Motion Control Resources
B&H Labeling Systems Speeds Changeovers with SMARTdrive™ Technology
Siemens Industry, Inc. Posted 08/28/2006
Siemens Automation Components Critical to New Design
Dr. Beverly Politzer, product manager at B&H Labeling Systems, Ceres, Calif., says downtime is the biggest cost factor in the roll fed labeling business. Changeover times, the most common reason for downtime, often make the difference between profit and loss in this highly competitive market. Since B&H was founded 38 years ago, the company has manufactured mechanically driven machines. Changeovers to accommodate a new container size or label could delay production for hours.
Recently, B&H has dramatically reduced the downtime and enhanced the speed, flexibility, and reliability of its machines with a new multi-axis servomotor labeler. The Marathon series of roll-fed labeling systems, engineered with B&H’s SMARTdrive™ technology (Servomotor Automatic Registration and Timing System), utilizes components supplied by Siemens Energy & Automation. The high speed labeler handles a wide range of cylindrical containers: from eight ounces to five liters and 1.5 to 6.69 inches (3.81-17.0 cm) diameters.
“Our customers depend on these fast changeovers,” technology has allowed us to reduce changeover time by 50 percent.” Politzer says. “Increasing the productivity of the machine is very important.”
The brains of the Marathon SMARTdrive technology resides in a SIMATIC S7300 PLC that is connected via PROFIBUS to a 10-inch. MP270 B HMI. Two
“We knew we could have a 30 percent smaller footprint by placing the components in a smaller box,” Politzer says. “That is always an advantage because less expensive factory floor space is required.”
“Marathon is a unique system in the industry,” Politzer says. “It is the only servo motor-driven machine and the only labeler with a third generation drive system. The system has allowed us to redefine changeover time.”
Politzer said B&H and other labeling companies had commonly defined changeover time as the amount of time required to change mechanical change parts to accommodate new bottles or new labels. With Marathon labeler, B&H now defines changeover time as the amount of time needed to go from one full production speed to another full production speed.
“Our competitors may be able to change parts quickly because of their mechanical design,” Politzer says, “but it will take another 30 minutes to 1 ½ hours to tweak the machine to get it to run with those new mechanical components. By having software recipe downloads you can do that instantaneously.”
The entire labeling process is monitored and controlled on the 10-inch. MP 270B HMI that is connected to the S7300 PLC Via PROFIBUS communicating at 12 Mbaud.
“We developed a number of screens that the operator could interface with – maintenance, set up, troubleshooting and productivity screens,” Politzer says. “We designed the screens with Siemens ProTool. The screens are very intuitive and highly useable and are available in Spanish, German, French and Portugese. It is critical that operators find the HMI clear and easy to use and easy to understand, no matter the language. The Siemens HMI and ProTool software allowed us to do that.”
The MASTERDRIVES MC Servo drives, utilizing the SMARTdrive system controls the precise synchronization and time of all critical operations, including label feeding, cutting, gluing and container metering (via the machine’s starwheel). In the past, B&H mechanically linked the machine’s rotating components using gears, belts or chains. Over the life of the machine, the gears, belts and chains wore out, causing problems with positional accuracy.
According to B&H, the Marathon labeler maintains the label cut position at +/-1/32” (0.8 mm) at all machine speeds.
“We perceived there would be a tremendous number of advantages associated with going to an electronic drive train,” Politzer says, “including reduced part counts for mechanical components. The moving parts are always the biggest source of failure in a system.”
The Siemens servomotors are used for all critical machine axes: feed roller, cutter, vacuum drum, and starwheel. The servomotors communicate their instantaneous positions via Siemens SIMOLINK high speed digital communications bus. Politzer said this ensures extremely accurate timing and synchronization with absolute feedback on motor shafts. In fact, the company guarantees labeling defect rates of less than 0.05 percent.
“Accurate labeling requires very precise synchronization of all of the rotating and moving components in a machine,” Politzer says. “There are five or six key manufacturing steps that have to be done very precisely and synchronized with one another. After all, you are moving containers through these machines at about 350 to 650 per minute. When you do that, you have to very carefully synchronize that motion with the feeding, cutting and gluing of a label.”
Variable frequency motors with encoders were used for less critical rotational axes, including label unwind, glue roller and infeed/discharge conveyor. PROFIBUS is used to communicate between these motors, the multi-axis servo system, and the S7300 PLC.
“We need very high speed communication between these servo motors,” Politzer says. “In order to have them accomplish the synchronization, the motors must communicate instantaneous position at a very high rate of speeds. That allows us to correct for backlash of the motors when you have to overcome a certain amount of inertia to start it going. By communicating over SIMOLINK and PROFIBUS, we have very precise positioning of all the servo drives.”
Politzer says B&H is moving ahead with plans to increase the speed of the Marathon labeler from 350 containers per minute to 650. She said the company has recently introduced another servomotor axis for a feed screw.
“It will offer the highest rate of speed available with a third generation drive train,” Politzer says. “We chose Siemens because the company meets the specifications we’ve used over the years. Siemens has been a good partner and worked with us a lot on the SMARTdrive system. I would say Siemens has been an excellent partner.”