Roller coating on wood and its derivatives is an ideal way to accurately and evenly apply coating on panels, cabinet doors, doors, flooring and any other object with flat surfaces. Various techniques and lines are available to help you set up this type of process: each one has specific characteristics and, depending on the type of result you wish to achieve, has its own pros and cons.

While a customised solution is always the best response to any manufacturer's finishing needs, this article gives a general overview of how wood and wood-derivative roller coating machines work and illustrates their advantages.

When should roller coating be used for wood and its derivatives?

These days, roller coating is universally seen as a tried and tested industrial technique. This is thanks to increasingly reliable technology. Such technology meets the needs of a variety of product categories (one of the foremost being items in the furnishing sector), with panel and edge coating playing a crucial role in the wooden accessory manufacturing process.

In addition to wood and its derivatives, roller coating is also suitable for glass, cork, plastic and fibre cement surfaces. Indeed, a growing number of companies are choosing it to make production more efficient and boost their capacity for differentiated production. Lines can, in fact, be customised to meet specific requirements; they’re designed to meet the needs of both companies that repeatedly perform large-volume, same-batch processing and plants that require frequent colour and thickness changes, thus reducing downtime. A roller coating line maximises flexibility: this makes it perfect for third-party finishing set-ups, which require that the switch from one colour or thickness to another be completed without prolonged machine downtime.

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Composition of roller coating lines for wood and wood derivatives

Getting into the specifics, what do wood and wood-derivative roller coating lines consist of?

The lines are generally made up of a sander, followed by coaters which, in turn, precede a series of UV ovens.

After the sanding process, if the panels have flat edges (i.e. a sharp edge with respect to the surface), coatings are mainly applied with roller machines and curtain coaters to obtain finishes with differing degrees of gloss.

On a modern coating line, being able to control the process via interactive dashboards is essential: by monitoring performance, manufacturers can boost the operational versatility of their plant over time.

Moreover, manufacturing companies require maximum flexibility across a range of different products. That’s why they increasingly choose easy-to-use, modular, customisable solutions that smoothly adapt to production/space requirements and contain consumption: not just in terms of the stability of the basis weight of the applied coating and the reduced need for cleaning solvents, but also in terms of the time the operator has to dedicate to washing, which can be partially automated.

What are the advantages of roller coating wood and its derivatives?

Compared to a traditional, manual manufacturing process, industrial roller coating of wood and wood derivatives offers a series of tangible, measurable advantages that range from more precise coating application to better control of the production process. More specifically, the main benefits of adopting a roller solution are:

• even, precise application of the coating, with consistent quality
• monitoring and optimisation of each stage of the process
• better control over the materials used, allowing waste reduction
• flexibility when diversifying production lines
• partially automated cleaning operations, significantly reducing solvent consumption and costs.

Cefla Finishing solutions for roller coating wood and its derivatives

After making an in-depth assessment of the needs of companies that process wood and wood derivatives, Cefla Finishing breathed life into a series of solutions that simplify the adoption of roller coating processes. For example, Smartcoater PRO is designed to combine better control of the different processing phases with greater flexibility and ever-better performance: different shapes, different thicknesses and panels with varying degrees of deformation require maximum agility, and the Smartcoater PRO dashboard helps automate parameter settings on each process.

The machine is designed to ensure effective, efficient operation: the lifting system, which uses four screw jacks, provides greater stability and rigidity, while the optional pneumatically-controlled floating head system responds perfectly to surface variations on the panels transiting through the machine. Belt adjustments are automatic. There’s also an optional alignment system. Smartcoater PRO also features a dosing roller positioning mechanism and an independent electric applicator. Lastly, thanks to the latest innovation to be added to the machine - a soft rubber applicator roller - Smartcoater PRO now has an even more appealing set of functions that include the roller coating of raised panels.

As stated, a roller coating line also includes a series of ovens. Cefla Finishing offers the UV-R series: a UV drying oven (also usable on spraying lines) that can halve the number of lamps needed for processing (and, consequently, the machine's running costs). The system also incorporates a PLC-controlled electronic transformer that allows adjustment of lamp power, recipe management and energy savings in the event of missing pieces.

Who is Cefla Finishing for?

The Cefla Finishing range of plants and machines continues to evolve by leveraging decades of worldwide experience in the surface finishing sector. With no less than 300 active patents and approximately 15,000 machines installed all over the world, Cefla Finishing develops coating equipment that aims to maximize production efficiency and bolster the sustainability of woodworking companies that make flat cabinet doors, parquet, doors and panels in general. What’s more, the range extends beyond the wood and furniture sector to encompass supply chains for glass surfaces and items in cork, plastic and fibre cement.

So, regardless of the industry you’re involved in, if you’re looking for an innovative roller coating system simply contact a Cefla Finishing expert to receive a free consultation and identify the solution that’s right for you.

