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Eco-friendly drying with UV-I to minimise photoinitiator requirements


UV technology and sustainability: a viable combination

UV technology is an innovative paint drying solution guaranteeing shorter drying times and greater energy efficiency. However, one of the main obstacles to the widespread adoption of this technology is the use of photoinitiators, which can be harmful to the environment and to human health. Fortunately, UV technology and sustainability can now be combined by minimising the use of photoinitiators.

UV drying can be made more sustainable by minimising the amount of photoinitiators used, as well as by decreasing energy consumption or reducing the use of mercury (present in UV lamps).

Thanks to UV technology, it is possible to obtain much faster drying times than traditional solvent-based or water-based drying systems, and it is for this reason that this solution is now increasingly popular.

Reduced photoinitiator use: environmental and health benefits

Reducing the use of photoinitiators implies a number of advantages for both the environment and human health. Photoinitiators are chemical compounds that can damage human health if inhaled or in contact with the skin. Additionally, once released into the environment, they can persist for a long time and cause pollution.

By using 100% UV paints with a reduced amount of photoinitiators, the risk of exposure to harmful substances is significantly reduced. This is particularly important for workers in the painting industry, who may be exposed to these substances on a daily basis. Reducing the amount of photoinitiators needed also contributes to preserving the environment, reducing pollution and the potential damage to ecosystems.

Innovation in UV drying: use of nitrogen

A major breakthrough in UV drying: use of nitrogen. Our UV-I oven allows nitrogen to be used to reduce the environmental impact. In this way we can reduce the amount of photoinitiators used, reduce the energy requirements of the cross-linking oven and minimise the impact of mercury by using fewer crosslinking lamps.

UV-I-oven

In each of the previously listed cases (or combinations of them), while reducing the amount of oxygen inside the oven, we are still able to guarantee perfect (and in some cases even superior) drying of the workpieces.

Future outlook: trends and developments in sustainable UV drying

Sustainable UV drying is a growing trend in the painting industry. Companies are increasingly aware of the importance of reducing their environmental impact and improving the health of their workers. Environmental regulations are becoming increasingly strict, encouraging companies to seek sustainable solutions for their paint-finishing processes.

In conclusion, UV-I drying is a valuable, eco-friendly solution for reducing mercury and photoinitiators requirements, improving environmental sustainability in the painting industry. Thanks to the use of nitrogen, it is possible to protect operators' health and safety with a lower impact on the environment.

Looking to future scenarios, further development of increasingly sustainable and high-quality UV drying technologies and materials is to be expected.

UV technology and sustainability: a viable combination UV technology is an innovative paint drying solution guaranteeing shorter drying times and ...

Article

Cabinet door coating: what’s the best coating cycle?

 
Cabinet doors may seem like simple products to finish; however, they demand a suitable process that ensures good final quality and, above all, a level of manufacturing efficiency that lets companies in the furniture industry enjoy sufficient margins. Certain distinctions also need to be made: flat panels and raised panels require different finishing techniques.


How to coat flat cabinet doors?

Cabinet door coating requires meticulous preparation and careful selection of the coating application method. The process typically begins with edge finishing, using advanced technologies such as vacuum coating, followed by coating of the panel surface. Depending on the specific requirements of the doors and their thickness, manufacturers can adopt roller, spray or hybrid coating techniques. However, for thinner doors, it’s possible to proceed directly with spray coating using automated systems such as iBotic, which also features a spray gun specifically designed for edge finishing.

