SigmaKalon Protective Coatings; a reliable partner in the Tank Storage industry

With a heritage of outstanding expertise in coatings technology and decades of international investment in research and development for the protective coatings market, no company could be better placed than SigmaKalon to meet the fast-changing global challenges of this technically demanding sector.

SigmaKalon provides world-beating tank linings which are used for all types of cargoes and
stored products. The range includes pure epoxy and zinc silicate tank coatings offering long term anti corrosive performance as well as solvent based and solvent free coatings for tanks storing crude oil, gasoline and a variety of petrochemicals and chemicals. SigmaKalon’s highly specialised coatings not only meet the operational needs of today’s cargo and storage industries but the demands of constantly evolving legislation.

For economic reasons, multi-coat solvent borne epoxy coatings are used in storage tanks. But when these coatings are used there are risks involved when applied at high dry film thicknesses like for instance:

• Solvent retention resulting in possible cargo contamination.
• Shrinkage of the film during curing process.
• Build up of residual stress levels.
• Possibility of osmotic blistering due to solvent entrapment.

Solvent containing phenolic epoxies are recognized as possessing outstanding chemical resistance to a broad range of cargoes. However, such coatings have high solvent content and therefore require great care in application particularly in an enclosed space. Solvent retention can also substantially reduce performance and, with the growing concern over the release into the atmosphere of volatile organic compounds (VOC), buyers have been looking for low solvent or solvent-free alternatives that offer equivalent performance. For instance a 65 meter diameter crude oil storage tank coated for 1.5 meter up the side walls results in an emission of 500 liter solvent for a medium solid coating whereas for Sigma NovaGuard 840 this is zero!

The latest technology to be available in the market is an exciting step in the development of solvent free technology. The new generation of solvent free phenolic epoxy coatings represented by Sigma NovaGuard 840, is designed for application by standard airless spray equipment and is ideally suited for the lining of new tankage, major refurbishment and the reclassification of old tanks. Although its chemical resistance is slightly more restricted than that of it’s solvent containing counterpart, it possesses much improved chemical resistance over the epoxy solvent containing and solvent free coatings. Furthermore, this new coating eliminates the risks of lining failure due to solvent retention and cuts health and safety hazards from VOC’s and is therefore, becoming the preferred option.

A typical application for land storage tanks might comprise a single 400 micron coat. However, solvent borne phenolic epoxies are in most cases applied in multiple coats. Therefore Sigma NovaGuard 840 results in benefits like one-coat application only and resulting in cost savings and reduction of down time of the storage tank.

This new phenolic epoxy technology provides a more effective yet still cost-efficient option combining a broad range of chemical resistance encompassing all common chemicals together with other aggressive products, as well as a solvent free formulation and the ability to be built up easily to high film thicknesses. Because poor light in storage tanks during application and in order to get good contrast with the steel, Sigma NovaGuard 840 is available in light colors enabling easier application and inspection afterwards.

Gerard de Vries, Marketing Manager PC