From the film to the finished envelope

The US company CMD developed a system for the production of mailing bags for the fast-moving e-commerce business. CMD knows that flexible automation and high repeat accuracy are essential in the packaging industry. The OEM provider meets these requirements by continuously developing its customized plastic processing solutions.

The company began developing a new machine for the production of shipping packaging for a contract manufacturer in the e-commerce sector. According to Scott Fuller, Product Line Manager, Intermittent Motion Products at CMD, high throughput and intuitive operation were the top priorities: "The new machine has become much faster thanks to the higher level of automation, and that was crucial for our end customer." This end customer produces packaging for online retailers who mainly send the ordered goods in plastic bags. Another customer requirement was that the bags should be suitable for automatic filling.

A powerful real-time control platform was required to support these demanding functions. In addition, the development team had to meet tight deadlines, as it was crucial to complete the project on time and deliver an error-free, reliable solution.

Powerful programming tools

As an integrated engineering and runtime platform, the TwinCAT automation software combines all functions from PLC and motion control to integrated safety and IoT. When programming the new user interface with TwinCAT HMI, CMD was able to use modern web design standards such as HTML5, JavaScript and CSS. The new responsive interface increases user-friendliness with intuitive operation. When programming the machine controller with TwinCAT, CMD benefited from the close cooperation with the software experts from the Special Projects Team (SPT) at Beckhoff USA. The SPT framework is based on industry standards such as ISA-TR88 and PackML as well as the corresponding libraries in TwinCAT. It simplifies the programming of communication between the machines in a production line. The advantage for programmers is that they do not have to start from scratch for every project, but can reuse existing code or simply adapt it to new requirements.

A CX2033 Embedded PC serves as the machine controller for the entire line. The high performance of the DIN rail-mounted controller from Beckhoff is ensured by a dual-core AMD Ryzen processor, which also offers performance reserves for the future. "If you work with a less powerful controller, the HMI reacts more slowly. However, if TwinCAT HMI Server is set up on a CX2033 with its generous computing resources, the touch panel responds immediately," explains software engineer Adam Benson from CMD.

Safety for the entire machine line

EK1914 EtherCAT couplers integrate communication along the entire line with digital standard and safety I/Os. In addition to EtherCAT Terminals for standard signals, the I/O segments of the various stations also include TwinSafe Terminals for functional safety. This allows CMD to conveniently assign safety functions such as emergency stop to each tool in the machine line.

CMD's motion-intensive application also benefits from the precise synchronization of the powerful Beckhoff drive technology via EtherCAT. The AX8000 multi-axis servo system and AM8000 servomotors control the machine's fourteen axes. "The AX8000 servo system is very compact for its high performance," says Jason Plutz, electrical engineer at CMD. "And by using the integrated safe torque-off functionality, we were able to save two large contactors, which significantly reduces the space required in the control cabinet."

CMD uses the cam disk function in TwinCAT 3 for two axes of the pouch packaging machine. The pouch opener was originally positioned in the intermittent movement area, but was moved further back to increase efficiency. By extrapolating the continuous path processing via cam plates, the bag opener is controlled precisely so that the desired movement is executed at the right moment.

Well positioned for the future

By using the Beckhoff software framework, CMD was able to increase the reusability of the code to 90 %. TwinCAT HMI helped the team to develop a more intuitive user interface that also offers great customizability. "The new user interface is similar to our old HMI, but now offers a much clearer and more user-friendly design," says software engineer Adam Benson.

Controlling the machine with the powerful CX2033 Embedded PC via EtherCAT reduced the cycle times. "The fact that everything is scanned at the same high speed is a big advantage. You no longer have to worry about communication between process stations working at different speeds, as everything is updated at the same time," explains Jason Plutz. This enabled the CMD team to achieve the targeted throughput rate of around 60 m of plastic film per minute. At around 100 bags per minute per lane, this equates to an impressive total of 300 to 500 bags produced per minute.

In the future, CMD plans to upgrade to the CX2043 Embedded PC with an AMD Ryzen quad-core CPU in order to further increase the performance of the machine controller. Because the broad Industrial PC portfolio from Beckhoff is designed for scalability, it enables such performance adaptations without additional engineering effort.

Madeline Donkers-Lundquist, Social Media & Content Specialist, Beckhoff Automation USA

Automatica, Hall B6, Stand 310