Accuracy and throughput of labeling machines increase with Trio

A large labeling machine OEM in the USA has upgraded the motion controllers on its machines to boost throughput and increase label application accuracy. The labeling machine builder has integrated controllers from motion control specialist, Trio Motion Technology, to increase throughput by over 25% with labeling accuracy improving to +/- 0.5mm, as well as create a future-proof design. 

Requiring precision and speed 

Founded over 100 years ago, the OEM designs and builds hundreds of machines every year for packaging and labeling applications, primarily in the food & beverage market as well as the medical and pharmaceutical industries. In addition to packaging meat, poultry and seafood, the packs have to be labeled, placed with a high degree of accuracy that is repeatable over thousands of units. High volume production also means that high speed is required to maximize throughput.  

The machines can include both top labeling for branding and bottom labeling displaying product data such as nutritional information. Added directly after the packaging machine, the inline labelers form part of the production process and must coordinate with the speed of the infeed conveyor, which can vary based on multiple factors including conveyor loading, mechanics, and voltage fluctuations to the driving motor. The next challenge is for the labeling machine to accurately apply the labels, maintaining accuracy even when infeed of packs is high. Previously, the labeling machine OEM used a programmable HMI to provide control. However, greater accuracy in label placement was required by the OEM’s customers which decreased with variation in conveyor speed.  

Trio’s solution  

The labeling machine OEM turned to experienced motion control manufacturer, Trio Motion Technology, to provide a solution that improved accuracy which would not deviate at high throughput. The controller also had to provide easy integration as well as increased reliability to maintain productivity. Trio’s Euro404 Motion Coordinator was selected to control two stepper motors and accept a line encoder for precise conveyor tracking. The Euro404 accurately registers and feeds the top and bottom labels to the incoming packs. 

Equipped with precise 64-bit motion calculations on an ARM11 Processor and floating point math, Trio’s Euro404 controller has increased accuracy in label placement by 50%, from +/-1.0mm to +/- 0.5mm. Crucially, the Trio controller maintains high accuracy repeatability irrespective of the speed of the conveyor and product inflow, meaning that throughput can be increased. This is achieved with standard features in the controller for registration capture-to-motion triggering and electronic gearing. The gearing feature tracks the speed of the conveyor via encoder input and precisely synchronizes the label feed motion. 

Total throughput depends on the size of the pack, but the machine is now capable of placing up to three labels per second, or 180 labels per minute. This has increased machine throughput by over 25%.  The previous system was unable to track the speed of the conveyor and the incoming packs in real time, resulting in the throughput versus accuracy tradeoff. 

Trio’s Euro404 controller is provided ready to mount onto a control board, in this case manufactured by the labeling machine OEM, that interfaces directly to the controller. The Euro404 required no modifications, enabling faster time to market and reduced cost. It was also a requirement of the control board to have a compact footprint to minimize the overall size of the machine. The controller fits into a low-profile board and enclosure, helping to achieve the low floorspace requirement.   

The original smart HMI also presented a program compatibility challenge depending on the model required for the various labeling machines in the OEM’s range and it didn’t have an upgrade path for obsolescence. Instead, Trio’s controllers use the same program with no reprogramming required, and the Euro range has an upgrade path for both stepper or servo control. Trio’s future proof system allows previous generation programs to load and run into the latest generation controllers. 

Time and cost savings  

The Euro404 is also very easy to use. Interfacing with a control panel and e-stop, all settings are managed through a compact touch screen. Flexible control is provided though the user only needs to set the label size along with a calibration run in order for accurate, high throughput operation to start. As Trio’s environment for motion and machine control is a single integrated system, it’s easier to work with and doesn’t require an HMI or PLC to coordinate and control additional devices required for label registration.  

A more stable programming system compared to the previous smart HMI approach is also combined with more reliable hardware in a robust package and a single unit, reducing the volume of required connections. For the OEM this has significantly reduced downtime contributing to more productive machines.  

Combined with increased accuracy and throughput, Trio’s controller has also helped to reduce cost, with fewer maintenance requirements, less development time required, and better value hardware compared to PLC or HMI options. The OEM manufactures around 150 labeling machines per year, meaning that significant cost savings are achieved.  

Trio also provides controllers for stepper, servo and Ethercat labeling applications that can scale to more demanding and complex labeling systems.