Micro laser perforation of line patterns in strip material involves repeated cutting of rows of waveform, zig-zag or similar pattern lines over a set material length using a deflected laser beam

摘要

Laser beam deflections are synchronized with the speed of the strip material passing below each perforating head. Perforations produced by each head have a waveform(47), zig-zag or similar shape as single(33) or multiple(34) perforation lines over a set strip length(36,37). The repeated pattern of lines does not run parallel with the direction of strip movement(32). Laser beam deflection is controlled by vibrating or non-symmetric, rotating beam deflectors which move the beam from its central axis to vary the position of perforated lines(33,34) parallel to the transporting direction. Use of a non-symmetric reflecting cone continuously changes the deflection angle of the laser beam as the cone rotates through 360[deg]. A wide range of perforation patterns can be produced with regard to the number of lines and their profile. Line profiles are precalculated in a control unit and used to control the beam deflections. Perforating heads for producing a group of lines are not in the same horizontal plane, but are offset laterally and driven synchronously. Use of the waveform(47) or zig-zag pattern allows optimized use of a filter surface area and thus gives better air flow and mixing inside a cigarette filter or other product when compared with coaxial perforated lines. Zig-zag and waveform perforated line patterns extend over a longer axial length along a cigarette filter or other product when compared with coaxial perforations. Independent claims are included for: a) a piezovibrator or non-symmetric rotating reflector for laser beam deflection; and b) a product feature created by the process comprising patterns of single or multiple perforated lines with a waveform or zig-zag shape on a cigarette filter tip paper wrapped around the circumference of a filter or other product.