Laser texturing is a laser beam forming technique for imparting specific properties to the surface layer of an workpiece. In the machine industry, laser technology is more associated with cutting, bonding and marking than with precise surface shaping. Illustrations 1 and 2 show examples of the use of laser texturing.
As shown in Figure 2, laser texturing allows the application of not only colored markings but also engraving of the surface. It is a treatment that gives the final surface texture. This technique is particularly suited to the production of molds and dies in plastics processing (eg tire industry, plastic packaging, automotive lamp reflectors). Thanks to this, it is possible to obtain certain functional and visual properties of final products (eg camera or smartphone case). In the past, the method of photochemical etching was used to create a specific texture. However, with this method, it was not possible to talk about repeatability, which constituted a serious limitation of this method.
Illustration 2 is an example of the versatility of the GF Machnining Solutions AgieCharmilles Laser P machine (figure 3), which provides the possibility of different processing of the surface layer of the workpiece and giving it different properties. It is possible to reproduce the rainbow color transition in the selected outline. Thanks to this, you can create a specific watermark on the surface of the mold, which will be mapped on the surface of the final product. An important feature in these cases is high contrast. This is a desirable feature in the case of engraving and marking because it naturally improves the readability of, for example, alphanumeric data.
An alternative method is to use EDM (electroconstriction). Application of this method to give a specific texture surface using a working electrode made of copper or graphite. The disadvantages of this method include the rate of electrode wear, which is particularly evident in the case of copper electrodes. The cost of making electrodes is a factor significantly affecting the cost of EDM.
Laser texturing – advantages
Laser texturing has the advantage of not only because of the high accuracy of geometrical dimensions, repeatability, processing time but above all due to the synergy of these factors, which enables:
- increasing the usable properties of final products (eg in an ergonomic context – a better, more reliable camera grip);
- modification of visual features of the product surface;
- better adjustment to the modern nature of production scale (unit and small lot).
The design of the AgieCharmilles Laser P400 / 600/1000/1200/4000 and 1200 U Dedicated families by GF Machining Solutions are constructions based on the already proven machining solutions of CNC milling centers. As a result, laser texturing can be done on workpieces weighing from 4 to 20,000 kg. In the case of the GF Machining Solutions AgieCharmilles Laser P 4000 the maximum travel in the X axis will be 4000 mm.
However, the efficiency of these technological machines depends primarily on the type of laser – ytterbium and laser head equipped with:
- an additional red indicator for the positioning of the laser head;
- a high-resolution camera supporting the positioning process and enabling the monitoring of the ablation process in real time;
- a nozzle extracting the vapors from the treatment process;
- two scanners;
- probe (positioning of the workpiece);
- nozzle for blowing with compressed air;
- focusing lenses (specify the size of the laser beam spot: 25, 40 and 70 μm), which are rapidly exchangeable components.
As befits the machine tool construction company GF Machinins Solutions and in the case of the AgieCharmilles Laser P family, some models (Laser P 600 and 1000) are predisposed for technological processes with a higher or high degree of automation (fig. 4).
The laser texturing method is constantly being developed, and the work concerns, among others, even more effective ablation process, which would significantly shorten the processing time and thus allow for wider application in industry. It should be mentioned here that within the AgieCharmilles Laser P family, the Laser P 1200 U Dedicated machine is just a technological machine dedicated to a specific production, namely for the manufacture of side molds of tire walls.
- GF Machining Solutions information brochures
- Notes and author’s own observations.