Non-electric corrosion protection technology
replaces e-coating: Uniform interior and exterior coating

Modern chemical autodeposition processes have evolved into a powerful alternative to cathodic dip coating (e-coating). Especially in cases where uniform coating of interior surfaces and edges is required, or where powder topcoating is used, they can deliver significantly better corrosion protection results. In Germany, companies like Räckers and BBL have therefore opted for the non-electric Aquence technology from Henkel, a sustainable coating process that additionally does completely without hazardous heavy metals.

When planning a new coating line, the first important step is to determine the requirements. To enter new fields of application, the Räckers company decided in late 2008 to expand its production facilities by adding a high-quality corrosion protection coating line. The comprehensive scope of this systems supplier of commercial vehicle technology covered a variety of methods for producing vehicle superstructures, including metal processing, CNC cutting, and the use of modern foaming and adhesive technologies. While initially considering installing a classic e-coating line with metal pre-treatment, Räckers finally decided on Henkel's chemical autodeposition process Aquence in combination with a downstream powder coating stage.

Perfect performance on all corners and edges
"This process for coating ferrous metals is purely chemical and offers a number of decisive advantages over classic e-coating. Foremost among these is the absolutely uniform one-hundred percent coating of components or assemblies, which simply cannot be achieved with electrodeposition," explains Claus Räckers, CEO of Räckers. Even poorly accessible areas, cavities or sharp corners and edges can be provided with a continuous layer of corrosion-protection. With Aquence, there are none of the restrictions associated with the Faraday effect. "As a component manufacturer for commercial vehicles, full corrosion protection on all exterior and interior surfaces is a crucial performance feature for us and our customers," says Mr. Räckers, explaining why the decision went in favor of the Aquence autodeposition process. At Räckers, it is used to provide long-term corrosion protection on complex tubular and pre-assembled components with intricate geometries and lengths of up to eight meters.

Chemical instead of electrical action
The Aquence process also differs from classic e-coating in that it requires no metal pre-treatment and no electricity to form the coating. Through a chemical reaction in a bath of polymer emulsion, an organic layer is formed on the degreased metal surface. A mild acid releases divalent iron ions which then combine with the paint particles in the solution and re-bond with the surface of the substrate so that each ferrous area of the component is uniformly coated in the desired thickness, while leaving plastic parts uncoated. This makes it possible not only to coat complex structures evenly inside and out, but also to process complete assemblies consisting of different materials.

The production line at Räckers uses the non-electric Aquence coating process to protect metal parts durably against corrosion.

Uniform coating of complex parts with cavities is a major performance feature of the Aquence process.

The immersion coating line has now been in operation at the Räckers production site in Ahaus, Germany, for more than a year, and its performance in terms of corrosion protection and toughness has completely convinced Mr. Räckers. "In our lab tests, the process easily achieved 1000 hours in the neutral salt spray test." Scanning electron microscopy images show a uniform, dense wet film before curing, and consistent coating thickness even on sharp-edged geometries.

Seven steps to optimal results
The robust and simple coating concept comprises just seven baths. After a four-stage cleaning and rinsing sequence, chemical deposition takes place in the Aquence bath directly on the degreased substrates. The two-stage post-rinse removes any chemical residues from the parts. "Compared to the e-coat process, the investment costs are about 20 percent lower. At the same time, the line has a smaller shopfloor footprint, partly because the usual phosphating or chromating steps are not required and also because the oven size can be much smaller than for e-coating," says Eric Ardourel, Technology Manager Europe at Henkel. The environmentally responsible process is therefore free of any toxic heavy metals such as zinc or nickel and also generates practically no volatile organic compounds (VOC) or hazardous sludge, all of which significantly reduces waste generation and disposal costs.

Co-cure process
Another positive effect on the overall process costs is the fact that it consumes less energy. Besides needing no electricity to produce the reaction in the coating bath, energy savings are also achieved due to the lower bake temperature in the subsequent 2-zone ovens. "Unlike e-coating, which needs a cure temperature of about 190 degrees centigrade due to the high VOC content, the coated components are first dried at just 60 degrees centigrade, then briefly pre-baked at 140 degrees centigrade. This naturally also shortens the time it takes the parts to cool down before the topcoat is applied," says Eric Ardourel, pointing out another special feature of the Aquence process.

(Left): Co-cure: After application, the powder coating and the primer cure together in the same oven. (Right): The first co-cure Aquence line in Germany went into operation at BBL Oberflächentechnik in 2007.

About 95 percent of all parts at Räckers are powder coated. Crosslinking of the Aquence primer and the powder coating is performed in the same oven, also at a reduced temperature of some 170 degrees centigrade. "In addition to improved energy efficiency, our tests have shown that thanks to the co-cure process, the inter-coat adhesion is enhanced, thus improving mechanical performance," says Eric Ardourel, explaining the advantages of being able to cure both coatings in one step. Furthermore, superior performance is achieved when bonding with structural adhesives as well.

