Advancement and Use of Lasers in Various Marking Industries

History of UV laser Marking Machine Development

In the early 1970s, most ultraviolet (UV) applications relied primarily on UV lamps. The development of the excimer and solid-state UV lasers, however, gave researchers access to higher-power UV radiation. Lasers rapidly became the enabling technology for many new applications. High-growth markets including semiconductor, medical, and micromachining now rely on excimer and solid-state UV lasers.

With the continuous development of UV Laser Marking Machine, the high-power ultraviolet lasers has spawned many new applications, which cannot be achieved by low-power lasers. For example, a smaller laser engraves information on the objects, which is slow in printing and inhomogeneous in colour. It can not satisfy the industrial mass production capacity. The application of UV laser marking machines in many industries is expanding, because the UV laser marking machine could get a perfect marking on the nonmetal objects, better than any other laser types. 

However, the UV laser marking machine is a series of laser marking machines, but it is developed by a 355nm ultraviolet laser. The machine adopts three order intracavity frequency doubling technology. Compared with the infrared laser, 355 UV focal spot is small, can largely reduce the material mechanical deformation and processing of small thermal effect, because it is mainly used for ultra fine marking and carving, especially suitable for food and pharmaceutical packaging materials, marking holes, high-speed glass material and the division of wafer complex graphics and other applications.

In the international advanced technology, high energy ultraviolet photons direct damage to the molecular bond nonmetal material surfaces, the molecules from the object, this way does not

produce high heat, ultraviolet laser beam machining and minimal aggregation has almost no heat effect, so it is called cold processing, it is suitable for the special nonmetal materials. 

The main features of the UV laser marking machine are high electro-optical conversion rate, high beam quality, very small spot size, and ultra-fine marking. The nonlinear crystal has a long service life, very stable operation, high accuracy positioning and high efficiency working. The modular design is easy to install and maintain, the machine overall is smaller and compact, working smoothly and stable. The UV laser marking is perfect quality, because the heat-affected zone is small, ther

e is no thermal effect, the material will not get deformed and not burnt.

Principle of UV Laser Marking Machine

The ultraviolet laser marking machine is a series of laser marking machines. Therefore, the principles are similar to those of laser marking machines. They are permanently marked by laser beams on various material surfaces. The effect of marking is to expose deep matter through the evaporation of surface matter, or to engrave traces through the chemical and physical changes of surface matter caused by light energy, or to burn out some substances by optical energy, and to display the patterns and characters needed to engrave. 

The UV laser marking machine is mainly based on its unique low-power laser beam, which is especially suitable for high-end market demand for ultra-fine processing, such as cosmetics, pharmaceuticals, medical equipment, and polymer materials. Used for marking and surface treatment of various glass, liquid crystal screen, plasma screen, plastic, textile, sheet, ceramic, monocrystalline silicon wafer, grain, sapphire, polymer, building materials, film and other materials. It is also important to know that the UV laser marking machine can mark some metals but not as deep as it would appear on a metal marked with a  fiber laser machine.

Component Parts of a UV Laser Machine

Below are the main components of a UV laser marking machine.

• Laser source- The UV laser marking machine adopts a wavelength of 355nm ultraviolet laser which is a kind of cold light. The laser source is responsible for feeding the laser beam with the adequate power it needs for marking on materials. 

• Laser marking head- The laser marking head consists of two scan mirrors, two galvanometers, drive cards, a set of softwares and DC power supply.  

• F-theta lens- The F-theta lens has a laser spot position linearly proportional to the scan angle, which offers exceptional durability and enables users to perform high precision laser material processing. 

• Control board and marking software- The control board contains all buttons and switches that are needed to control the laser marking machine.

• Computer- The computer contains all softwares that is required for laser marking processes. It supports AUTOCAD, CORELDRAW, PHOTOSHOP, etc. 

• Lifting Piller- The lifting pillar supports the laser marking head and sometimes the computer.

• 2D work table- The working table allows optimal configuration for all marking and engraving applications. 

• Power supply- UV laser power supply can be 3w, 5w or 8w with a power supply of AC220V/50HZ.

• Water cooling unit- This part of the UV laser machine is responsible for regulating the laser machine temperature.

Types of UV Laser Marking Machine VanklaserProvides to Customers

Desktop fiber laser marking machine

The stationary UV laser marking machine is an economic equipment designed to make high precision marks on certain materials such as; plastic products, electronic parts, common household appliances, PCB, glass, acrylic, certain stones, wood, garments, etc. The stationary UV laser marking machine carries less heat energy with a beam. So that materials like plastics will not be affected by heat. The marking effect is fine and can be repeatedly processed, and the high-precision and tiny spot ensures the perfect marking result, and there is no contact marking, so the marking effect is permanent.

The stationary UV laser marking machine does not require heavy power due to the fact that the laser beam does not generate heat for marking. The power requirement of our stationary UV laser marking machine is between 3w to 8w. The marking speed of the stationary UV laser marking machine is nothing less than 7000mm/s, which means that marking is done very fast which makes it suitable for a busy and demanding production industry. Many industries apply the UV laser technology on their nonmetal products for the sole purpose of identification, traceability and creative design.

