DISK LASERS: CALCULATING THEIR APPLICATION IN MODERN 2D LASER CUTTING
This efficient technology uses comprehensive, compelling and unique energy management to save on resources and make money for fabricators on a full range of laser cutting applications.
The future of 2D laser cutting will be defined by the diverse laser wavelengths available for flatbed laser cutting machines. Alternative laser sources for specific applications are giving modern sheet metal shops the ability to diversify while selecting the most cost effective laser source for their respective applications.
To this end, there are intense discussions by research institutes in an effort to determine the ideal laser source for future 2D laser cutting applications. These same discussions are considerably more laid back when held with sheet metal fabricators. The end user, regardless of if it is a job shop or an OEM, is interested in the best solution for its parts as well as the quality and capability of the total “laser and machine” package.
The efficiency and profitability of the machine in respect to the part spectrum is the determining factor. The most profitable machine is the one that can produce parts in the most cost effective way.
Historically, the CO2 laser was the only viable option for 2D laser cutting. However, with the development of modern, robust and reliable solid-state laser technology, customers now have options when choosing the machine and laser source that fulfills their needs in the most cost effective and profitable way.
There are two types of lasers now used in 2D cutting: CO2 lasers for industrial applications emit light in the mid-infrared spectrum with a 10 micron wavelength and multi-kilowatt solid-state lasers have a ten times shorter wavelength of about one micron. Disk lasers fall into this one micron category.
The shorter wavelength emitted by one micron lasers has decisive results for the laser cutting process. As many metallic materials better absorb the light of a shorter wavelength, particularly in thinner gauges, superior process efficiency of a disk laser is shown in these materials. These lasers are also able to cut nonferrous materials, such as copper and brass.
Compared to a CO2 laser, thin materials can be processed up to five times faster using a disk laser while utilizing significantly less energy. As a result, cutting times are reduced by up to 50 percent depending on part geometry, further reducing the cost per part.
But how does the disk laser work? How does it create its highly efficient laser beam?
It all starts with the pump source. Disk lasers use efficient diodes to pump the laser light. Together with an optimized resonator design that results in optical-optical efficiencies of up to 70 percent, the system is capable of achieving overall beam source efficiencies of well over 30 percent.
From the resonator, the beam makes its way to the workpiece through components such as the fiber-optic cable, the control system and the focusing optics. Approximately ten percent of the energy applied is lost in these components. To determine accurate consumption figures, the laser power at the workpiece that integrates the typical power losses must be considered. Calculations that only look at beam-source power consumption will often not factor in these losses.
Laser system cooling is also a major factor. Here the disk laser generates energy savings with its efficient heat exchanger and integrated water management. Realistic judgment of energy consumption should include the infrastructure and actual power usage at full laser power at the workpiece as the basis for calculation. Following this process clearly establishes disk lasers as an extremely energy-efficient laser concept.
But there’s more: The disk laser’s integrated energy management senses when the laser has stood idle for a while and will put it in standby mode. There are also gains to be had between the laser and the power station. The intelligent electricity management system found in disk lasers makes it possible to reduce reactive power as well as currents known as harmonics. This leads to additional cost savings of up to 10 percent as well as an improvement in grid voltage quality that allows medium-voltage transformers to operate more effectively.
All in all, this means disk lasers offer comprehensive, compelling and unique energy management that not only saves on resources, but also saves fabricators money.
The disk laser has become a viable option for a full range of laser cutting applications. As a result, this technology has been implemented into 2D laser cutting machines and has made its way into a wide variety of sheet metal shops in North America and around the globe. These high performance laser cutting machines are available with up to 5 kW of solid-state laser power and, while they are particularly well known for their high performance in thinner materials, they can cut up to one inch thick mild steel.
Performance such as this increasingly establishes the solid-state laser as the choice for increased efficiency and profitability.
About the Author: Stefan Fickenscher is the product manager of the TruLaser Product Group at TRUMPF Inc., 111 Hyde Road, Farmington Industrial Park, Farmington, CT 06032, 860-255-6046, Fax: 860-255-6421, firstname.lastname@example.org, www.us.trumpf.com.