Smartvacuum: improving the basecoat application process

Verniciatura fondo pannelli piani

Applying a basecoat to a flat panel is usually performed using one of the following techniques: roller coating, spray coating or curtain coating. Each system has specific advantages depending on a number of factors. Introducing an innovative application technique using vacuum technology adds a new set of opportunities and benefits for manufacturers of cabinet doors, panels and bathroom furniture.

Any wood or wood-based flat panel can be coated using vacuum application technology, especially those with rounded edges.

Would you like to have more information?

A closer look at vacuum application technology

Easily used to process flat rounded doors, J-pull versions and panels with ABS edges, Smartvacuum applies 100% UV acrylic paint in a single pass without the application head coming into physical contact with the substrate. Between 100 and 140 g/sqm are deposited in an extremely clean, homogeneous manner avoiding any product build-up on any parts of the panel. The process is simple, clean, eco-friendly and cost-efficient.

Flash-off is performed after basecoat application and prior to the panel completing its drying in a UV-R oven.

Which benefits does Smartvacuum add to the coating process?

Using a 100% solid UV product, this makes it a relatively sustainable process and the coating is more stable over time compared to polyurethane or polyester-based products, also requiring a shorter drying time. One benefit which distinguishes the use of vacuum application techniques regards the matching between panel surface and edge.

Smartvacuum: the perfect partner for Smartedge

Smartvacuum and Smartedge use the same technique and the same lacquer. That makes it simple to achieve the best junction seam between the flat surface and the edge of the panel. Softer to the touch than what can be achieved using other techniques, the quality of the finish on panels with rounded edges is improved and fewer operations are required to obtain the perfect finish.

A complementary solution to other application techniques

Vacuum application boasts several advantages over other coating technologies, but there is no need to consider it an alternative. To appreciate the benefits, we need to consider the current techniques.

Roller coating lines

Roller coating lines include:

  • substrate sanding
  • application of basecoat for adhesion
  • three base coat applications with single and double coaters and intermediate gelling
  • final drying
  • base coat sanding followed by finishing

Curtain coating lines

Curtain coating lines include:

  • substrate sanding
  • basecoat application
  • UV gelling 
  • UV base coat application with curtain coater and special flash-off tunnel
  • drying
  • base coat sanding followed by finishing

Spray coating lines

Spray coating lines are a closed-circuit solution applying polyurethane or polyester-based basecoats in multiple steps on flat surfaces and edges. This is followed by lengthy drying times since the panels must be stabilised at suitable intervals in the warehouse before the sanding and finishing processes.

Smartvacuum and Smartedge for vacuum painting of flat panels

Vacuum application technology: benefits compared

Starting from the eco-friendliness of 100% UV acrylic paints, there are a host of benefits which will reduce consumables, costs, lead times, handling requirements and the need for space.

  • no need to round off corners after drying and before sanding
  • fewer machines required, so less cleaning and lower consumption
  • lower sanding costs and less waste
  • shorter lead times, production flexibility
  • smaller footprint, more space in the factory
  • fewer process stages resulting in fewer panel handling requirements
  • clean edge at machine inlet vs. curtain coating
Linea verniciatura con Smartvacuum

Implementing Smartvacuum, the coating line would look like this:

  • panel sanding
  • basecoat application and gelling
  • application of 100-140 g/sqm of 100% UV product in a single pass
  • flash-off for 5/6 minutes
  • UV oven drying
  • sanding or matt/glossy finish, if required, performed using another coating technique

 

The Smartvacuum technology, associated with the Smartedge range for edge finishing, makes the process simpler, faster, ecological and cost-efficient, eliminating many manual operations.

Frequently Asked Questions

Which substrate materials are suitable for vacuum coating?

Vacuum coating is suitable for wood and its derivatives, metal, plasterboard, composite materials and PVC profiles.

This technology is perfect for the coating of…?

This technology is ideal when coating lineal profiles in high volumes, achieving high levels of production efficiency.

What are the advantages of vacuum coating?

This technology has many benefits. To start with, transfer efficiency reaches an astonishing 99%. Vacuum coaters have a limited footprint, so they occupy little factory space. Production efficiency is optimised because by using a vacuum coater, 360° sanding, coating and curing of a profile is dealt with in a single pass. Overspray is absent and the process is environmentally friendly. Coating thicknesses are high and, for example, can reach 700 µm on glass wool panels.

How can I measure coating quality?

This is an aspect that can primarily be evaluated subjectively. However, where rigidity is a required characteristic of the coated object, this technology enables high coating layer thicknesses (e.g. 700 g/m2 in the case of ceiling tiles) by using paints with 80% solids, leading to further benefits in terms of reduced drying costs. Constant coating thickness is also a key quality achieved with vacuum coating techniques, even in the case of complex profiles.

What are the consumption factors I need to take into account in a vacuum coating process?

The factors will depend on whether you are using UV-curable coating or water-based coating. UV Vacuum Coaters apply between 25 and 75 µm (1 to 3 mills) of coating per pass, whereas WB Vacuum Coaters apply between 25 and 150 µm (1 to 6 mills) of coating per pass. You will also need to consider electrical energy consumption and compressed air consumption.

What are the size limitations for pieces that will be vacuum coated?

The minimum length is 915 mm (36”) and the maximum width is 305 mm (12”). Any size between these two limits is possible.

How long does it take to clean a vacuum machine?

Cleaning times vary according to the size of the machine and the type of paint being used. Water-based paints require less time than viscous UV lacquers. On average, when changing profiles, it will take between 10 and 15 minutes. If you are also required to change colour, this will take up to 30 minutes.

Can coating consumption be controlled?

Yes. By adjusting the template opening, vacuum pressure and speed of the coating line, you can control the coating thickness, thereby affecting coating consumption. Paint viscosity is temperature-controlled in the case of UV lacquers and according to the formulation of water-based paints. This also affects overall consumption.

What do I need apart from the vacuum coating machine to complete the process?

To make the process smoother, you can add infeed and outfeed conveyors. In any case, our solution is a fully integrated one comprising material preparation, application and drying. Edge-coating units are often installed in existing double-end tenoners for more precise workpiece guidance and consequent absence of overspray.

How flexible is the machine?

As vacuum coating is suited for large volumes of the same or similar type of profile, flexibility is not a key feature of machine or process. When the profile changes, the user simply has to change the template or painting head.

ceflaLab

We believe technological research and continuous innovation to be essential for the achievement of rewarding results. First and foremost, our goal is to be a consultant and partner.

discover more