Split UV Laser Marking Machine

Split UV laser marking machine is made to mark various inscriptions on acrylic, different types of plastics (PVC, PCB), certain metals, etc. The split UV laser marking machine size is more portable compared to the stationary UV laser machine; thereby suitable for small and large marking needs. 

The split UV laser marking machine adopts a high-quality and imported ultraviolet laser generator. The ultra-small focusing spot of 355nm ultraviolet light can ensure hyperfine marking and the minimum marking character can be accurate to 0.2mm. During the period of operating, the machine’s heat affected zone is inappreciable and the materials can still be nondeformable. Accordingly, the system is suitable for processing those materials that have big reactions to thermal radiation.

The UV laser marking machine adds a portable design to the traditional split body, easy to carry and  operate. 

The laser power is between 3w and 8w with a marking speed of 7000mm per second and a marking range of 110mmx110mm. The cooling mode of the split UV laser is through a water cooling system.

UV Laser Machine for Marking and Engraving Different Material Surfaces

UV Laser Marking Machine for Plastic

The most common processes for laser marking on plastics are carbonization, colour change, foaming and removing. 

Foaming– Foaming leaves a tangible mark on the plastics. It can be seen as laser-induced boiling, which melts the surface. Due to the rapid cooling, bubbles are encapsulated in the material. These bubbles leave a positive mark, which is tangible.

The laser works on a low power level and longer pulses. Foaming works on all polymers, but also on some metals. Depending on the material, the mark can be light or dark.

Carbonization- Carbonizing enables strong contrasts on bright surfaces. During the carbonizing process the laser heats up the surface of the material (minimum 100° C) and oxygen, hydrogen or a combination of both gases is emitted. What’s left is a darkened area with higher carbon concentration.

The laser works with lower energy, which leads to slightly longer marking times compared to other processes. Carbonizing can be used for polymers or bio-polymers. Since carbonizing always leads to dark marks, the contrast on dark materials will be rather minimal. 

Colour change- Colour change on plastic guarantees highest legibility. Laser marking with colour change is basically an electrical process, which reorders the macromolecules (by changing the direction). No material is removed, but partial foaming is possible.

The plastic engraving machine works with a maximum pulse rate but low energy per pulse. Otherwise material would be removed or foaming might occur. Colour change works on plastics and the change of colour can be bright or dark. Most colour changes are dark.

Removing- Removing is used with multilayer plastics (laminates). During the removal process the laser beam removes the top layers, which had been applied to the base material. This results in colour contrasts due to colour differences in the layers.

UV Laser Engraving on Crystal

Crystals are part of the materials the UV laser marking machine can engrave upon. Crystals are often used for awards and trophies, they are also used as materials for souvenirs, hence, the need to engrave on crystals. The UV laser marking machines are built with a quality galvanometer head and a laser UV power source, ensuring high quality and stability at the time of engraving with high speed without damaging the material surface. 

There are three steps to engraving a 3D crystal:

Step 1: Convert the image, logo or texts you want to engrave to a 3D series of points that the UV laser engraving machine uses as a stencil for engraving.

Step 2: Align the crystal you are engraving. Proper alignment ensures an excellent engraving result.

Step 3: The crystal is then set for engraving. The UV laser engraves each point individually and pulsed. Each pulse creates a tiny hole in the crystal. The energy at the end of the laser is what causes the distortion, therefore, allowing carving inside the crystal without damage.

UV Laser Marking for PVC

PVC is one of the common materials in our life, usually it is used as water pipes, control panels and electric cases. With a UV laser marking machine, we can make permanent colours on the surface; the marking will not damage the material surface as it is very light.

Laser marking of PVC produces high contrast marking on any colour. The process is also very fast and efficient. However, it is important to consider that the polyvinyl chloride is a polymer composed of chlorine. During the photodecomposition of the material, it undergoes dechlorination producing the emission of gas.

UV Laser Engraving on Glass

Glass engraving machines can mark 3D glass with the subsurface engraving or surface engraving using the UltraViolet laser technology. Letters, digits, and machine readable codes are transferred into or unto glass by a UV laser beam in just a few seconds. The laser markings cannot be removed or rubbed off. 

During engraving the intense laser beam creates micro-cracks on the substrate and bypassing the marking area creates a nice “field of micro-cracks” that reflects light and appears as a beautiful sand-blasted matt finish that you see in the final artifact. The actual mechanism of laser interaction with the material is rather complex. It depends on the type of laser as well as the conditions of radiation, such as its power, wavelength, focusing, frequency of pulses and more. This is so small that the integrity of the substrate is not compromised; yet big enough to create the visual effect of a matt finish.

 Conclusion

Purchasing a UV laser marking machine requires a careful and conscious decision. Understanding that the UV laser marking machine is an advanced and suitable technology for marking delicate and fragile material such as glass, making a wrong choice of laser marking machine has a way of impacting your business negatively. In order to make the right choice of laser marking machine for your business, we guide you through the process of purchase, instalment and use. 

Our UV laser marking machine continuously serves your business for long hours each day, and you can guarantee high quality marks on your products. The UV laser is easy to use and maintenance free.