Assist gases are the most expensive part of laser cutting operations. Many fabricators use bulk nitrogen, but considering the cost, they’re often looking to reduce this expense. Typically, a nitrogen generation system comes to mind, however, high-performance dry air systems are also a viable option, if the application allows for it.
Matthew Jaskolski, national sales director for Liberty Systems, which manufactures nitrogen generators and high-performance dry air systems, says, “Dry air is a lower initial investment at about half the cost compared to a nitrogen generation system. Plus, the high-performance dry air system’s air compressor uses half the horsepower of a nitrogen generation system. The nitrogen generator has a $5 cost per hour, a traditional supply of liquid nitrogen is $16 per hour and the high-performance dry air system is $3 per hour.
“At Liberty Systems, the typical ROI on these dry air systems is one year or less on two shifts,” he adds. “the high-performance dray air system typically pays for itself.”
High-performance dry air systems, often referred to as high-pressure air, are taking the laser cutting industry by storm. Over the past few years, high-performance dry air advancements have grown into an assist gas movement.
But what is high-performance dry air? How is it different than the air from the compressor in the back of a fabrication shop? There are two major factors that set high-performance dry air apart from shop air: dryness and pressure.
“The first difference is that typical shop air compressors only have a refrigerated air dryer,” Jaskolski says. “While it is a drying system, it does not dry enough – the air is still wet. The problem is that wet air at a high pressure can cause contamination. While CO2 lasers are more forgiving because of the larger beam diameter, fiber lasers are far more sensitive. If water accumulates om the optics, debris will start to gather in those wet spots. It’s essential to have an extremely clean beam path that is dry and free of contamination.”
To ensure that the air is dry and free of particulates, Liberty Systems uses a device similar to a high-performance dry air systems. This desiccant air dryer features a proprietary blend of activated alumina and other molecular sieves that provide the clean and dry air source required for fiber laser cutting.
“The second difference in high-performance dry air versus shop air is pressure,” he continues. “If you want to cut thicker material with a fiber laser, you an air booster deliver the 400 psi. This psi level allows for cutting the full range of material and thicknesses.”
A high-pressure air system may not be for all fabricators; it all depends on the application. However, three material types make the most sense: aluminum, mild steel and stainless steel.
“The biggest benefit of high-performance dry air is with aluminum,” Jaskolski says. “The high-performance dry air, which contains around 20.9 percent oxygen, provides more heat in the cut to burn away certain properties in the aluminum versus nitrogen. This results in a burr-free edge. As laser wattages for cutting increase, we are starting to see even smoother edges with less striations, which has customers blown away.”
Mild steel is another material where high-performance dry air is ideal.
“Using dry air on 1/4-in. or thinner carbon steel is more effective versus nitrogen; in most cases, there is a slight speed increase,” Jaskolski says. “When cutting carbon steel with oxygen, there is a scale that needs to be removed before welding or painting. But with air, it is embedded into the steel. Most fabricators find this edge acceptable to weld or paint. For mild steel, we recommend customers get cut samples and test it for themselves.”
The third material that is ideal for high-performance dry air is stainless steel.
“The biggest advantage is in thick stainless steel,” Jaskolski notes. “There is a major speed increase and reduced cost per part. Mid-range thickness stainless is a case by case basis with many fabricators finding dry air acceptable for their applications.”
Since implementing their Liberty Systems’ high-performance dry air systems, bought in concert with new Mazak fiber lasers, several companies have seen phenomenal assist gas price reductions and increases in productivity.
Baxley Blowpipe Co. is a family-owned company that has been designing and installing industrial ventilation systems for more than 74 years. The Baxley job shop cuts galvanized, carbon and stainless steel and aluminum with its new Mazak Optiplex Fiber 8 kW laser and high-pressure air system.
It was at an open house at machine distributor Capital Machine in Atlanta that Eric Baxley, shop foreman and part owner, saw the high-performance dry air system and thought it made a lot of sense for his shop.
“I knew I was going to buy a laser cutter, but I when I saw the high-pressure air system in operation at an open house, I was intrigued,” Baxley says. “After seeing it in operation and realizing the cost savings that I could achieve, I did some research into investing in a system. We now have Liberty System’s D75.
