Revestimento em pó de duas camadas protege os geradores

Modernos geradores a diesel e gás garantem o abastecimento de energia em mar aberto, em estações de pesquisa antárticas ou em grandes eventos e muitas vezes possibilitam o abastecimento Conexão de residências e áreas industriais em regiões distantes. Para isso, o fabricante espanhol HIMOINSA fabrica seus geradores a gás, geradores a diesel e torres de luz para suportar muitos anos de uso sob as condições climáticas mais difíceis e até a mais alta categoria de corrosividade C5I-H.

Cerca de 60.000 geradores são produzidos em todo o mundo a cada ano. Dez subsidiárias e 130 parceiros de distribuição estão disponíveis para clientes HIMOINSA interessados e existentes em todo o mundo para suporte de vendas e atendimento ao cliente. O revestimento em pó equipamento da Nordson desempenha um papel fundamental em seu processo de fabricação.

As coberturas do silenciador são essenciais para garantir uma proteção durável para o interior sensível dos próprios geradores. Sua resistência é determinada e classificada por meio de testes de névoa salina. "Pulverizar as coberturas com água salgada simula as condições agressivas que muitos de nossos dispositivos têm que suportar por um longo período de tempo quando usados em um clima com alta umidade e alto teor de sal", explica Manuel Ingles, chefe global de compras.

"Para passar pelos requisitos estabelecidos na categoria de corrosividade mais alta C5I-H, por exemplo, um dossel silenciador deve suportar 1.440 horas de exposição extrema à névoa salina. Isso equivale a 15 anos de uso em tal ambiente. E para maximizar a resistência de nossas coberturas silenciadoras, focamos em dois aspectos: A qualidade do nosso aço e a qualidade dos nossos revestimentos."

With this goal in mind, HIMOINSA installed a new powder coating system from Nordson in 2018, initially in San Javier, Murcia, Spain. The highlight: After the metal canopies have been pretreated, they pass through two independent coating processes in succession. In the first coating process, a primer is applied using the conventional Venturi process before the finish is applied using Nordson dense phase technology.

“What may sound simple now was actually the biggest challenge of this project,” says Manuel Ingles. “Both coating processes had to be coordinated in such a way that at the end of an economically and ecologically sensible process, a durable and highly satisfying surface finish was available in the correct coating thickness – and repeatable an unlimited number of times,” he says, summarizing the goal of numerous calculations and tests from the initial phase of the system.

State-of-the-art ColorMax3 powder coating booths from Nordson are used for both coating applications in San Javier. As soon as the conveyor moves a workpiece into the primer booth, eight Encore® LT automatic powder guns start the coating process. Six of them are mounted vertically on a reciprocator, one each fixed at the top and bottom of the powder application zone. For the rare cases of rework, a ninth, manual powder gun is available.

In the second ColorMax® booth, powder application is performed by eleven Encore HD automatic powder guns using dense phase technology. Unique to Nordson, dense phase technology offers patented HDLV® pumps, which deliver a high concentration of powder to the spray gun with only a fraction of the air required by conventional, ejector-pump systems. This spray pattern air is added separately, straight to the spray gun. The separation of powder and air allows powder coaters to fine-tune the powder output for the required production rate and customize spray velocity and pattern size for the best application results. “Because the powder particles hit the surface of the workpiece relatively slowly, they practically do not bounce off.

This results in a high first pass application efficiency, even with complex surfaces,” explains Manuel Ingles, who also immediately names other advantages of the technology. “Of course, there is also less overspray. And because a smaller amount of air only has to be moved relatively slowly, this type of coating is also very energyefficient and environmentally friendly.”

“Basically, we coat in a single 8-hour shift operation,” explains Manuel Ingles “but the powder coating line operates 12 hours a day. Two hours after the end of the shift in the evening and two hours before the start of the shift in the morning, we coat parts so that they are ready for further processing right when we start working.” The coating department team at HIMOINSA is made up of five employees, one of whom works as a system operator. “The low need for manpower in operating the system is a big plus, because in Spain we also suffer a lot from the shortage of skilled workers.”

The line is designed for workpieces with a maximum height of 2,150 mm and a width of 900 mm. “If we run at a conveyor belt speed of 1.5 meters per minute, we coat around 220 square meters in an hour.” There are only short breaks when a color change is due. “The booth, guns and powder center together provide a very efficient color change system. When we change between our six main colors, it only takes about ten minutes for the system to go back in production. This functionality makes coating very flexible and even small batch sizes economical,” says Manuel Ingles with satisfaction.