Acrylic Laser Cutting: How to, Process, Best Laser Cutter
Learn more about acrylic and the different factors to consider when laser cutting with this material.
Acrylic is a widely used thermoplastic and is favored for its optical clarity. It is a low-cost alternative to transparent polycarbonate. Acrylic laser cutting and engraving are relatively easy on low-powered CO2 laser cutters.
There are two types of acrylic: cast and extruded. Cast acrylic is better suited for engraving, and extruded acrylic is best for cutting. These types of acrylics are more commonly known by the trade names Perspex® and Plexiglas®.
This article will discuss what acrylic is, how to laser cut and engrave it, what steps to take when laser cutting it, and what the optimal acrylic laser cutting settings are. Figure 1 below shows a laser-cut acrylic part:
A transparent acrylic laser cut part.
Image Credit: Shutterstock.com/Edinaldo Maciel
What is Acrylic?
Acrylic is a thermoplastic that is naturally transparent but can also be colored. It can refer to any material that contains acrylic acid or acrylates. Acrylic is often used as a shatterproof glass replacement due to its optical clarity and strength. It is brittle and will crack rather than bend. Acrylic is known by different trade names, such as Plexiglas® or Perspex®. It is sold as cast or extruded acrylic sheets. Various additives can also be added to acrylic to improve various properties such as UV resistance, electrostatic dissipation, and abrasion resistance.
What Are the Uses of Acrylic?
Acrylic has many uses that take advantage of its low cost, optical clarity, strength, and ease of use. Acrylic laser cutting and engraving is a popular method of producing acrylic parts. Some typical applications are listed below:
- Awards
- Lenses
- Marketing signs
- Artistic products
- Furniture
- Glass replacement
What Are the Types of Acrylic?
Acrylic plastics are generally broken down into cast acrylic and extruded acrylic. Extruded acrylic comes in sheet form, either transparent, semi-transparent, or opaque, and is relatively flexible. Cast acrylic is also cast into sheets and produces acrylic with excellent clarity, at the expense of increased brittleness. Cast acrylic is best for laser engraving as it produces a frosty white color when engraved which is sometimes desired if filling an area.
How to Laser Cut Acrylic
Laser cutting acrylics are relatively simple. The basic steps for achieving good quality cut acrylic parts are listed below:
- Select material: For cutting, extruded acrylic is better. Cast acrylic is best for engraving.
- Prepare material: Acrylic sheets are often sold in relatively large sizes. Most entry-level and mid-range laser cutters have relatively small beds, so the acrylic must be cut into smaller sheets before it can be used. This process can be done with a table saw or jigsaw.
- Prepare design: Next, the design file must be prepared. This can be done using laser cutting software which turns images or line drawings into a set of laser instructions for the machine. Make sure the correct settings are used for optimal results. Most software packages have presets for acrylic.
- Cutting: Load the cutting instructions into the laser cutter. Make sure the enclosure is secured and the ventilation system is functional, then begin cutting.
- Finishing: Once the parts have been cut, they can be removed from the machine and post-processed. With the right settings, acrylic parts will have a very smooth cut edge that requires no further processing.
Is it Hard to Cut Acrylic?
No, cutting acrylic is not hard. Cutting acrylic is just as easy as cutting any other type of plastic with a laser cutter. It is, however, recommended to reduce the amount of airflow blowing onto the cut to produce flame-polished edges which means they are transparent and glass-like which is especially beneficial for acrylic.
What is the Process of Laser Cutting Acrylic?
The most common type of laser cutter used for acrylic laser cutting is a CO2 laser. This laser works by ionizing a glass tube filled with CO2 gas using a strong electric field. These molecules then release photons of a specific wavelength that bounce back and forth in the tube with the aid of opposing mirrors, one of which is semi-transparent. Once the light reaches a certain intensity, it passes through the transparent mirror and is directed to the cutting head by a set of mirrors. A focusing lens in the cutting head focuses the light into a high-intensity point which melts and vaporizes the acrylic. An air blast system will blow out any melted acrylic from the cut. However, multiple-pass cuts are often preferred to cutting through the material in one step.
What Are the Settings for Laser Cutting Different Materials?
