The Ultimate Guide to Laser Engraving Acrylic

Laser engraving acrylic is a popular process that involves using a laser beam to etch or engrave designs onto acrylic surfaces. Acrylic is a durable and versatile material that can be used to create a wide range of products, from signs and awards to decorative items and jewelry. In this article, we’ll explore the benefits of laser engraving acrylic, the applications of this process, and how to get started with laser engraving acrylic.

PETG Sheet

Acrylic Tube

Acrylic Rod

Acrylic Sheets

Types of acrylic for Engraving

Acrylic broadly refers to heat-sensitive plastic manufactured by a wide range of brands. The other names used in the industry include Lucite and Plexiglas. There are different types of acrylic utilized for different applications.

When it comes to laser engraving applications, cast and extruded are the primary types of acrylic used. Before you begin experimenting on acrylic with your laser, it is vital to know which material fits your scope of needs.

Cast Acrylic 

Which is made by pouring liquid acrylic into the space between a set of tempered glass sheets. A rubber gasket of a specific thickness is inserted between the sheets to define the desired thickness. Meanwhile, the monomer solidifies and hardens into an acrylic polymer sheet.

When engraved, cast acrylic transitions to a frosty material that is sought after in many customization applications. It can be molded into different shapes and sizes and is often used to make awards, thanks to its good optical quality.

Extruded acrylic

Just like cast acrylic, extruded acrylic is also commonly used in laser engraving projects. To manufacture extruded acrylic, pellets of resin are fed to an extruder that in turn melts them. This molten mass of plastic is then passed through a die on high pressure to make a molten sheet after which this sheet is moved across rollers to create the thickness and surface finish.

Making extruded acrylic is easier than making cast acrylic and this makes extruded acrylic cheaper. Additionally, extruded acrylic creates clean and smooth engravings with flame-polished edges.

So instead of a frosted look which is the case with cast acrylic, you will have a clear laser engraved product. It is also much softer and has a tendency to gum up during the rotary engraving process. Extruded acrylic is great for blanks, profile-cutting letters, and shapes that require a polished, smooth edge.

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Other factors to consider when choosing the acrylic to use

When looking for the best acrylic to use for your laser engraving project, you have a choice between extruded and cast acrylic. But there are other factors worth considering – e.g. the color of the acrylic. Most people often settle for clear acrylic because it is popular and easy to work with. However, if you are looking for something out of the ordinary, try a tinted color such as red, gold, jade, or sapphire.

Opaque colors are also quite amazing. Some of the opaque options that are readily available on the market include black, white blue, red, and brown. You could also choose a mirrored accent which is simply the normal acrylic which is laminated with material on the top, bottom or the side for a stunning colorful reflection and a unique distinction.

What are the Engraving methods of Acrylic?

What is laser Engraving?

What are the correct laser settings for engraving acrylic?

The appearance of your acrylic engravings product will largely depend on the settings:

Focus

The focus of the laser beam is most important. Generally, if you engrave huge fill areas on material, you will end up with horizontal raster lines that make your engraving coarse and unpleasant.

The raster lines uphold to create an ugly horizontal pattern shown on the product. To reduce these lines, enlarge the laser spot size. Searching for a focus lens with a cone-shaped beam. This is what enlarges with distance as it moves away from the focal point. best practices on focus are as following:

• Avoid defocusing  less than 6mm;
• Only defocus if the cut edge has wavy lines at the bottom or it’s not straight;
• Defocusing ensures better beam usage;

Power and speed

Low power and high speeds generate the best outcomes for Laser engraving acrylic. Working on painted acrylic or one that is screen-printed on the side, turn the power up by 10%  but keep the speed on unpainted acrylic. That gives the laser more energy to cut through the paint.

Sometimes, occur a few problems when engraving acrylics such as melting or cracking. when you are using too much heat. The solution to this problem is reducing the power or increasing the speed of the laser. Refer to your laser system to identify the correct speed and power settings for the material you are working on.