“We’ve only had the system a month and a half, but we’ve already seen some gas savings,” he continues. “Because we don’t buy as much bulk nitrogen or oxygen, it looks like we are going to save $1,200 per month initially – just on gas.”
Baxley goes on to say that the shop has increased throughput by half a day using the high-pressure air system because they don’t have to wait on a supplier to resupply the gas when it runs out. When all is said and done, he estimates a savings of $2,000 per month with the Mazak Optiplex Fiber 8 kW and high-pressure air system.
“The biggest advantage has been the cost savings and not having to worry about running out of gas,” Baxley concludes. “Right now, we’re using oxygen for 1/4-in. mild steel but for galvanized, stainless and aluminum, from 20 gauge to 1-in. thick, we are using straight dry air. We have replaced our bulk nitrogen use almost 100 percent and replaced oxygen use about 50 percent.”
Fluid Power LLC is another company that has benefitted from high-pressure air. The company opened its doors 20 years ago doing hydraulic repair and consulting, but now has its own sheet metal shop, which includes a Mazak Optiplex Fiber 8 kW laser. The shop cuts mainly carbon steel, 3/16-in. steel and 1/4-in. mild steel with high-pressure air, with some stainless steel as well.
“We can run high-pressure air on the fiber laser faster than oxygen or nitrogen on our CO2 laser,” says Dustin Larue, shop manager. “We aren’t paying for gases, and we’re cutting faster than what we can on the other laser. After the initial investment, you can quickly regain that cost. As a job shop, it was a no-brainer.”
Right out of the gate, Fluid Power saw a $40 per hour savings using high-pressure air compared to oxygen or nitrogen. While the shop ran it fairly solid for about a month, the schedule changed with the coronavirus. Understandably, the company is looking forward to ramping back up to regular operations to re-evaluate the overall savings.
Samuel Jackson Inc. in Lubbock, Texas, is a third-generation – going on fourth-generation – small, family-owned manufacturing company with more than 90 years of experience. They design and manufacture specialized machinery for moisture control of fibers and cotton fibers. Components vary in size, from brackets the size of a hand to pieces the size of a car hood.
The shop processes cold-rolled mild steel and stainless steel from 26 gauge to 1/4-in. plate. One hundred percent of what the shop laser cuts is done with high-pressure air provided from a Liberty system. The company has a Mazak 3-kW Optiplex Champion 3015 fiber cutter.
“The Mazak reps connected me with Liberty Systems,” says Chris Jackson, president. “Those guys really put it in perspective for me. What impressed me was that Mazak recognized the impact the Liberty system has for its own product. It’s my job to recognize good people when I see them, and Mazak is a hotbed of good people.”
Jackson also recognizes that as an OEM, they have the advantage of knowing exactly what materials they will be cutting at all times.
“I consider cutting with high-pressure air a natural choice for an OEM like us working with relatively light steel,” he notes. “If a manufacturer cuts the same materials over and over, they’d be crazy not to consider high-pressure air.”
Welage Corp., another happy Liberty system user, began as a tool and die shop but has evolved into a modern metal fabrication company. Products cover a variety of industries, from conveyors and accessible ramps to mining, construction equipment and military hardware.
The job shop runs all types of mild steel, stainless steel and galvanized steel, but aluminum makes up for about 40 to 50 percent the company’s material. The shop has a Mazak Optiplex Fiber 8 kW laser and has gone from using nitrogen as the assist gas to high-pressure air delivered from a Liberty system.
“It’s a cost-effective option that interested us – but only as long as we were able to continue delivering high-quality products,” says Kent Holocher, laser department manager. “While using the system, we’ve been able to achieve great cuts with no quality issues at all. The transition was quick and within a week or two we had everything running well. The biggest advantage is minimizing nitrogen usage without sacrificing part quality or speed.”
Dave Welage, owner and president, adds that, “When we run high-pressure air, we achieve a 75 percent savings because we are not paying for our assist gas whatsoever. And that’s a very large savings.”
While a high-performance dry air system may not be for every fabricator, it is a viable option for many. The outcomes from utilizing this assist gas can dramatically reduce monthly operating costs, increase throughput and reduce laser idle time.