White multi-layer, laser-cuttable polyester film

摘要

White, coextruded, oriented polyester film comprises a base layer B containing 2-35 wt.% of a white pigment or void-forming incompatible polymer and 0.1-15 wt.% of a pigment that absorbs laser energy and a covering layer A containing 2-35 wt.% of a white pigment or void-forming incompatible polymer. An independent claim is also included for producing a film as above by compressing and melting materials corresponding to layers A and B in an extruder, forming the melts into flat films in a multilayer die, superposing the films and pressing them in a fishtail die, drawing the film over a cooling roller and one or more take-off rollers, and biaxially stretching, fixing and relaxing the film.