Patent ID: 8671951

Claim:
A method of manufacturing cigarette filter subassemblies comprising the steps of: A. providing a filter member comprised of absorbent material surrounded by a cover, the filter member defining a longitudinal center axis; B. passing a plunger axially through the absorbent material such that a generally pointed leading end of the plunger displaces the absorbent material radially outwardly, wherein the displaced absorbent material forms a liner along an inside surface of the cover and defines a hollow axial opening within the absorbent material; C. axially inserting at least one absorbent member and at least one capsule into the hollow space, the capsule containing a releasable material for modifying characteristics of tobacco smoke during smoking; and D. providing a coating on an inner surface of the liner which is substantially impermeable to the releasable material in the at least one capsule prior to step C, wherein the coating is provided by applying to an outer cylindrical surface of the plunger, a binder material which is transferred to the inner surface of the liner as the liner is being formed.