Laser is a mechanism of producing electromagnetic radiation through the process of stimulated emissions. LASER means light amplification by stimulated emission of radiation.
There are many industries that are growing and die to the competition, each and every company try to produce the best modern technology. Through this competition, laser technology was implemented for many industrial applications. These include; marking, cutting, stamping, cutting, engraving and embossing. What make this technology superior than other systems is the speed, flexibility, performance and control. The marking system used software which is accessed through PCI interface card. This laser is directed by the mortar or etching files to send the laser beams and produce the required markings through the digital signals sent by the computer. There are various types of laser markings.
There are carbon dioxide laser which create a permanent marking and codes that can be traced for a lifetime. This system reduces the production cost and it can be integrated to an automatic system.
There are excimer laser which are available on different wave lengths: 157 nm, 308 nm, 248 nm ad 351 nm. It is normally applied on marking eye glasses, inkjet drilling and many other operations.
YAG lasers are the most commonly used because it can produce different wavelengths when well aligned. Infrared (1064) is the most used wavelength. The wavelength can mark several objects such as metals, plastics, ceramics and composites.
There are various processes that are done using laser marking technology.
Laser marking is a digital process where there is no any contact of the laser beam with the material. The information is applied on the surface of the material with minimum penetration. This process is done using the YAG laser which has the ideal properties for this kind of process. The texts that can be inscribed through this process include; graphics, logos, bar codes, alphanumeric texts, symbols and many other texts. The mechanism of this process is to irradiate the plastic with a high -energy radiation source. The material will absorb the radiation energy and convert it to thermal energy. The material will then react due to the induced thermal energy.
Engraved marking is a method of marking where depth is required. To produce this depth, the base material is vaporized. It is a similar process like surface etching in metals. The beam is passed over the surface repeatedly to obtain the required depth of the mark.
Thermal marking is done by controlling heat parameters of the beam. Other parameters like speed, focus, power and pulse frequency are regulated.
Special markings can be done on plastics. Contrast of the plastics can be altered. The plastics can be heated or coupled with a wavelength that causes the chemical formula to change. More additives can be introduced to achieve a variety of colors.
Surface annealing removes the carbon in the plastic to get more contrast. Sharp contrasting lines will be produced by the laser beam around the area where contrast is needed with very little penetration. It is very effective method where a smooth and undamaged surface will be achieved. It is mostly applied on medical tools