Laser marking is a process that permanently changes the color of a surface without using ink or chemicals or losing any material. CO2 lasers are often used to mark plastic, metal, glass, ceramic and wood surfaces with barcodes, serial numbers, logos, text or graphics.
The assembly, defense, metal working, fabrication, medical, military and aerospace industries all use laser marking to serialize, identify or add details to many products, ranging from pens to gun parts. This marking process is clean, inexpensive, permanent and done at high speeds-mere milliseconds are used per character. Recently, the laser cutting technique has been used to inscribe a bar code into diamonds without damaging their surface. This proves and ensures the authenticity of real diamonds. Instead of using a rotating or vibrating tool, laser marking uses CO2 lasers to alter the surface of a product. CO2 lasers create laser beams through the chemical reactions of four elements; hydrogen, carbon dioxide, nitrogen and helium. Introduced onto the market in nineteen sixty four, the CO2 laser was one of the earliest gas lasers developed as well as remaining one of the most widely used because it can be utilized for cutting, engraving and welding too.
Depending on the material, there are three different results to the laser marking process. Charring causes a black mark by heating the material so that its color changes. This is the most widely used method. Laser marking plastics will result in the formation of small bubbles in the heated polymer and heating the plastic until it melts, which leaves a clean mark. This process is called foaming. Ablation happens when plastic melts and is degraded, leaving a clean mark. These marks are high contrast, high resolution and may be very detailed. They are chemical, solvent and temperature resistant up to 1800°F. While black is the only color for metals and wood, different colored marks are available for most glass and ceramic products. An incredibly positive laser marking characteristic is its very small ecological footprint. Because there is no material shaving to dispose of nor extra ink or dye since none is used, it is an environmentally sound process. This makes it significantly more attractive to industries requiring tracking codes on their products.