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In the coating systems industry, process efficiency is now an increasingly strategic priority, both from an economic standpoint and in terms of sustainability. Managing paint consumption is one of the most critical aspects, as it directly affects operating costs, the quality of the final result, and the environmental impact of the entire process.

In this article, we at Cefla Finishing provide an overview of overspray and the latest solutions for improving the performance of coating systems and reducing waste.

What is overspray in coating systems and how does it affect performance?

In coating systems, overspray refers to the portion of the coating material that, during the spraying phase, fails to adhere properly to the surface of the workpiece and is dispersed within the booth or the exhaust system. 

From a physical standpoint, this phenomenon is linked to the dynamics of atomized particles: the paint is sprayed in droplets of varying sizes which, due to the exit velocity, air turbulence, and the distance between the spray gun and the surface, may deviate from the ideal trajectory and fail to reach the target.

Among the main factors contributing to overspray formation are excessive atomization energy, suboptimal airflow distribution within the system, and application parameters that are not perfectly balanced with respect to the type of paint and the workpiece being treated. The result is a reduction in transfer efficiency – that is, the amount of paint actually transferred to the substrate – which directly impacts system performance in terms of material consumption, finish quality, and process stability.

For this reason, overspray control is a key factor in the design and optimization of industrial coating systems.

Overspray control system: the solution from Cefla Finishing

In coating plants, overspray control also involves the use of systems designed to effectively manage the behavior of the coating material during the spraying phase.

This is where the “Airsphere” air diffusion plenum comes in, a solution developed and patented by us at Cefla Finishing to optimize operating conditions inside the machine. The system is designed to ensure uniform and controlled air distribution, reducing turbulence and creating a stable environment for paint application. This improves spray quality, promotes more uniform coating on the workpiece, and increases transfer efficiency.

Integrating such solutions into coating systems therefore allows for a structural approach to addressing overspray, improving overall process performance and reducing material waste.

How to reduce overspray: some operational tips

In addition to implementing advanced equipment solutions, reducing overspray also requires proper management of application parameters and operating conditions. In fact, certain measures can help optimize the spraying process and improve overall efficiency:

• Selecting the nozzle size: it is essential to choose the most appropriate size based on the type of paint and the desired application result. In many cases, a larger nozzle size allows for operation at lower working pressures, thereby reducing product waste.
• Adjusting the atomizing air flow: keeping the atomizing air flow at the minimum necessary level helps limit the energy imparted to the paint particles, thereby reducing the risk of them veering off course and minimizing overspray.
• Optimization of ventilation parameters: it is recommended to minimize the plenum and exhaust air flow rates to prevent excessive turbulence inside the cabin.
• Setting the spray area: it is important to configure the spray area precisely via the machine’s display, limiting it to only what is strictly necessary for the part being painted to avoid unnecessary overspray.
• Spray gun positioning: keeping the spray guns as close as possible to the surface of the workpiece improves paint transfer and reduces the amount of paint lost to the environment.
• Spray mode: whenever possible, it is preferable to use the “all” mode (back-and-forth) rather than the “front” mode (one-way), as it ensures more uniform distribution and greater control over the deposit.

Conclusion and Cefla Finishing's key role

Reducing overspray is now a key strategy for improving the efficiency of coating systems, optimizing material consumption, and ensuring consistently high quality standards over time. Addressing this issue involves not only adjusting process parameters but also adopting advanced technological solutions and an integrated design approach capable of balancing all the factors that influence the application phase.

This is precisely the direction we at Cefla Finishing are taking, designing and manufacturing turnkey coating and finishing systems for the international market, with customized solutions that combine technological innovation, efficiency, and sustainability. 

Contact us to find out how to optimize your coating system!

Painting car components requires machines and procedures able to combine innovation, efficiency and precision. Plastic parts are increasingly popular in the automotive industry and the finishing process should not only improve their perceived quality but also guarantee their durability over time. In this regard, being able to control the processing parameters with extreme precision and to perform completely automatic paint finishing is essential to optimise end results, regardless of whether the parts are inside or outside the passenger compartment.

What are the available coating techniques for automotive parts?

Usually, finishing of car parts and components is done by spray coating on overhead lines. However, there are also systems that allow parts to be processed at ground level, inside painting booths with horizontal air flow integrated with chain conveyors and anthropomorphic robots with point-to-point programming.

Then there are finishing lines known as flatbed lines. These use a different approach: parts placed on supporting jigs (which are not fixed to the line in the solution designed by Cefla) that lie on a horizontal conveyor while being painted.

Thanks to a conveyor belt and a vertical air flow blowing from top to bottom, this solution drastically improves end product quality. The machines of the most advanced lines are also able to detect the shape and position of the parts and, consequently, process them without requiring any specific programming.

