Making Your Mark: Design & Engineering

For those who need to permanently mark products with designs, letters or numbers, the latest laser engraving machines offer significant improvements in process efficiency and marking quality. According to companies that make the machines, technological progress has improved both the process of laser marking and the results users can expect. What’s more, manufacturers of laser marking systems point out that their systems have become more accessible to machine shops in some important ways despite the advanced features that have been added in recent years.

When it comes to accessibility, the cost of laser marking equipment has gone down “pretty dramatically” compared to what it was a decade ago, noted Rudy Lyobard, general manager at Technomark North America in Conroe, Texas, which sells laser marking systems. But it turns out that this development isn’t as much of a boon to buyers as one would think. While equipment costs have decreased, the expertise needed to implement and maintain these systems hasn’t, Lyobard explained, noting that shops still need “the staff, the engineers and the sales support … to do the work and make sure the laser is properly implemented [and] serviced. So the total solution cost is not going down dramatically.”

Better news for those in the market for new laser engraving equipment can be found on the software side. Software in advanced laser marking systems makes it easy for process developers to program their workflow, according to Roland Mayerhofer, product marketing manager at Coherent Munich in Gilching, Germany. Mayerhofer pointed out that the software in Coherent’s laser marking systems guides users through the programming process step by step and allows them to establish the sequence of events simply by arranging some icons.

Software Divide

Some manufacturers of laser marking equipment “don’t care too much about the software,” Lyobard noted. “As long as it works, it’s going to be okay.” These companies tend to opt for standard software from Chinese sources, he added.

On the other hand, “we are seeing that most of the leading companies are developing their own software,” he said. At Technomark, “we took the approach of rethinking the way the software was done.” This, he noted, led to a focus on user-friendly features that simplify the task of selecting values for speed, frequency and other settings that control a laser marking process in order to allow non-experts to operate the equipment.

As a result, he said, “the laser is so easy that even 30 minutes of offline training is enough for any operator to get the point and start selecting the marking they want.”

Combined with advanced hardware, the latest software also gives users the flexibility to easily change a key laser marking parameter. Mayerhofer points out that laser pulse widths can range from longer (measured in nanoseconds) to very short (measured in picoseconds or even femtoseconds). With fiber lasers, he noted, users can change the pulse width with a single click—allowing a quick transition, for example, from slower, higher-quality engraving to higher-volume, lower-quality marking that may require more post-processing.

When space is tight on the shop floor, the size of a laser system can be an important consideration for potential buyers. According to Lyobard, the portable lasers currently on the market come almost exclusively from China. Though small, he pointed out that these lasers are not designed for marking in high-volume production settings.

By contrast, Technomark’s new Graphix XS Inline laser is, as the name suggests, aimed at inline industrial applications, mainly in the automotive industry. Measuring 10″ x 2.9″ x 4.3″—about half the size of the company’s previous comparable product—the unit should be relatively easy to position along a production line, Lyobard noted. And once it’s in place, he added, users will find that compact system is up to the task of continuous, high-volume marking. “We are not talking about a laser which has limited capabilities because it’s smaller,” he said. “It’s a laser that is able to do whatever the other lasers are doing.”

Marking Milestones

Lasers capable of marking a wide variety of materials are particularly prized in job shops. Many of these shops are now using fiber lasers featuring MOPA (master oscillator power amplifier) technology, which can handle most material applications and are especially good at removing material for deep engraving, said Clinton Coleman, TruMark product and project manager at Trumpf Inc.’s Laser Technology Center in Plymouth Township, Michigan. But in cases where shops only want a surface marking on highly reflective materials such as copper, aluminum and brass, Coleman noted that fiber lasers sometimes don’t provide consistent marking due to a combination of high surface reflectivity and the laser’s low pulse energy. Also problematic, he added, is the fact that fiber lasers can’t provide a dark contrast when marking highly reflective materials. So for these applications, he said, the systems of choice are new solid-state YAG lasers such as Trumpf’s TruMark 6030, which offers a combination of high average power (starting at 25 W) and high peak pulse power (40 kW). “This allows you to mark every metal, even reflective metals, and still get a nice dark contrast and a fast cycle time,” he said.

Another significant advancement in recent years has been the introduction of 3D laser marking technology. The TruMark 6030 and Trumpf’s TruMicro Mark 1020, another solid-state YAG laser, are equipped with this technology, as are laser markers made by other companies, noted Bill Holtkamp, manager of Trumpf’s technology center in Santa Clara, California. Typically, the curved surface of a round tool would be laser marked by putting the tool on a rotary axis and then creating the desired mark a little at a time as the tool is rotated on the axis, Holtkamp explained. With 3D marking, by contrast, users can mark 120 degrees around the curved tool surface without rotating the tool or moving the head of the laser.