PROCESS FOR FORMING FILM COVERED SHEET METAL MATERIAL AND SHEET METAL MATERIAL SO COVERED

摘要

A plastic film (44) is bonded with an adhesive (48) to a sheet metal substrate (46). The sheet metal substrate is processed in a laser operation to form grooves, openings or cuts in the sheet metal. The laser operation has a pressurized gas stream that is directed to the laser beam cut to clean and cool the cut. The gas enters the film-substrate interface at the opening formed by the beam. The film has slits (50) or other perforations throughout so that as the pressurized gas impinges upon the film and its opening formed by the laser beam and enters the film-substrate interface, the adjacent slits bleed the pressurized gas from the film-substrate interface to prevent significant lifting of the film from the substrate into a bubble which otherwise interferes with and can stop the laser operation. The perforations may be in the form of weakened recesses (47) in the film which open in reponse to lifting of the film by gas pressure at the interface with the underlying metal sheet. The dimensions of the perforations are such that the sheet metal is protected during prior handling and the laser processing while maintaining the integrity of the film so it can be easily removed as a unit and not shared during such removal.