Mitsubishi develops sustainable wrapping machine

To optimise operations, the Norpak machine also features other system-matched components from Mitsubishi Electric, such as a GOT2000 series HMI and MELSEC-iQ-F PLC.

Mail wrapping machines are time- and cost-effective automated solutions that package a wide range of mailings, such as catalogues, magazines and brochures, for subsequent despatch. They consist of two main parts: a feed station, where rolls of packaging material are unwound, and a wrapping section, where the mailing pieces are enclosed in a protective layer.

This activity is traditionally known as ‘polywrapping’, as plastic materials, such as low-density polyethylene, are commonly used for the packing of mail pieces. In the case of Mailroom Machines, a leading provider of wrapping solutions for the mailing industry, the company sought to increase the sustainability of its solutions. To achieve this, the machine builder planned to adapt the design of one of Norpak’s existing solutions to utilise paper as a more sustainable alternative to plastic wrappers.

In order to modify the unit, the company contacted Mitsubishi Electric to provide key automation components and engineering support throughout the project.

Paul Jones, Managing Director at Mailroom Machines, said: “We looked at various automation specialists and quickly decided to work with Mitsubishi Electric because of its remarkable products and services. In particular, we were impressed by the competitive, reliable hardware solutions as well as the comprehensive, localised support the company offers. This helped our in-house engineering team effectively complete the project and was extremely important for us.”

The right level of tension

For the wrapping machine to support paper, the feed station required modification to accommodate rolls with a thickness three times higher than the thin plastic film rolls. In addition, the tension used by the system had to be adjusted. In effect, while polyethylene (PET) is rather flexible and malleable, paper wrappers are more rigid, posing the risk of tearing and creasing if the tension applied is too high or low.

To provide advanced control over the tension applied in the machine, Mitsubishi Electric recommended its innovative FR-A800-R2R inverter, which has dedicated functions for roll-to-roll applications.

James McClelland, Account Manager at Mitsubishi Electric, explained: “We decided to use the FR-A800-R2R because the specific winding and unwinding capabilities of the inverter matched the intended application perfectly and greatly simplified programming tasks, as the customer only has to input the necessary values for the key process parameters.” These parameters are adjusted easily through the GOT2000 HMI, which supports real-time monitoring during operations.

Furthermore, Mitsubishi Electric specified a MELSEC-iQ-F FX5UC micro PLC to control loading and unloading operations when new paper rolls are required. The FX5UC features one of the most powerful CPUs available on the market and can perform positioning and advanced motion control functions for up to four axes. This controller also contains a unique spring clamp terminal block, which maintains the I/O connections even as machines vibrate, as is common in this type of application.

A solution that raises interest

As a result of this collaboration, Mailroom Machines and Mitsubishi Electric created a highly sustainable, stand-alone mail wrapping machine, which can be integrated into different types of production lines, supporting a wide range of applications and manufacturers. Paul Jones comments: “We are very happy with Mitsubishi Electric’s high-quality products and service team. The automation devices were extremely easy to install and use. Also, our in-house programmer was able to quickly learn how to code and operate all of the equipment.

“The results of this successful collaboration are already benefiting our global customers, with many of them having ordered the new machine that has been developed. In addition, we are now working with Mitsubishi Electric’s specialists on a new project to further increase efficiency and productivity of the wrapping section,” McClelland concluded. “We are delighted to support ground-breaking sustainable projects, such as the one from Mailroom Machines, with our state-of-the-art automation solutions. We look forward to collaborating with the company again to further enhance its capabilities and develop a system that is able to advance the mail industry.”