Taking the guilt out of rock-and-roll

 作者:公西骋由     |      日期:2019-03-07 07:05:07
By Duncan Graham-Rowe GUITAR players performing at the next “save the rainforest” benefit gig could have one less embarrassing question to answer. Thanks to a technique for moulding acoustic guitars out of plastic, guitar makers will not be forced to use endangered Brazilian rosewood to make quality instruments. Previous attempts to make acoustic guitars from plastic have failed to reproduce the resonant tones of a top-class wooden instrument. Until now, plastic construction has been limited to amplified electro-acoustic models, says Owain Pedgley, who developed the technique while he was a graduate student in industrial design at the University of Loughborough. Any deficiencies in the sound of these instruments can be overcome by electronic manipulation, he says. According to Pedgley, the problem with building guitars from other materials lies in reproducing the acoustic qualities of the holed flat panel known as the soundboard, which forms the front of the instrument. Some guitar makers have concentrated on trying to reproduce wood’s rigidity by using expensive carbon-fibre composites. Now Pedgley has used polycarbonate to do the job. The surface of his soundboard is made of expanded polycarbonate containing bubbles of air that help to provide the necessary resonant properties. Ribs of non-expanded material on the back of the board add the required stiffness. The result is a sound matching that of wood, claims Pedgley. “The sound quality is very promising,” agrees Rob Armstrong, who has made guitars for George Harrison and bands such as the Levellers and Fairport Convention, among others. Pedgley’s polycarbonates can also be injection moulded. This makes it possible to build a complete guitar by assembling five or six preformed parts,