Laser marking is fast becoming an essential process in brand identification and product branding. For many years, companies such as Rolls Royce, Rolls Roofing, and Alcoa have used lasers to mark their products. A few decades ago, this technology was reserved for industrial applications. In recent years, laser marking on metals has been an active research topic. There are now a number of advanced laser marking systems available for use in the high-volume production of metal products. On numerous blogs, writers have previously written extensively about the technical fundamentals of laser marking on metal, the correct choices of keeping media and methods, and high-quality laser marking on aluminum, copper, brass, and stainless steel.
In order to apply this technique correctly, a user needs to understand the fundamentals of laser bonding and annealing. A laser beam is emitted from the laser source at a particular angle and energy pattern. Depending on the type of media to be marked, the shaft may be cast at different angles and in varying strengths. The user is able to control the thickness of the beam depending upon the properties of the media.
Annealing is the first step in the laser bonding process. Annealing is usually done in the cold environment of a laboratory. High-frequency sound waves are used to generate an annealed heat in an inert atmosphere. The heat generated affects the properties of the media to be marked. This determines how the media will react when it comes into contact with the mark. Annealing cycles are commonly used in applications where minimal alteration has to take place to the substrate.
Laser marking is often executed using an electrochemical process called laser ablation. Laser ablation is used in applications where the final product requires a stiff or hard surface, such as in the case of tool parts. In addition to using laser ablation, some metals can be treated using a secondary processing method called electrolysis. This process uses chemicals or acids to treat the metals involved in the application process. The chemical reactions that cause the marking effects are commonly assisted by an electrochemical step to increase sensitivity or reduce any potential for interaction with other metals.
The primary benefit of laser bonding is that it produces a much uniform product, even between similar metals. Laser marking is typically performed on thin to medium thickness metal substrates using fiber optics or light beams. The most commonly used metals to undergo this treatment include polyethylene (PE), polypropylene (PP), and nylon. The coarseness of the substrate typically determines how well the coating is bonded to the base metal.
Laser marking is commonly used to create barcodes, provide infrared illumination, and mark metals using short wave laser beams. The short wavelength of these lasers makes them ideal for applications where high resolution is required. Additionally, it has been found that the high energy needed to perform this process can often cause temperature changes which affect the performance of the additives. Therefore, it is commonly used in conjunction with a thermoforming process. The combination of low temperatures and coexisting coatings makes this process especially practical and extremely useful.