Laser Etching: Everything You need to Know

What is laser etching? Laser etching is a surface marking method where a focused laser beam interacts with the top layer of a material to create visible marks. A laser etch does not cut deep into the object. Instead, it changes the surface texture and color. Many people ask how does laser etching work, and the simple answer is that heat from the laser melts the surface slightly to form contrast.

Laser etching is sometimes written as lazer etching, and while the spelling is different, the process being discussed is usually the same in everyday use. Today, laser etching is widely used because it is fast, flexible, and suitable for many laser etching materials.

1. Working principle of laser etching

In the evolution process of engravers, we generally distinguish between laser etching and laser engraving. Understanding simple theoretical principles may play an intrinsic role in our better completion of the carving process. This is especially important when learning what is laser etching and how does laser etching work in real production settings.

To put it simply, laser etching is a surface marking process. Through the contact between the laser beam and the material surface, only the workpiece surface is melted, forming a clear contrast in texture. The laser beam must provide high energy that can melt the outside. The result is a black, white, or gray marker. This laser etch method is famous for its versatility in laser etching metal and glass applications, and it works well with many laser etching materials.

From the birth of the first continuous laser beam in 1960 to the invention of the CO2 laser four years later, laser etching technology has gradually been used for laser welding, laser cutting, and other applications. Now, laser etching has been used in automobiles, aerospace, electronics, military, and other industries. It is most widely used in manufacturing, etching serial numbers and barcodes on various parts and sub-assemblies of automobiles, aircraft, medical equipment, and other industrial products. This shows how does laser etching work in large-scale production environments.

2. Is laser etching permanent?

There are a few different types of laser etching. These include CO2 laser etching, YAG laser etching, and fiber laser etching. Each laser etching material reacts differently depending on the laser source used.

CO2 is the most common type of laser used for this purpose because it's affordable and can be used on many different materials including wood, metal, and glass. For beginners learning what is laser etching, CO2 machines are often the first choice.

YAG lasers are better suited to smaller projects like jewelry or personal items like name tags because they're more precise than CO2 lasers but also more expensive to buy and maintain due to their high power output (upwards of 10 kW). Fiber optics are another option if you want something that produces less heat than CO2 or YAGs but still offers high precision. They are usually used for engraving text onto metal surfaces such as watch faces or cufflinks, especially when a clean laser etch is required.

3. Differences between Laser Etching, Laser Marking, and Laser Engraving

Differences between laser etching and laser marking

Laser marking is the process of forming marks on the surface of materials. Although this sounds like laser etching, there is a big difference between the two. In laser marking, the material will not melt or evaporate. Instead, the laser heats the surface, causing the material to stain due to oxidation. In contrast, laser etching involves melting and/or evaporating the top layer of the material to produce voids or micro bumps that highlight the desired shape or pattern. This distinction helps explain how does laser etching work compared to other marking methods.

Differences between Laser Etching and Laser Engraving

Laser etching is faster, but laser engraving is more durable. This is because the energy required to reach the melting point of the material in laser etching is less than that required to evaporate the material in laser engraving. Deep laser engraving may even require multiple laser scans and inevitably takes longer.

You can laser etch glass. The glass is laser etched with the Monport 40W CO2 laser to obtain a gray-white effect and enhance the contrast of the design. In addition, laser etching of glass is preferable to laser engraving because it is a fragile material, and making deep grooves will weaken the glass. This makes laser etching material choice very important.

Different cutting depths
One obvious difference is the cutting depth, which plays an important role in the visibility and wears resistance of the mark. The cutting depth depends on the hardness of the material and the rated power of the laser mark. But laser etching makes the surface melt and has a little cutting effect, which is why a laser etch is usually shallower.

Different yields
Engraving has been the most cost-effective choice in some industries, while laser etching is a cost-effective choice with higher output because it has better versatility across different laser etching materials.

Different durability
Compared with engraving, laser etching mark does not have good wear resistance. Generally, etching marks last about 5 to 10 years, making them unsuitable for manufacturing heavy products or products exposed to harsh conditions. Laser engraving products are very durable due to deeper indentation because their engraving marks are not easy to wear.

Different costs
Under the same design, same material, and output requirements, the cost of laser engraving is higher than that of laser etching, because it requires more time and high power laser technology.

How to perform laser etching?

1. What materials are suitable for laser etching?

Laser etching is a process that can be performed on a variety of materials. Understanding laser etching materials is key to getting good results.

Materials Suitable for Laser Etching include:

• Metals (steel, copper, brass)

• Wood

• Plastic (acrylics, polycarbonate)

• Glass (flat or curved)

• Ceramics

Each laser etching material reacts differently, so testing is always recommended before production.

2. What type of laser can be used for laser etching?

Some sculptors may think that only fiber lasers can be used for laser etching. This is because etching is a process for metals, which react better to fiber lasers. In fact, the laser you need depends on the type of material you want to etch, not your marking process. Therefore, CO2 laser engraving machines can also realize the laser etching process on some materials, especially non-metals.

The nature of the material determines the frequency required to properly penetrate the material and achieve permanent marking. In view of this, fiber laser and CO2 laser can easily produce this effect. Ideally, optical fiber lasers can only penetrate metals and other materials that require high frequencies. On the other hand, CO2 lasers will penetrate glass, wood, and other low-frequency materials. A CO2 laser engraving machine is a good tool for laser etching glass and similar laser etching materials.

3. Process parameters of laser etching

The optimal process parameters of laser etching depend on the materials used for etching and the laser engraving machine. Some of the most important process parameters that affect the quality of laser etching are laser power, etching speed, spot size, and focus distance.

Choose the Mid-range Laser Engraver
The power of the engraving machine used for etching cannot be too small or too large. It is better to use the engraving machine with medium power. The power is generally better to be above 30w. High power laser usually causes excessive burning of materials, which is not conducive to some minor laser etch details.

Do not use Air Assist
The etching speed should be lower than the general engraving speed. It is also easy to overlook that it is better not to use laser air assist. Air assist uses compressed air to protect the focus lens, promote the removal of engraving materials, and reduce the heat generated by the laser beam. However, using laser air assist during laser etching will cause slight traces of materials on the surface and reduce the etching quality.

FAQs about laser etching

1. What is laser etching commonly used for?

Laser etching is commonly used for marking serial numbers, logos, barcodes, and decorative designs on metal, glass, plastic, and other laser etching materials.

2. How does laser etching work on metal?

How does laser etching work on metal mainly depends on heat. The laser beam melts the surface layer of the metal, creating contrast without deep cutting.

3. Is laser etching the same as lazer etching?

Lazer etching is just a common misspelling. It usually refers to the same laser etching process in casual or online use.

4. Can a laser etch wear off over time?

Yes, a laser etch can wear off, especially in harsh environments. Laser etching marks usually last 5 to 10 years depending on use and exposure.

5. What is the best laser etching material for beginners?

Wood and acrylic are often considered the best laser etching materials for beginners because they are easy to mark and show clear contrast.

Conclusion

Laser etching is a great way to add a personal touch to your business. It can be used on many different materials, including glass, metal, and plastic. Laser etching allows you to create custom designs that are unique and eye-catching. It's also an affordable option for small businesses looking for ways to stand out from their competitors in the marketplace. Understanding what is laser etching and how does laser etching work helps businesses choose the right process andfor their needs.