5 Tips for Working With

There are many different types of acrylic out there for both rotary and laser engraving. These acrylic types include extruded, cast, mirror, and multi-ply. Multi-ply acrylic is typically an extruded acrylic consisting of two or three different colors layered on each other. It may also be called multi-layer or two-tone acrylic depending on whom you talk to. With that in mind, let’s get into my five tips for working with multi-ply acrylic.

Tip 1 – Take off the plastic coating. Every piece of acrylic, no matter what type, comes with either a paper or plastic film on it. With the multi-ply materials, there will be a plastic film on the engravable side of the material. When you go to machine the material, I recommend taking this plastic film off. By removing this film, you will directly engrave the top thin layer of material instead of machining the plastic film first. There are two main reasons why you should remove this film: and result in inconsistent engraving. Not only will it turn to a paste-like consistency but it will also have inconsistent engraving results.

I highly recommend experimenting with a couple of different colors for yourself and seeing first-hand what happens when you take it off or leave it on.

Tip 2 – Turn off the air assist.

CO2 lasers have an air assist system that is usually driven by a compressor. The compressor itself is sometimes built into the laser but more often, it is an additional piece of machinery that is connected to the laser via an air hose. This air assist system helps keep materials from flaring up or catching on first. CAUTION: If you turn off the air assist, you need to monitor the machining process to ensure and shut it down if you start to see larger-than-normal flare-ups. Be careful any time you shut this off.

1. If you leave it on during the engraving process, the laser will engrave through the plastic film and melt it. As it melts it will travel into the path of the laser and will continue to get engraved more which will make it adhere to the acrylic itself. This results in a paste-like consistency that will be incredibly difficult to clean and you will never get a great result this way.

2. The second reason you should remove it is for consistency. As you machine, this film will tend to lift in areas as it heats up causing it to move

In the image below you’ll see two engravings. The engraving on the left was done with the air assist turned on while the one on the right was done with the air assist turned off. Let’s start with the engraving on the left. As the engraving is occurring, fine dust is created by the machining process. As the laser engraves through the red layer, that red layer is becoming dust that is then sucked up by the exhaust system. Here in lies the problem with the air assist. As that dust is being created, the air assist is blowing the dust around and it is landing back on the ma-