each one has its advantages and disadvantages. In both cases, FBE is applied in direct contact to the freshly grit blasted pipe in order to provide good anchoring to steel.
Domains
Material chemistry
Origin : Files produced by the author(s)
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