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Edge finishing

Edge finishing is a crucial stage as it ensures doors have an impeccable appearance and long-lasting protection. This process begins with thorough sanding of the edge to prepare it for application of the primer and subsequent coatings. Cefla Finishing machines such as Smartedge allow for the application of primer and coatings in vacuum mode, ensuring even coverage. Each coating application is followed by controlled drying, which involves semi-curing in a UV oven. Summing up, the steps are:
  • Sanding: sanding the edge is the first step. This ensures proper preparation before application of the primer and edge finishes. Abrasive wheels or belts can be used.
  • Primer application: the primer is applied on the edge using roller or vacuum systems such as Smartedge, the Cefla Finishing solution for edge sanding and coating. 
  • Coating applications: this involves two or more vacuum applications of transparent or pigmented UV coating, using a total of 180 g/m2 of product. Each application is followed by a gelling or UV drying process.
  • Drying: after each coating application, a semi-curing process takes place in a UV oven; for pigmented products a gallium lamp is used. 
  • Sanding: the process ends with automatic sanding of undercoats using a sanding wheel or belt. 

Spray coating

After vacuum-technology edge finishing, the panels are spray-coated. The process stages are:
  • Spray coating: application of a quantity of primer suitable for the type and density of the substrate. This is achieved using a sprayer such as iBotic, the high-capacity Cartesian spraying robot; iBotic can also process J-Pull profiles and standard flat panels. The robot can spray both flat surfaces and edges, obtaining a high-quality finish. 
  • Drying: the doors are then dried completely in a vertical oven. Omnidry is a flexible vertical oven: with its optional FLEXPRO function, it can automatically process pieces of different size and/or thickness.

Hybrid coating

Depending on specific production requirements, manufacturers can adopt a hybrid coating cycle that combines the best available technologies. Edges can be finished with Smartedge before coating the panel with Smartcoater Pro. Where doors have contouring, the latter can be equipped with a soft roller. Subsequently, a high-quality finish can be achieved by spray coating with robot systems such as iBotic or oscillating systems such as Easy or Mito. This hybrid approach provides the advantages of both technologies, ensuring excellent results on edges and flat or raised surfaces.

Raised cabinet door coating

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Let's take a detailed look at how to coat cabinet doors (for kitchens or other rooms) if they are raised. Raised panels are often spray-coated. This is because, until recently, roller coating technology was unsuitable for raised doors. However, roller coating has evolved and can now be used on raised panels such as kitchen cupboard doors, or any substrate with a groove shallower than 10 mm.

Smartcoater PRO is a roller machine equipped with a soft rubber applicator roller. This special roller not only performs the intended task: combined with other exclusive features on this next-gen machine, it also guarantees an even result.

Such features include a special stabilising framework for the application head that uses 4 screw jacks. This set-up exerts considerable pressure on the panels passing over the machine and, thanks to the floating pneumatic system (another exclusive feature that can be integrated into Smartcoater PRO), the applicator head follows the irregular contours of the panel; it also compensates for panels that have been insufficiently calibrated.

The raised cabinet door coating steps can be summed up as follows:

  • Primer application: (35 g/m2) using Smartcoater PRO.
  • Drying: in UV ovens with a gallium lamp for gelling.
  • Roller coating: again, using Smartcoater PRO.
  • Second drying: carried out under 2 gallium and mercury lamps.
  • Sanding.
  • Spray coating: to apply the final finishing layer, using spray-coating machines such as Mito or iBotic. 

The advantages of coating cabinet doors with Smartcoater PRO

Coating raised panel surfaces with a machine that has a soft roller offers multiple advantages:
  • transfer is more efficient that with spray-coating.
  • the process no longer requires sanding between undercoats.
  • fewer handling tasks.
  • all this results in shorter coating times.

The process also guarantees lower costs and higher speeds:
  • less coating and solvent consumption.
  • shorter delivery times.
 
READ ALSO: The advantages of the new soft roller

The perfect cabinet door coating partner

In conclusion, coating cabinet doors is a crucial stage of the finishing process as it significantly affects the quality, appearance and durability of the final product.
At Cefla, we’re proud to offer not just machines but complete turnkey solutions, tailored to the specific needs of each customer. Our goal is to provide furniture companies with close support, helping them set up production lines in a way that best matches their processes so they can maximise efficiency and deliver excellent finishes.

Talk to one of our experts to find out how we can help you achieve your goals

 

 
Cabinet doors may seem like simple products to finish; however, they demand a suitable process that ensures good final quality and, above all, a ...
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