Optimising cutting-edge printing processes for packaging materials
Flexographic printing, also called Flexo, employs a thick polymeric printing plate, like a stamp. It is wrapped around a rotating cylinder conventionally made of a steel plate to print on flexible substrates. Flexo has evolved substantially but still requires skilled operators and much time to set up the machine and intervene in the case of malfunction. Improvements could have major economic impact. With this in mind, the EU-funded SCYPRI (Smart cylinders for flexographic printing industry) project set out to modernise flexography. Project members integrated fibre-optic sensors in a cylinder body made of state-of-the-art carbon fibre. They also designed an autonomous control system to adjust driving parameters in real time. A low-cost fibre-optic sensing system for remotely monitoring temperature and strain during the curing process was developed. Another wireless sensor system exploiting microelectromechanical systems technology monitored cylinder vibration and was experimentally validated. Researchers developed dedicated software in an effort to build a high performance cylinder that minimises thermal stresses. It does this by thoroughly examining the thermal reaction of the composite material and its thermal stresses. The software was further enhanced and then validated by the fibre-optic sensing system. They are looking to provide more extensive use of the software to better understand composite behaviour during polymerisation and to implement the most optimal lamination strategies. The team also investigated the behaviour of the main electroactive polymers as connection devices and developed composite material and heat transfer models. Partners expect the technology to be on the market within two years of project completion. To this effect, they are looking at ways of easily using the sensing system in printing cylinders and other rotating applications in a cost-efficient manner. SCYPRI expects a significant enhancement in process control thanks to the integration of smart monitoring and control technologies as well as improvements in Flexo components. This will provide higher throughput, enhance print quality and reduce system failure.
Keywords
Printing, packaging, flexographic printing, smart cylinders, flexography, sensing system
