Hempel's two new launches - the topcoat Hempaxane 55000 and the reinforced high-build epoxy coating Hempadur Multi-strength GF 35870 - are making waves in various industrial sectors for their many features including protection against corrosive elements.
The Hempaxane 55000 is described as a high-quality topcoat ideally suited for steel structures exposed to severely corrosive atmospheric environments.
"This unique product is based on both epoxy- and polysiloxane binder chemistry, thus combining the excellent anticorrosive properties of epoxies with very long colour- and gloss retention from the polysiloxane binder," said a Hepmel spokesman.
"Most of its product features clearly outperform those of polyurethane topcoats. Furthermore the product has an environmentally friendly profile, which is clearly on the forefront of all foreseeable restrictions concerning solvent emission," he added.
Hempaxane 55000 has undergone thorough testing at every stage of development. This has involved in-house testing and field trials on a wide variety of different structures. The product has obtained certification by some of the world's most recognised coating institutes. It has already passed pre-qualification for the Norsok M501 - rev 4 standard using only a zinc-rich primer as a preceeding coat. Other tests include mechanical strength tests, abrasion resistance tests and colour and gloss retention tests, all according to recognised standards.
Hempaxane 55000 has proven superior to other topcoat products currently used in the market in terms of colour and gloss retention, impact, abrasion resistance and anticorrosive barrier properties, helping to ensure longer durability of structures protected with this coating, the spokesman said.
Hempaxane 55000 is designed to protect steel structures from the harmful effects of weather, environment and operating conditions, whether this is offshore, onshore or inland. Some of the more typical constructions include offshore installations, petrochemical plants, tank farms, wind turbines and bridges - all structures where a very long durability is expected and where maintenance can be difficult and expensive due to limited access. It forms a hard coating within only a few hours, making the product ideal for use in online production facilities or other situations where fast drying means faster throughput and increased production flow.
"Hempaxane 55000 provides much better corrosion protection than conventional topcoats such as polyurethanes. This is possible because it forms an exceptionally effective barrier to the passage of water and also a very hard, impact- and abrasion-resistant coating to protect against mechanical damages," the company spokesman said.
"Furthermore, it is extremely resistant to UV light from the sun, meaning that the coating maintains its gloss and colour for a much longer period than other topcoats, such as acrylics, alkyds and polyurethanes. Structures painted with Hempaxane 55000 will therefore maintain their nice appearance for many years to come."
Due to the combination of colour and gloss stability with corrosion protection properties, Hempaxane 55000 can substitute both an epoxy coat and polyurethane coat, and thereby in certain cases reduce the number of coats in a coating system.
As an example, a typical coating system in a C3-C4 environment (according to ISO 12944), would include a zinc-rich primer, followed by both an epoxy intermediate coat and a polyurethane topcoat. The last two coats can be substituted with just one coat of Hempaxane 55000.
With the increased attention on the environment, most countries are in the coming years expected to impose further restrictions related to solvent emission and content of hazardous material in coatings.
Hempaxane 55000 has a solids content as high as 85 per cent and a VOC level (Volatile Organic Compound) as low as 160 g/litre. This means a significant decrease in solvent emission compared to alkyds, polyurethanes and most epoxies.
It is also totally free of isocyanates. At present, isocyanates are only prohibited in coatings in a few countries, but their health and safety aspects are an issue of continuous consideration. It is expected that more countries in the years to come will enforce the use of alternatives to isocyanate-containing topcoats.
Hempaxane 55000 is available from most Hempel companies around the world. Information on the product is available at any Hempel office or at the company's headquarters in Denmark at the following e-mail address: protective@ dk.hempel.com
Giving details of the other new product, Hempadur Multistrength GF 35870, Hempel said the high-build epoxy coating reinforced with lamellar glass flakes met the protection requirements from some of the most extreme corrosive environments.
The use of lamellar glass flakes provides superior barrier properties and thus improves the corrosion properties of the coating. Glass flakes are impermeable and increase the distance that water has to take when passing through the paint film to make contact with the substrate, and start corrosion, the company explained.
Glass flakes are also chemically inert, which provides additional protection in the case of any chemical attacks on the coating. They also improve the abrasion-resistance properties of the coating.
"Hempadur Multistrength GF 35870 combines all the features of a high-build epoxy coating with the properties of glass flakes and thus makes the product extremely resistant to wear and tear, chemicals and corrosion. It is based on a pure unmodified epoxy resin composition with which Hempel has experience in the Oil & Gas industry," a Hempel statement said.
The product is designed to withstand the severe conditions prevailing in the offshore industry, on areas such as splash zones, helidecks and working decks. These are areas exposed to severe abrasion in a highly corrosive environment.
But the product is not limited to application on offshore constructions only. Water treatment facilities, sheet piling, pulp and paper mills and water dams are just a few examples of land-based constructions also requiring proper protection against abrasion and corrosion.
"With a volume solids as high as 87 per cent, Hempadur Multistrength GF 35870 can be applied in dry film thickness as high as 350 - 500 micron, even on vertical surfaces. Furthermore, the product is self-priming and can therefore provide structures with extremely good corrosion protection in just a one-coat system," Hempel said.
"Another product feature is its fast-drying properties. Curing proceeds very fast, even when applied in high film thickness. Due to the fast curing of the product, structures can be exposed to water only few hours after the product is applied. This makes the product an ideal solution for repair of structures in tidal zones.
