METHOD AND APPARATUS FOR DEBOSSING AND SELECTIVELY APERTURING A RESILIENT PLASTIC WEB

摘要

METHOD AND APPARATUS FOR DEBOSSING AND SELECTIVELY APERTURING A RESILIENT PLASTIC WEB Delmar John Bishop Method and apparatus for constructing a three-dimensional film forming structure for imparting a selectively apertured three-dimensional pattern to a heated plastic material which is either fed in film form from a supply roll or extruded as a melt directly onto the surface of said forming structure and subjected to a fluid pressure differential while in contact with its surface. In a preferred embodiment, the film forming structure comprises a stacked laminate of initially imperforate planar sheets having continuous patterns of apertures therein and at least one initially perforate selectively apertured planar sheet located beneath the uppermost continuously apertured sheet. The laminate forming structure is preferably tubular in shape so as to facilitate continuous plastic web processing against its outermost surface. Film to be debossed and selectively apertured is brought in contacting relation with the laminate structure and subjected to a fluid pressure differential on said forming structure while at a temperature above its softening temperature. The fluid pressure causes the heated plastic film to be debossed in those areas where said initially perforate selectively apertured lamina contacts the film and debossed and apertured in those areas where said initially perforate selectively apertured lamina does not contact the film. The debossed and selectively apertured film is thereafter cooled below its softening temperature before removal from the forming structure.