International Report: Finding the sweet spot in laser cutting automation

Smart integration of automation shortens lead-times—regardless of geography

June 1, 2010

Walking a block north of the Leie River flanked by the medieval Broel towers—two of the few original structures left standing in Kortrijk after World War II—I noticed the trees. The Belgians pruned them several years ago, leaving nubs where large branches used to be. From those nubs emerge a spidery cluster of new growth. Such pruned hardwoods dot the countryside.

Those trees could be a living metaphor for modern manufacturing. Years ago they had large, thick branches (large-batch manufacturing). But recently they were cut back only to grow again in a new way, with thin branches (smaller batches) appearing in an intricate array (a diverse, large customer base providing many small-volume jobs).

My mind kept straying to this metaphor as I toured the region’s manufacturing facilities. Earlier this year I took part in an international press tour organized by Belgian fabrication equipment maker LVD Company n.v. and its across-the-pond subsidiary, Strippit Inc., based near Buffalo, N.Y. During the first quarter, the company invited the trade press from North America, South America, and Europe to its headquarters in Gullegem, in the northwestern outskirts of Kortrijk and a little more than an hour west of Brussels. In early March Canadian Industrial Machinery paid a visit.

In the area you’ll likely hear Flemish (a Dutch dialect), French, and English, all spoken in one conversation between two Belgian citizens. LVD headquarters are on the southern edge of the country’s Flemish-language region. To the north of Kortrijk, most speak Flemish; to the south and west, French. You can hear a little German too. Business conduct here has an international feel, mainly because to grow significantly, most Belgian companies must do business beyond the border.

According to Carl Dewulf, LVD’s president and managing director, company executives could brag about its 70 percent market share in Belgium, but they don’t.

“Our home market of Belgium is only a small part of our group turnover. It’s only about 7 percent of our total sales,” said Dewulf.

The rest happens outside Belgium. Half of LVD’s sales come from Europe, the other half everywhere else, including Asia, the U.S., and Canada. The company employs more than 1,000 people who operate in 45 countries, but only several hundred call Belgium home.

This isn’t to say that Belgium’s metal fabricators aren’t successful. Like LVD, their reach extends beyond Belgium. Good quality and high on-time delivery rates get companies to the table. To succeed and grow, shops must shorten manufacturing time while minimizing debt and maximizing profits.

Automation, integrated correctly and with proper training, allows shops to respond quickly to customer demand. Perhaps more important, the right level of automation maximizes the value of each employee. The more valuable that employee is, the more stable his employment becomes, in good times and bad. Matthew Fowles, LVD’s group marketing manager, explained this phenomenon (see Figure 1).

Figure 1

Adopting the optimal level of automation involves finding the "sweet spot," balancing labor cost reduction with equipment investment costs.
Images courtesy of LVD.

“We’re aiming for the sweet spot, the crossover point between the most labor-cost-per-part reduction and the start of the expediential curve of [equipment] investment cost per part,” said Fowles.

The sweet spot depends on a shop’s customer mix. The key, he said, is to find the point at which a shop can best meet the flexibility, lead-time, and cost demands of its most profitable customers.

That’s a balancing act that takes place on both sides of the Atlantic.

Maintaining Laser Uptime

Figure 2

A panel at garmat make sits way into an automated paint booth. Sixteen years ago, this panel would have been fabricated out of five pieces.

At a paint booth manufacturer called Garmat, an LVD Axel series laser cutting center’s material handling system crawls. It moves slowly not only to save energy and handle material carefully, but also because it has no need to move fast. The suction cups pick up a 13- by 6.5-ft. sheet from one of three bays. When the schedule calls for that material, the system transfers the sheet to one of two cutting tables, while a sheet on the other cutting table is already being cut by the laser. Only when the laser stops does the material handling system kick into high gear. The tables switch out in 30 seconds, with one table actually moving up and over another.

