The issue of corrosion poses a major problem around the globe, both in terms of the associated occupational safety issues as well as the economic losses that it causes each year.
In more developed countries, the annual cost of corrosion has been estimated at 3.1% of GDP, which is why scientific institutions and communities are devoting time and resources to analysing and preventing it.
In this respect, Adapta has seen an interesting avenue of research in testing its state-of-the-art ROC (Rustproof One Coat) anti-corrosive powder coating systems with respect to ISO 20340: 2009, since we understand that the technical committee that drew up this regulation has incorporated a truly interesting component; the stress of the coating in the face of atmospheric and temperature changes.
Regulation ISO 20340: 2009 for paints and varnishes ‘Performance requirements for protective paint systems for offshore and related structures’, anticipates a total exposure for the coating of 4,200 hours, divided into 25 cycles. Each cycle is divided into the following stages:
- 72 hours of UV exposure and condensation according to regulation UNE EN ISO 16474-3:2014, alternating four hours of artificial aging under UV light at 60 ± 3º C and four hours of condensation at 50 ± 3º C. Type 1 Lamps (UVA 340).
- 72 hours of exposure to salt spray according to UNE-EN-ISO 9227:2012.
- 24 hours of exposure at low temperature, at -20 ± 2º C.
At the end of 25 cycles, this adds up to the following number of hours of exposure during each of the various stages:
- 1,800 hours of QUV 340.
- 1,800 hours in the Salt Spray Chamber.
- 600 hours at -20 ºC.
Before beginning the cycles, a 50-mm incision is made in the coating with a width of 2 mm.
The repeated exposure cycles are an attempt to simulate the extreme environments of offshore structure, that is, structures exposed to a marine environment and submerged in sea water or brackish water. Offshore structures may be floating or fixed to the sea floor, with many of these being oil and gas extraction platforms. A great number of these platforms are located in the North Sea and the Norwegian Sea.
Adapta has selected two types of substrates prepared according to NORSOK Standard M-501 (Surface preparation and protective coating – Edition 6, February 2012): galvanised steel (Figure 1) and aluminium (Figure 2). Both substrates received, prior to painting, a phosphate-free nanotechnological surface treatment,
The NORSOK standards are based on internationally-recognised regulations and incorporate additional requirements that are deemed necessary in order to satisfy the extreme demands of the Norwegian oil industry. It compiles the requirements for selecting coating materials, preparing the surface, application procedures, and inspection of protective coatings that are applied during the construction and installation of offshore structures.
The anti-corrosive coating applied consists of a coating system of two powder coating layers. The first layer is made up of a primer, Adapta ROC, RB-7708, and the second is a metallic finish in super-durable quality (Adapta SDS), DX-9006-XW. The total thickness of both layers in both systems is between 140 and 180 microns, this being less than the minimum required (>225 microns) for systems based on liquid paints.
This also provides a reduction in costs and procedures compared to these liquid systems.
The tests were performed in the certified laboratories of Tecnalia Research & Innovation, where tests were performed with respect to the evaluation of defects, according to UNE-EN-ISO 4628, adhesion according to UNE-EN-ISO 4624, and pull-off test for adhesion according to UNE-EN-ISO 4624. Satisfactory results were obtained from all of these tests. The anti-corrosive system Adapta Rustproof System® is, therefore, highly recommended in extremely corrosive environments, such as, for example, coastal buildings and facilities.