PROCEDIMENTO E DISPOSITIVO PER PERFORARE MATERIALE DI RIVESTIMENTO A INVOLUCRO PER SIGARETTE

摘要

A running web or discrete tubular wrappers of rod-shaped articles of the tobacco processing industry are perforated with a variable-intensity high-energy pulsed laser beam which is controlled in such a way that the intensity of radiation and/or the length of pulses is altered in response to variations in the speed of advancement of the web or discrete wrappers past the perforating station. This ensures that the permeability of the thus obtained ventilation zones is not influenced by the speed of advancement of the material to be perforated past the perforating station. The intensity of radiation and/or the length of pulses can also be influenced by one or more monitored characteristics of the articles, such as the permeability of their wrappers.