The Best Laser Marking Machine of 2024

Types of Laser Marking

1. Laser Engraving

Laser engraving is a widely utilized method of laser marking, commonly employed for inscribing ID numbers, crafting sketches, logos, QR codes, and various other designs. While both laser engraving and laser marking are used to create permanent marks on various materials, they have key differences in terms of the depth, appearance, and applications of the resulting marks.

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In the laser engraving process, material is removed from the surface, creating discernible depth and texture. This technique results in a 3D effect when viewed from specific angles, as well as a tactile sensation when touched. 

During engraving, laser beams elevate the surface temperature to the material's boiling point, causing it to melt and eventually evaporate. In some instances, the material may burn due to the intense heat, transforming into dust or debris.

On the other hand, laser marking, which includes techniques such as annealing and coloration, alters the material's surface properties. This process generally produces a shallower, smooth mark, with a color change or contrast visible on the surface. Laser marking is typically used for creating barcodes, serial numbers, or decorative patterns on materials like metals, plastics, and ceramics.

Laser engraving is particularly well-suited for materials such as wood, plastics, ceramics, and certain metals. When engraving metal, it is important to use a fiber laser with sufficient power to achieve the desired depth and 3D effect. Insufficient power may result in shallow markings, lacking the characteristic depth and texture of a proper engraving.

In contrast, laser marking is more suitable for applications requiring minimal surface disruption or when the material is sensitive to high heat. It is also preferable when a smooth, unaltered surface is desired, as the process does not create any depth or grooves in the material.

2. Laser Annealing

Laser annealing is a technique that uses a laser beam to heat metal slowly. This causes oxygen to diffuse below the surface of the metal and oxidize it from within. When the metal cools down, its color changes. This process is also referred to as heat marking and involves a laser beam applying a small amount of heat to the surface of an object, causing a thermo-chemical reaction . 

While the most common color produced is black, adjustments to the laser's power settings can yield other colors such as red, yellow, and green. Unlike laser engraving, laser annealing does not create cuts or deep marks; instead, the marking is formed on the surface through oxidation, maintaining a smooth appearance. Laser annealing is predominantly employed on metals, particularly titanium, steel, iron, and other ferrous materials. It is widely used in various industries for metal marking, including medical, automotive, and aerospace sectors, due to its non-invasive and precise nature.

3. Laser Foaming

In the laser foaming method, the surface of the material is melted, leading to a phase change that generates gas bubbles. As these bubbles attempt to escape from the surface, they oxidize, creating an eye-catching foaming effect. The foamed bubbles exhibit a visually appealing appearance, characterized by a lighter color, light refraction, and a glittering effect. This combination of properties lends a distinctive and exceptional look to the marked material. Laser foaming is primarily suited for plastics, and it is not compatible with materials such as metals and wood. One notable advantage of this method is that the resulting bubble marks are lighter in color than the original material, making it particularly useful for marking dark plastics.

4. Laser Carbonizing

Carbon migration laser marking is a process that occurs in certain metals and alloys containing carbon. When laser beams are applied to the material, high temperatures cause the carbon molecules to migrate to the surface, where they form bonds with surface molecules, facilitated by the heat. As a result of this bonding, dark marks appear on the surface. This specific laser marking technique is applicable exclusively to metals containing carbon, such as steel, stainless steel, titanium, and numerous other metals and alloys. By leveraging the unique properties of carbon migration, it is possible to create durable, dark markings on these materials.

5. Laser Coloration

Laser beams can generate a range of colors on both metal and non-metal materials, depending on their composition and the laser's speed, power, and other specifications. For example, when laser beams are applied to a metal surface, such as stainless steel, different colors may appear based on the settings used. This phenomenon occurs due to the oxidation of molecules on the metal surface, allowing for the creation of multicolored marks. This technique is also effective for plastics, as the application of laser beams can result in the formation of bubbles. The color of these bubbles is influenced by the laser settings and the specific type of plastic used. Consequently, the desired colored mark can be achieved on the material.

 To utilize this laser marking method effectively, it is essential to experiment with various settings on the laser machine. Through testing and adjustments, the optimal settings for achieving the desired color can be identified and applied.

Laser engraving systems face big challenges when it comes to marking on plastics. Let&#;s take a look at the issues manufacturers face and why fiber lasers are typically not the best answer.

