Laser marking is generally some form of non-contact labeling on a workpiece or material with a laser beam. Marking is both precise and repeatable thereby yielding consistent results. There are multiple processes that can be classified as laser marking such as engraving, surface annealing, ablation or removing material, frosting (for bar codes), foaming, and staining. Each technique has certain advantages depending on the requirements needed as well as the substrate.
Laser engraving results in removing material creating an impression in the workpiece. The depth of the engraving can vary precisely. Staining is a process that will change the chemistry of the material and generally produces a contrast mark; mostly used in plastics. Ablation is the process of removing material from a material surface. This is commonly used in marking anodized, coated, or painted surfaces. Annealing is a process whereby the laser produces a heat affected zone in which oxidation occurs under the material producing a dark (often black) contrast. This works particularly well on stainless steel. Finally, foaming is a process used mostly in dark, opaque plastics in which gas bubbles are produced in the material which in turn will lighten the areas that have been marked.
Laser Marking (both flat and rotational) can be achieved on a broad spectrum of materials: metals (including brass, copper, stainless steel, aluminum, carbon steel, nickel, silver, gold, super alloys, titanium, tungsten, nitinol, bronze); ceramics; polymers (rubbers and plastics); wood; glass; leather; card stock; carbon steel; brick; or virtually any material.