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Is There A Fiber Laser In Your Future?

Jan./Feb, 2011

For an increasing number of shops the answer is yes.

According to Massimo Denipoti, president and CEO of CY Laser, fiber lasers “are really the future of the industry.”

Denipoti’s opinion isn’t isolated.

Many well-known laser-system manufacturing companies are adding fiber lasers to their product lines, and many shops are adding the technology to their floors.

These changes are fueled by the advantages that fiber lasers offer over other types of lasers, especially the CO2 laser.

The advantages are many: faster cutting time, higher efficiency, lower maintenance, longer service life, lower environmental footprint, ease of operation and competitive pricing.

Yet despite all their advantages, fiber lasers are not meant as a complete replacement for CO2 lasers. According to Frank Arteaga, laser product manager for Bystronic, CO2 lasers still do better at cutting thicker materials.

However, fiber lasers are still the new kid on the block.

“Fiber lasers, in a cutting environment, have been out in the market, I would say, between three and five years,” says Tate Picard, general manager, Hypertherm Laser. “They’re still in the early, early stages.”

And because they’re still in the early stages of their life, many companies and shops are still not yet aware of them and how they function.
“There’s a very small group of people actually making fiber lasers for metal cutting right now,” Picard mentions. “I can think of three or four, Hypertherm being one.”

Hypertherm is a little different because it offers a fiber-laser solution that contains all of the components needed to put together and run the laser – the fiber laser itself, the management system for the assist gas, the laser-cutting head, the height control for the cutting head, the CNC and the cutting control programs.

Doug Shuda, fiber laser product manager for Hypertherm, explains further: “So essentially what we’ve done is taken all of the critical components, pulled them together, defined the operating parameters and validated the process. We basically provide an off-the-shelf solution to an OEM table manufacturer or integrator and they can take [it] and just plug it in and run it.”

Some shops might prefer to build their own fiber laser. In this case, other companies, such as IPG and Rofin, offer the power source (the fiber-laser box) as a standalone.

With all these companies, there are a number of different fiber lasers on the market. However, the way they all work is basically the same.

How they work

A fiber-laser resonator consists of an Ytterbium-doped active fiber optic, which is pumped (excited) using light emitted from semiconductor diodes. At least that’s the way the IPG fiber laser works, according to Eric Stiles, IPG laser applications manager. The pump diodes are fiber-coupled and then spliced into the active fiber to deliver the pump light.

Arteaga adds that the light source is pumped through the outer core of a double-clad flexible fiber cable called the active fiber medium.

Once the light excites the Ytterbium atoms, they produce a one-micron wavelength beam in the inner core of the active fiber medium. The laser light is then delivered through what Arteaga terms the passive fiber, which delivers the laser beam to the cutting head.

Stiles explains that, with the IPG fiber laser, another advantage is that there is zero possibility of any type of misalignment of the optics, thermal shift or temperature effects because the optics throughout the system are actually fused to the laser itself.

In fact, he says, “there’s nothing that the user has to maintain – there’s no pump, there are no gases, no flash lamps and no consumable items inside the laser.”

Additionally, due to the unique construction of fiber lasers, they’re about three times as electrically-efficient as a CO2 laser and about 10 times as much as a YAG laser, says Stiles.
It’s also important to note that fiber lasers are scalable.

“A typical high-power fiber laser is actually composed of several smaller lasers called modules,” notes Stiles.

In fact, seven 600-W modules might make up a 4-kW laser.

“With the IPG construct, depending on how much power you want to get out of it, you just add more modules,” he says. All the modules are spliced together and come out as a single beam.

Cutting speeds

As mentioned earlier, one of the advantages of a fiber laser is its cutting speed.

“If we compare a fiber laser to a gas laser, the fiber laser will be extremely fast – even up to 250 percent faster – at cutting thin sheet metal than a CO2,” says Arteaga.
Yet the higher speeds still don’t sacrifice the quality of the cutting process. Arteaga explains that a CO2 will start to create a rougher cut edge at higher cutting speeds, but “that’s not the case of the fiber laser at high speeds; it still produces a very smooth cut edge.”

However, as the thickness of the material being cut increases, the speed of the laser has to decrease. For example, Hypertherm’s fiber laser will cut 10-gauge mild steel at about 110 ipm and 18-gauge stainless steel at about 400 ipm, but only cuts half-inch mild steel at about 30 ipm.

Arteaga also points out that the Bystronic Fiber 3015 machine platform, which has high acceleration and dynamics capabilities, can even “cut up to 2400 ipm, even with only 2 kW [of power].”

Efficiency, maintenance, service life and footprint

Fiber lasers also save time. Denipoti mentions that when applied to an external cutting system, they require no warm-up time as opposed to the 20 to 30 minutes that some CO2 systems require. Saving on warm-up time can add hundreds of hours of production in the long run.

