Decades ago, stainless steel was considered a high-end option for food packaging equipment. But in recent years, sanitary washdown requirements in the global food processing and packaging industry have tightened. As a result, industry associations have established standards and directives to help manufacturers and their machine builders adhere to these tougher requirements.

For example, one of the American Meat Institute’s “10 Principles of Sanitary Design” requires machine builders to design equipment with “compatible materials,” meaning those that will stand up over time to high-pressure washdown cycles.

There is no question that stainless steel is the best material for withstanding caustic chemicals and high water pressure, making it a crucial element to food packaging machinery. Machine builders that incorporate stainless steel into machine designs will be able to better serve manufacturers that regard food safety and sanitary design with paramount importance.

Figure 1. FR Drake is the worldwide leader for automatic food-loading machinery in the frankfurter industry.

The challenge
With 90 percent of the worldwide market share, FR Drake is a clear leader for 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. Manufacturers look to FR Drake to help automate manual, hand-loading packaging processes with equipment that can help boost production reliability and integrity.

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 would catch and collect on seams and rivets surrounding the housing. Also, washdown fluids would eventually work their way into the housing and make contact with the motor. Finally, the caustic chemicals would damage the point where cables connect to the motors, and potentially corrode the housing itself.

Even with a stainless-steel housing, standard servo motors typically last only five to seven years in a rigorous washdown application. Because each FR Drake frankfurter loader uses four servo motors, end-users of the machinery could potentially find themselves replacing a motor 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 for 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 life cycle of the machinery.

Figure 2. Pictured here, stainless-steel servo motors help improve machine cleanliness and performance.

Solutions
FR Drake turned to its longtime automation solutions provider, Rockwell Automation, for a new option. A few years ago, FR Drake engineers attended the Automation Fair event hosted by Rockwell Automation to discuss the problem their food-manufacturing customers faced and the type of motor solution they were seeking. Based on input from FR Drake and other machine builders, Rockwell Automation brought the Allen-Bradley MP-Series stainless-steel servo motor to market to help manufacturers in the food industry improve hygienic machine design.

The motors feature a smooth, round design that is ideal for 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. Additionally, the motors have factory-sealed cable exits that help maximize product reliability.

Just like standard servo motors from Rockwell Automation, the MP-Series stainless-steel motors are part of the company’s Allen-Bradley Kinetix Integrated Motion portfolio. As the motion control component of the Rockwell Automation Integrated Architecture system, Kinetix features the seamless integration of Logix controllers, servo drives, servo motors and actuators.

“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 the 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.”

FR Drake’s machinery architecture also includes an Allen-Bradley ControlLogix programmable automation controller (PAC), an Allen-Bradley industrial computer, and FactoryTalk View Machine Edition human-machine interface software that all work together to provide improved machine performance information.

Helping to round out the integrity of the machine – particularly for international markets where CE-certified equipment is mandated by law – FR Drake incorporated advanced safety controls from Rockwell Automation. Engineers implemented Allen-Bradley SensaGuard Safety Sensors and Allen-Bradley Guardmaster safety relays to help operators more safely access areas of the machine where there is motion.

The results
The MP-Series stainless-steel motors allowed FR Drake to eliminate the design time and costs required for building the extra protective housing unit.

Subsequently, the improved reliability of FR Drake’s loading equipment has reduced the number of warranty requests the company receives, and has reduced the amount of motor maintenance the company must provide for customers. In fact, 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.

Finally, because of the CE certification of Rockwell Automation safety controls, and because manufacturers around the world have a high level of familiarity with the Logix Control Platform and Integrated Architecture system, FR Drake can continue building business in international markets, which comprise 75 percent of the company’s business.

The results mentioned above are specific to FR Drake’s use of Rockwell Automation products and services in conjunction with other products. Specific results may vary for other customers.

For more information on these products, visit www.ra.rockwell.com.