Table 1 below lists some recommended settings for acrylic laser cutting and engraving:
| Material | Power (W) | Speed (mm/s) | Points Per Inch (PPI) | Passes | Depth (in) |
|---|---|---|---|---|---|
Material Cut (Extruded Acrylic) (6 mm) | Power
(W) 100 | Speed
(mm/s) 2 | Points Per Inch
(PPI) 1000 | Passes 1 | Depth
(in) 0.25 |
Material Vector Engraving (Cast Acrylic) | Power
(W) 2 | Speed
(mm/s) 4 | Points Per Inch
(PPI) 1000 | Passes 1 | Depth
(in) 0.005 |
Material Raster Engraving - Shallow (Cast Acrylic) | Power
(W) 22 | Speed
(mm/s) 100 | Points Per Inch
(PPI) 500 | Passes 1 | Depth
(in) 0.002 |
Material Raster Engraving - Deep (Cast Acrylic) | Power
(W) 100 | Speed
(mm/s) 90 | Points Per Inch
(PPI) 500 | Passes 1 | Depth
(in) 0.01 |
Table Credit: https://academics.design.ncsu.edu/
What is the Speed Needed When Laser Cutting Acrylic?
The required speed for acrylic laser cutting depends on the thickness of the sheet and the power of the laser. The cutting speed decreases as the thickness of the sheet increases. At 100 W a laser can cut 3 mm acrylic at 25 mm/s and 25 mm acrylic at 0.3 mm/s
What is the Minimum Power When Laser Cutting Acrylic?
As a general rule of thumb, cutting acrylic requires at least 10 W for every mm of acrylic.
What To Keep in Mind When Laser Cutting Acrylic
When cutting and engraving acrylic, turning off the air jet can prevent unwanted frosting which is a white dusting-like appearance near the cut edge. It's important to ensure that the ventilation system is enabled to prevent any fires. When cutting thicker sheets, it is often better to perform multiple cut passes instead of trying to cut the sheet in one pass.
Can I Laser Engrave Acrylic?
Yes, acrylic can be easily engraved. Even transparent acrylic can be engraved. Cast acrylic produces the best finish when engraved, and is often used for custom manufacture awards.
How to Laser Engrave Acrylic
The process of laser engraving acrylic entails the following steps:
- Make sure to use cast acrylic for laser engraving. Cast acrylic produces a crisp matte finish after engraving.
- Cut the sheet to size so that it can fit into the machine.
- To get the best results, engrave on the back side of the acrylic sheet, i.e mirror the design during cutting so that it is the right way around after engraving.
- If rastering across large areas of fill, it may be beneficial to slightly defocus the laser beam so that larger areas are covered when shading. This process prevents the unpleasant effect of having areas filled with many thin lines instead of a continuous fill. This is only recommended on sheets less than 6 mm thick as a thicker sheet will require a higher power beam which may melt the plastic.
Ready to laser-cut acrylic? Check out our Custom Cut Acrylic Services.
What is the Best Laser Cutter for Engraving and Cutting Acrylic?
The Glowforge® plus is the best laser for cutting and engraving acrylic. The Glowforge® has preset profiles for cutting and engraving acrylic. This feature allows users to get started without having to figure out the optimal settings for themselves. It also has an optional filtered ventilation system, which is critical for the safe and effective cutting of acrylic. The ventilation system removes the vaporized acrylic by-products, which can result in a fire if not removed. These laser cutters are also relatively affordable for small businesses, at approximately $5000 per unit.
Are There Alternative Tools to Cut Acrylic Aside From a Laser Cutter?
Yes, there are alternative tools to cut acrylic aside from a laser cutter. While laser cutting is the most optimal solution for cutting acrylic, there are some other methods, as listed below:
- CNC Mills: A CNC mill can easily cut thick acrylic sheets to almost any profile.
- Table Saw: A table saw can be used to cut acrylic as long as the correct blade is used. These typically have more teeth than wood-cutting blades.
- Box Cutter: Acrylic is brittle. A blade can be used to score the acrylic, which can then be broken, similarly to glass cutting.
- Waterjet Cutting: For complex cuts in thick acrylic, waterjet cutting can also be used.
Summary
This article laser cutting and engraving acrylic, explained what the process is, and discussed the different factors to consider when using this process. To learn more about laser cutting acrylic, contact a Xometry representative.
Xometry provides a wide range of manufacturing capabilities, including sheet cutting and other value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.
Copyright and Trademark Notices
- PLEXIGLAS® is a registered trademark of Röhm GmbH.
- PERSPEX® is a registered trademark of ICI Chemicals & Polymers Limited.
- Glowforge® is a trademark of Glowforge Inc. CORPORATION DELAWARE.
Disclaimer
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