The craze for laser engraving, marking and etching is increasing day-by-day because of the regulations set by the government regarding product identification.

All of them provide permanent marking solutions that can add that distinct mark on your products.

But, there are only a few people who understand the difference between them. While these three techniques look similar, their applications set them apart.

The major difference between laser marking, engraving and etching lies in what they could do to the marking surfaces. The difference also lies in how deep the laser goes and the way it changes its overall appearance.

Laser marking damages the surface of the material, whereas laser etching and engraving removes the portion of the area it marks.

The other difference between laser engraving and etching is the depth at which it enters the surface.

Without any further ado, let’s explore more differences between them.

1. Laser Marking Process

Laser marking is the process when beam comes in contact with the surface of any material and alters its properties or appearances. You should use laser machines having parts like Mazak parts, Fanuc spare parts, and Fanuc CNC parts for best laser marking results.

Here we have mentioned steps for laser marking which will give you some insights on how it works.

• It uses a method called distortion by moving a low powered beam across the material.
• This creates high contrast marks without damaging the material.
• Laser heats the material and causes the oxidation under the surface turning the material black.
• It uses low temperature to solidify the surface.
• The major advantage is that all these steps do not damage the surface.

Now, let's look at some of the characteristics which make it different from the other two:

• Laser marking is not a common thing and there are only a few that provide these services.
• It is known as laser coloration, laser dark marking or charring when it works with plastic materials or annealing metals.

There are four types of laser marking:

                 - Annealing

                 - Carbon migration

                 - Foaming

                 - Coloration

Laser marking is popular in the medical device industry for marking stainless steel and titanium parts, but you can use it on other materials as well.

A laser market is perfect for bar codes, UID codes, QR codes, logos, etc.

2. Laser Engraving Process:

In laser engraving, the laser beam physically removes the surface of the material and exposes a portion of the image at the eye level.

Let’s look at laser engraving steps:

• Laser releases excessive heat during the engraving process which results in vaporization of the material.
• It is a quick process that vaporizes materials at each pulse.
• This makes the surface vulnerable and noticeable to eyes and you can touch it too.
• If you want deeper marks on the material then make sure that you repeat the process several times.

• Below mentioned are features of laser engraving which will help you know the difference between them and the other too:

There are three types of laser engraving:

                 - Etching

                 - Deep laser engraving

                 - Laser ablation

The major difference between the above three engraving types is the surface you are engraving and how much you remove.

• Maximum engraving depth for metal is 0.020” but it can even go as deep as 0.125” in materials like graphite.
• Mostly, people use engraving when they want to create personalized items.
• It is not suitable to mark the critical parts.
• It is the fastest way to create a mark with a laser.
• It’s suitable for parts expected to experience high wear and tear.
• You can use it to engrave serial numbers and logos, among other things.
• You can engrave on almost any kind of surfaces like metal, plastic, wood, leather, and glass.

3. Laser Etching Process:

It is a subset of laser engraving. It occurs when the heat from the beam melts the surface of the material. For best results, invest in parts like Mazak parts and Fanuc CNC parts.

Below mentioned are some of its characteristics:

• It uses excessive heat to melt the surface of the material.
• It expands material to create a raising mark.
• The depth here is 0.001”.

The major difference between laser etching and the other two are:

• Laser etching changes the reflectivity and increases the contrast of the metal and so it is preferable when you want to provide a better finish.
• It removes 0.001” or less from the material.
• Etching works on bare, plated metal surfaces, polymers or ceramics.

Wrapping it up:

I know there’s a lot of confusion about these terms among people which is common and people use it interchangeably very often, but there are wide differences between them and their applications. After selecting the process, make sure you are choosing a laser machine with the right laser parts like Mazak parts, Fanuc spare parts, etc.

Laser, a technical word, is one of the most common words which we have been using and hearing for a long time.

But,

Did you know that laser is an acronym for “Light Amplification by Stimulated Emission of Radiation”? It is a byword for efficiency and quality in materials processing since its emergence in the sixties.

It offers an entirely new way of using energy which helps manufacturing, medicine, and communications. You can heat, melt and even vaporize materials using lasers. It is an ideal medium for channelizing intense but controllable energy.

But they are most popular for cutting.

So, let’s brush up the basics of laser cutting and its uses?

Laser cutting is the thermal process that focuses laser beams on a particular area to melt material. It uses a coaxial gas jet to eject molten material and create a kerf.

As the laser beam or workpiece moves continuously under CNC control, it produces a cut.

There are three varieties of laser cutting:

1. Fusion Cutting
2. Flame Cutting
3. Remote Cutting

Let’s look at each in brief.

Fusion cutting: This cutting uses molten material to expel the kerf. Nitrogen gas does not react with molten material and as a result, it does not contribute to the energy input. It is advisable to use lasers with Trumpf spare parts and Fanuc spare parts for the best quality work.

