The CO2 laser is generated through the excitation of a gaseous mixture based on carbon dioxide, helium and nitrogen. The main difference for the user is in the transmission method, in the size of the light beam and in the energy consumption. The transmission method in the Fiber Laser takes place through an optical fiber of different sections depending on the application. In CO2, however, the beam is reflected through a series of mirrors to the cutting head. The CO2 laser, therefore, historically has dimensional limits and high maintenance costs for the adjustment of the mirrors.
The spot of a fiber laser is an order of magnitude smaller than CO2. Energy is therefore very concentrated. The cutting speeds for a fiber laser on thin thicknesses of stainless steel or aluminum are therefore very high. On the contrary, the cut quality intended as surface roughness for the aforementioned materials is better in CO2 technology.
Finally, the electrical power installed with the same power of the laser source is approximately 50%.
The advantages of the fiber laser are a reduction in the cost of cutting for three factors::
– Cutting on thin thicknesses is up to 100% faster.
– The energy cost for the same nesting is 50% less.
– Maintenance costs are practically zero.
The limit of the fiber laser is the field of use limited to sheet metal, while the CO2 laser can also cut fabrics, plastics, glass.
The fiber laser has a light frequency that is dangerous to the eye and therefore the cabin must be closed with special and certified glass. This makes handling of the sheet less easy (loading from above or inserting small sheets) and visual process control.
Finally, the surface roughness is greater than with the CO2 laser and for some applications not acceptable. However, in recent years excellent results have been obtained by changing the laser frequency mode and bringing the quality of the two technologies very close.
The general principles of cutting are the same in terms of focal position, power or speed. However, the parameters are not the same. The fiber laser due to the reduced focal size is much more susceptible to material quality changes.
To correctly size the investment, it is not enough to know the types of material and in which sheet format. It is very important to understand how often thickness / material change, the type of production, the quality of the material that will be purchased, working spaces in the company, value of the asset in the future, level of knowledge of the working staff.
The two main elements that could overturn the investment are the power of the generator and the level of automation (automatic loading and unloading), which must be considered carefully also in collaboration with the sales representative.
There is no definitive answer to this question. The historical limits of the plasma are the drawing tolerances, the taper, the thermal alteration, the presence of burrs and the diameter of the holes. For the Laser, on the other hand, the limit beyond the level of investment on medium-high thicknesses is represented by the speed and variability of the process depending on the material (e.g. degree of surface oxidation). It is necessary for the customer to analyze his production and identify its added value. Whit the same cut thickness the choice between a contractor and a manufacturer of own machinery could be different: having to cut 10-15 mm of carbon steel, the most suitable investment will depend on the number of slots / holes or on the intended use of the product?
Another field of application is ventilation. The laser, due to its cutting speed, precision and repeatability, has acquired some market share. However, the difference in terms of investment and use of a plasma cutting with an air generator still rewards plasma in numerical terms.
Historically, in plasma cutting, stainless steel has been cut in nitrogen/nitrogen or with dedicated and expensive mixtures. Thermal Dynamics more than 25 years ago introduced a nebulization technology on the secondary water in order to cool the cut and make it shiny and immediately weldable. In recent years Hypertherm, with the XPR series, has bridged this technological gap: the market, in fact, over the years has rewarded this solution also for the cost of cutting. The water, although it must be filtered and requires its own system, is cheap compared to nitrogen or H35.
The automatic gas console is becoming more and more popular. This accessory allows you to adjust the cutting gases and amperes directly from the NC according to the programming. The system becomes more and more independent from the operator (advantage in a historical moment where qualified operators are difficult to find) and allows the marking.
In some models of the latest generation of cutting generators, the automatic gas console has become an integral part of the basic solution and no longer an optional, given its widespread use and relatively low cost.
Oxy-fuel cutting is a technology dedicated to cutting medium-high thicknesses of carbon steel. Cutting speed is slower compared to plasma and multiple torch solutions are often used to run the same profile at the same time. The first torch represents the master and the others will be the slaves.
The oxy-fuel technology is often underestimated, the particular being huge iron plates. On the contrary, working with oxy-fuel technology requires great knowledge of the process. Furthermore, the margin of error is very small: making a mistake in an oxy-fuel piece can correspond to a loss of thousands of euros.
The technology has focused on the control part during the breakthrough phase, in the ignition of the torch and the capacitive sensor.
During the breakthrough phase, the molten material comes out and must be managed in different phases in order not to damage the torch. The ignition of the torch is now internal, therefore safer and always managed by the NC.
Customers cut different materials, usually Carbon Steel, Stainless Steel, Aluminum. When cutting for many hours, aluminium or titanium produce dust which, if in contact with a spark, flame or electric discharge, can generate a deflagration. The ATEX filter has a reinforced structure and a back pressure relief system and is always equipped with a safety rotovalve.
When the hole is made with a thermal cutting system, the surface is thermally altered and harder. Consequently, a subsequent tapping/threading operation becomes very complicated. The drilling unit also allows you to countersink: the distance between the sheet and the tool attachment is known and therefore the depth of the countersink is very accurate.
This equipment is ideal from a production logistics and repeatability point of view.
XDREAM is a unique product that Promotec has been producing since 2012 and a flagship of Made in Italy.
The combination of the two technologies allows to use the best in terms of cutting quality and/or speed and/or cost of use. The user interface is already set up to select the technology on the different cutting lines, making programming very simple for the technical office. The ideal customer for this solution produces large plates even with the need for subsequent welding (plasma that can be equipped with bevel as an option), in which internal processing such as high-precision holes and slots are required.
XDREAM is also useful for contractors who can always manage the cost of production to a minimum and who have two technologies in the same company space