Importance of lacquer and paint quality

Vertical spray coating lines are best suited to larger parts, such as bumpers. 
Smaller parts - generally used in the passenger compartment and therefore requiring flawless precision and quality - are instead ideally processed on flatbed lines. In addition to ensuring greater productivity, flatbed lines also allow output efficiency to be improved - thanks to the machinery's ability to minimise defects caused by overspray, as the special machine architecture allows any overspray to be removed from the bottom.

The flatbed line proposed by Cefla Finishing, for instance, ensures up to 20% more productivity than other solutions, guaranteeing an excellent quality glossy piano black finish, ideal for parts designed for key dashboard sections and for the internal finishing of car doors.

This kind of performance is also achieved through partnerships that Cefla has initiated with several paint suppliers: in-depth knowledge of the technical characteristics of the best products available on the market allows production lines to be configured with the greatest precision, so as to optimise the consumption and efficiency of all the paint types used.

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The steps required to paint automotive parts

It is thanks to this approach that the benefits we offer to customers in terms of quality, productivity and cost-effectiveness are easily measurable throughout the value chain. For each type of processing, Cefla Finishing develops bespoke techniques, solutions and processes.

When it comes to coating car components, a high efficiency line should include, based on our expertise, the following steps:

• Surface preparation: automatic cleaning with carbon dioxide snow and deionisation with our Mito oscillating spray coater.
• First coat application: Parts are fed through a digital 2D or 3D reading barrier to the iBotic Cartesian spraying robot for (usually black) paint coating.
• First drying: the painted parts are moved to the Omnidry vertical oven for a 20-30 minutes' hold time.
• Second coat application: a new coat of clear lacquer is applied, possibly double-cured using UV rays, again by a iBotic Cartesian spraying robot.
• Final drying: Omnidry oven hold time of 45 minutes at 70°C then UV oven (UV-R M2) drying to increase the surface hardness of the paint coat.

Painting of internal parts

Any solutions should be adapted to the type of product to be painted. When it comes to a car’s internal components (listed below), the main priority is to obtain a finish that ensures the best result in terms of aesthetics and excellent durability of the materials.

• control panel
• dashboard
• air vents
• central console
• door panels and controls
• car seat upholstery
• boot bottom panel (highly resistant coating)

Coating of external parts

As for external parts, quality coating must guarantee, in addition to a pleasant surface feel, a layer of protection against weathering and minor impacts.

• door protector strips
• wheel rims
• wheel covers
• brake shoes and brake pads (adhesive coating)
• radiator grille
• window frames
• side view mirrors
• headlamps: transparent scratch-resistant coating
• fuel tank door
• parking sensors
• spoilers
• bumpers
• side skirts
• engine gaskets (special coating)

Automation in the paint finishing process for automotive parts

The painting process of parts and components in the automotive sector is particularly effective when integrated and automated lines are used. We are referring to complete, turnkey solutions, which in addition to robots and drying ovens also include, for example, dry ice cleaning equipment, capable of minimising the environmental impact.

Automation is also essential for smart, efficient handling of parts that require multiple coats of paint. To rise to this challenge, users can now rely on specially designed line software such as cTracker, a line monitoring tool developed by Cefla Finishing that automatically regulates painting operations and sets the correct temperatures for the drying phase. Each component can thus receive the most suitable treatment without any need to slow down or stop production.

The platform also monitors the parts on the line, records data and analyses performance in terms of productivity. Thanks to these advanced features, it is possible to implement production changes without having to empty the line, tracking and managing individual parts and adjusting all the machines from a single control point.

The adoption of integrated lines, especially of the flatbed type, ultimately represents a strategic choice for companies aiming to position themselves on the automotive market as cutting-edge players, achieving a competitive edge thanks to superior production performance and excellent quality levels.  

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Entirely free from size constraints

OMNIDRY, the final frontier in vertical drying oven design, provides the revolutionary capability for fully automatic management of piece height, while retaining all the outstanding characteristics of a standard Cefla vertical oven. It can carry out all three stages (flash off, drying and cooling), even for coatings that need longer drying times, while minimising the use of floor space. The number of trays can be varied from 16 to 168.

Flexibility and productivity

FLEXPRO (patented), is the revolutionary feature of the new vertical drying oven Omnidry, which allows you to manage the loading thickness completely automatically. It represents the perfect compromise between productivity and flexibility. Thanks to FLEXPRO, the system recognizes inbound objects, independently adjusting the load height. The oven handles the entire cycle without operator intervention and never stops the production. This innovative solution is perfect for robotic applications that allow the finishing of pieces with different sizes.

Cefla’s expertise enables us to take another major step forward: the new generation of
Omnidry vertical drying ovens provides automatic management of piece variation.

Flexible system layout

Belt or rack trays can be incorporated facilitating the handling of workpieces entering and exiting the oven: a roller conveyor combined with rack trays or a belt conveyor using motor-driven belt trays.

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