Contents:
Neon signs with red lights, glass in the hands, heavy rainаfall behind a window drums on the canopy, and because of it headlamps of the awaiting outside car are not well-visible… In that half-noir scene, all of the decorations might be acrylic! Don’t you believe us? Read on, and we’ll tell you what can be made out of acrylic and, most importantly, how.
What is acrylic and why is it important?
Acrylic, acrylic glass, or plexiglass. Those are names for, as we can say, the same materials. The difference between the first and the third is so little that it’s insignificant. So, let’s consider them synonyms.
Acrylic is a light polymer that practically fully copies glass’s features: transparency and light conductance. But it is also deprived of its flaw — fragility. Acrylic is solid and has low thermal conductivity.
Plexiglass cannot be broken by temperature drops. And if something still could break it, then a huge amount of shards is not going to appear.However, for us and the laser machine, acrylic has bad news: it, like all of the other plastics, is easily inflammable, which is important during the work with it. Also, acrylic has a sensitive nature, so you can leave a lot of scratches on its surface.
What can be done out of acrylic
- some of the glass cover, for example, shop windows;
- advertising: outdoors signs, charms, and other branding materials;
- canopies, greenhouses, terrariums;
- modeling;
- glasses, souvenirs, lamp;
- tags, labels;
- In the car industry headlamps or protective glasses for motorcycles are made out of acrylic.
What kind of plexiglass is utilized during laser cutting
There are two types of acrylic: extruded and cast.
- Cast. It can be 1.5 mm to 25 mm thick or made in cubes. This type has a wide range of colors. Cast one shrinks less when heated; it is stronger and more heat-resistant than extruded.
- Extruded. Despite all of the minuses mentioned above, this acrylic has one important advantage: extruded plexiglass can be of any thickness and length when cast is limited at this parameter. Also, this acrylic has a higher predisposition to gluing.
Another distinction is the consistency of thickness over the entire sheet. Because of the unique characteristics of cast acrylic manufacture, it cannot be perfectly even and equal in depth, unlike extruded acrylic.
As a result, cast plexiglass is preferable for laser cutting acrylic since extruded acrylic has a higher risk of cracking due to residual stress that builds during the process, causing their appearance.
Let’s begin cutting!
Layout
The beginning of any laser business. While working with acrylic there are two major points we better pay attention to.
First, the inflammability of the material, as we previously discussed. So the external edges wouldn’t melt, you can use the special function in the RDWorks that allows you to add loops at the corners. That way, you’ll save them from overheating.
Second, the hooks. They might appear during the CO2 laser acrylic cutting. To avoid them, use the instrument “margin” in the RDWorks, which lets you leave some free space and overcut.
Setting your acrylic cutting machine
| Work area | 900 x 600 mm |
| Tube power | 80-90 W |
| Max engraving speed | 700 mm |
| Dimensions | 1490x1030x670 mm + 315 mm (if on its wheels) |
Usually, to cut 1,5 mm of acrylic, 10W of power is used. The power of the tube itself influences the speed we adjust. Or it can affect the percentage we set in the “power” field. Let’s give you some examples of customizing for 3 mm of acrylic, depending on the tube:
- 60W: power 65%, speed 16.
- 90W: power 65%, speed 20.
- 100-120W: power 65%, speed 25.
- 100-120W: power 90%, speed 10.
All four variants allow you to cut plexiglass. Here you can choose by experiments (acrylic may differ one from another based on shipment or manufacturer), or you can put the decision on the ground of time you are willing to spend for the production of a single piece.
After all, power is one of the most important things you should take into consideration while working with any material. It actually affects the maximum thickness that your machine can cut.
How to choose the CO2 laser acrylic machine, you can read in this article.
Airflow
In general, plexiglass cutting up to 2-3 mm is no big difference from other materials of the same thickness. The most important thing in this matter is proper alignment, focus length, and correctly set airflow. Way too much blowing will summon the so-called “foam” on the upper edge of the acrylic end.
While cutting thick material from 5 mm, you may run into roughness or stripes. To avoid them, it’s necessary to lower the pressure of the auxiliary air. Under the high pressure, acrylic will start to partially freeze, just like some horror-movie characters in danger, and the unwanted lines or “images” on the ends will appear.
