USING CO2 LASER MACHINES
There are various applications for CO2 lasers, not just for laser engraving. CO2 lasers have military applications for rangefinding, medical applications for skin resurfacing and laser surgery and high powered CO2 laser are used for cutting and welding. Mid-to-lower power CO2 lasers are commonly used in laser engraving and cutting machines, as seen on the Perfect Laser website.
CO2 lasers are not generally suited for metal cutting or engraving (except for the range of Oxygen assisted machines) and generally are applied to materials such as acrylic, leather, rubber, cork, wood, bamboo and some fabrics and papers. Whilst CO2 lasers are not intended for use with metals they can be used on coated metals such as anodized aluminium. An anodized aluminium iPod case can be easily and beautifully engraved with the use of a CO2 laser giving it a unique pattern.
If Laser Marking Materials (LMM) are applied to stainless steel (and some other metals) a CO2 laser can be used to create permanent staining of the metal. The LMM is applied as you would a spray paint and once dry, the application of CO2 laser engraving will result in a black stain on the metal. Though this marking appled to the metal with LMM and a CO2 laser engraving machine is not engraved into the metal, it is a permanent mark and is often used for applying barcodes or serial numbers.
The power rating (wattage) of a CO2 laser determines the engraving rate as well as cutting thickness. An almost identical engraving can be done using a 40W CO2 laser as could be done on a 100W though a 100W CO2 will yield a higher production rate, especially on thicker materials. The application that the laser engraving material will be used for will determine what power rating is suitable.
THE LIST BELOW ILLUSTRATES A GENERAL GUIDE TO LASER POWER AND APPLICATION
| 40 TO 50 WATT | Entry level laser for general engraving, not for cutting thick materials |
| 60 TO 80 WATT | Offers higher speed and deeper engraving as well as well as thicker cutting |
| 80 TO 100 WATT | Higher production yield (speed) as well as deeper engraving and cutting |
| >100 WATT | Higher speed cutting of thicker materials |
What to cut – and what NOT to cut when it comes to foams and plastics
OK to cut :
Polyester (PES)
Polyethylene (PE)
Polyurethane (PUR)
Neoprene (wet suit material)
Teflon (PTFE)
NOT ok to cut :
PVC (Poly Vinyl Chloride)/vinyl/pleather/artificial leather : Emits pure chlorine gas when cut! Don’t ever cut this material as it will ruin the optics, cause the metal of the machine to corrode, and ruin the motion control system.
ABS : Emits cyanide gas and tends to melt. ABS does not cut well in a laser cutter. It tends to melt rather than vaporize, and has a higher chance of catching fire and leaving behind melted gooey deposits on the vector cutting grid. It also does not engrave well (again, tends to melt).
HDPE/milk bottle plastic : Catches fire and melts. Don’t use it.
PolyStyrene Foam : Catches fire! It also melts, and only thin pieces cut. This is the #1 material that causes laser fires!
PolyPropylene Foam : Catches fire. Like PolyStyrene, it melts, catches fire, and the melted drops continue to burn and eventually turn into rock-hard stuff.
Fiberglass : Emits fumes. It’s a mix of two materials that can’t be cut. Glass (etch, no cut) and epoxy resin (fumes).
Coated Carbon Fibre : Emits noxious fumes. A mix of two materials. Thin carbon fiber mat can be cut (with some fraying) – but not when coated with epoxy.
