Wood & Model Boards
Laser Processing of Wood and Model Boards
“Timber“ is used by our UK cousins to describe sawn wood products (that is, boards). The laser processing of these items using low wattage CO2 lasers depends on the thickness and type of wood.
Most wood applications are best handled by lasers over 75 watts.
COMPOSITE WOODS and the glue that binds
For instance consider the composite woods like plywood, fiber board, task board and chipboard. These can be both laser marked and laser cut.
6 mm is the maximum thickness that we would recommend cutting with a laser under 75 watts. .What we have found is the problem is more with the plywood glues (bonding agents) used. These adhesive bonds can behave like mirrors requiring variable amounts of laser energy to get a good clean cut.
Urea glue, commonly used for interior grade and low moisture resistance products adsorbs the laser radiation, and cut more easily. While Phenol glue, commonly used in composite woods for exterior use is more difficult to laser cut.
Best woods for laser processing
Italian Poplar and Baltic Birch along with a composite product called Luan seems to work the best as it tends to be uniform in structure than ordinary plywood and remains fairly flat.
MODEL BOARDS (urethane)
Model boards can be laser marked and laser cut. Model Boards are typically urethane, and come in a variety of colors and can range in thickness from 6 mm to 200 mm.
Both the pigment additives used to create color in the urethane and the thickness of the urethane board will determine the correct laser power required. Our general rule of thumb is “hit it hard and hit it fast” to minimize discolorization. We would like to see at least a 75 watt laser used for this application (however, we have witnessed acceptable cuts on thin model boards using 30 watts of laser power).
The importance of air assist and good exhaust
Air assist and good exhaust is mandatory to minimize burning. Failure to cut through in all areas is usually due to a change in composition in the material (voids, knots, percentage of glue, etc…). Proper ventilation is always required. The material has a tendency to flame up if the laser beam is not moved rapidly through the laser marking or cutting process