But fully reducing airflow would be a mistake! First of all, it’s protecting the focusing lens from the carbon deposits. Secondly, it doesn’t give acrylic a chance to burst into flame.
We recommend setting the airflow to 0,5 atm. Less might be dangerous for the lens.
Other specifics
Acrylic is a transparent material, and on it, as on a blank and cristal-white paper sheet, it will be cleanly visible, even the smallest mistake during the operations. For example, a pitted edge. It is a result of the rough and abrupt movement of the laser head.
That’s why Wattsan machines are equipped with three-phase stepper motors with a 1,2 step instead of the 1,8. Also, beltgears and rubber belts 3 mm thick help with this. So, the motion becomes smoother, and the pitted edge gets lost.
Extractor. It is required while working with plastics since not very pleasant or healthy smoke, methyl acrylate, and smell are emitted in the process. And the gases, which can cause a boom. Aside from the extractor, you may make it a habit to open windows every now and then.
As previously said, airflow should be present, albeit in small amounts. Nobody wants a tiny ripple on the edges. But the clarity of the cut is guaranteed by one more thing: the nozzle.
During laser cutting acrylic, you should use a truncated nozzle with a small diameter output so that the airflow is concentrated in one direction.
Film. We don’t remove it from the material if there aren’t any complicated or little details in our layout. Otherwise, it’s better to get rid of it since it will be very difficult to do so afterwards. And be careful during the placement of the acrylic on a working table. Be patient, and keep an eye out for scratches.
Safety
As with all of the other plastics, you should work carefully with the plexiglass so you don’t damage the machine or yourself.
Due to the acrylic’s ability to inflame, the operator should stay near the equipment while it does its job.
It is also essential to use safety equipment, like gloves. In the odd event that some hot bits fall on your body, they never reach you, inflicting injury.
Post-cutting step
| Work area | 200 x 300 mm |
| Tube power | 40 W |
| Max engraving speed | 700 mm |
| Dimensions | 810x500x265 mm |
Sometimes a little bit of further development might be required after the cutting itself. A little fouling on the edges that looks like white stains can occur. You can remove it with a single hand movement; clean it with acetone, white spirit, or other agents. But, on any occasion, do not use alcohol! It might cause the appearance of cracks.
What else?
Acrylic can be operated not only by CO2 laser machines but also by milling ones. We’ve talked about that on our YouTube channel; you may watch by clicking on the link.
| Work area | 500 x 300 mm |
| Tube power | 60 W |
| Max engraving speed | 700 mm |
| Dimensions | 1040x650x575 mm |
Also, plexiglass can be easily engraved, as explained in another of our videos. If these topics interest you, please click and watch!
Conclusion
- Acrylic is a light polymer that practically fully copies glass’s features: transparency and light conductance. But it is also deprived of its flaw — fragility. Acrylic is solid and has low thermal conductivity.
- Some of the shop windows, outdoors signs, charms, canopies, greenhouses, glasses, souvenirs, and lamps are made out of acrylic. It is used in the automotive sector to make headlights and motorbike protective eyewear.
- There are two types of this material: cast and extruded. For the CO2 laser acrylic cutting, the cast one is preferable since it doesn’t crack under heat impact, unlike the second.
- Before the operation’s beginning, check your layout. You may use the instrument “margin” in the RDWorks or add some loops at the corners to save the material from overheating.
- Usually, to cut 1,5 mm of acrylic, 10W of power is used. The power of the tube itself influences the speed we adjust. Or it can affect the percentage we set in the “power” field.
- Strong airflow will summon the so-called “foam” on the upper edge of the acrylic end, roughness, and stripes. But fully reducing airflow would be a mistake. We recommend setting the airflow to 0,5 atm. Less might be dangerous for the lens.
- Extractor is required while working with plastics. During laser cutting acrylic, you should use a truncated nozzle with a small diameter output.
- The decision to leave or take the film off is based on the complexity of your layout. If there are no small details, then you may not remove the film.
- Be accurate and cautious while plexiglass cutting. Not very pleasant or healthy smoke, methyl acrylate, and smell are emitted in the process.