Flame cutting: This laser cutting uses oxygen along with other gases and exerts the mechanical force on the molten material. This, in turn, creates an exothermic reaction which increases the energy input process.

Remote cutting: In this laser cutting, the material partially evaporates because of the high-intensity laser beam. As a result, this cuts the thin sheets without using any gas.

You can use automation in the laser cutting process using offline CAD/CAM systems. It helps in controlling three-axis flatbed systems or six-axis robots for three-dimensional laser cutting.

With the improvements in accuracy, edge squareness, and heat input control, the laser cutting technique is replacing other profiling cutting techniques like plasma and oxy-fuel.

Let’s look at the most vital thing in a laser cutting machine which we tend to forget easily.

Yes, you guessed it right, we are talking about the lens in laser cutting machines. We often forget that lenses can affect the thickness of the cut which is important for the cut.

So, let’s understand how it works.

In laser cutting, you focus laser beams using a lens (sometimes a concave mirror) on a small spot where you need to produce a laser cut.

One can define a lens by its focal length. And what is focal length? It’s the distance from the lens to the focused point.

There are two basic things which affect the efficiency of laser cutting:

1. Focused point diameter(d)
2. Depth of focus (L) - Focal Length

The effective distance which gives you satisfactory cuts is known as the depth of the focus. You can also define it as the distance at which the area of the spot doesn’t increase beyond 50%.

These two things, depth of focus and focal spot diameter, depend on the raw laser beam diameter on the lens and the focal length of the lens. And on the spare parts you use. For best results, use Trumpf spare parts and Fanuc spare parts.

Understand, constant raw laser beam diameter decreases the focal length of the focusing lens which results in smaller focal spot diameter and focus depth.

If there is a constant focus length lens then it increases raw beam diameter which reduces the spot diameter and depth of focus.

To compare lasers with different beam diameters we use focus f-number, which is focal length, F, and then divide it by incoming raw beam diameter, D.

There are two major requirements you need to consider for laser cutting:

1. High power density which focuses on small spot size.
2. Long depth of focus to process thick materials providing a reasonable amount of tolerance to focus on position variation.

But, the problem occurs when we realize that these two requirements are in conflict and you need to make some or the other compromises.

Hence, you need to consider the fact if the focal length is short, then the lens would be closer to the workpiece which can cause damages to the lens during the cutting process.

Wrapping it up:

It is necessary to understand the basics of any machinery part before you buy it. Because as an owner of that product you need to understand why you are investing in that thing and how even a small machinery part can impact highly on your business. Also, make sure to replace any worn out parts with only high-quality parts like Trumpf spare parts and Fanuc spare parts.

Picture this scenario:

You are offloading a sheet of cut parts from the laser machine. From all these pieces, you will pick up a few pieces to reveal clean edges for the next step. And you leave the rest of the pieces with the burred finish.

In order to avoid such burred finishes, you need to know which parameters you exactly need to work on. Here are some handful of strategies to help you get the burr-free prints the way you want.

What Causes Burr?

During the process of laser cutting, the laser beam’s intense energy brings the metal beyond its melting temperature, and the powerful action of the assist gas leaves the metal from the kerf. When you use nitrogen, the cutting process relies on the beam’s energy to melt the metal. When carbon steel is cut, the oxygen interacts with the hot metal for an exothermic reaction. And that adds extra heat.

This is why you don’t need as much gas pressure to eject the material. With oxygen cutting, you have much lower pressure and slower dynamic flow of the gas. Overall, these burrs form from the molten metal solidifying faster than its evacuation. The solid material becomes a deposit at the bottom of the kerf. You can also control the burr by using the right nozzles, Mitsubishi spare parts, and Fanuc spare parts.

The Gas Dynamic

When it comes to nitrogen assist gas, operators need to make changes with quality, efficiency, and costs in mind. It can make up to 35 to 50 percent of the variable cost in laser cutting. Hence, it is important to control the overall consumption. When you set up cutting parameters, it is important to minimize the nozzle diameter. It is also essential to choose the smallest nozzle diameter that you can use to achieve the anticipated quality and performance.

After determining the smallest nozzle diameter, you need to determine the lowest possible pressure to obtain a quality cut with good molten metal separation with no burrs.

It is not the Speed

A burr-free finish is not something achievable with nozzle diameter and gas pressure. You also have to pay attention to the spare parts you are using. Make sure they are either Mitsubishi spare parts or Fanuc spare parts. Additionally, when you go too slowly, you might end up injecting more heat than needed in the kerf. And this might end up raising the temperature to an extreme level. Eventually, it causes vaporization which disturbs the gas flow

That disturbance, in turn, causes more burrs, not less. This means that an operator can make cut quality worse by slowing the feed rate.

