| 摘要 |
There is described a flexible oriented film ( 301 ) which acts a replacement for tear film, the film ( 301 ) having at least one tear susceptible line ( 307, 309 ) or pattern thereon (preferably weaker than the surrounding film), the film tearing substantially therealong when tearing is initiated therealong, characterised in that the line ( 307, 309 ) or pattern has substantially the same thickness normal to the film surface (gauge) as the rest of the film; and/or the film material therealong is substantially differently (preferably more) oriented (in extent and/or direction) to that in the rest of the film. The means for forming the line ( 307, 309 ) or pattern is preferably a laser (e.g. infra-red CO<SUB>2 </SUB>laser) set at a sufficiently low power not to ablate material therealong but at a sufficiently high power to reorient the film therealong. A method of preparing such films ( 301 ) and packaging ( 721 ) (such as cigarette packs) overwrapped with such films ( 601 ) are also described. |
