Discriminating consumer products manufacturers demand high quality at every point in their supply chain – from raw ingredients to packaging supplies. Plastic bottle producers who serve this market must meet exacting specifications that encompass bottle composition and design – and extend to product labeling. Autotec Engineering, a design house focused on high-speed, servomechanical solutions, provides plastic processors with the finishing equipment required to satisfy end-user demands.
Founded in 1972 and based outside Toledo, Ohio, Autotec delivers innovative custom-tooled solutions including plastic bottle trimmers and in-mold labeling machines. Unlike heat-fi red transfer labeling systems that apply paper labels to bottles with adhesives, in-mold labeling places label material within the plastic mold cavity while the bottle is being formed. “The label material and molten plastic become one fused piece,” said Jeff Thomas, service manager, Autotec Engineering. From a sustainability standpoint, in-mold labeling offers a number of advantages. First, the completely fused end product is 100 percent recyclable. Second, the process itself – which is completed inline as part of the molding system – is more energy efficient than offline transfer labeling systems. In addition, in-mold labeling removes the use of label adhesives and related fumes and venting.
The Autotec in-mold labeling equipment is coupled to the bottle producer's molding machine. “Our equipment also saves space on the plant floor ” Thomas explained. “The machine is coupled to the bottle producer's molding machine to perform the labeling operation. Therefore, it has a much smaller footprint than offline labeling machines.” To achieve the functionality required for the operation, the Autotec equipment includes a linear motor carriage, label placer arms and label magazines. The linear motor carriage positions the placer arms to pick multiple labels from the magazines. The carriage stages the next set of labels outside of the mold and moves forward to place the labels within the mold cavity at the precise moment the mold opens.
Autotec began producing in-mold labeling machines in the mid-1990s. In many cases, this durable equipment is still in service today. “We're proud these machines have been operating for 20 years or more,” said Thomas. “However, servicing these products was becoming challenging.” The original equipment utilized early generation linear motors and other automation components from a variety of suppliers. In many cases, replacement parts and chipsets were no longer available. To provide their customers with an up-to-date and maintainable solution, Autotec designed a control system retrofi t, based on Rockwell Automation technology. “By standardizing on Rockwell Automation components, we were able to bring an existing piece of equipment in line with current technology very cost eff ectively,” said Thomas. “We were also able to deliver a more fl exible solution to our customers.” To achieve the precise high-speed positioning required, the retrofi t is based on Allen-Bradley® LDL-Series™ linear servo motors and Allen-Bradley Kinetix® 300 EtherNet/IP™ indexing servo drives. Allen-Bradley CompactLogix™ controllers, communicating on EtherNet/IP,™ manage all control and drive functionality. Integrated Allen-Bradley SensaGuard™ non-contact interlock switches and Guardmaster® safety relays help provide machine and personnel protection. The system is monitored on Allen-Bradley PanelView™ Plus 6 600 graphic terminals.
“Accuracy and high speed are key requirements for this application,” Thomas explained. “But high speed can also introduce hazards for operators and the molding equipment itself.” Utilizing the Kinetix drive's Safe Torque-Off feature, the system can improve both machine safety and availability.
Safe-off capability removes rotational power from the motor without powering down the entire machine. As a result, the in-mold labeling equipment can be brought to a stop more safely – and restarted more quickly. Now installed, the fi rst retrofi tted machine achieves accuracy ± 0.001 inch and exceeds the molding equipment's high-speed cycle requirements.“The customer gave us high marks – it was a job well done,” said Jim Mihaly, chief operating offi cer, Autotec Engineering. “From where I sit, this was a beautiful collaboration between Autotec and Rockwell Automation.”