Smoking article with a restrictor that reduces carbon monoxide but maintains a high resistance to draw

摘要

A smoking article filter (114) is disclosed. The filter (114) includes a flow restrictor (126) and a cavity (146) downstream of the flow restrictor. The restrictor (126) reduces carbon monoxide but maintains a high resistance to draw. The flow restrictor (126) includes an orifice (130) or flow channel for directing smoke into the cavity. The filter (114) is attached to a tobacco rod (112) with tipping paper (116) and includes an air-admissible ventilating zone (140) at a location downstream of the restrictor (126). The invention also provides methods of making filters and smoking articles.