| abstract |
A method of forming a line of weakness in at least one but not all layers of multilayer laminate which comprises effecting relative movement between a beam of radiant energy of a particular predetermined wavelength and intensity and the laminate so that the energy is selectively relatively absorbed by at least one layer in an amount and manner that alters the structure of the layer and thereby forms a line of weakness in the laminate. The source of radiant energy preferably is a laser. The laminate layers can be comprised of any material used in manufacturing multilayer packaging laminates such as thermoplastics, thermosets, paper and foil. Preferably, the laminate includes at least one layer of thermoplastic material. The layer that absorbs more energy can be an adhesive. |