As most of us know, acrylic is one of the most popularly used materials in Australian industry. It is fabricated and moulded to create a wide range of essential as well as daily use products. In general, there exist several techniques which are used for personalising acrylic as per requirements, out of which laser engraving is a common one.
Acrylic is very sensitive to some particular wavelengths of light. It behaves almost like a sponge when exposed to laser, and essentially absorbs the emitted energy. That is why, even lasers with low watt can be used for producing excellently engraved acrylic cosmetic displays and display plinths.
Laser engraving an acrylic product is usually an easy task for qualified and experienced professionals, but sometimes there can be certain problems. For instance, people who engrave the large fill areas often complain about the appearance of raster lines. These lines can create a linear horizontal pattern and impart a coarse texture to the engraved areas. This problem can, however, be tackled using a simple solution. For reducing appearance of the raster lines, spot size of the laser must be enlarged.
Professionals working in the field of plastic fabrication generally claim that the best way to engrave with laser is by using low power and high speed. While using laser on an acrylic product that has been either screen printed or painted on one side, it is better to maintain the same setting of speed as for an unpainted acrylic item. However, the power must be increased by around 10 percent. It would enable the laser to pass and cut through the paint cleanly.
At some occasions, there can also be other problems like hazing, melting or cracking. Such issues usually occur due to presence of extra heat. To prevent the occurrence of these problems, one should either try reducing the power or increasing the speed, or both. Optimum speed and power settings would rely upon the laser system being used and the acrylic product that needs to be engraved.
A good work practice at the time of laser engraving acrylic is to elevate the material sheet slightly above the table. This would prevent chances of distortion and pitting that can be caused by reflection of beams off the metal table of a laser system. Creating a space between table and acrylic can dissipate the reflected light, which in turn would enhance the cut.