In addition to their faster cutting speeds and time savings, fiber lasers can also cut materials with which a CO2 laser might have some difficulty.

“The wavelength [of a fiber laser] is particularly friendly to a lot of interesting metal, especially brasses, copper and aluminum,” says Stephen Lee, product manager for Coherent.
According to Arteaga, this is because of its one-micron wavelength, which has 2.5 times the absorption factor of a CO2’s wavelength.

Fiber lasers are also very efficient. Picard explains that – because of their completely solid-state, monolithic design – fiber lasers have higher wall-plug efficiency than CO2 lasers.
“If I plug something into the wall, and I put 100 W of energy in, how much do I actually get to use?” Picard says. “With a CO2 laser, eight to 10 percent is pretty common, but on the fiber laser, you’re going to see efficiency numbers between 25 and 30 percent.”

Because of their design, fiber lasers also require virtually no maintenance. CO2 lasers use CO2-lasing gas as part of their system, and this gas can collect impurities over time, which then need to be cleaned out. Many also use high-velocity turbines to move the lasing gas around, and these require maintenance and eventual overhauling as well.

Fiber lasers have no lasing gas, and thus they have one less thing that needs to be maintained. This also means that a job shop will save money. According to Picard, maintaining the lasing gas on a multi-kW CO2 laser may end up costing somewhere between $20,000 and $30,000 on an annual basis.

Fiber lasers can also run longer before needing service. A press release from CY Laser mentions that they can run up to 100,000 hours before needing maintenance, while Picard says that a CO2 laser needs maintenance after about 20,000 hours. This maintenance might involve cleaning the lasing gas of impurities and removing contamination from the glass tubes used for energy generation, as mentioned earlier.

In addition to lower maintenance needs, Shuda notes that fiber lasers also have a much smaller footprint and have less cooling requirements. When these things are combined with the fact that their lens is made from non-hazardous material, the fiber laser is relatively eco-friendly.

Fiber lasers offer longer life, too, which complements their low need for maintenance and relative eco-friendliness. Arteaga reiterates that it can be up to 13 years before maintenance is required, which is “quite a long lifespan for that type of laser technology.”

Ease of operation

Perhaps one of the most shop-friendly features of a fiber laser – aside from its fast cutting speed, low maintenance and long service life – would be its ease of operation.
“Any customer that uses a Bystronic CO2 laser can work with a fiber-laser control system right away. There’s really no learning curve at all,” Arteaga says.

Arteaga also explains that because a fiber laser’s physical delivery system does not wear down over time, unlike the mirror-delivery system on a CO2, the operator doesn’t have to worry about readjusting the cutting parameters. This makes a very consistent laser beam.

“Your beam is consistent, therefore your cutting results are consistent,” he notes.

Also, both laser technologies are controlled through a CNC. If you know how to program a Hypertherm EDGE Pro CNC, you can operate a Hypertherm HyIntensity fiber laser. And the cutting process with a fiber laser is easier overall because, according to Picard, some of the factors that cause problems in cutting with a CO2 are simply not present when cutting with a fiber laser, which are machine vibration and beam delivery that can vary with temperature and humidity.

Pricing

According to Lee, the pricing of fiber lasers is very competitive when compared to CO2 lasers.

A CY Laser using a standard 5 ft. by 10 ft. table, says Denipoti, would be “in line or slightly below five to 10 percent [in price]” when compared to a CO2 laser unit. Those numbers go up for the larger 8 ft. by 14 ft. table – the company’s prices “are more competitive in the range of 30 to 35 percent, even 40 percent in some cases.”

In regard to the cost of owning fiber laser equipment, Denipoti specified that it’s about $15 to $16 per hour of use, including the cost of utilities and maintenance.

Despite all this, it should be noted that when looking on a watt-per-watt basis, the fiber laser may actually be more expensive than the CO2, according to Picard. However, this is made up for by the fact that the wavelength of its energy is such that, up to a certain material thickness, you can “typically do the same work with half the power.”

As an example, Picard says: “In our space, while we’re going up to 12 mm or half-inch mild steel, our 1.5-kW fiber laser actually performs like a 3-kW CO2. And it’s priced comparable to a 3-kW CO2.”

Safety issues

 Even with all their advantages, fiber lasers, just as with any industrial machinery, can be hazardous to an operator’s safety. When operating a fiber laser, it is imperative that the operator wear eye protection.

Shuda says that the one-micron wavelength of energy of a fiber laser is “actually more hazardous to the eye than a CO2 laser.”

