Method and apparatus for inspecting and controlling tipping paper perforation

A method for controlled perforating of a running elongated strip of tipping paper comprising:

• perforating the tipping paper with a laser beam perforator;
• imaging the perforations in the tipping paper downstream of the perforator;
• determining the area of perforations imaged;
• calculating an expected pressure drop from the determined area and producing a signal which is a function expected pressure drop;
• and
• controlling the power output of the laser beam perforator in response to the pressure drop signal.

An apparatus for monitoring of tipping paper having one or more lines of perforations in a base paper strip moving through the apparatus comprising:

• a CCD line sensor with plural sensor cells located across a width of the tipping paper strip;
• means for illuminating the tipping paper strip with a constant, essentially uniform light in an area on the opposite side of the strip from the CCD line sensor;
• means for scanning the sensor cells to obtain sensor cell signals representative of a profile of the optical transmission of the tipping paper across the width of the strip;
• means responsive to said sensor cell signals for providing a first signal which is indicative of a characteristic of the base paper strip and a second signal which is indicative of the average area of perforations in the one or more lines;
• and
• means for calculating an expected pressure drop from said second signal and providing a third signal indicative of said calculated pressure drop.