Powder Coating for Retail and HORECA

The sustainable path is evolution, change and adaptation”. With these words Exkal explains its global brand, a company based in Marcilla (Navarra, Spain) founded in 2005 with the goal of becoming the technology leader in the field of industrial refrigeration (Ref. opening photo).

Faithful to this concept, the company is moving rapidly towards the Industry 4.0, simplifying, balancing, synchronising and minimising anything that does not add value to the product. Exkal is evolving its production processes, from the working of sheet metal to painting and all the way to logistics, towards flexibility, quality and the reduction of delivery times, gradually increasing automation and interconnecting processes through the “Internet of Things” in order to convert the collected data into information that is useful for continuous improvement.

“In the 2014-2016 management plan the company planned investments of about 8 million euros both in facilities and personnel to triple production, reaching a total of 60,000 refrigeration appliances per year”, explains Miguel Fernández, production engineer at Exkal.

A major portion of this investment was for painting because it was a bottleneck for us: the first line, with a monorail conveyor and a single spray booth, was fully maximised with three shifts and had no room for an increase in productivity. At the end of 2014 Exkal approved an investment in a coating line that was on the cutting edge for pre-treatment, paint application and handling of parts with the aim of increasing production capacity and quality while reducing costs”.

The consortium of companies that designed and supplied systems and equipment according to Exkal specifications included Geinsa (Fig. 1) for the painting system,

Futura Convogliatori Aerei for the conveyor and the design of the line’s logistics, Proquimia for the process chemistry, while Nordson was the brand of the systems and application equipment that offered the product characteristics and service best aligned with Exkal’s needs with regard to application, efficiency and quality of the coating.

“At Exkal we paint using a lean system, order by order. This means that when we start working on an order for a new supermarket, for example, the furniture is painted in various stages, even months apart”, explains Fernández. “So for us repeatability, uniformity and reliability over time are critical. The Nordson technology with Encore HD guns and HDLV pumps guarantee such a result”

The layout of the new Exkal coating line is extremely flexible. The starting point for the project were three work shifts and 40 colour changes per day. The goals were to double production reducing downtime during colour change, improve quality and have a robust control over the process. The current line has made it possible for the company to reach a downtime equal to zero during colour change, reducing shifts to one and a half.

ColorMax 3 booths in parallel and the strategic positioning of overflow areas before and after the booths it is possible to either paint two colours at the same time or use one booth for painting while changing colour in the other. Any colour can be painted at any time with total flexibility.

Thanks to the HDLV powder coating pumps that use dense phase powder technology, which allows for a better control of coating and automatically performs many stages of system cleaning, the time to change colours has been reduced to four minutes.

“The HDLV pumps provide great application accuracy, perfect adjustment of the thickness, increased layer uniformity, greater penetration and, above all, increased process repeatability. In a few months, by using the same application parameters, you can get the same painting result”, begins Sebastián González de Zárate, Area manager of industrial coating systems at Nordson Ibérica.

“This is because dense phase technology does not use Venturi but rather HDLV pumps that require only a small amount of compressed air to convey the powder at low speed. This allows greater application accuracy and total control of the process. Furthermore, it also helps to decrease colour change times because all the cleaning of the circuits, the fluidised hopper and the system is automatic”