Shops need both chemical and five-axis laser texturing capabilities to generate patterns that were once considered unattainable and effectively compete in today’s market, according to St. Paul Engraving Inc. President John Seiberlich.
Such a hybrid approach enables the Stacy, Minn.-based shop to generate patterns faster and more cost effectively than its competitors. By using a laser and chemical process in tandem, the shop can create intricate, complex patterns and streamline its chemical engraving operations.
The process starts by developing the pattern needed for the application with five-axis lasers, which is followed by chemical etching techniques. This allows patterns to be applied to complex geometries with precision and repeatable results.
St. Paul Engraving added five-axis laser technology as customer application needs became more complicated. Lasers allow the shop to maintain extremely tight tolerances as well as exact pattern repeatability, according to Seiberlich. The five-axis laser technology has allowed St. Paul Engraving to expand its customer base as the shop can now generate pattern details down to 0.0015” [0.038 mm] in size and lettering as small as 0.007” [0.18 mm] tall, all the way up to textures that cover the roof of an ATV.
“As far as we are concerned, the laser and chemical processes do not compete with each other,” Seiberlich said. “The only time we need chemical etching is when a part feature is in the way and impedes the laser beam from hitting its target surface. If you can’t reach it, you can’t laser texture it. Other than that, it’s our process of choice.”
St. Paul Engraving’s laser texturing systems include a LASER P 1000, LASER P 1200, and LASER S 600, all from Switzerland’s GF Machining Solutions Management SA, with U.S. headquarters based in Lincolnshire, Ill. The LASER S 600—the shop’s most recent machine—features dual Flexipulse, laser sources with a Z-focus shifter allowing for improved surface finishes while decreasing machining time by up to 40 percent depending on individual applications, the company said.
Flexipulse technology, paired with dual sources, allows for adjustment of the pulse duration from four to 200 nanoseconds and the ability to switch between a 100- and 30-W source. This allows for the ability to improve the surface finish and complete multiple applications with one setup on one machine, GF Machining noted. Flexipulse sources also can accommodate various materials, including steel, aluminum, graphite, copper, ceramic, glass, sapphire, and polymers.
Utilizing Flexipulse technology, St. Paul Engraving can lengthen or shorten beam pulse width for more usable energy, less burn, better surface finishes, faster removal rates, and an overall reduction in production time.
The shop’s LASER S 600 and LASER P 1000 work together in a WorkPartner 1+ System 3R cell. The cell’s robot can load large Dynafix pallets on the LASER P 1000 and lighter Macro pallets on both the P 1000 and the S 600, with a total capacity of 10 Dynafix and 90 Macro pallets.
St. Paul Engraving started with simple pallet changing on its LASER P 1000 but soon realized the need to expand production capabilities, which prompted the two-machine cell setup, explained Vice President Bryan O’Neill. As a result, the shop can provide customers with 24/7 continuous production—allowing the setup of multiple parts and jobs to be run at the same time. With the right configuration of parts, they can run multiple jobs on one pallet and then load several pallets in the machine for high-volume production jobs.
“Although we can combine lasers with our chemical etching, some patterns can only be produced with the laser, including detailed patterns for osseointegration on small medical components such as titanium screw implants,” said O’Neill. “Because it is hard to control the acid used in chemical etching, the process also involves material restrictions, along with those involving size, pattern depth, and detail.”
O’Neill also noted that because St. Paul Engraving can quickly generate unique patterns that chemical etching couldn’t achieve, more of its customers are pushing the envelope in terms of product design. In many case, these patterns are trademarks or logos that St. Paul Engraving can reproduce consistently using five-axis laser texturing.
St. Paul Engraving completes about 2,000 projects per year, serving the medical, consumer goods, firearms, packaging, automotive, recreational-vehicle, and heavy-equipment markets. It specializes in part marking, engraving, and texturing on mold-tooling surfaces and individual components. Job volumes can range from one part to thousands.
The shop’s part-size processing capacity leans toward smaller, more critical parts and surface areas with tighter tolerances. The patterns themselves don’t require tight tolerances, just the ability to apply them to very small and precise areas, such as a dimple pattern for light diffusion in automobile headlights.
“Part run times on the laser machines can range from minutes to days, but one to eight hours is more typical,” O’Neill said. “With chemical etching, it’s a trade-off. On a part the size of a quarter, laser texturing will be faster than chemical etching. As part surfaces become more expansive, chemical etching may take less time, but the process involves a lot more labor in terms of preparation,” he continued. “Also, duration of exposure to the part controls depth with chemical etching, whereas sweep speed and power settings control depth much more precisely with a laser.”
St. Paul Engraving hit the ground running when the first five-axis lasers were introduced, thanks to earlier investments in laser technology for engraving logos, texts, and small texture areas more than 20 years ago. The actual laser sources haven’t changed dramatically over the years, but the machine and software capabilities have, according to O’Neill. “GF Machining Solutions’ LASER machine and the five-axis software made it easy to implement our existing knowledge of the lasers and texturing process to program and achieve complex textures,” O’Neill said.
“Basically, the software allows us to take a gray-scale texture, then apply it to a mesh, render the pattern, and lay it on the part surface digitally,” he explained. “In the software, we ‘flatten’ the surface that will be textured, create the pattern, and then the program lays out the flattened mesh and wraps it onto the part surface. With chemical etching, we’d have to lay patterns together and then touch up the seams. The laser machine software, however, is perfect at seamlessly wrapping the pattern around any geometric shape.”
St. Paul Engraving’s success has led to annual growth of between 10 and 20 percent in recent years. However, to ensure efficiency, the shop strives to keep expansion at a manageable rate.
“It’s one thing to go out and get the work, but it brings no value if we are unable to complete it in a timely fashion,” Seiberlich acknowledged. “One reason for this is that finding skilled labor is tough. Fortunately, however, our laser texturing machines allow us to automate the process, whereas chemical etching is skilled-labor intensive. So, the lasers allow us to do more work with our existing workforce. At the same time, we constantly evaluate our machine capacity, and if we need more down the road, we will invest in additional laser systems, both large and small,” he concluded.
“Wherever the work takes us, we rely on GF Machining Solutions technology.”
For information about St Paul Engraving, visit stpaulengraving.com or call 651-462-9356. For information about GF Machining, visit gfms.com/com/en.html or call 201-555-0123.
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