The cured group of the coating of autodeposición and the painting in dust

Thus, in Germany, companies like Räckers and BBL have opted by the technology of autodeposición chemical (no electrical) Aquence of Henkel, a process of sustainable coating that, besides, prescinde totally of the use of dangerous heavy metals.

When projecting a new line of coating, the first important step is to determine the requirements. To go in in new sectors of application, to finals of 2008 the company Räckers decided to expand his installations of production adding a line of protective coating against the corrosion of high quality. This provider of technological systems for the commercial vehicles had a wide range of methods to produce superstructures of vehicles, included the processing of the metal, cut CNC, and the use of modern technologies of espumación and adhesion. Although initially it thought in installing a traditional line of cataforesis with pretratamiento of metal, Räckers finally decided by the process of autodeposición chemical Aquence of Henkel in combination with a back application of painting in dust.

“This process of coating of ferrous metals is totally chemical and offers a series of advantages determinantes with regard to the cataforesis traditional. The most stood out is the absolutely uniform coating and total of components or assemblings that simply can not achieve with the electrodeposición”, explains Claus Räckers, general director of Räckers. Even the less accessible areas, cavities or corners and edges very sharp, can treat with a continuous layer of protection against the corrosion. With Aquence does not give any of the restrictions associated to the effect Faraday. “Like manufacturer of components for commercial vehicles, the complete protection against the corrosion in all the external and inner surfaces is a characteristic of key performance for us and for our customers”, says Claus Räckers when explaining the reasons that carried them to decide by the process of autodeposición Aquence. In Räckers uses to provide a protection on a long-term basis against the corrosion in tubular components complexes and components premontados with geometries complicated and lengths until 8 metres.

The process Aquence also differentiates of the cataforesis traditional because it does not require any pretratamiento of metal and prescinde of the electricity to form the coating. Through a chemical reaction in a bathroom of emulsion of polymers, forms an organic layer on the surface of metal degreased. A feeble acid frees ions of ironinging divalente that combine with the particles of painting of the solution and go back to join to the surface of the sustrato so that all the ferrous surface of the component remains uniformly recubierta with the thickness wished, leaving the parts of plastic without recubrir. This no only allows recubrir complex structures of uniform form inside and out, but also process complete assemblings formed by distinct materials.

The line of coating by immersion carries more than a year in operation in the plant of production of Räckers in Ahaus, Germany, and his performance in terms of protection against the corrosion and resistance has convinced completely to the Räckers. “In our proofs of laboratory, the process easily reached the 1.000 hours in the proof of fog neutral saltworks”. The images of the electronic microscope of scanning show a uniform film, dense and humid before the cured, and a thickness of consistent coating even on geometries with sharp edges.

This solid and simple concept of coating comprises only seven bathrooms. After a sequence of cleaning and wash of four phases, the chemical deposition takes place in the bathroom Aquence directly on the substrata degreased. The two-phase successive wash deletes any chemical residue that have been able to remain in the pieces. “In comparison with the process of cataforesis, the costs of the investment are 20% inferior. Besides, the line occupies a lower space on the plant, partly because they are not necessary the steps of fosfatado or cromado and also because the size of the oven can be much smaller that in the case of the cataforesis", it says Eric Ardourel, European director of the Technology Aquence in Henkel. Like this then , this process medioambientalmente responsible is free of toxic heavy metals like the zinc or the nickel and practically does not generate compound organic volatile (COV) or dangerous slime, which reduces significantly the generation of waste and the costs of elimination of the same.

Another positive effect of the general costs of the process is the fact that it consumes less power. Apart from not needing electricity to produce the reaction in the bathroom of coating, also saves power because the temperature of cured is lower in the ovens of 2 contiguous zones. “Unlike the cataforesis, that needs a temperature of cured of some 190 °C because of the high content of COV, the components recubiertos first dry to 60 °C and afterwards does a brief prepolimerización to 140 °C. Of course, this also reduces the necessary time so that the pieces cool before applying the layer of final painting, ” says Eric Ardourel, signalling another special characteristic of the process Aquence.

Around 95% of all the pieces of Räckers receive a layer of painting in dust. The reticulación of the layer of imprimación Aquence and the painting in dust realises in the same oven, also to a temperature of some 170 °C. “In addition to improving the energetic efficiency, our essays have revealed that thanks to the process of cured group improves the adhesion between the layers, improving the mechanical performance, ” says Eric Ardourel, when explaining the advantages to be able to cure both coatings in a same step. Besides, it achieves an excellent performance also in the union with adhesive structural.

Strategy of sustainable and economic coating

The technical progress and the continuous development are also characteristic important of the corporate strategy of the group BBL Oberflächentechnik. The company, situated in Roth, south of Núremberg, Germany, is specialised in the coating by commission and the treatment of surfaces for distinct customers. Apart from distinct operations of pretratamiento, like the granallado, the decapado with carbon dioxide and the cleaning with chorro of sand, his range of services comprises a wide variety of solutions of coating for pieces until 20 tonnes. The first line of cured conjoint Aquence of Germany went in in operation here in 2007. To complement his lines of existent production, in this period the company was looking for a method of protection against the corrosion of high quality, respectful with the environingingment, that did not have dangerous heavy metals and that it could surpass the lacks of the cataforesis, mainly in attention to his capacity limited of coating of the cavities. Nowadays, in BBL recubren pieces of steel until 500 kilos with Aquence. Apart from offering better results, Aquence impressesed to this user by his sustainability and performance.

“Thanks to the continuous maintenance of the bathroom, the system does not produce waste water, ” indicates the General Director Robert Lumpi. The tank of immersion can house pieces of a size until 3.000 x 1.600 x 800 mm. Besides, the low content of COV deletes the need of postcombustión of the broadcasts, and the fact to be able to recubrir complete assemblings provides profits in terms of logistics put that reduces the number of transports and simplifies the storage. A high degree automation of the dosage of chemical product reduces the need of maintenance and manual control. It is a compact line and to his flexible time, which allows to use Aquence like layer of imprimación of cured group combined with distinct paintings in dust and like only coating of an alone layer and of big resistance with some extraordinary mechanical properties. “For us, Aquence is a clear winner in terms also of environingingmental protection”.

In 2010 Henkel Corporation received the prize Automotive News PACE Award by his new process of coating Aquence Co-Cure. The prize Automotive News PACE Award is a prestigious galardón awarded in the EE UU that recognises the innovation, the technological progress and the business performance of the car providers.