Food Engineering

A simpler solution for a clean machine design

November 8, 2010
This frankfurter machine maker switched to totally enclosed SS motors rather than using open motors that had to be protected from washdown environments.


(Left): FR Drake makes automatic food-loading machinery for the frankfurter industry. (Right): Stainless steel servo motors help improve machine cleanliness and performance. Source: Rockwell Automation.
FR Drake is a manufacturer of automatic food-loading machinery in the frankfurter industry. The Waynesboro, VA company builds loading equipment that prepares individual frankfurters for packaging by lining them up in rows just before they enter a horizontal form-fill-and-seal (HFFS) machine.

FR Drake engineers have always been proactive about meeting their customers’ needs, including the need for sanitary machines that can tolerate rigorous and frequent machine washdowns. Since standard servo motors cannot withstand high-pressure, caustic washdown processes, FR Drake engineers historically addressed the situation by building stainless steel covers in an effort to protect the motors.

Unfortunately, food particles often caught and collected on seams and rivets surrounding the housing. Also, washdown fluids eventually worked their way into the housing and made contact with the motor. Finally, the caustic chemicals damaged the point where cables connected to the motors, and potentially corroded the housing itself.

Even with stainless steel housing, standard servo motors typically last only five to seven years in a rigorous washdown application. Because each frankfurter loader uses four servo motors, end users of the machinery could potentially find themselves replacing a motor about once every two years.

“The stainless steel covers we were building helped increase the longevity of the servo motors, but not to the extent that we wanted for our customers,” said George Reed, vice president of engineering, FR Drake. “We identified a few characteristics of the motor housing that, if remedied, could further improve the reliability of our machinery.”

Since a typical FR Drake frankfurter loading machine is in the field for many years, Reed and his team decided to find a motor solution that could withstand the lifecycle of the machinery. The machine builder turned to its longtime automation solutions provider, Rockwell Automation, for a new option. Rockwell Automation suggested the Allen-Bradley MP-Series stainless steel servo motor to help improve hygienic machine design.

The motors feature a smooth, round design suited to cleaning because it provides a surface area where meat and liquids cannot easily collect. The motor is comprised of 300-grade stainless steel, which goes through special processing after component fabrication to remove impurities and promote greater corrosion protection. The motors also have factory-sealed cable exits.

“Updating our machinery with the MP-Series stainless steel motor was a very simple and straightforward retrofit,” said Reed. “Since we already were standardized on [Rockwell’s] Integrated Architecture system, and because these motors come in the same form factor, torque and programming language as other Allen-Bradley servo motors, it was a virtual drop-in replacement for the motors we were using.”

The MP-Series stainless steel motors allowed the machine builder to eliminate the design time and costs required for building the extra protective housing unit. Subsequently, the improved reliability of the manufacturer’s loading equipment has reduced the number of warranty requests the company receives, as well as the amount of motor maintenance the company must provide for customers. For example, in the first two years of using the MP-Series stainless steel motors, FR Drake personnel have not been called for a single field service issue, and the company is currently working toward making the motors standard on all of its loader machinery.

For more information, Tanja Bartulovic, 440-646-4117, Rockwell Automation.