You can prevent such events by increasing the cutting speed incrementally.

Consider Oxygen Cuts

When it comes to oxygen cutting for carbon steel, consider the exothermic reaction. It is a fact that with both CO2 and fiber lasers when you increase oxygen global purity to 99.95 percent or above, you can increase the cutting speed in production. Sometimes between 30 to 40 percent.

When an oxygen vacuum flask or cylinder has a drop in purity level, it is usually argon. It happens because the oxygen gets produced cryogenically in an air-separation unit, both oxygen and argon liquefy at similar temperatures.

When you add argon into it, it changes the exothermic reactions. It, in turn, affect the cutting performance. The exothermic reaction works in conjunction with the gas flow rate to burn and evacuate the molten material. If the molten material and oxidized slag aren’t removed effectively, it remains as a burr on the cut edge.

At last pumping

In most laser cutting systems, installers know to avoid elbows in the gas plumbing or to oversize the piping diameter to compensate for pressure drops. With downtime and gas not flowing to the laser, air penetrates and fills the pipe. It can cause problems when the laser is restarted for the next shift or operation.

Final Words!

In order to achieve the burr-free cut, the beam parameters and gas dynamics should work together to ensure the right amount of molten metal evacuates the kerf at the prime time.

Utilizing heavy machinery demands its proper usage to avoid pitfalls. Whether a novice or an experienced engineer, it is important to learn how you can avoid common mistakes while operating heavy machinery like Laser engraving. It may harm its sensitive parts as not all the parts come with a great resistance power except for Mitsubishi spare parts and Fanuc spare parts. 

When issues occur, you might end up just guessing what went wrong while using it. So, to help you we have come up with common mistakes you might be making. 

1. Using Wrong Fabrics

Using laser on a fabric which cannot withstand with it will end up burning. Research and understand which fabrics can combat high power settings during the process. Denim, leather, canvas can resist high power settings. When you use delicate fabrics, set your settings at high speed and gradually lower the power to 5%-10%. And to avoid wasting any material, test a small piece, in the beginning, to see if the fabric can withstand. Adjust the power until you get the results.

While attempting direct-to-garment engraving, lower the DPI (dots per inch). Engraving at a lower DPI will ensure the laser vaporizes the top layer and doesn’t burn entirely through the fabric. General engravings work best at 150 to 300 DPI.

2)Using the Wrong Acrylic

There are two types of acrylic used in laser engraving. 

1. Liquid Acrylic
2. Extruded Acrylic

Liquid acrylic is best when producing cast acrylic sheets and objects. You pour it into the molds to set into various shapes and sizes. It is the perfect type of acrylic for engraving as it turns frosty white color while engraving. It won’t give your projects flame-polished edges on cutting it with the laser.

Another type of acrylic used for engraving is Extruded acrylic. A machine turns extruded acrylic in sheet format. And because of the high-volume manufacturing technique, it is less expensive.  It cuts clean with smooth outputs and produces a flame-polished edge. And when used for engraving, it provides you with clear engraving. So, if you want a frosted white finish, do your engraving project with liquid acrylic.

3) Inconsistent Glass Engraving

While you are using laser engraving on glass, sometimes it does not get through it properly. As a result, it fractures the surface. Eventually, it will produce the fractured glass surface with a frosted appearance. Rough and chipped. 

To avoid that and produce a smooth frosted finish, here are some tips to help you:

• User lower resolution. Up to 300 DPI. As you separate the dots you are engraving, it will produce better results.

• A DIY tip: Apply a thin, wet sheer of newspaper or a paper towel to the area to help with the heat dissipation. It improves the overall process. Make sure the paper you are applying is flat and not wrinkled.

• You can also try changing the color black in your graphic to 80 percent black.
• Polish the area with a non-scratch scouring pad. 

• User better laser parts. Mitsubishi spare parts, Fanuc spare parts will increase the efficiency of your machine. 

• Apply a thin layer of liquid dish soap in the area.

4) Not Getting Same Results while Wood Engraving

We see maximum engraving happening on the wood. It is one of the most laser-friendly materials available out there. As woods have different types, they might react differently to laser engraving. For example, if you make a large square from a piece of cherry, it would have a uniform appearance. If the same piece was made out of oak, it might vary in height with a non-uniform appearance.

• To smoke and debris, try engraving from the bottom up.

• Wipe off the surface of the wood with a damp cloth when engraving the stained wood.

5) Lack of Efficiency in the Engraver

When it comes to maintenance, it is important to clean the machine on a regular base. You get the manuals along with your machine. It is also important to inspect the optics on a weekly base when needed. Notice when your optics look smudgy. Because that’s when you have to clean them.

Conclusion

These are the most common mistakes you could be making. If you are a manufacturer, designer, or a layman, avoid these mistakes and increase the efficiency of your laser machine.