Assembly in Action: Surface Treatment Ensures Adhesive Performance
August 20, 2007
Automotive supplier Hella Australia Pty Ltd. (Mentone, Australia), a subsidiary of Hella KGaA Hueck & Co (Lippstadt, Germany), manufactures plastic moldings and a range of light fixtures, including headlamps, reflectors, lenses, signal lamps and auxiliary lamps.
Automotive supplier Hella Australia Pty Ltd. (Mentone, Australia), a subsidiary of Hella KGaA Hueck & Co (Lippstadt, Germany), manufactures plastic moldings and a range of light fixtures, including headlamps, reflectors, lenses, signal lamps and auxiliary lamps. The Hella factory includes injection molding machines, polycarbonate lens molding machines and thermoset molding machines, as well as various types of painting, hot-foil stamping, aluminum-metallizing and lacquering equipment.
Recently, the company faced a challenging new assembly in the form of a headlamp for the Toyota Camry. The lamp includes a polypropylene housing with a glue track that is used to secure a polycarbonate lens with a silicone adhesive. Because today’s headlamps include features like washing systems and swiveling modules, as well as Halogen and BiXenon bulbs that burn hotter than bulbs in the past, manufacturers are increasingly using silicone to accommodate the more stressful workloads. Current styling trends also call for smaller lamps set to tighter tolerances between the headlamp and car body, a condition that puts additional stress on headlamp assemblies.
To ensure its adhesives perform reliably, Hella Australia Chief Engineer, Andrew Meads, and his team implemented a Dyne-A-Mite blown-arc air plasma surface treatment system from Enercon Industries Corp. (Menomonee Falls, WI), to prep the track areas with micro etchings prior to assembly.
To maximize flexibility and precision, Hella Australia engineers installed the system’s discharge head on a six-axis robot from Motoman Inc. (West Carrollton, OH). This robot follows the path of the glue track at the precise speed and air gap required to optimize treatment. The air plasma system’s electronic architecture also monitors power usage, voltage, current and frequency to ensure accurate power regulation. A controller employs high-speed programmable logic in conjunction with wide bandwidth analog circuitry to measure and control all parameters.
A few months after Hella installed its air plasma system, Enercon introduced a new blown-ion air plasma surface treatment system, called the Dyne-A-Mite IT. Although Hella was happy with the performance of its initial system, it quickly upgraded to the Dyne-A-Mite IT to take advantage of its shorter treatment dwell times.
“We have found that we can speed up the robot application of the plasma to the robot’s mechanical speed limits, yet the treatment level is still adequate,” Meads says. “This has dramatically reduced our cycle time.”
The company has since purchased yet another Dyne-A-Mite IT for use on a second headlamp assembly line.
For more on air plasma surface treatment, visit www.enerconind.com or call 262-255-6070.
For more on robotic assembly, call 937-847-6200 or visit www.motoman.com.