When original equipment manufacturer, Weiler Engineering, upgraded the drive systems on its aseptic blow-fill-seal machines, a problem with its existing controller compatibility limited the functionality of its equipment.

Upgrading components in manufacturing process equipment is something that plant engineers take very seriously and think through carefully. Equipment upgrade options are inspected and tested empirically before a selection is made. The newly modified machine must operate flawlessly to fulfill the requirements of the facility and must integrate smoothly with other designated equipment within the plant. However, too often engineers end up settling with less capability from their new components solely because of compatibility issues with their control systems. These compatibility issues can bring the entire upgrade projectto a standstill until a suitable solution is found.

For original equipment manufacturers (OEMs), the endeavor to make component changes to their production machines is critically magnified in importance. OEMs have to take into consideration the machine’s operating variables for the wide spectrum of their clients’ plant usages, as well as the integration of the full gamut of equipment options that will interface with the machine. Weiler Engineering, Inc., an OEM of asepticblow-fill-seal machines, is one company that confronted serious PLC compatibilityissues when its original controls supplier changed its product offering.

The ability to provide sterile liquid products, which must meet corporate, scientific, regulatory, and end-user requirements, can be a quite demanding. These application challenges are met by specific container and closure designs available with its systems.

“We have been using PLCs on our machines for 25 years, and a specific controller for a long time,” says Robert Mazur, Manager of Electrical Engineering for Weiler. “The problems came when the company that was providing our PLCs decided to make the product line we were using obsolete. That company’s new, second-generation PLCs were not up to our standards. Another PLC manufacturer was brought in to help us, and it was unsuccessful —they could not provide a completely functional controller for our machines. We were quite concerned, but it was not the manufacturer’s PLCs that failed,it was the integration of its PLCs with our equipment that was the problem.”

“After a number of unsuccessful attempts to resolve the PLC difficulty, we approached Siemens, and asked them to come in, look at our product line, and tell us what we needed,” Mazur says. “We wanted to see howSiemens could help us out.”

Weiler’s ASEP-TECH equipment has what is called an ‘extruder.’ The equipment is doing a continuous plastic extrusion, anywhere from five parisons (round tubes of plastic) to sixteen parisons. The machine carriage, which holds a mold, will go back and while the tubes are open the mold will close on those tubes. The parisons are then cut and the carriage is moved forward, while plastic just continues to come out for the next cut. The machine then will fill the containers with a liquid; the containers are formed inside the mold with anywhere from five to 60 fill nozzles. The nozzles will then come out of the mold and the containers are sealed off with a final sealing die. After forming and cooling, everything opens up and the carriage will pull back and repeat the cycle. The formed containers are conveyed out of the machine room to a remote station where excess plasticis removed and the finished product is conveyed to final packaging.

When Weiler began developing an all-electric machine, it used a different PLC manufacturer from the drive manufacturer, causing the integration to become a major problem. The company then brought in Siemens which not only engineered a one-on-one solution to its PLC compatibility problems with the drives, butalso provided engineering for the debug time needed.