Page 32 - MetalForming August 2017
P. 32

6-kW Fiber Laser
   BMG’s initial fiber-laser cutting machine, when cutting with nitrogen, doubled the cutting speed on material to 1⁄8 in. thick compared to using CO2 machines. Cutting speed for the company doubled again when it upgraded to a 6-kW LCG-AJ machine (above). As an example, when processing 11-gauge mild steel (the nest on the right), cutting speed went from 300 in./min. with the 4-kW fiber laser to 630 in./min. with the 6-kW machine. On the left: 7-gauge steel cut at 310 in./min.
F1 CO2 6k
F1CO2 4k
FOM2CO2 4k
The Right Laser Machine for the Job
     325 300 275 250 225 200 175 150 125 100
75 50 25
                                                                  14ga - P5J11064
11ga - 118540
10ga - 120696F Sample Parts
7ga - 118942
0.25" - 118894
Shown is how cutting speed and, ultimately, the processing time required to cut specific parts at BMG, varies based on material thickness and the type of laser-cutting machine.
be separated and sorted.
“We have found that the labor sav-
ings gained by sorting each nest as they are completed provide a better return than does running lights-out,” Bren- neman says.
Making Nitrogen
Another cost-saver for the company: use of a pressure-swing adsorption (PSA) system to generate the nitrogen it needs to feed its four laser-cutting machines. Compared to the costs of having nitrogen cylinders delivered to the shop by a local gas distributor, or having said distributor regularly fill an onsite bulk tank, generating nitrogen onsite from dry, compressed shop air with its PSA system saves BMG thou- sands upon thousands of dollars/yr.
Analysis conducted by Brenneman shows that on an annual basis, the shop would have to spend $186,000 on liquid nitrogen. Generating its own nitrogen costs the company $56,000/yr. to feed its four machines, for an annual savings of $130,000.
“In order for us to grow and remain competitive,” Brenneman says, “we have to reinvest in the technology and equipment to meet our production goals, without increasing our floor space. A big part of that achievement is upgrading the laser-cutting machines as the technology allows so that we can increase efficiency and productiv- ity, and expand our capabilities.” MF
backup plan to cut 3⁄8-in. plate should our CO2 machine be running at capacity or go down for maintenance, we’ve developed a specialized oxygen-cutting process. We can use that process to cut the plate using the 6-kW fiber machines.”
Brenneman again offers an example, citing a cutting speed of 70 in./min. on 3⁄8-in. plate with the 6-kW CO2 machine, and 95 in./min. on the 6-kW fiber machine cutting with oxygen.
That oxygen process, Brenneman explains, revolves around tweaking the cut conditions provided by Amada. Technicians adjust laser-pulse fre- quency as well as the ratio of beam power to cutting speed, to obtain the
desired edge quality.
“Now that we have refined the oxy-
gen-cutting process for cutting 3⁄8-in. plate on the fiber machines,” says Bren- neman, “we’re turning our attention to cutting 1⁄2 in. plate on the fiber machines.”
BMG’s laser-cutting machines run 24 hours/day, five days/week. Howev- er, the company does not run lights- out or unmanned. Instead, explains Brenneman, it prefers to staff the shop while the machines run, so that oper- ators can pull parts from the nests and stack them immediately, rather than coming into work in the morning fac- ing stacks of nested parts waiting to
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