The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation". Commonly used for parts manufacturing and other industrial applications, fiber laser cutting involves high-powered lasers that use a short wave length to slice through tube, pipe or flat sheet. These truncated wave lengths are readily absorbed into metals, resulting in greater cutting speed and efficiency.
Some materials are very difficult or impossible to cut using traditional means due to their shape or type of metal. Conversely, laser cutting can handle multiple shapes and highly reflective materials such as brass, copper, bronze, galvanized pipe and aluminum, as the beam is readily absorbed, versus bouncing off the surface of the metal.
This absorption of the fiber wavelength and the higher power density created by the focused beam accelerates the cutting speed for thin materials that are less than 1/8” thick. Fiber laser can cut thicker materials at a faster speed, but the “sweet spot” where the most valuable benefits are is in the 1/8” and under range in comparison to CO2 lasers.
How it Works
Light-emitting diodes are pumped through a glass fiber to produce a beam of light. The beam gets delivered at a constant, unchanging length allowing for high-precision cuts on all types of metals.
The laser heats the material above its melting point in the focal point of the beam. In the same step, high-pressure nitrogen is blown from the diode to sweep the particles of molten metal out of the kerf. The cut specifications can be adjusted by raising or lowering the focal point of the beam from just above the surface of the plate, at the surface, or just below the surface.
A 4,000-watt laser can cut up to .75-inch metal. A 6,000-watt laser can accommodate an additional half inch. Examples of laser cut parts in various thicknesses can be found here.
Shapes and Sizes
One of the greatest advantages of using a laser is that it can create just about any shape required, with few limitations except the size of the part, which needs to be able to fit within the clamp and in the machine cabinet. Additionally, sizing of the shape being cut can be easily adjusted on-machine, without additional tooling.
Precision is better as the laser beam does not wear during the process. There is also a reduced chance of warping the material that is being cut, as laser systems have a small heat-affected zone, meaning that the beam only hits a small and very targeted portion of the metal.
Unlike many mechanical cutting processes, fiber lasers produce an extremely tight focal spot diameter (up to 100 times smaller compared to the CO2), producing hole sizes significantly smaller than the thickness of the substrate.
Laser cutting is requested by manufacturers in numerous industries, due to the ability to process parts easier. For example, industries such as aerospace and automotive rely on laser cutting for the reliability it offers. Parts made for high sanitary environments such as medical device and food and beverage equipment are ideal for laser cutting for both precision and the reduced risk of contamination (since there is minimal contact).
Additionally, a laser is able to deliver a cleaner edge, reducing the need for deburring or other finishing techniques used to clean up parts after cutting, as with conventional machines. This also helps to streamline any secondary operations required, and mitigates any inconsistencies that could arise from the manual process of grinding or smoothing edges.
With laser cutting it is also possible to accommodate complex machining, incorporating multiple manual operations into a single automated process. For example, a part can be bent and then easily laser cut, sometimes on the same machine. All these factors contribute to lower set-up time and hence reduced labor costs involved in comparison to manual or traditional operations.
Efficiency and Reliability
In addition to being maintenance-free with a long service life, fiber lasers are known to be more energy-efficient. Also, the laser cutting process is much safer than other forms of cutting. This is because the laser beam is emitted securely within a tight light box, offering an increased level of security and reliability for the operator.
From a labor standpoint, once a laser is set up to start a job, there is little supervision required by the machine operator until the process is complete, freeing up technicians to perform other tasks within the plant.
Overall, laser cutting can offer peace of mind for manufacturers seeking a consistent and reliable process for their parts production. For more information on laser-cutting, please click here.
This blog was authored by Marshall Arndt, Estimating Engineer, Sharpe Products. Marshall can be reached at email@example.com.