Linear Motion In-Mold Labeling: CASE STUDY
Design & Build Machine Shop Develops High Speed Automation for In-Mold Labeling
A leader in glass and plastics machinery manufacturing. A design and build machine shop that develops automated solutions for molders. They are heavily involved in the blow mold plastics industry for packaging and large part commercial applications. They produce custom-tooled solutions including plastic bottle trimmers and in-mold labeling machines. Their material handling systems feature automated and robotic solutions that transfer and package products.
The design house applies paper labels to bottles with adhesives, in-mold labeling places label material within the plastic mold cavity while the bottle is being formed.
In-mold labeling produces a completely fused end product that is 100 percent recyclable. The manufacturing process itself, which is completed inline as part of the molding system, is more energy efficient than offline transfer labeling systems.
To achieve the functionality required for the operation, the 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.
This technology was developed 20 years ago and has become difficult to service. The original designed used 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 a modern and easy to maintain solution, we worked together to design a control system retrofit using Rockwell Automation technology. By doing this, they were able to bring an existing piece of equipment in line with current technology very cost effectively. In addition, it provided their customers with a more flexible solution.
The system required high-speed positioning, which made the Allen-Bradley® LDL-Series™ linear servo motors and Kinetix® 300 EtherNet/IP™ indexing servo drives ideal for the solution. They also utilized the Allen-Bradley CompactLogix™ controllers, communicating on EtherNet/IP™, to manage all control and drive functionality.
Key requirements for the application is accuracy done at a high speed. The speed of the machine can be hazardous to the operator and the molding equipment if proper safety procedures aren’t in place. To mitigate any safety concerns, the Allen-Bradley SensaGuard™ non-contact interlock switches and Guardmaster® safety relays were added to help provide machine and personnel protection. The system is monitored on Allen-Bradley PanelView™ Plus 6 600 graphic terminals.
By using the Kinetix drive’s Safe Torque-Off feature, the system improves machine safety and availability. The safe-off capability removes rotational power from the motor without powering down the entire machine. Resulting in the in-mold labeling equipment being able to be brought to a stop more safely – and restarted more quickly.
The retrofitted machine achieves accuracy ± 0.001 inch and exceeds the molding equipment’s high-speed cycle requirements. The end customer is saved cycle time because the label is placed in process versus after production.
PRODUCTS AND SERVICES USED
- Allen-Bradley CompactLogix Programmable Automation Controller
- Allen-Bradley Kinetix 300 EtherNet/IP Indexing Servo Drive
- Allen-Bradley LDL-Series Linear Servo Motor
Posted on Wednesday Nov 23, 2016