Picard explains that the light energy from a CO2 can hurt the cornea of the eye, and this can usually be repaired through surgery. But a fiber laser’s energy, due to its wavelength, “goes right through the cornea, doesn’t really hurt it, and [instead] goes to the retina, and the retina can’t be repaired by surgery.”

Therefore, when using a fiber laser, an operator needs to wear eye protection or check with the manufacturer on what types of safety measures have been built into the machine.

One company among the 16 offering fiber lasers, as of this article, that supplies fiber lasers worldwide is Salvagnini America.

In early 2008, the company was researching new technical developments in lasers and was informed by their supplier of CO2 lasers about fiber-laser technology, says Bill Bossard, president of Salvagnini America.

“The initial information was pretty astounding to us, especially in two specific areas: that it cut so much faster, and that its cost of operation was sometimes as much as five times lower,” he says.

After learning about fiber lasers, Salvagnini then talked with IPG and completed a prototype mock-up that was adapted to their current platform and then put on display at Euroblech in October of the same year.

While the solution offered by Hypertherm focuses on OEMs since it’s easily integrated into an OEM’s system, Salvagnini’s fiber laser solution is a simple design that allows job shops to use one quickly.

Bossard says that, unlike many other companies’ fiber laser products, Salvagnini’s machine is not a retrofitted CO2 laser.

“The Salvagnini machine is specifically designed for fiber from the ground up,” he says

In this way, the company can truly take advantage of the fiber laser’s full potential, leading to better overall performance.

Salvagnini’s laser also completely automates the material-handling process, which is another strength of its equipment.

The company will have shipped 100 fiber lasers to customers worldwide by the time this article is released.

“I don’t think anybody has the depth of experience on fiber-laser cutting that we do,” he says. “Right now, I would say that we are the leading supplier of that technology on a worldwide basis.”

As this article points out, fiber lasers offer a myriad of advantages: faster cutting time, higher efficiency, lower maintenance, longer service life, lower environmental footprint, ease of operation and competitive pricing.

Considering these advantages, could there be a fiber laser in your future?

Denipoti thinks so. He says, “The magnitude of change of going from a CO2 to a fiber laser, in my opinion, is similar to going from [having] no lasers to [having] lasers 20 years ago. At this time we find that, realistically, there is no reason not to buy a fiber laser, if you have the choice.”

Bystronic

Coherent

CY Laser

Hypertherm

IPG

Rofin

Beam Delivery

Many companies offer the fiber laser system as a whole. Laser Mechanisms is a bit different in that it offers the individual components necessary for the beam delivery in fiber lasers.
Laser Mechanisms, according to their website, is “the recognized world leader in the design and manufacture of laser beam delivery components and articulated arm systems.” Their products fit every industrial application and are used with every type of laser, including fiber lasers.
“We produce beam delivery as custom units specifically for a customer, as well as standard units that fit a lot of general applications,” says Tom Kugler, Laser Mechanism’s fiber systems manager. “So we easily customize our equipment for the customer, and we can also make high-volume standard equipment that most customers will find work for their systems.
“For example, [take] our fiber-cut robotic beam-delivery series: With just a few different versions, we can pretty much cover all the applications that a customer might have.”
Kugler emphasizes how Laser Mechanisms works with the customer.
“We typically will produce and engineer a drawing, give them a 3-D model, [and then] work with them directly to engineer and build it — and that’s generally at no extra charge.”
The laser beam delivery system that the company offers starts with the customer’s fiber output, and connects a collimating system to that physically. The collimated beam then goes through the rest of the delivery system.
If necessary, it can be further focused with mirrors, fiber optics or other elements. After that, it will pass through a gas nozzle system, which may have tips that are a millimeter and a half with capacitive height sensing, depending on the application.
If necessary, the nozzles might also be larger to accommodate shield gas for welding.
Laser Mechanisms typically also builds viewing systems for cameras or monocular or binocular systems into the beam delivery so operators can align it as needed.
Kugler explains further: “Most of the beam delivery system involves collimation, more manipulation of the beam to get it to the focal point, viewing systems, gas nozzle systems that might involve capacitive height sensing, or shield gas delivery for welding. “We even manufacture very high-power systems that use directly-cooled reflective optics, rather than transmissive lenses, to minimize focus shift and make a very robust beam delivery system – we’re talking systems in the 5 to 10 to 20 kilowatt range for those.”
As far as pricing for Laser Mechanisms’ beam delivery systems, Kugler says that they’re “usually less expensive,” since all the engineering and manufacturing is done domestically and in high volume.
Kugler wants to ensure that people know that Laser Mechanisms is willing to work with the customer for their specific needs in regard to a beam delivery system.
“The basic message is that we do standard and custom equipment, and we can pretty much produce anything a customer needs from this facility.”

Laser Mechanisms, http://www.lasermech.com/