VERFAHREN ZUR PERFORIERUNG EINES POLYMEREN FILMS UND POLYMERER FILM

摘要

Apparatus for the non-impact formation of perforations in a web of substrate material such as a polymer film (15) includes a static laser (20), movable beam deflector means, e.g. rotatable drum (30), carrying a plurality of optical reflectors (35) arranged to sequentially and selectively deflect the beam onto successive target sites on the web to perform perforation by ablation of the surface. Either the laser is selected on the basis that its emission wavelength coincides with a molecular absorption band at a resonant frequency or the material itself is doped to provide a suitable absorbance at the standard emission wavelength of the available laser.