What’s Laser Marking and Its Applications
Laser marking technology is one of the biggest applications of laser processing. It is a marking method that makes use of the high energy density laser to irradiate the work piece locally, so as to make the surface material vaporize or change the color, leave a permanent mark. Laser marking can mark a variety of words, symbols and patterns, the size of the characters can range from millimeters to microns, which has special significance for the product anti-forgery tag.
The basic principle of laser marking is that the laser generator generates high-energy continuous laser beam. The focused laser beam acts on the printing material to melt and even vaporize the surface material instantaneously. So that the required laser image can be marked by controlling the path of the laser on the surface of the material.
Laser marking is characterized by non-contact processing. It can mark almost all the parts (such as the piston, piston rings, valves). The mark is stand wear and tear, the technology is simple and auto-operation is easy, and the marked part is deformed little.
Given the numerous types of lasers and materials involved, picking the best laser for a marking application can be a challenge. An understanding of the laser characteristics, the material properties, and how the material to be marked absorbs laser light at the wavelength of the laser chosen is essential to making an optimal choice.
The most common terms used in laser marking include: engraving, annealing, ablation, and color change of plastics. Each of the lasers discussed can be chosen to optimize the performance of the laser marking process. When ablating day/night design components, a vanadate laser performs well due to the short pulses and pulse-to-pulse stability at higher repetition rates. This allows removal of a painted top surface without damaging pad-printed plastic base material. Ablation also is a common practice in marking anodized aluminum, which is by far the most forgiving laser process.
Another very common application is annealing stainless steel and titanium medical components such as implants and instruments. Here, it is important to have high concentrated peak energy with a slightly longer pulse duration in order to draw the carbon to the surface to achieve a crisp dark mark that will withstand test requirements such as passivation and autoclave cycles.
When engraving material, it is important to have optimum parameters in regard to frequency and speed in order to evaporate the material. Typically, lasers with short pulses and high peak power perform best for this application.
All three laser technologies will have a place in industrial manufacturing for years to come. The technology will continue to evolve in order to meet the changing demands of the manufacturing environment. When selecting a laser marker, it is important to partner with a laser company that can demonstrate the advantages of each technology as it relates the material to be marked. Many manufacturers have application labs that will test materials with a laser that fits in regard to speed, quality, and budget.