Though there was once a large cut quality gap between the two technologies, the gap between plasma and laser is narrower than ever.
Laser is renowned for delivering excellent fine feature and hole cutting thanks to its narrow kerf — roughly 0.2mm to 0.4mm (008”-.015”) on mild steel with oxygen and even narrower when using nitrogen to cut mild steel up to 25mm (1”) in thickness. Fiber laser also produces excellent cut angularity and can cut to very tight tolerances, in the range of 0.007” (0.2mm).
However, Hypertherm’s invention of high definition class cutting, along with continued advances in torch and consumable technology and the introduction of XD technology in 2008 are responsible for markedly improving the cut capabilities of plasma over the past two decades. And now a new class of plasma cutting, called X-Definition, is further enhancing plasma’s ability to tackle high precision applications. When installed on a high-quality cutting machine, equipped with linear ways and elliptical racks, for example, Hypertherm’s new XPR300 plasma system, featuring X-Definition cutting, is capable of maintaining ISO 9013 Class 1 and 2 tolerances and ISO 9013 Range 2 and 3 cut quality.
Further, an XPR300 plasma system can deliver edge surface finish that is generally smoother than fiber laser in the thicker ranges and extremely consistent edge quality over the full life of a consumable set.
As plasma kerfs can range from 1.5mm (0.05”) thickness on very thin metal and up to about 5mm (0.225”) on 25 mm (1”) thick material at 300 amps, a laser system can actually be the best option if extremely fine feature cutting or small holes (with a less than 1:1 thickness to diameter ratio) are required. But, if high quality perimeter cuts are called for, and tolerances in the range of 0.020” are acceptable, the higher cut speeds associated with plasma, especially when cutting material thicker than 10 mm (3/8”), could make plasma a better option. At this thickness, for example, a 170 amp plasma X-Definition process would deliver high quality cuts at speeds two times faster than a 4 kW fiber laser using oxygen.
In addition, Hypertherm’s invention of the True Hole process for mild steel in 2008 and further refined with the launch of the XPR300 provides the ability to easily fabricate bolt ready holes down to a diameter-to-thickness ratio of 1:1.
Another application which may favor plasma is bevel cutting. The advent of True Bevel technology, means it is now feasible to eliminate secondary operations by using plasma to quickly cut parts with beveled edges. And because cutting bevel angles increases the effective thickness of the plate being cut, plasma can have a significant advantage.
In addition, it is important to consider the initial investment cost associated with an X-Definition plasma system as compared to laser. A complete XPR300 plasma system mounted on a high-quality cutting machine and capable of cutting 25 mm (1”) at speeds of more than 1,900 mm/min (75 ipm) would likely cost somewhere between $175,000 and $225,000. A comparable laser system can easily cost three to four times more depending on the power level.
Beyond this, plasma is a much more forgiving process when it comes to cutting so called “dirty” steel such as plate with oxidation and other imperfections. It really makes no difference to the plasma arc. This is not true, however, with fiber laser. Lastly, while plasma does require personal safety devices for noise and glare protection, fiber laser systems require the construction of a safety enclosure around the entire system to protect from the potential harm of the fiber laser beam.
Are you interested in comparing the two technologies for yourself? Send an email to firstname.lastname@example.org.
Hypertherm designs and manufactures industrial cutting products for use in a variety of industries such as shipbuilding, manufacturing, and automotive repair. Its product line includes cutting systems, in addition to CNC motion and height controls, CAM nesting software, robotic software and consumables. Hypertherm systems are trusted for performance and reliability that result in increased productivity and profitability for hundreds of thousands of businesses. The New Hampshire based company’s reputation for cutting innovation dates back 50 years to 1968, with Hypertherm’s invention of water injection plasma cutting. The 100 percent associate owned company, consistently named a best place to work, has more than 1,400 associates along with operations and partner representation worldwide. Learn more at www.hypertherm.com.