Sustainable and economical coating strategy
Technical progress and further development are also a firm feature in the corporate strategy of the BBL Oberflächentechnik group. The company, located in Roth south of Nürnberg, Germany, specializes in job-coating and surface treatment for various clients. Aside from various blasting operations, such as shotblasting, carbon dioxide blasting and sandblasting, their product portfolio comprises a wide variety of coating solutions for part weights up to 20 tons. The first Aquence co-cure line in Germany went into operation here in 2007. To complement their existing production lines, the company was looking at that time for a high-quality, environmentally benign corrosion-protection method with zero hazardous heavy metals that would also overcome the shortcomings of e-coating, primarily regarding its limited cavity coating capability. Today, steel parts weighing as much as 500 kg are coated at BBL using Aquence. Besides delivering better results, Aquence impressed this user with its sustainability and performance.

"Thanks to continuous bath maintenance, the system produces no wastewater at all," reports CEO Robert Lumpi. The dip tank can accommodate parts with a size of up to 3,000 x 1,600 x 800 millimeters. Moreover, the low VOC content eliminates the need for post-combusting emissions, and the fact that complete assemblies can be coated provides logistical benefits by reducing the number of transports and simplifying warehousing. A high degree of automated chemical dosage reduces the need for manual maintenance and control. The compact yet very flexible line design allows the use of Aquence as a co-cure primer in combination with various powder coatings and as a highly resistant stand-alone single-layer coating with outstanding mechanical properties "For us, Aquence is therefore a clear winner in terms of environmental protection as well.

(Left): Parts coming out of the Aquence bath at BBL Oberflächentechnik. (Right): All-over protection for parts thanks to the Aquence autodeposition process from Henkel.

Henkel Corporation received a 2010 Automotive News PACE Award for its new Aquence Co-Cure coating process. The Automotive News PACE Award is a prestigious US award recognizing automotive suppliers for superior innovation, technological advancement and business performance.

Henkel operates worldwide with leading brands and technologies in three business areas: Laundry & Home Care, Cosmetics/Toiletries and Adhesive Technologies. Founded in 1876, Henkel holds globally leading market positions both in the consumer and industrial businesses with well-known brands such as Persil, Schwarzkopf and Loctite. Henkel employs about 48,000 people and reported sales of 15,092 million euros and adjusted operating profit of 1,862 million euros in fiscal 2010. Henkel's preferred shares are listed in the German stock index DAX and the company ranks among the Fortune Global 500.

For further information, e-mail: evelyn.necker@henkel.com or view website: www.henkel.com   Refer to page 18

Westermo industrial mobile broadband router provides
resilient high-speed access to remote systems and devices

By providing resilient and secure access to remotely located Ethernet and RS-232 systems and devices it is possible to eliminate the need for time consuming site visits required to take manual readings, diagnose problems or recalibrate instruments. To help support this need Westermo has released a new industrial mobile broadband router that provides secure access to your assets and helps to lower operational costs associated with the cost of travel and time spent away from the main site.

The newly launched Westermo MRD-350 is a robust industrial mobile broadband router designed for remote access across a cellular network and uses the Internet to cost effectively inter-connect systems, allowing HMIs, PLCs, and other devices to communicate with each other. The router has an uplink capacity of up to 5.7 Mbit/s and downlink of 14.4 Mbit/s, making it suitable for high data rate transmissions. Typical mobile or static applications include video surveillance, SCADA/DNP3 telemetry systems and remote access to machines and devices. For solar powered applications energy efficiency is vital and the MRD-350 has a special low-power mode to only be fully powered when needed.

The newly launched Westermo MRD-350 is a robust industrial mobile broadband router.

The MRD-350 supports a wide variety of wireless standards including GSM, GPRS, 3G UMTS, HSDPA, and HSUPA. The MRD-350 features dual SIM card support, which ensures that site connectivity is not dependent on a single carrier. Should a carrier network failure take place the unit automatically switches to the alternative SIM card. When applied to on board applications (train, truck, buses, off road vehicles, etc.) the routers will automatically use the most efficient network available according to the geographical area.

A rugged enclosure, operating voltage range from 10 VDC to 60 VDC and compact design with all interfaces and LEDs positioned at the front makes the unit extremely well suited for industrial DIN-rail applications in harsh environments. With isolation between the PSU and the Ethernet and serial ports, protection is provided against issues caused by ground loops.

Devices connected to the Internet require counter measures towards cyber threats. The MRD-350 offers protection from malicious eavesdroppers via encrypted communication tunnels - Virtual Private Networks (VPN). The device also features a simple, yet powerful, packet inspection firewall. Using the on-board web interface it is easy to set up a VPN tunnel running between sites even over insecure networks such as the Internet.

To extend the life of legacy equipment there are a number of tools included that will ensure connectivity with PLCs and other RS-232-based devices. A built-in two port 10/100 Ethernet switch and RS-232 port allow a broad range of devices, machines and systems to seamlessly connect over any distance. The RS-232 port provides a simple modem replacement solution with the benefit of not having to reprogram or change any other component.

Westermo in profile
Westermo provides a full range of industrial data communications solutions for demanding applications in the transport, water and energy markets among others. For more than 35 years Westermo has been at the forefront of technological development and often pushed the limits of what is technically possible. In order to provide the best possible support, we have local presence in more than 35 countries through our authorized distributors and own offices. Since 2008 Westermo has been part of the Beijer Electronics Group, a fast growing technology company with extensive experience of industrial automation, developing and marketing competitive products.

For further information, e-mail: magnus.jansson@westermo.se or view website: www.westermo.com  Refer to page 104