Purchased three years ago, the machine is the company’s first laser investment, and it has allowed Garmat to increase throughput without adding labor. The company even knocked out part of a wall between the shop and the raw stock warehouse to maximize floor space. The material handling system is at the edge of the warehouse, convenient for workers to move sheet onto three pallet stations. From there, the material handling system feeds material into the system on the shop floor side.

The machine can run unattended, and during the day shift one operator manages both the laser and an older turret punch press. Why did the company bring in a laser instead of another turret machine? One obvious reason was speed, but the company also benefited from the better edge quality. The punch press often produces blanks with sharp edges that must be deburred.

Based in Flemish-speaking Erpe-Mere, northwest of Brussels, Garmat opened in 1975 with two people, one of whom was Herman De Mil, the current CEO. The company has an additional plant in Denver, Colo., which it opened in the 1980s to serve the North American market.

Ben De Mil, company vice president and son of the founder, pointed to a panel with intricate hole patterns, on its way into an automated paint booth (a booth made by Garmat). The design is a far cry from the ones his father used in the 1970s, when the shop had only a manual shear and other basic shop equipment at its disposal, and such designs were either impossible or impractical (see Figure 2).

“Sixteen years ago, we couldn’t have made that,” said Ben. “This one panel would have been made out of five pieces.”

Thanks in part to the punch press and laser, the shop has simplified overall design and sped lead-times. It replaced most of the welding with riveting, a faster process, and manufacturing time for an average-sized paint booth now is one to two weeks instead of months.

Booths range from several feet in diameter for small parts, to ones large enough for fighter jets. But the business was built in part on people’s bad driving habits. Car body shop customers provide the lion’s share of Garmat’s revenue, and it’s a good thing. People crash their cars in good economic times and bad.

The Universal Value of Quick Response

Figure 3

This two-tower laser cutting center remained at LVD headquarters for testing before being shipped to a shop in the U.S.

Earlier this year a massive piece of laser cutting automation sat in a testing bay at LVD headquarters (see Figure 3). The flying optics, driven by linear motors, performed some eye-popping rapid traverses. It was a unique experience to stand near the protective glass and see the cutting head roar toward you, then stop inches from your face.

This unit had a massive, 6-kW, two-turbine resonator with two chillers. A capacitive sensor integrated into the nozzle keeps the cutting head continually moving in Z to ensure a constant 0.040-in. offset from the material surface.

“The material is never perfectly flat,” said LVD’s Laser Product Manager Stefan Colle. “The most important parameter is the position of the focal point.”

Of course, speed, power, and accuracy don’t count for much if the machine has to wait forever for material. What really drives productivity is efficient material handling. Like at Garmat, this laser is down only for about 30 seconds between sheets, when the two cutting tables change out. As the laser cuts, material is removed from two towers. The grade, size, and thickness of every sheet in those towers are recorded in the system’s software for inventory control.

Doing the handling are suction cup lifters together with a fork system. Unlike the flying optics, these material handling systems aren’t in a hurry. The suction lifters pick up the material from several bays and place the sheets into the tower. Pressurized cylinders blow air to ensure the cups don’t pick up multiple sheets; multiple stainless sheets, for instance, may stick together from static charge. A gauge measures the sheet thickness and size. Meanwhile, an empty fork loader moves over the cutting table to ensure that it has no material. It then takes material from the tower and carefully places it onto the cutting slats. The forks actually fit in between the table’s slats, so the system can carefully place the sheet on the working surface, then slide out from underneath.

All this happens at a snail’s pace to ensure careful and accurate material handling and to prevent any crashes, which can get expensive if they occur when the laser is running lights-out over a weekend. Besides, the material handling system doesn’t need to move fast if the laser continues to cut. As long as the next sheet is ready before the laser finishes the previous sheet, laser idle time remains minimal.

The machine was headed to a manufacturer in the U.S. (The company name was withheld because of a confidentiality agreement.) Such investment now means managers at the U.S. company probably foresee orders ramping up, and automation will help them respond quickly. Such investment perhaps portends good economic times to come, and that’s welcome news for companies on both sides of the Atlantic.

For more information, visit www.lvdgroup.com.