Axalta Coating Systems Corrosion Protection with Thermoplastic Powder Coatings
No industry can do without effective and efficient corrosion protection. Coatings with thermoplastic powder coatings have been successfully used. Apart from their primer-free application and maximum protective properties, they offer maintenance-free operation and high cost-effectiveness even under extreme conditions.
Whether outdoor furniture, light poles, metal sheets for the storage of food in cold storage rooms, pipelines for drinking water and sewage supply, cable ducts and cable trays, elements for swimming pools, the maritime sector or offshore facilities - as diverse as these components may be, they all have one thing in common: They need effective and durable corrosion protection. For decomposition, erosion and corrosion entailed in the Latin word "corrodere" lurk everywhere. The best-known corrosion process is oxygen corrosion, in which iron or steel is converted into rust by being exposed to oxygen and humidity. The contact with acids and other chemicals also leads to the corrosion of metals. Under certain conditions, corrosion can also be caused by bacteria, for example in underground pipes and in humid, warm environments.
Thermoplastic Powders - Useful Properties
Coatings with wet or powder coatings are an effective means of protecting metallic components from corrosion. Depending on the application of the component to be protected, several layers of coating including primer are applied. In many applications, reliable and long-term corrosion protection can be achieved even more effectively and economically with Plascoat and Abcite thermoplastic powder coatings from Axalta Coating Systems. The fact that these powders are based on a polymer whose chemical composition can be adapted to different operating conditions makes a significant contribution to these features. Thermoplastic powder coatings can be applied to components made of all kinds of metals, such as steel, aluminum and galvanized substrates, both in a fluidized bed and flame spraying, as well as in conventional electrostatic spraying processes, without prior application of a primer. Depending on the application method, layer thicknesses of between 300 and 600 micrometers can be realized. All processes achieve very good coating even in corners, edges and complex areas. The application process and the surface preparation have an influence on the performance of the corrosion protection.
Thermoplastic powder coatings form a "thicker" barrier than conventional, mostly decorative powder coatings. The closed paint layer prevents media from penetrating or escaping. In addition, the pore-free and smooth layer prevents the formation of biofilms. In addition, the coated surface is characterized by very high mechanical, chemical and UV resistance, is electrically insulating and noise-absorbing. Another advantage is the elasticity of the coating. It prevents the paint from flaking off when temperatures fluctuate greatly or are low. This also means that the coating layer is maintenance-free throughout the service life of the coated component. If repairs or conversions are necessary, the coating can be repaired on site. On the one hand, this reduces operating costs and, on the other hand, results in significant time savings. When it comes to environmental compatibility, thermoplastic powders can also score points: They do not contain solvents, VOC or halogens, bisphenols, PVC, phthalates or other plasticizers.
Meet the Highest Requirements with Just One Layer
These properties make thermoplastic powder coatings, especially the Abcite series, ideal for applications where heavy corrosion protection is required, such as in the maritime and offshore sectors. Even with a single layer of paint, requirements up to corrosion protection class Cx according to the former DIN 20340 can be fulfilled without priming or other adhesion-optimizing measures. A wet paint system requires four to six coats for adequate protection. Axalta's portfolio of thermoplastic powder coatings also includes a system that has been included in List II of approved coating systems for corrosion protection in hydraulic steel structures for seawater (Im 2) and soils (Im 3) by the Federal Institute for Hydraulic Engineering (BAW). It also meets the required criteria with only one layer and without primer. Thermoplastic powder coatings are also certified for the coating of drinking water pipes.
In all of these applications, thermoplastic powder coatings provide noticeable material and energy savings. Often, they also enable the use of more cost-effective materials. This is the case, for example, with cable trays, which are usually made of stainless steel. The coating allows these components to be manufactured with cheaper steel. Apart from lower material costs, protection is improved with simultaneous electrical insulation. Sheets used for food containers in cold storage can also be coated with stainless steel instead of steel. Other applications in which thermoplastic powder coatings have proven their advantages include the coating of vehicle components, components for traffic and road equipment, elements of buildings and industrial facilities, and outdoor fences and furniture. In order to meet decorative requirements as well, the corrosion protection layer can be painted over with a conventional powder topcoat.
This article was first published by MM MaschinenMarkt.
Original by Frauke Finus / Translation by Alexander Stark