Laser Cutting And Laser Engraving: Everything You Need to Know
Laser machines play a significant role in numerous industries, from the jewelry industry to plumbing services. Companies use them for various manufacturing purposes, such as shaping valuable gems and stones or cutting piping materials. Whether working with steel, plastic, or wood — if you have a suitable laser machine, you can mold it however you want.
But, cutting is not the only functionality laser machines offer; they are also exceptional tools for engraving. For example, you can use a laser engraver for hobby-inspired purposes at home, creating perfect replicas of fictional objects with just one press of a button.
If you want to purchase a small laser machine or order a laser cutting service but are still in the dark about this technology, read on! Below, you will find an in-depth guide to laser cutting and engraving where we explain the differences between the two. Additionally, we list some useful tips to help you pick the best laser machine for your needs.
What Is Laser Cutting?
Let's start with the process of laser cutting. It can be described as a manufacturing method involving a laser to vaporize materials to create a cut edge. It consists of a series of cuts by the laser beam that traverses predetermined geometries saved on a CAD file.
Laser cutting begins in the machine, where electrical discharges stimulate a lasing material within a closed container. This operation creates a beam reflected internally by a partial mirror until it forms a high-energy stream of monochromatic coherent light. Next, the light is transferred to a lens and out of the machine.
Main Types of Lasers Used in Laser Cutting
Laser cutting using a fiber laser cutter. Image source:Genesis systems
Since the creation of the first laser in 1960 by Theodore H. Maiman, lasers have been continuously improved. It resulted in the construction of specialized laser types, including:
- CO2 laser cutters,
- Nd (neodymium) laser cutters,
- Nd:YAG (neodymium yttrium-aluminum-garnet) laser cutters.
Each of these laser types serves specific purposes. For example, while CO2 lasers are commonly used to cut materials like cardboard, plywood, MDF, or acrylic, manufacturers usually opt for Nd: YAG lasers if they need high power boring and engraving.
Different types of lasers also work in a slightly different manner. In CO2 lasers, the gas is responsible for propagating the laser's infrared light. On the other hand, Nd laser cutting uses neodymium for the same process, allowing the machine to operate at increased pulse energy and power.
Other Types of Lasers
Besides gas (CO2) and solid-state (Nd and Nd: YAG) lasers, users can also opt for:
- Fiber lasers (a unique type of solid-state laser where the light is guided in a single-mode optical fiber),
- Free-electron lasers (lasers that use a relativistic electron beam to generate coherent, high power radiation)
- Photonic crystal lasers (lasers based on nano-structures)
- Semiconductor lasers (electrically pumped diodes)
However, these lasers are rarely — if ever — used in the processes of cutting or engraving.
Laser Cutting Methods
Much like specific laser types are employed for different purposes, manufacturers can use several unique laser cutting methods to achieve desirable effects. Here are some of them:
- Melt and blow — Also known as fusion cutting, this method uses high-pressure gas to produce the results. First, the machine heats the material to a melting point and then blows the molten material out of the kerf.
- Stealth dicing of silicon wafers — This method separates a small block of semiconducting material (called a die) from a wafer of a semiconductor. In this particular case, a pulsed Nd: YAG laser with the wavelength adapted to the electronic bandgap of silicon performs the procedure.
- Reactive cutting — Often called "flame cutting," this method uses a laser beam as the ignition source to cut very thick steel plates. It is similar to oxygen torch cutting.
- Thermal stress cracking — This method takes advantage of thermal fracture, using a beam to create cracks in brittle materials, like glass.
- Vaporization cutting — In this method, the focused beam heats the material to a flashpoint. It creates a keyhole that is further enlarged by vapor generated by the beam. This vapor also blows eject out, allowing the hole to increase in size even more.
What Is Laser Engraving?
Laser engraving, although to some extent similar to laser cutting, is a process intended to achieve entirely different goals. Instead of cutting the material into a specific shape, it is about engraving a shape, graphic, or picture on a particular surface.
Laser engravers usually generate a beam with decreased intensity than laser cutters. It makes it easier to avoid cutting too much of the material. The power produced by the laser should be just enough to leave a mark without cutting the object all the way through.
A laser engraving machine, much like a laser cutter, consists of three main parts:
- a laser
- a controller
- a surface
The primary difference between an engraver and a cutter is that the former features a lens with a shorter focal length. It provides a finer spot size for working with materials like plastic and wood.
We can distinguish two subgroups of laser engravers: stationary and non-stationary. Non-stationary laser engravers move over the desired engraving area, much like an ink printer over a piece of paper. This way, the laser can cover a larger surface area. Conversely, stationary laser engravers do not move. The advantage of this method is that the machine works faster and at higher power.
How Does It Work?
Usually, when the beam produced by the laser engraver touches the material, it heats the surface, vaporizing it. Nonetheless, it can also incise marks in some other way. For instance, some laser engravers might make the material fracture and flake off the surface. This process is known as "glassing" or "glassing up."
A huge difference between cutting and engraving is that the latter needs to deal with the debris on the material's surface. Because of this, many laser engravers have blowers or a vacuum pump that remove the debris and allow the machine to keep working without issues. An additional benefit of this solution is the removal of toxic fumes and smoke created during the process.
Laser engraving is frequently used for engraving 2D codes that have to be readable after post-process treatments (such as shot blasting and e-coating) and the procedure itself.
What Kinds of Materials Can Be Engraved?
The most frequently used materials in the engraving are metal and wood. Still, pretty much everything can be engraved — provided it offers a hard enough surface for the machine to work with. As a result, it is not surprising to see engravings on glass, leather, plastic, and fiber.
Softer materials (e.g., wood, plastic) require less power, while more rigid materials (e.g., steel) need to be treated with a higher-power beam to leave a long-lasting mark.
How To Pick the Best Laser Cutter & Engraving Machine?
If you are interested in entering the world of laser machines, an excellent way to start is to determine what you actually want to do. Do you want to cut some objects out of metal, engrave something on them, or both? Moreover, do you want to work with metal, or do you plan to use wood or plastic? Answering these questions will help you pick the best type of laser cutting machine for you.
Another thing worth considering is the machine's average lifespan, power, and the size of its work area. After all, you need different equipment for putting various shapes on wooden plates than if you were to work with plastic cutlery. Considering the average life of a laser tube spanning between 1,200 to 2,000 hours, you can expect around three months of continuous operation out of yours. As long as you want to use your machine only for hobby-related purposes, it should be a sufficient amount.
Regarding the power, you should opt for a weaker model. You do not need a powerful machine if you only need to do a few small engravings every week or so. The price of your laser cutter and engraving machine can range anywhere from $500 to $12,000. All the factors mentioned above play a role in how costly your device will be. If you still have some doubts, we recommend consulting an expert. They will help you go over all the necessary factors before making the final call.
The Bottom Line
Laser engraving and cutting are different technologies that offer additional benefits. The former leaves marks on objects while the latter cuts holes in them. Nevertheless, some machines available on the market combine both functionalities, making them worthwhile investments for mass production.
With that said, if you are looking for a laser cutting or engraving machine for your own needs, you might want to pick a model that offers a better rate of return. Think about what you plan to achieve with your equipment and consult a professional. Thanks to it, you will make a sound investment that will continue to pay off for many years to come. Good luck!
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