Plastics are very diverse in their chemical and material composition, so they can be quite unpredictable when it comes to producing good markings with a laser. Most laser markers will simply overpower a plastic surface with heat, which can lead to burning, bubbling, scorching, melting, or otherwise damaging the material. With certain types of plastics like nylon, Teflon or rubber-based materials, the traditional nm wavelength of a fiber, YAG, or YVO4 laser may not absorb at all, resulting in no mark. 

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Why fiber lasers struggle with plastic

Fiber lasers use state-of-the-art technology and are the bonafide standard for industrial laser marking on most metals. At RMI Laser, we offer an array of very popular fiber lasers, including MOPA solutions. The results you get when trying to mark plastics with fiber lasers, however, can be mixed. Fiber lasers tend to be overkill for plastic surfaces due to their high-powered delivery characteristics. 

Fiber lasers that have a fixed-pulse width are particularly challenging for plastic marking because of their longer pulse duration. This exposes the plastic product or part to more heat and energy, which leads to overheating and overpowering the material that you are trying to laser engrave. 

It is possible for fiber laser users to experiment with lowering the power and changing the line spacing and the number of pulses and passes of the beam to get a better result. Lowering the power too much, however, can lead to beam instability, which can produce erratic marking results.  

One alternative is to use a MOPA-based fiber laser marker with a variable-pulse-width (duration) beam delivery. This may improve results, but at a cost premium with time-consuming experimentation required.  

DPSS lasers offer an ideal alternative

Thanks to their unique power delivery characteristics, lesser-known DPSS (diode-pumped solid-state) systems offer some inherent advantages that make them excellent plastic-marking lasers. Because a DPSS laser has shorter pulse widths, it can deliver an effective high-peak power beam that can laser engrave without hanging out on the surface too long. As a result, there is no damage due to excess heat.

One advantage of DPSS lasers is that they are able to create marks with much less power than their fiber cousins. RMI Laser offers DPSS lasers with average power levels of 1 watt, 5 watts or 10 watts compared to the 20 watts that most fiber laser marking systems use. 

DPSS lasers can be designed to produce &#;green&#; laser light at 532nm through an optical process called &#;frequency doubling&#;. Because materials like nylon and Teflon have a much easier time absorbing this type of light, DPSS lasers are able to produce a mark on them that fiber lasers cannot match.

Marking on plastics for the medical industry

In the medical field, plastic parts are crucial for many applications. Some must be marked with a unique device identification (UDI) as required by the FDA. This marking must be on the device or part itself and not printed onto a label. These markings must be permanent and not fade over time.

UDI markings cannot compromise the object&#;s strength, durability or ability to be sterilized in an autoclave (if applicable). This is why DPSS lasers are ideal &#; both in cost and desired results &#; when it comes to marking plastic medical parts. Because DPSS lasers have high peak power over a shorter pulse duration than fiber lasers, they make much more effective plastic-marking lasers. You can compare it to using a scalpel as opposed to a sledgehammer.

DPSS solutions from RMI Laser

RMI Laser produces laser markers for almost any type of industrial or medical need. Our complete lineup of DPSS laser marking systems produces outstanding results on virtually any plastic material. We offer a compact, low-powered UM-2 (1w YAG laser), a higher speed U-10 (10w YVO4 laser) and a U-5G (5w Green laser) for special materials.

Our low-powered UM-2 Micro Laser is a good laser marking machine at an affordable price point for small businesses and those just beginning to offer laser-engraved products. Its small footprint and portable design make it ideal for small work cells or even trade shows, festivals, conferences and retail environments with on-demand marking.

The user interface of the UM-2 (1w YAG) laser is simple enough that a new user can learn to operate it easily with just a few minutes of practice. Since it&#;s not a high-powered piece of equipment, it operates slower than its heftier counterparts. However, the UM-2 Micro Laser is still ideal for sensitive plastics like polycarbonate, a material commonly used in the medical industry.

If you need to output a higher volume of parts than the UM-2 can handle, we also offer the U-10 Laser, a more powerful laser marking machine designed specifically for marking on a variety of plastic materials with precision and speed. Our U-5G Green Laser marking machine is also an excellent option for super-sensitive or hard-to-mark plastic materials.

Take the next step in choosing a plastic-marking laser

If you&#;re not sure which plastic-marking laser will best suit your needs, RMI Laser welcomes you to submit a sample of your product so we can determine which machine will work the best. (See the form at the top of this page.) Before spending thousands of dollars on new equipment for your business, we recommend testing on a full range of lasers first to ensure that you&#;re getting the ideal solution.

For more mini fiber laser marking machineinformation, please contact us. We will provide professional answers.