The laser cutter is an incredibly versatile piece of equipment, one that has found applications in many different industries. One of the key advantages of a laser cutter is a wide range of materials it can be used on. But because laser cutting involves burning, it means that not all materials are safe to be processed on a laser cutter.
What materials should NOT be cut with a laser cutter
PVC (Polyvinyl chloride)
Can be found in: plastic pipes, bottles, electrical wires insulation, vinyl records, flexible packaging, wall coverings, fake leather (rexine), toys…
It shouldn’t be cut because: it emits chlorine gas when cut which combines with moisture in the air to create hydrochloric acid. This is not only going to ruin your optics and corrode metal parts of your machine quickly (voiding the warranty in the process) but is also dangerous for humans if it gets into the lungs or eyes. Just stay away from it.
ABS (Acrylonitrile butadiene styrene)
Can be found in: pen housing, toys (lego bricks for example), keycaps for keyboards, protective headgear, furniture edging, some instruments…
It shouldn’t be cut because: it emits cyanide and carbon monoxide, melts. ABS has a very low melting point which makes it difficult to process with any equipment which produces heat – especially laser cutters because it can easily bend and burst into flame. When burned ABS decomposes to several components, a few of which are carcinogenic to humans. It also smells like death, so stay away from this as well.
HDPE (High-density polyethylene)
Can be found in: plastic milk bottles and mail envelopes, bottle caps, reusable plastic bags, shampoo bottles
It shouldn’t be cut because: it melts and easily catches fire. Similar to ABS, has a low melting point which means it melts rather than cut. No nasty fumes, or machine damage (unless it catches fire or sticks to laser bad) but even if you manage to cut through it the results are less often less than satisfying.
Can be found in: CD’s, DVD’s, Blue-ray disks, glasses, polycarbonate water bottles, greenhouse sheeting…
It shouldn’t be cut because: catches fire, difficult to cut, discolors. Polycarbonate has good heat-resistant and infrared absorbing characteristics, which is why windows on some laser cutters are made of these materials. For this reason, the laser cutter is quite ineffective with this material, you will need lots of power to cut through it and results will be far from perfect.
Can be found in: car parts (knobs, instrument panels, child protective seats), food packaging,
It shouldn’t be cut because: it catches fire easily, rapidly burns, melts, drips on your bed and only thin pieces are possible to cut. By some sources, this is the No.1 reason for laser fires.
Fiberglass and Coated Carbon Fiber
Can be found in: traffic lights, pole vaulting poles, printed circuit boards, helmets…
It shouldn’t be cut because: emits noxious fumes. These are a mix of two materials. Fiberglass is a mixture of glass (possible to etch but not cut) and epoxy resin (bad fumes). Carbon fiber can be cut (thin sheets) but not when coated.
All this being said, it should be pointed out that laser cutters are perfectly capable of cutting most of the materials on this list but that doesn’t mean you should cut them. If for whatever reasons you have to do it, you better be super confident that your ventilation system will vent out all of this nasty stuff.
What materials can be cut with a laser cutter
Like most natural materials wood is safe to be cut on a laser cutter. Other than natural, solid wood there are also several composite/engineered wood products suitable for laser cutting.
- Plywood – several thin sheets of wood glued together. Because the grain of the sheets is alternated on adjacent layers it offers greater mechanical resistance and flexibility.
- MDF or medium-density fiberboard – made with wood, wax, and resin binder. Its lightweight, cheap and does not crack or deform when cutting on a laser.
While many above listed are not suitable for a laser cutter, there are plenty of suitable ones that give great results like:
- Cast Acrylic – a popular choice in laser cutting community. Offers best optical clarity, cuts are well polished while engraving leaves consistent white finish.
- Extruded Acrylic – are a bit cheaper than cast acrylic, can be bent a little more (one way to tell them apart), but cuts and engraving are not as polished as wit cast acrylic.
- Delrin – much more ductile compared to acrylic. Commonly used for electronic enclosures, drones, guitar picks, etc…
- Mylar – non-reflective only, gold-coated will not work
Being very light, cheap, and easy to work with (bend, cut, fold…) cardboard is a good choice to experiment and create prototypes of your designs first before you waste some other more expensive material. You can also use it to cut make packaging for your products. Just be aware that holes between corrugated cardboard can trap excess smoke produced during the laser cutting process which can reduce cutting efficiency.
While expensive, it offers a high-quality look and finishes. Just stick with natural, untreated leather and avoid synthetic ones.
Can a laser cutter cut metal
This depends on the type of laser in question. There are laser cutters that are specifically intended for metal cutting (like fiber ones) and special oxygen/nitrogen assisted high power CO2 lasers. These machines are much more expensive than your typical desktop hobby grade laser cutter.
What your hobby grade laser can do is marking or etching. It works by removing layers (paint) from the surface of the metal, like with anodized aluminum. For marking non coated metals, you can also use chemical products specifically made for this purpose (like CerMark). You add a layer of chemical on the metal surface you want to cut, let it dry, and then engrave on it. The heat of a laser causes chemicals to react with the metal and “print” your design on the surface of the material. This technique is quite popular for engraving knives, flasks, metal cups, but be aware that even though the printing with this technique is quite durable it doesn’t last forever, it can wear off over time if exposed to heat or stress of some kinds (rubbing, touching often etc…). For permanent engraving on a metal go for a fiber laser.
How to identify types of plastic
If you are wondering how to identify the type of material you want to cut, there are several easy tests you can perform to identify commonly used types of plastics.
Fist and most obvious “test” is to check the label if there is one.
In order to improve the recycling of plastic and make it easier for workers in recycling facilities to sort and separate different items, the resin identification code system was designed. Each type of plastic types have an identifying number assigned (see table below)
Now that we got that out of the way, here are some experiments you can perform your material.
There are two types of tests:
- Density tests (will the material sink in the specific liquid)
- Reaction tests (how the material reacts when exposed to chemicals or heat)
Copper wire test is one of the most common ways to determine if the material contains chlorine. Basically, you use heated copper wire to remove the piece of material you want to test and then set the removed piece on fire. If the flame turns green – material contains chlorine.
Here are in detail instructions on how to perform each of these tests, written by Chemist David A. Katz.
LaserHint: One other common (and much less scientific) test which is not included in the document is the hammer acrylic test. Acrylic (cast) shatters when you hit it with a hammer, while stuff like PETG and polycarbonate are pretty resilient to physical damage.
Can laser cutter cut glass?
The answer is yes and no. For good quality cuts, you will need expensive high-powered C02 laser with specialized cooling system to quickly cool down and fracture glass along the thing line. Most hobby lasers cannot cut glass, at least not in the specific meaning of the word. What you can do is engrave or score the surface of the glass enough so that you can snap the pieces like you would when you cut it manually. The problem is glass can shatter more often than not and even if it doesn’t the edge quality will be similar to the ones you get from manual cutting techniques making the whole process pointless.
Cutting glass can also be dangerous not only because you can cut yourself on shattered pieces, but also because glass dust and chips can be hard to get out of the workshop.
With such a wide variety of material with different characteristics that can be cut on a laser, it can be tempting to try to use something that might not be suited for laser cutting.
Before cutting new materials always check to make sure that it doesn’t contain any dangerous chemicals that can be released when burnt.