A laser has been used to give the inexpensive building material MDF, or medium density fiberboard, a surface finish that can match that of expensive wood grains.MDF is a strong, flexible material often used in place of solid wood for building furniture, interior doors, ceiling tiles, paneling and flooring because it is cheaper. Made of powered wood products mixed with wax and resin and then pressed to form smooth-surfaced boards, MDF is notable more for its heaviness than its attractiveness and is usually covered by paint or glued-on veneers that add wood grain. J. Peter Hancocks, Warwick Manufacturing Group research fellow, holds a piece of medium density fiberboard (MDF) into which a CO2 laser has etched a wood grain. (Photo courtesy University of Warwick) But now researchers at Warwick Manufacturing Group (WMG) at the University of Warwick in Conventry have devised the LaserCoat system, which can etch simulated wood grain directly onto the product's surface and also add a durable, powder coating. "MDF is a superb and highly versatile material. It's easy to work with and cheap. It is usually made from waste material so it is much kinder to the environment than using more real wood. But normally it looks rather dull in its raw state. Until now there has been no way to liven it up other than painting it," said WMG researcher Ken Young, PhD. "Using lasers to produce a wood grain in MDF could help bring a more natural quality into homes and businesses without the financial and environmental cost of having to use new wood."WMG is using a CO2 laser to etch the material. "We are currently using 200 W of power but would like more to go faster," Young told Photonics.com. "Unfortunately our 6-kW one is a bit too powerful and we haven’t quite got enough control of it to prevent MDF worm developing.""MDF worm," Young said, is what he and his colleagues call it when "the laser blows a hole straight through the MDF that looks just like wood worm. (It is) caused by either a power spike when the laser starts or a delay before the scanner moves."Hancocks beside a door made of MDF that has a laser-etched wood grain to look like a solid wood door. (Photo courtesy George Archer Photography Ltd.) The LaserCoat technology also has great potential for commercial use, he said, as it is very hardwearing and can be used for flooring or other applications where cost is an issue but where looks are also important. It can mimic a vast range of real wood grains, it can produce logos, decoration, or even colored and shaped decorative surfaces using a powder coating version of the new laser technology. "We are hopeful that it will reach the consumer market through one of our collaborators who manufactures doors and windows," Young said. "If you look at the door we have made you would struggle to tell that it isn’t real wood without damaging the door."Mick Toner, factory manager for Howarth Windows & Doors, one of the partners in the program, said he sees significant benefits from the new technology for his business. "We would love to use MDF for the glazing beads in doubling glazing (windows), but customers do not like the look of raw MDF. This LaserCoat technology will provide a grained look that will delight our customers, give us much more manufacturing flexibility and cut the cost of the raw materials fourfold," Toner said. "MDF is also an ideal material for providing the thermal insulation required for modern doors. Our customers are increasing using translucent coatings on their doors which are not aesthetically pleasing on MDF panels -- the LaserCoat technology cuts through this problem providing an attractive surface for MDF no matter the coating used." Hancocks holds a piece of MDF that has been powder coated twice by a laser, once to add the yellow layer and again to add the black LaserCoat logo. (Photo courtesy University of Warwick) The LaserCoat project, a collaborative research effort consisting of eight UK academic, research and commercial organizations, is supported by the Furniture Industry Research Association and the Timber Research and Development Association. It is funded, in part, by the Department for Business, Enterprise and Regulatory Reform and the Technology Strategy Board. For more information, or to watch a video of the LaserCoat process, visit: www2.warwick.ac.uk/fac/sci/wmg
CO2 Laser Sources