After pretreatment, the parts enter the 5,000 gallon electrocoat tank, passing through a “dead zone” at the entrance, followed by two minutes in front of tubular anodes to achieve a 0.8 mil coating.
Brunner International is a family-owned manufacturer of OEM and aftermarket heavy-duty truck components. Originally founded in 1981 in Niagara Falls, Ontario, Canada, the TS-certified Brunner opened its Medina, NY, facility in 1992. But strict coating performance specifications from its OEM customers, including a 500-1,000 hour salt spray test, eventually threatened to put the brakes on Brunner’s expansion of its truck brake product line. Within 10 years of opening the New York facility, Brunner was faced with the decision of building a new system to accommodate customer demand or outsourcing. The decision was not an easy one to make, especially because only the OEM portion of the brake shoe market required the higher-performance coating. Could Brunner justify the cost of installing a new system?
To answer the question, Brunner assembled a team of its preferred suppliers to help gather critical information and analyze the possibilities. In the end, Brunner installed a cathodic electrocoat system that took the plant from a simple but messy liquid dip system with an air-dry paint, to a state-of-the-art electrocoat finish. The transformation, completed in 2004, now plays a key role in positioning Brunner as an industry leader.
The Cost Factor
Brunner competes in an extremely price-sensitive market and knew that amortizing a new coating system would not be easy. To make the decision whether to invest in a new system, Brunner conducted a detailed cost evaluation that compared the in-house operating costs of powder and electrocoat with the cost of outsourcing.Patriot Metal Finishing Systems, Inc. provided paint material costs and agreed to consign the paint if electrocoat was selected. Nalco, the chemical supplier, provided estimates of the washer chemicals and water use. Nalco also calculated waste disposal costs based on the expected tank dump schedule. Herr Industrial, Inc., the turnkey systems house, provided cost estimates of energy use, equipment maintenance and spare parts, as well as the capital and installation costs. The systems house also agreed to guarantee the energy estimates as a condition of the contract. Brunner completed the analysis with a cost estimate of direct and indirect labor and verified that the regulatory agencies were comfortable enough with the system concepts to assure no unexpected compliance costs would arise down the road. Brunner’s use of black as its sole color kept equipment costs down by eliminating the need to change colors.
Brunner’s cost analysis indicated that electrocoat provided a lower operating cost compared to in-house powder coating, as well as outsourced powder or electrocoat. Electrocoat also provided an acceptable ROI timeframe and met Brunner’s goal of becoming an industry leader. With the new system, Brunner would be able to provide customers with a high quality, durable, coating at a competitive cost while remaining an environmentally friendly neighbor.
The electrocoat system is located on an elevated mezzanine to conserve floor space.
A Turnkey Solution
To take advantage of electrocoat’s ability to evenly coat complex surfaces, Brunner worked with Herr Industrial to develop a series of prototype part fixtures that maximized part density in order to minimize the work opening and line speed and, in turn, the equipment size and cost. The rack was then sent to the paint supplier to evaluate coating efficiency and approve the design. The final ware package measured 2 x 2 x 3 ft high, and the fixture was designed to rotate to expose all surfaces to direct spray impingement in the washer and post rinses.The painting process begins with loading multiple brake shoes on a rack suspended from an overhead “I” beam conveyor. Moving continuously at 6 feet per minute (fpm), the parts first go through an all-stainless-steel five-stage spray washer before exiting the washer through a virgin reverse osmosis (RO) halo. After pretreatment, the parts enter the 5,000 gallon electrocoat tank, passing through a “dead zone” at the entrance, followed by two minutes in front of the anodes to achieve a 0.8 mil coating. A three-stage, stainless spray post-rinse removes the excess coating after the parts leave the tank. The ancillary equipment includes the rectifier, tubular anodes, anolyte system, ultrafiltration, bag filter and chiller.
To cure the parts, a gas-fired convection oven is used at 375°F for 35 minutes. Although the oven is a single zone, the supply ductwork is adjusted to provide the desired temperature gradient to promote dehydration prior to crosslinking. Both the oven exhaust and cooling tunnel following the cure oven were designed to address the smoke commonly encountered from the curing process. After exiting the cooling tunnel, the parts travel to an unload area. The entire system is PLC controlled and was subsequently expanded after installation to include additional process data collection for quality control and troubleshooting.
Construction of the new paint system was restricted to the existing, overcrowded building. Management insisted “no bricks and mortar.” By installing the electrocoat system on an elevated mezzanine, the systems house was able to conserve floor space and ensure the same product flow through the plant. The old system ran unimpeded during construction. The mezzanine design was unique in that it incorporated spill containment at the mezzanine level for the safety of personnel working below. The electrocoat tank is also embedded into the mezzanine floor for part clearance over the tank wall. The elevated location of the tank, ancillary equipment and piping also had a secondary benefit by enabling convenient gravity draining to storage tanks on the first floor.
Multiple brake shoes are loaded on a rack suspended from an overhead “I” beam conveyor.
The Payoff
Startup of the system was not without the usual problems inherent with changing from a simple to a more complex coating technology. Fine-tuning adjustments were required, such as changing the anode spacing to eliminate an intermittent pinhole issue. Along with the usual adjustments, a unique issue also arose. The plant’s close location to Lake Ontario’s eastern shore makes it prone to very cold winter conditions and resulted in a low water temperature from the city supply. In addition, the initial production rate was lower than the design capacity, which meant that the heat imparted to the paint bath from the rectifier did not keep the tank in the desired 90°F temperature range. To maintain the temperature, a heating system was required (in addition to the typical cooling system), and an electric hot water tank was installed and connected to the heat exchanger. An automatic mixing valve directs chilled or hot water through the exchanger, depending upon the bath requirements.According to John Brownrigg, the maintenance supervisor at the time the system was installed and now working in the engineering department, the system has been operating well and problems with reject parts are very low.
“I rarely have to even visit the system more than one time a month,” said Brownrigg.
As the saying goes, “It pays to do your homework.”
For more information about turnkey finishing systems, call 800.700-HERR or 717.569.6619, e-mail sales@herrindustrial.com or visit www.herrindustrial.com.