The suggested CO2 Laser speed and power settings for Engraving Acrylics are as follows:

Frequency

The material in question will determine the ideal frequency setting of your laser. A good way to begin on a high frequency of 10,000 – 20,000 Hz on cast acrylic and a lower frequency of 2,000 – 5,000 Hz on extruded acrylic. A lower frequency results in a low pulse which in turn increases the pulsed energy or reduces the constant energy in the acrylic. This phenomenon causes less boiling, flaming, and slower cutting speed.

Exhaust

Having some form of suction beneath your acrylic is optional but highly recommended. It can help you get rid of gases that may otherwise get trapped in the cut kerf. This helps to avoid flaming, controls frosting of the acrylic and prevents the gases from igniting. Compressed air of 15PSI (maximum) in a large cone diameter should do the trick.

How Does a CO2 Laser Engraver Work?

The laser engraver consists of a gas-filled tube with mirrors on either end. One is reflective and the other one only lets a considerable amount of light pass through. To produce light, electric power is passed through the gas tube which comprises of nitrogen, carbon dioxide, helium, and hydrogen.

The beam generated travels through the machine with the help of the mirrors until it reaches the laser head where it is magnified and focused on a single point. The result is a very powerful laser beam that can cut through a wide range of materials including paper, wood, rubber, plexiglass, plastic, leather and cloth.

When an electric current is passed through the gas tube, it stimulates the nitrogen molecules causing them to be excited thereby releasing energy. Once both nitrogen and carbon dioxide molecules are excited, the laser machine reaches a state of population inversion. This means that the excited particles in the system are more than non-excited ones.

To produce a light beam, the nitrogen atoms must lose their excitement by releasing energy as protons. This can only take place if the nitrogen atoms come in contact with extremely cold helium atoms. This contact causes the nitrogen molecules to release light. Nitrogen gas is preferred over other gases because it can become excited for long periods of time without really giving off its energy in the form of light or protons.  

The laser produced by a CO2 laser is very powerful when compared to normal light. This is because the mirrors surrounding the gas tube reflect most of the light traveling via the tube.

It is this reflection that causes the nitrogen light to build intensity as it travels back and forth in the tube. Even though the light from a CO2 laser can engrave many materials, you need a powerful machine to cut through steel and other materials.

The common ones used in machining fall in the range of 25 Watt and 100W while the high-powered can be as high as 10,000W. The light produced is infrared and therefore invisible to the human eye. The light also has a long wavelength (approximately 10.6 micrometers).

Advantages of CO2 lasers

CO2 laser engravers are high-power machines that fit perfectly in the personalization industry. Check out some of their advantages.

• Precision: With a general hole center deviation of between 0.1 and 0.4 mm and a contour deviation of 0.1–0.5 mm, you are guaranteed a perfect cut and a smooth surface finish.
• Perfect for thicker materials: CO2 laser can engrave on thick materials(above 5mm), both a fiber laser. However, the latter will ensure you get a smoother, high-quality finish.CO2 lasers will deliver a faster initial piercing time and quicker cutting, especially on a straight line.
• High production efficiency: Compared to other laser engraving technologies, CO2 lasers have a high production efficiency. High-speed engraving and etching can be done immediately and resembling the pattern output from the computer software.
• Safe and reliable: CO2 laser technology is a non-contact process meaning the light beam doesn’t touch the material it is engraving on. Instead, it allows the material to melt on its own through intense heat. This way, your material is exposed to minimal mechanical stress. Additionally, you will have zero“knife marks” and hence no damage to the workpiece surface and no deformation of the material.
• Eco-friendly: CO2 laser engravers don’t use chemicals or UV light during the process of engraving. They only need a small amount of carbon dioxide and water to function. This means there is limited emission and waste. When working with a CO2 laser, the working environment of the operator is greatly improved. As a matter of fact, the only time you have emissions is when working with plastic.
• Lower cost: If you have a smaller batch of processing, a CO2 laser is the most affordable option since it’s not limited by the amount of processing. Compared to other laser technologies like fiber, CO2 lasers are reasonably priced. Ultimately, the power of the individual machine determines the cost but they are generally cheaper.

In conclusion

laser engraving acrylic is a versatile and durable process that can be used to create a wide range of designs and products.By following these tips and guidelines,you can create high-quality laser engraved acrylic items that are sure to impress.Contact us now for our laser engrave service!

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