Pretreatment tunnel with TORAN 3®: the tailor-made solution

Tailor-made system for pre-treatment with Toran 3 and
subsequent powder coating: Eurotherm technology for Omet

Over the years, printing labels automatically has become one of the crucial phases of industrial production.

Food, wine and beverage, pharmaceuticals: basically, no sector that has remained idle. Markets are
constantly expanding, places where products are stored have increased and diversified, design has pushed
on creativity: packaging and labels evolve, enriching themselves with chromatic and tactile effects
that stimulate the consumer’s emotions.

The new challenge for label printing machines

Label printing designers are facing a new challenge: inks and varnishes can be very corrosive and can damage the printing machines’ coatings, compromising their operation. Furthermore, some cleaning products are too aggressive and therefore not suitable.

Omet’s Project Manager himself explains “UV inks can be removed more easily than water or solvent-based ones, which are more aggressive and can leave behind streaks. If the paint coating is not fully bonded to the surface, solvents and ethyl acetate can remove it. It is therefore vital to use a finishing coat which is resistant to cleaning products and inks.”

If you’re a company with a business unit fully dedicated to label printing presses, you need to take action.
That’s what Omet did by turning to the Eurotherm team.

Toran 3 pre-treatment and powder coating: Eurotherm’s solution for Omet

Omet, the historical company from Lecco, Italy – founded back in 1963 – turned to Eurotherm’s technicians to
devise a combination of pre-treatment and coating that would ensure the coatings on its machines would
resist to extra-ordinary chemical aggression.

Step 1: pre-treatment with TORAN 3®

The choice for pre-treatment fell on Toran 3, a single-stage solution from Chemtec of Lombardy, Italy.

Polymers and special additives are dissolved in a mixture of organic fluids that works at cold temperature: once dried, the mixture leaves on the product’s surface a very thin polymeric film (about 1 micron), that is capable – in addition to protecting from oxidation – of incorporating the oily contaminants, which do not become waste. This minimizes the environmental impact, as well as the cost of disposal of sludge and wastewater.
Such a technology enables fast, safe and efficient pretreatment and is a more economically viable alternative to phosphodegreasing or phosphating followed by passivation.

Step 2: Powder coating

Omet subsequently chose to switch from liquid to powder coating. The need is not only to improve the coatings’ performance: the goal is also aesthetic. With powder coating, in fact, it is possible to create more attractive surfaces, such as pitted surfaces.

Conceptually, the move is logical. Those who work in packaging, and therefore buy label printing presses, also expect them to have a visual value, capable of matching the new production environments: increasingly clean, bright, safe and functional.

Tailor-made tunnel for pre-treatment with TORAN 3® and subsequent powder coating

Eurotherm engineers have custom-built the pretreatment tunnel, which performs the following steps:

• The parts are manually introduced into the automatic Toran 3 pre-treatment tunnel, which is sprayed.
• The sprayed parts undergo the dripping and blowing phase.
• A passage through the oven dries the parts and starts the polymerization of Toran 3. At this stage, the temperature can be adjusted based on the color and mass of the pieces to be treated.

The mixture is capable of self-cleaning, requiring no further dissolution in water and therefore no washing of the pretreatment tunnel. The positive impact on the operators’ health and safety is important.

The powder coating system follows

As already mentioned, Omet needed to be able to configure new aesthetic parameters for the machinery it produced. Being painted in a limited palette (ranges of grays and whites), the visual impact of the painted metal parts contrasted with that of the third party components.

To allow the customer to color match the parts, Eurotherm’s engineers relied on the concept of flexibility, designing a solution that would allow Omet to paint parts of any size and in varying quantities: the modular system’s gantries, which can support up to 2 tons of weight, support already assembled structures as well as large and small carters.

Finally, the possibility to connect the pre-treatment and painting system to the management software used by Omet in a perspective of Industry 4.0, reaffirmed how Eurotherm was the right partner for this technological transition.

Omet technicians can thus monitor every production datum: the piece, identified by code and drawing, is identified in the position it has reached throughout the process and at what point of the treatment it is.

The system was installed at Omet’s headquarters in late 2020, and kicked off in early 2021.