Materials Digital Library > Acrylics (11)
Acrylics are cut by "vaporisation". The absorbed laser radiation initiates a process which comes close to a physical phase change from solid to liquid to vapour with a remarkably low level of chemical degradation. The vapour, colourless with a distinctive smell, is highly inflammable and burns with a sooty flame. A gentle stream of pressurized air or nitrogen blows the vapour away from the cutting zone to prevent its ignition. It also dries the remaining liquid melt on the cut edge, creating a glossy, smooth, flame-polished like cutting edge.
Should the flow of air be too forceful, the solidifying layer becomes disturbed and the cut edge gets a "frosted" appearance. Due to the amount of filler added to the acrylics to change their appearance from transparent to coloured, the cutting process changes and the cut edge loses its glossy appearance. Because the fumes generated by the laser are highly inflammable, the system must never be left unattended while acrylics are being cut.
