UV tube coating

UV coating is a well-established technique in the steel tube industry that has gained popularity in recent years. Selmers developed a UV-coating process line with advanced features and clear benefits. It is a full-service solution. The line delivers a complete UV-coating factory for applying a scratch- and corrosion-resistant cosmetic coating. It includes all equipment for cleaning, pre-heating, coating, curing, and handling long steel or aluminium tubes and profiles. The system operates with either traditional UV lamps or LED lamps.

Selmers’ UV coating line is suited for a wide range of applications and industries. In the building industry, for example, it is used for sprinkler pipes, OCTG (Oil Country Tubular Goods), and many other products. The UV-coating equipment applies a layer of paint that effectively functions as a hard, durable, scratch- and corrosion-resistant protective coating. When a cosmetic finish is required, any desired colour can be applied. The coating offers a wide colour range, enhances the product with a shiny, appealing gloss, and delivers clear advantages over commonly used water-based coatings.

• Handling equipment: Tailored to the specific needs of the customer consisting of rollers side-shifting systems and tube racks.
• Cleaning system: Engineered to prepare the surface for coating by means of cleaning and drying.
• Pre-heating system: Prepares the surface of the tube in terms of temperature for perfect adehesion of the coating. (Only needed with LED curing)
• Coating system: Applies the coating efficiently.
• Curing system: Cures the coating almost instantly with UV Led lamps or UV Mercury lamps.
• With traditional UV: Less machines but also less colors only opaque and transparent colors are possible. 
• With UV LED: Almost all colors are possible and no ozone emissions.
• Air cooling system: Cools the tube down for the finishing touch on curing. Air cooling is only needed with LED curing.
• Electrical controls.
• Suited for: flat-sided-oval, rectangular, round long steel or aluminum objects.
• Adjustability: The individual systems are adjustable for various sizes. Minimizing change over time.

• Efficient use of resources: The washing and coating system uses water and coating materials efficiently and recovers almost all of both. This significantly reduces overall resource consumption.
• Decrease in scrap: The automated set-up system with adjustable settings minimizes the margin for error, resulting in less scrap material.
• Sustainable: The washing and coating system can reclaim and filter excess water or coating.
• Smaller floorspace: Compared to water-based coating lines there is much less space needed because the drying area is reduced.
• Clean working space: Compared to water-based coating lines the working area is cleaner because no coating is escaping in the air or drips on the ground.
• Complete integration: Selmers can provide all the listed systems making a fully functioning UV coating line.
• Lower Energy consumption
• Higher ROI
• Reduced Reporting & EHS

When UV coating is exposed to UV light, it initiates a chemical reaction in which photo initiators, special components in the coating, absorb the UV-light energy. This absorption triggers the polymerization or cross-linking of monomers and oligomers in the coating, causing the material to harden and form a durable film. This process is photochemical because it involves light (UV-radiation) driving the chemical transformation, converting liquid coatings into solid layers, without requiring heat or long curing (drying) times.

Watch the video to see it in action!

The UV coating line contains all the necessary equipment to transport, clean, handle, operate, coat and cure the tube or profile. There are 2 options for curing, by means of Traditional UV lamps or LED lamps.

• With LED curing, additional steps are involved. First, handling equipment positions the tube. Next, the cleaning system thoroughly cleans and dries it. Then the tube is pre-heated (induction or gas), depending on the coating type. After that, the coating is applied. The tube proceeds to the curing system, where UV LED lamps cure the coating. Finally, the tube is air-cooled. Once cooled, the handling equipment moves the tube to the next station.
• With Mercury curing the same handling equipment moves the tube to the first system which is the cleaning system. The cleaning system cleans and dries the tube. After the cleaning system the tube goes through the coating system where it is provided with the coating layer. After this the tube is guided through the curing system where the coating is cured with UV Mercury lamps.