Lasers the key to productive, high-quality parts marking

For as long as there have been parts, they have needed to be marked. The tools used to accomplish this include permanent markers, adhesive labels, electric engraving pencils, rubber stamps and ink pads, metal stamps, ball-peen hammers and electrochemical etching machines.

There is no shortage of ways to mark parts. Laser marking, however, is faster than any of the methods just mentioned and more permanent than most. Best of all, it’s simple: Just properly place the workpiece in the marking machine, close the door, and the text, serial number, logo or bar code that had been keyed into the device interface will be transferred quickly to the part surface via a laser beam. For more on part marking, see this related guide.

Kaiser Tool laser-marks all its products to make identification and reordering easy. Images courtesy Laser Images

The biggest downside to laser markers is the price tag, potentially costing up to hundreds of thousands of dollars. Also, the lasers of yesteryear were difficult to operate and needed routine maintenance from a trained technician. Many people in the industry assume that situation is still the case.

The Case for Outsourcing

Ken King began laser marking when those drawbacks were far more significant than they are today. The COO at Kaiser Tool Co. Inc., Fort Wayne, Indiana, is responsible for the company’s marking division, Laser Images, which performs laser engraving.

According to King, the cost of laser equipment and its maintenance requirements has come down significantly over the past 10 years. Although older lasers required intensive operator training and programming experience, newer ones typically are graphically driven and work much like a desktop printer.

Despite the lower costs and ease of use, King emphasized that adequate time is needed for experimentation to optimize the laser’s settings for speed, power, focus and frequency for each material.

Because they don’t raise the part surface, lasers are often the first choice for marking carbide tools. Image courtesy of Laser Marking Technologies

It’s also important to select the right kind of laser. Some highly reflective materials do not absorb enough energy to allow the laser energy to change the surface. Some materials—plastic, for instance—may melt around the area being marked. King’s message is clear: For shops that need to cover a wide spectrum of materials, different types of lasers and settings may be needed.

Because of this learning curve, he encourages shops to try a laser engraving service provider before investing in their own laser marker and gaining the required experience. “Instruments, dials, wheels, scales, cutting tools and more—we can engrave workpieces of virtually any shape, size or material,” King said.

Kaiser Tool practices what it preaches, engraving each of its million-plus products with a part and lot number. This makes it easy for customers to reorder. In addition, because Kaiser Tool can track when the parts were made, on which machines, by which operators and to which print revisions, as well as quality results and subcontract information, the engraving process provides complete traceability in the event of a problem.

Traceability is one of the biggest benefits of laser marking, although its potential goes well beyond corporate quality requirements. For example, a Laser Images customer operating a food production line needed to identify a series of stainless steel trays. The customer had found that, if the trays were not maintained properly, the line could become jammed and production would cease. Once the trays were engraved with machine-readable bar codes, the customer used them to record jam events and tie information back to maintenance records, something that previously had been impossible to do.

Similar examples abound, such as in the medical industry. Medical equipment often needs serial numbers to track sterilization routines and product life cycles. Medical implants are marked to ensure they are for the correct patients and for duty tracking.

1,064 Nanometers

How fast are laser markers? According to Sam Palmeter, president of engineering and new product development at equipment manufacturer Laser Marking Technologies LLC, Caro, Michigan, it’s possible to laser-mark a 1⁄4″-dia. carbide tool shank in less than two seconds with only a minute or two of setup. “Perhaps more important is that we can produce a mark without raising the part surface,” he said. “Around 14 years ago, we developed a ‘recipe’ to eliminate surface raising, which is why more than 100 cutting tool manufacturers now use our equipment. You might say we cut our teeth on carbide.”

The 1,064nm fiber laser found in Laser Marking Technologies equipment is ideally suited for carbide and other metal, he said. The laser is also much less expensive to own than previous laser generations. Maintenance is about as difficult as cleaning out a toaster, and the laser is no more challenging to operate than any other computer-controlled device.