Digital converting processes are useful in transforming a roll of material into a different form or shape. They provide the flexibility to deliver unique designs or changes on-the-fly, unlike traditional mechanical processes. The field of digital printing results in tremendous progress. Its increased adoption requires that converting processes also be more flexible and cost-effective while delivering high cut quality. Due to the high cost of storage and maintenance of a plurality of conventional dies and long set up time, using CO2 lasers in combination with fast and precise laser scanning has proven to have great potential in paper and cardboard processing, flexible packaging and label cutting. At the same time, the capability to control the laser beam power density delivered on the material processed is critical to achieve high quality finish goods.
In this paper, we demonstrate the capabilities of all-digital galvanometer scanning technology in combination with a highly frequency stable CO2 laser. This provides stable laser power density by modulating the laser power in coordination with beam scanning speed. Our system also demonstrates high scanning speed of more than 10 m/s and a focal spot size of less than 150µm.
The rapidly growing market of roll-to-roll converting systems for thin materials, where flexibility and precise repeatability is key to success, is ideal for CO2 lasers that pair with high-speed galvanometer scan heads. The materials involved are often thin plastic films, paper, cardboard, fabric and textiles. These materials fall into a wide range of end uses. Including, flexible packaging, product labels, greeting cards / envelopes, high performance optical films, and athletic apparel fabrics.
The digital printing revolution has changed the landscape of these roll-to-roll converting machines significantly. Especially for label and customized packaging. Traditionally, cutting is done with mechanical die-presses. Where the user is locked into one design for a production shift. The cost and hassle of storing multiple dies made it unfeasible to have many cut shapes available. With the newly added flexibility of digitally printed designs, the need to easily change the cut or perforation shape has become more important. Replacing die presses with laser cutting in combination with high-speed scan heads has changed this to a dynamic and easily flexible process. The cut design changes can be done on-the-fly via software without stopping the production line.
Additionally, there are some special features which have been difficult or impossible to create until now. A non-contact process can enable the processing of finer features in more sensitive materials. The digital nature also allows short-production runs or one-off prototypes that would not have been time- or cost effective in the traditional mechanical system. Further unique examples can be found in the apperal market.
