Foam injection device and method of filling cavities

摘要

A system and method for adding material such as foam material to spaced cavities within a cigarette filter. A belt is provided and adapted to be driven synchronously with a moving cigarette filter rod. A plurality of injection needles protrude from the belt at spaced intervals, with the spacing between the needles coinciding with a spacing between the cavities within a cigarette filter rod. A chamber containing an expandable foam material is in fluid communication with one or more of the injection needles at one or more positions along a path traveled by the injection needles.