UV Laser Marking

To produce a UV laser, the laser beam passes through two additional crystals that conventional fibre laser systems lack. First, By passing a standard wavelength laser (1064 nm) through a nonlinear crystal, the wavelength is reduced to 532 nm. Then, this light is further passed through another crystal, effectively reducing its wavelength to 355 nm. As a result, UV lasers are commonly called third-harmonic generation (THG) lasers because they are the third wavelength created. Marking using these lasers is called "Cold Marking", which refers to how they can perform marking and processing with minimal heat stress.

Compared with standard laser light (1064 nm) and green laser light (532 nm), UV laser light has a remarkably higher material absorption rate. This means more highly visible marks can be achieved with less power, ensuring a damage-free mark. The high absorption rate also means a UV laser marking machine tackles difficult materials such as plastics, highly reflective metals, and heat sensitive materials. For example, UV laser marking machines are used for product identification, medical device manufacturing, and aerospace components where heat damage from conventional lasers is not permitted. It is also used on different plastics and coloured plastics that are difficult or impossible to mark with the fibre wavelength.

UV lasers eliminate the need for tricky readjustment of laser marking parameters to counteract contrast decreases due to material changes, inconsistent surface conditions of moulded parts, and different resin lots. With high contrast, this robustness provides the characteristics, including resistance against ambient light, that enable marking operation with fewer failures.

The FDA requires all but Class I medical devices to contain traceability codes that machines and people can read. The "cold marking" process allows medical manufactures to mark anything, from PE medication bottles to implantable devices, with the confidence those marks will withstand stringent sterilisations cycles.

Why is a UV laser marking machine the superior choice in these types of applications? The main reason it was developed is that the absorption rate is incredibly high for a variety of materials. This allows marking and processing to be performed with minimal heat stress. It also provides reduced surface damage, allowing for corrosion-resistant marking. These attributes protect the materials or components from issues during the marking and manufacturing process. This is true even for highly reflective materials like gold, silver, and copper and sensitive materials like glass, rubber, ceramic, and plastic.

Electronic parts are becoming smaller, and their sealing resins are becoming thinner. Typical laser markers risk transmitting energy through sealing resins and damaging the internal components. However, UV laser markers have an incredibly high material absorption rate and can mark sealing resins without reaching down to the internal components and risking damage. Since a UV laser marking machine can mark sealing resins, manufacturers can add more identification or traceability marks to electronic part surfaces. Customers and manufacturers get quicker recalls and more up-to-date product information.

Quartz glass is used for windows or screens and is notable for being difficult to mark. It's sensitive to cracks yet heat resistant, requiring a gentle marking method. The UV laser uses its high absorption and power dense beam spot to mark slowly and produce clean, visible marks. The UV laser marker beam is strong enough to conquer the heat resistance yet delicate enough not to crack the quartz glass.

The 3-Axis UV laser markers use a UV wavelength of 355 nm to mark or process parts with cold-marking technology. These markers have three different axes to control the laser beam, designed for uniform marking over large fields of view or 3D shape parts. UV laser marker systems incorporate groundbreaking technology that is revolutionising the way we mark and engrave objects. Additionally, a 3-Axis laser marker allows complete control of the focal distance to keep the laser in focus through different height parts or difficult geometries.

The MD-U Series uses a proprietary sealing method to securely protect optical components. This ensures that these components are not affected by factors such as dirt, dust, and water. This also provides environmentaly resistant performance which allows for stable operation in even the harshest envirmonments. The MD-U Series has an enclosure rating equivalent to that of the fanless marking head of the MD-F. This is not the case for other UV laser marking systems.