Traditional ink-based methods are not the exclusive choice for imprinting variable data, such as expiry dates, on your packaging. In this era, lasers emerge as a remarkable alternative, and it’s crucial to comprehend that laser coding deviates from conventional printing. Rather than adding ink, lasers act as subtractive agents, employing a high-energy light beam to eliminate ink, coatings, or materials and thereby forming the desired code.
In the present landscape, there exist three distinct laser coding architectures, each possessing its unique characteristics. Let’s delve into each of them.
Pulse lasers, introduced in the 1980s, unleash a singular and intense pulse of light. This luminosity undergoes a path through an array of stencil masks, skillfully reflected by mirrors, and precisely focused by lenses onto the packaging material. They prove to be exceptional in scenarios where high-speed applications are necessary, accommodating more than 1,000 products per minute. Nevertheless, a drawback lies in the cumbersome management and replacement of the masks, resulting in a somewhat bulky design.
Dot matrix lasers adopt an approach similar to inkjet printers, utilizing a sequence of relatively less intense light bursts to craft the code. Two different architectural approaches are implemented in this category. The first entails generating a continuous sequence of light pulses, converging them onto the packaging material, much like a continuous inkjet printer. The second method involves multiple lasers transmitted via fiber optics, triggered on demand to produce the desired code, resembling the functioning of a drop-on-demand inkjet printer.
Steered beam lasers maintain a continuous stream of diminutive light pulses. These pulses are meticulously guided by a pair of mirrors, navigating the X and Y axes to meticulously inscribe the code onto the product surface. Although the pulses remain discreet, they overlap slightly, creating a visually cohesive and fully formed character. This meticulous technique enhances readability and elevates the aesthetics of the coded information.
It’s vital to note that lasers do not exhibit universal compatibility with all materials. For instance, most packaging lasers encounter limitations when dealing with high-density polyethylene (HDPE), primarily due to the wavelength of laser light and the molecular spacing of the plastic. However, lasers excel when marking other types of plastics. In the case of printed substrates, a contrasting color block is essential to attain optimal results. Where lasers do exhibit their prowess, they emerge as a brilliant and effective solution.