First, there are two recognized principle of laser marking machine:
1) Hot working
A laser beam with a high energy density, which is a concentrated energy flow, irradiates the surface of the material being processed, absorbs the laser energy at the surface of the material, and generates a thermal excitation process in the irradiated area so that the surface of the material coating temperature rise, resulting in abnormal, melting, ablation, evaporation and so on.
2) Cold working
UV photons with a high load of energy that interrupts chemical bonds in materials (especially organic materials) or in the surrounding media to the point where the material undergoes non-thermal processes. This type of cold working is of particular significance in laser marking because it is not thermal ablated but does not produce the thermal damage side effects that interrupt the cold stripping of the chemical bonds and therefore does not heat the inner layer and the vicinity of the surface being machined Or thermal deformation and so on.
Second, common classification of laser marking machine
The most common laser marking machine according to different lasers can be divided into: CO2 laser marking machine, semiconductor laser marking machine, YAG laser marking machine, fiber laser marking machine.
According to the different visibility of the laser is divided into: UV laser marking machine (invisible), green laser marking machine (visible laser), infrared laser marking machine (invisible laser).
1) YAG Laser Marking Machine: Krypton lamp as the energy source (excitation source), ND: YAG as a laser-generated medium, emit a specific wavelength can promote the production material level transition to release the laser, the laser energy amplification After the formation of laser processing of materials on the beam.
2) CO2 laser marking machine: CO2 gas is charged into the discharge tube as a medium for generating laser. When a high voltage is applied to the electrode and a glow discharge is generated in the discharge tube, gas molecules can be released and the laser energy can be amplified After the formation of laser processing of materials on the beam.
3) The semiconductor side of the pump YAG laser marking machine: the use of wavelength of 808nm semiconductor laser diode pumped Nd: YAG medium, the medium produces a large number of inverted particles in the Q switch under the action of the formation of a wavelength of 1064nm giant pulsed laser output, electro-optical conversion efficient.
4) Semiconductor end pump YAG laser marking machine: directly from the laser crystal end of the pump light (808nm) pumped into the optical lens group to produce laser output. Make line light conversion efficiency greatly improved.
5) Fiber laser marking machine: laser output directly from the optical fiber.