The uniqueness of this application is twofold: first, insulation in most power transformers is made from oil and cellulose (paper / pressboard), not crepe paper, and second, these materials are usually cut mechanically using blades, not by laser. Additional requirements were for the laser system to automate a process that had previously been done by hand, and that it should produce a clean cutting edge, as reported in the current issue of PhotonicsViews.

Tobias Beitz, sales manager at specialist machinery manufacturer BR Technologies, explains why Luxinar’s CO₂ laser sources were chosen for this process. “It is the only way that came to mind to cut the paper in the specified shape…Usually you’d alter the production process of a transformer to accommodate the machine. However this customer is more advanced in their quality requirements and wanted to automate the manual process without compromises or changes.” Beitz goes on to describe how the lasers are integrated in BR Technologies’ equipment, “…we used a beam splitter and some mirrors to guide the laser through moveable tubes. The laser is fixed while the material that is being cut moves in all directions.  The laser always cuts from above.”

The SR 15i is from Luxinar’s well-established SR series of sealed CO₂ laser sources with powers of up to 250W.  The laser is based on a diffusion-cooled slab principle that gives a high-quality, round, and symmetrical beam and, in addition to cutting, the SR series is used for drilling, engraving, marking, perforating, scribing and welding in a variety of industries. The two SR 15i lasers installed in BR Technologies’ machines are making approximately fifty short clean cuts per crepe paper coil on a production line that is operating at speeds of around 50 mm per second. 

BR Technologies has been supplying high-quality winding equipment since 1948 and chose Luxinar as “…it had the right specifications, a good price and was close enough to us in Germany. Since this is our first laser, we wanted to have a supplier close by in case we need support. And it paid off. Without the support of Luxinar we would have taken months longer to get the process running as smoothly as it does now.”

Read the full story: “Electrifying lasers for the transformer industry – How CO₂ laser sources are being used for paper cutting”, PhotonicsViews 19(4), pp. 50–51, September 2022